MAX16936,38 Datasheet by Maxim Integrated

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MAX16936IMAX16938 36V, 220kHz to 2.2MHz Step-Down Converters
General Description
The MAX16936/MAX16938 are 2.5A current-mode step-
down converters with integrated high-side and low-side
MOSFETs designed to operate with an external Schottky
diode for better efficiency. The low-side MOSFET enables
fixed-frequency forced-PWM (FPWM) operation under
light-load applications. The devices operate with input
voltages from 3.5V to 36V, while using only 28µA
quiescent current at no load. The switching frequency is
resistor programmable from 220kHz to 2.2MHz and can
be synchronized to an external clock. The devices’ output
voltage is available as 5V/3.3V fixed or adjustable from
1V to 10V. The wide input voltage range along with its
ability to operate at 98% duty cycle during undervoltage
transients make the devices ideal for automotive and
industrial applications.
Under light-load applications, the FSYNC logic input
allows the devices to either operate in skip mode for
reduced current consumption or fixed-frequency FPWM
mode to eliminate frequency variation to minimize EMI.
Fixed-frequency FPWM mode is extremely useful for
power supplies designed for RF transceivers where
tight emission control is necessary. Protection features
include cycle-by-cycle current limit and thermal shutdown
with automatic recovery. Additional features include a
power-good monitor to ease power-supply sequencing
and a 180º out-of-phase clock output relative to the inter-
nal oscillator at SYNCOUT to create cascaded power
supplies with multiple devices.
The MAX16936/MAX16938 operate over the -40ºC to
+125ºC automotive temperature range and are available
in 16-pin TSSOP-EP and 5mm x 5mm, 16-pin TQFN-EP
packages.
Applications
Point-of-Load Applications
Distributed DC Power Systems
Navigation and Radio Head Units
Benefits and Features
Integration and High-Switching Frequency Saves
Space
Integrated 2.5A High-Side Switch
Low-BOM-Count Current-Mode Control
Architecture
Fixed Output Voltage with ±2% Accuracy (5V/3.3V)
or Externally Resistor Adjustable (1V to 10V)
220kHz to 2.2MHz Switching Frequency with
Three Operation Modes (Skip Mode, Forced
Fixed-Frequency Operation, and External
Frequency Synchronization)
Automatic LX Slew-Rate Adjustment for Optimum
Efficiency Across Operating Frequency Range
180° Out-of-Phase Clock Output at SYNCOUT
Enables Cascaded Power Supplies for Increased
Power Output
Spread-Spectrum Frequency Modulation Reduces
EMI Emissions
Wide Input Voltage Range Supports Automotive
Applications
3.5V to 36V Input Voltage Range
Enable Input Compatible from 3.3V Logic Level
to 42V
Robust Performance Supports Wide Range of
Automotive Applications
42V Load-Dump Protection
-40°C to +125°C Automotive Temperature Range
Thermal-Shutdown Protection
AEC-Q100 Qualified
Power-Good Output Allows Power-Supply
Sequencing
Tight Overvoltage Protection Provides Smaller
Overshoot Voltages (MAX16938)
19-6626; Rev 18; 3/18
Ordering Information/Selector Guide and Typical
Application Circuit appear at end of data sheet.
MAX16936/MAX16938 36V, 220kHz to 2.2MHz Step-Down Converters
with 28µA Quiescent Current
EVALUATION KIT AVAILABLE
SUP, SUPSW, EN to PGND ................................... -0.3V to +42V
LX (Note 1) ............................................................-0.3V to +42V
SUP to SUPSW .....................................................-0.3V to +0.3V
BIAS to AGND .........................................................-0.3V to +6V
SYNCOUT, FOSC, COMP, FSYNC,
PGOOD, FB to AGND ........................-0.3V to (VBIAS + 0.3V)
OUT to PGND ........................................................ -0.3V to +12V
BST to LX (Note 1) ..................................................-0.3V to +6V
AGND to PGND ................................................... -0.3V to + 0.3V
LX Continuous RMS Current ...................................................3A
Output Short-Circuit Duration .................................... Continuous
Continuous Power Dissipation (TA = +70NC)*
TSSOP (derate 26.1mw/NC above +70NC) .............2088.8mW
TQFN (derate 28.6mw/NC above +70NC) ...............2285.7mW
Operating Temperature Range ........................ -40NC to +125NC
Junction Temperature .....................................................+150NC
Storage Temperature Range ............................ -65NC to +150NC
Lead Temperature (soldering, 10s) ................................+300NC
Soldering Temperature (reflow) ......................................+260NC
*As per JEDEC51 standard (multilayer board).
TSSOP
Junction-to-Ambient Thermal Resistance (BJA) .......38.3NC/W
Junction-to-Case Thermal Resistance (BJC) .................3NC/W
TQFN
Junction-to-Ambient Thermal Resistance (BJA) ..........35NC/W
Junction-to-Case Thermal Resistance (BJC) ..............2.7NC/W
(VSUP = VSUPSW = 14V, VEN = 14V, L1 = 2.2FH, CIN = 4.7FF, COUT = 22FF, CBIAS = 1FF, CBST = 0.1FF, RFOSC = 12kI,
TA = TJ = -40NC to +125NC, unless otherwise noted. Typical values are at TA = +25NC.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Supply Voltage VSUP, VSUPSW 3.5 36 V
Load Dump Event Supply
Voltage VSUP_LD tLD < 1s 42 V
Supply Current ISUP_STANDBY
Standby mode, no load, VOUT = 5V,
VFSYNC = 0V 28 40
FA
Standby mode, no load, VOUT = 3.3V,
VFSYNC = 0V 22 35
Shutdown Supply Current ISHDN VEN = 0V 5 8 FA
BIAS Regulator Voltage VBIAS VSUP = VSUPSW = 6V to 42V,
IBIAS = 0 to 10mA 4.7 5 5.4 V
BIAS Undervoltage Lockout VUVBIAS VBIAS rising 2.95 3.15 3.40 V
BIAS Undervoltage-Lockout
Hysteresis 450 650 mV
Thermal Shutdown Threshold +175 NC
Thermal Shutdown Threshold
Hysteresis 15 NC
Absolute Maximum Ratings
Note 1: Self-protected against transient voltages exceeding these limits for 50ns under normal operation and loads up to the
maximum rated output current.
Note 2: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer
board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial.
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional opera-
tion of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
Electrical Characteristics
Package Thermal Characteristics (Note 2)
www.maximintegrated.com Maxim Integrated
2
MAX16936/MAX16938 36V, 220kHz to 2.2MHz Step-Down Converters
with 28µA Quiescent Current
(VSUP = VSUPSW = 14V, VEN = 14V, L1 = 2.2FH, CIN = 4.7FF, COUT = 22FF, CBIAS = 1FF, CBST = 0.1FF, RFOSC = 12kI,
TA = TJ = -40NC to +125NC, unless otherwise noted. Typical values are at TA = +25NC.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
OUTPUT VOLTAGE (OUT)
FPWM Mode Output Voltage
(Note 3)
VOUT_5V
VFB = VBIAS, 6V < VSUPSW < 36V,
MAX16936/38/38____A/V+, fixed-
frequency mode
4.9 5 5.1
V
VOUT_3.3V
VFB = VBIAS, 6V < VSUPSW < 36V,
MAX16936/38____B/V+, fixed-frequency
mode
3.234 3.3 3.366
Skip-Mode Output Voltage
(Note 4)
VOUT_5V No load, VFB = VBIAS,
MAX16936/38____A/V+, skip mode 4.9 5 5.15
V
VOUT_3.3V VFB = VBIAS, 6V < VSUPSW < 36V,
MAX16936/38____B/V+, skip mode 3.234 3.3 3.4
Load Regulation VFB = VBIAS, 300mA < ILOAD < 2.5A 0.5 %
Line Regulation VFB = VBIAS, 6V < VSUPSW < 36V 0.02 %/V
BST Input Current
IBST_ON High-side MOSFET on, VBST - VLX = 5V 1 1.5 2 mA
IBST_OFF High-side MOSFET off, VBST - VLX = 5V,
TA = +25°C5FA
LX Current Limit ILX Peak inductor current 3 3.75 4.5 A
LX Rise Time RFOSC = 12kW4 ns
Skip-Mode Current Threshold ISKIP_TH TA = +25°CMAX16936 150 300 400 mA
MAX16938 200 400 500
Spread Spectrum Spread spectrum enabled fOSC Q6%
High-Side Switch
On-Resistance RON_H ILX = 1A, VBIAS = 5V 100 220 mI
High-Side Switch Leakage
Current
High-side MOSFET off, VSUP = 36V,
VLX = 0V, TA = +25NC1 3 FA
Low-Side Switch
On-Resistance RON_L ILX = 0.2A, VBIAS = 5V 1.5 3 I
Low-Side Switch
Leakage Current VLX = 36V, TA = +25NC 1 FA
TRANSCONDUCTANCE AMPLIFIER (COMP)
FB Input Current IFB 20 100 nA
FB Regulation Voltage VFB FB connected to an external resistor-
divider, 6V < VSUPSW < 36V (Note 5) 0.99 1.0 1.015 V
FB Line Regulation DVLINE 6V < VSUPSW < 36V 0.02 %/V
Transconductance
(from FB to COMP) gmVFB = 1V, VBIAS = 5V 700 FS
Minimum On-Time tON_MIN (Note 4) 80 ns
Maximum Duty Cycle DCMAX 98 %
Electrical Characteristics (continued)
www.maximintegrated.com Maxim Integrated
3
MAX16936/MAX16938 36V, 220kHz to 2.2MHz Step-Down Converters
with 28µA Quiescent Current
(VSUP = VSUPSW = 14V, VEN = 14V, L1 = 2.2FH, CIN = 4.7FF, COUT = 22FF, CBIAS = 1FF, CBST = 0.1FF, RFOSC = 12kI,
TA = TJ = -40NC to +125NC, unless otherwise noted. Typical values are at TA = +25NC.)
Note 3: Device not in dropout condition.
Note 4: Guaranteed by design; not production tested.
Note 5: FB regulation voltage is 1%, 1.01V (max), for -40°C < TA < +105°C.
Note 6: Contact the factory for SYNC frequency outside the specified range.
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
OSCILLATOR FREQUENCY
Oscillator Frequency RFOSC = 73.2kI340 400 460 kHz
RFOSC = 12kI2.0 2.2 2.4 MHz
EXTERNAL CLOCK INPUT (FSYNC)
External Input Clock
Acquisition Time tFSYNC 1 Cycles
External Input Clock
Frequency RFOSC = 12kI (Note 6) 1.8 2.6 MHz
External Input Clock High
Threshold VFSYNC_HI VFSYNC rising 1.4 V
External Input Clock Low
Threshold VFSYNC_LO VFSYNC falling 0.4 V
Soft-Start Time tSS 5.6 8 12 ms
ENABLE INPUT (EN)
Enable Input High Threshold VEN_HI 2.4 V
Enable Input Low Threshold VEN_LO 0.6
Enable Threshold-Voltage
Hysteresis VEN_HYS 0.2 V
Enable Input Current IEN TA = +25NC0.1 1FA
POWER GOOD (PGOOD)
PGOOD Switching Level VTH_RISING VFB rising, VPGOOD = high 93 95 97 %VFB
VTH_FALLING VFB falling, VPGOOD = low 90 92 94
PGOOD Debounce Time 10 25 50 Fs
PGOOD Output Low Voltage ISINK = 5mA 0.4 V
PGOOD Leakage Current VOUT in regulation, TA = +25NC 1 FA
SYNCOUT Low Voltage ISINK = 5mA 0.4 V
SYNCOUT Leakage Current TA = +25NC 1 FA
FSYNC Leakage Current TA = +25NC 1 FA
OVERVOLTAGE PROTECTION
Overvoltage-Protection
Threshold
VOUT rising
(monitored at FB pin)
MAX16936 107
%
MAX16938 105
VOUT falling
(monitored at FB pin)
MAX16936 105
MAX16938 102
Electrical Characteristics (continued)
www.maximintegrated.com Maxim Integrated
4
MAX16936/MAX16938 36V, 220kHz to 2.2MHz Step-Down Converters
with 28µA Quiescent Current
(VSUP = VSUPSW = 14V, VEN = 14V, VOUT = 5V, VFYSNC = 0V, RFOSC = 12kI, TA = +25NC, unless otherwise noted.)
SUPPLY CURRENT vs. SUPPLY VOLTAGE
toc09
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (µA)
2616
15
20
25
30
35
40
45
50
10
63
6
5V/2.2MHz
SKIP MODE
SWITCHING FREQUENCY vs. RFOSC
toc08
RFOSC (k)
SWITCHING FREQUENCY (MHz)
1027242
0.25
0.50
0.75
1.00
1.25
1.50
1.75
2.00
2.25
2.50
0
12 132
fSW vs. TEMPERATURE
toc07
TEMPERATURE (°C)
FSW (MHz)
11095-25 -10 5 35 50 6520 80
2.04
2.08
2.12
2.16
2.20
2.24
2.28
2.00
-40 125
VIN = 14V,
PWM MODE
VOUT = 5V
VOUT = 3.3V
fSW vs. LOAD CURRENT
toc06
ILOAD (A)
FSW (MHz)
2.01.51.00.5
426
427
428
429
430
431
432
433
434
435
425
0 2.5
VIN = 14V,
PWM MODE
VOUT = 5V
VOUT = 3.3V
fSW vs. LOAD CURRENT
toc05
ILOAD (A)
FSW (MHz)
2.01.51.00.5
2.12
2.14
2.16
2.18
2.20
2.22
2.24
2.26
2.28
2.30
2.10
0 2.5
VIN = 14V,
PWM MODE
VOUT = 5V
VOUT = 3.3V
VOUT LOAD REGULATION
toc04
ILOAD (A)
VOUT (V)
2.01.51.00.5
4.92
4.94
4.96
4.98
5.00
5.02
5.04
5.06
5.08
5.10
4.90
0 2.5
VOUT = 5V, VIN = 14V
PWM MODE
400kHz
2.2MHz
VOUT LOAD REGULATION
toc03
ILOAD (A)
VOUT (V)
2.01.51.00.5
4.92
4.94
4.96
4.98
5.00
5.02
5.04
5.06
5.08
5.10
4.90
0 2.5
VOUT = 5V, VIN = 14V
SKIP MODE
400kHz
2.2MHz
EFFICIENCY vs. LOAD CURRENT
toc02
LOAD CURRENT (A)
EFFICIENCY (%)
0.10.001
10
20
30
40
50
60
70
80
90
100
0
01
0
fSW = 400kHz, VIN = 14V
SKIP MODE
PWM MODE3.3V
3.3V
5V
5V
EFFICIENCY vs. LOAD CURRENT
toc01
LOAD CURRENT (A)
EFFICIENCY (%)
0.10.001
10
20
30
40
50
60
70
80
90
100
0
01
0
fSW = 2.2MHz, VIN = 14V
SKIP MODE
PWM MODE
3.3V
3.3V
5V
5V
Typical Operating Characteristics
Maxim Integrated
5
www.maximintegrated.com
MAX16936/MAX16938 36V, 220kHz to 2.2MHz Step-Down Converters
with 28µA Quiescent Current
b : Wm
(VSUP = VSUPSW = 14V, VEN = 14V, VOUT = 5V, VFYSNC = 0V, RFOSC = 12kI, TA = +25NC, unless otherwise noted.)
DIPS AND DROPS TEST
toc18
VIN
VOUT
VLX
VPGOOD
5V/2.2MHz
10ms
10V/div
0V
0V
5V/div
10V/div
0V
0V
5V/div
SYNC FUNCTION
toc17
VLX
VFSYNC
200ns
5V/div
2V/div
SLOW VIN RAMP BEHAVIOR
toc16
VIN
VOUT
ILOAD
VPGOOD
4s
10V/div
0V
0V
5V/div
5V/div
0V
0A
2A/div
SLOW VIN RAMP BEHAVIOR
toc15
VIN
VOUT
ILOAD
VPGOOD
4s
10V/div
0V
0V
5V/div
5V/div
0V
0A
2A/div
FULL-LOAD STARTUP BEHAVIOR
toc14
VIN
10V/div
0V
5V/div
0V
1A/div
0V
0A
5V/div
VOUT
ILOAD
VPGOOD
2ms
VOUT vs. VIN
toc13
VIN (V)
VOUT (V)
30241812
4.97
4.99
5.01
5.03
5.05
4.95
63
6
5V/400kHz
PWM MODE
ILOAD = 0A
VOUT vs. VIN
toc12
VIN (V)
VOUT (V)
3630241812
4.92
4.94
4.96
4.98
5.00
5.02
5.04
5.06
5.08
4.90
64
2
5V/2.2MHz
PWM MODE
ILOAD = 0A
VBIAS vs. TEMPERATURE
toc11
TEMPERATURE (°C)
VBIAS (V)
1109565 80-10 5 20 35 50-25
4.91
4.92
4.93
4.94
4.95
4.96
4.97
4.98
4.99
5.00
5.01
5.02
4.90
-40 125
ILOAD = 0A
VIN = 14V,
PWM MODE
SHDN CURRENT vs. SUPPLY VOLTAGE
toc10
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (µA)
30241812
1
2
3
4
5
6
7
8
9
10
0
63
6
5V/2.2MHz
SKIP MODE
Typical Operating Characteristics (continued)
Maxim Integrated
6
www.maximintegrated.com
MAX16936/MAX16938 36V, 220kHz to 2.2MHz Step-Down Converters
with 28µA Quiescent Current
nnnnnnnn l7
(VSUP = VSUPSW = 14V, VEN = 14V, VOUT = 5V, VFYSNC = 0V, RFOSC = 12kI, TA = +25NC, unless otherwise noted.)
COLD CRANK
toc19
VIN
VOUT
VPGOOD
400ms
2V/div
0V
2V/div
2V/div
LOAD TRANSIENT (PWM MODE)
toc21
VOUT
(AC-COUPLED) 200mV/div
2A/div
0A
LOAD
CURRENT
fSW = 2.2MHz
VOUT = 5V
100µs
LOAD DUMP
toc20
VIN
VOUT
100ms
10V/div
0V
0V
5V/div
SHORT CIRCUIT IN PWM MODE
toc22
VOUT
PGOOD
INDUCTOR
CURRENT
10ms
2V/div
0V
0V
5V/div
2A/div
0A
Typical Operating Characteristics (continued)
Maxim Integrated
7
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MAX16936/MAX16938 36V, 220kHz to 2.2MHz Step-Down Converters
with 28µA Quiescent Current
PIN NAME FUNCTION
TSSOP TQFN
1 16 SYNCOUT
Open-Drain Clock Output. SYNCOUT outputs 180N out-of-phase signal relative to the
internal oscillator. Connect to OUT with a resistor between 100I and 1kW for 2MHz
operation. For low frequency operation, use a resistor between 1kW and 10kW.
2 1 FSYNC
Synchronization Input. The device synchronizes to an external signal applied to FSYNC.
Connect FSYNC to AGND to enable skip mode operation. Connect to BIAS or to an
external clock to enable fixed-frequency forced PWM mode operation.
3 2 FOSC Resistor-Programmable Switching Frequency Setting Control Input. Connect a resistor
from FOSC to AGND to set the switching frequency.
4 3 OUT Switching Regulator Output. OUT also provides power to the internal circuitry when the
output voltage of the converter is set between 3V to 5V during standby mode.
5 4 FB Feedback Input. Connect an external resistive divider from OUT to FB and AGND to set
the output voltage. Connect to BIAS to set the output voltage to 5V.
6 5 COMP Error Amplifier Output. Connect an RC network from COMP to AGND for stable
operation. See the Compensation Network section for more information.
7 6 BIAS Linear Regulator Output. BIAS powers up the internal circuitry. Bypass with a 1FF
capacitor to ground.
8 7 AGND Analog Ground
9 8 BST High-Side Driver Supply. Connect a 0.1FF capacitor between LX and BST for
proper operation.
++
TSSOP
13
4
LX
OUT
14
3
LX
FOSC
15
2
PGND
FSYNC
16
1
TOP VIEW
PGOOD
SYNCOUT
10
7
EN
BIAS
11
6
SUP
COMP
9
8
BST
AGND
12
5
SUPSW
FB
EP EP
15
16
14
13
6
5
7
FOSC
FB
8
FSYNC
SUPSW
EN
LX
12
PGND
4
12 11 9
SYNCOUT
BST
AGND
BIAS
COMP
OUT SUP
3
10
LX
TQFN
PGOOD
MAX16936
MAX16938
MAX16936
MAX16938
Pin Descriptions
Pin Configurations
www.maximintegrated.com Maxim Integrated
8
MAX16936/MAX16938 36V, 220kHz to 2.2MHz Step-Down Converters
with 28µA Quiescent Current
Detailed Description
The MAX16936/MAX16938 are 2.5A current-mode
step-down converters with integrated high-side and low-
side MOSFETs designed to operate with an external
Schottky diode for better efficiency. The low-side MOSFET
enables fixed-frequency forced-PWM (FPWM) operation
under light-load applications. The devices operate with
input voltages from 3.5V to 36V, while using only 28FA
quiescent current at no load. The switching frequency is
resistor programmable from 220kHz to 2.2MHz and can
be synchronized to an external clock. The output voltage
is available as 5V/3.3V fixed or adjustable from 1V to
10V. The wide input voltage range along with its ability to
operate at 98% duty cycle during undervoltage transients
make the devices ideal for automotive and industrial
applications.
Under light-load applications, the FSYNC logic input allows
the device to either operate in skip mode for reduced
current consumption or fixed-frequency FPWM mode
to eliminate frequency variation to minimize EMI. Fixed
frequency FPWM mode is extremely useful for power
supplies designed for RF transceivers where tight emis-
sion control is necessary. Protection features include
cycle-by-cycle current limit, overvoltage protection, and
thermal shutdown with automatic recovery. Additional
features include a power-good monitor to ease power-
supply sequencing and a 180N out-of-phase clock output
relative to the internal oscillator at SYNCOUT to create
cascaded power supplies with multiple devices.
Wide Input Voltage Range
The devices include two separate supply inputs (SUP and
SUPSW) specified for a wide 3.5V to 36V input voltage
range. VSUP provides power to the device and VSUPSW
provides power to the internal switch. When the device
is operating with a 3.5V input supply, conditions such as
cold crank can cause the voltage at SUP and SUPSW to
drop below the programmed output voltage. Under such
conditions, the device operates in a high duty-cycle mode
to facilitate minimum dropout from input to output.
Maximum Duty-Cycle Operation
The devices have a maximum duty cycle of 98% (typ).
The IC monitors the off-time (time for which the low-
side FET is on) in both PWM and skip modes every
switching cycle. Once the off-time of 25ns (typ) is
detected continuously for 12μs, the low-side FET is
forced on for 150ns (typ) every 12μs. The input voltage
at which the devices enter dropout changes depend-
ing on the input voltage, output-voltage, switching fre-
quency, load current, and the efficiency of the design.
The input voltage at which the devices enter dropout
can be approximated as:
OUT OUT ON_H
SUP
V (I R )
V
0.98
=
Note: The equation above does not take into account
the efficiency and switching frequency, but is a good
first-order approximation. Use the RON_H number from
the max column in the Electrical Characteristics table.
PIN NAME FUNCTION
TSSOP TQFN
10 9 EN SUP Voltage Compatible Enable Input. Drive EN low to disable the device. Drive EN high
to enable the device.
11 10 SUP
Voltage Supply Input. SUP powers up the internal linear regulator. Bypass SUP to PGND
with a 4.7FF ceramic capacitor. It is recommended to add a placeholder for an RC filter
to reduce noise on the internal logic supply (see the Typical Application Circuit)
12 11 SUPSW Internal High-Side Switch Supply Input. SUPSW provides power to the internal switch.
Bypass SUPSW to PGND with 0.1FF and 4.7FF ceramic capacitors.
13, 14 12, 13 LX Inductor Switching Node. Connect a Schottky diode between LX and PGND.
15 14 PGND Power Ground
16 15 PGOOD Open-Drain, Active-Low Power-Good Output. PGOOD asserts when VOUT is above 95%
regulation point. PGOOD goes low when VOUT is below 92% regulation point.
— — EP
Exposed Pad. Connect EP to a large-area contiguous copper ground plane for effective
power dissipation. Do not use as the only IC ground connection. EP must be connected
to PGND.
Pin Descriptions (continued)
www.maximintegrated.com Maxim Integrated
9
MAX16936/MAX16938 36V, 220kHz to 2.2MHz Step-Down Converters
with 28µA Quiescent Current
H
Linear Regulator Output (BIAS)
The devices include a 5V linear regulator (BIAS) that
provides power to the internal circuit blocks. Connect a
1FF ceramic capacitor from BIAS to AGND. When the
output voltage is set between 3V and 5.5V, the internal
linear regulator only provides power until the output is in
regulation. The internal linear regulator turns off once the
output is in regulation and allows OUT to provide power
to the device. The internal regulator turns back on once
the external load on the output of the device is higher than
100mA. In addition, the linear regulator turns on anytime
the output voltage is outside the 3V to 5.5V range.
Power-Good Output (PGOOD)
The devices feature an open-drain power-good output,
PGOOD. PGOOD asserts when VOUT rises above 95% of
its regulation voltage. PGOOD deasserts when VOUT drops
below 92% of its regulation voltage. Connect PGOOD to
BIAS with a 10kI resistor.
Overvoltage Protection (OVP)
If the output voltage reaches the OVP threshold, the high-
side switch is forced off and the low-side switch is forced
on until negative-current limit is reached. After negative-
current limit is reached, both the high-side and low-side
switches are turned off. The MAX16938 offers a lower
voltage threshold for applications requiring tighter limits
of protection.
Synchronization Input (FSYNC)
FSYNC is a logic-level input useful for operating mode
selection and frequency control. Connecting FSYNC to
BIAS or to an external clock enables fixed-frequency
FPWM operation. Connecting FSYNC to AGND enables
skip mode operation.
The external clock frequency at FSYNC can be higher or
lower than the internal clock by 20%. Ensure the duty cycle
of the external clock used has a minimum pulse width of
100ns. The device synchronizes to the external clock within
Figure 1. Internal Block Diagram
FBSW
OUT COMP PGOOD EN
FB
SOFT
START
SLOPE
COMP
FBOK
EAMP
HSD
LSD
AON
LOGIC
CS
REF
HVLDO
SWITCH
OVER
PWM
SUP BIAS
BST
SUPSW
LX
PGND
SYNCOUT
BIAS
FSYNC FOSC AGND
OSC
MAX16936
MAX16938
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MAX16936/MAX16938 36V, 220kHz to 2.2MHz Step-Down Converters
with 28µA Quiescent Current
SS—
one cycle. When the external clock signal at FSYNC is
absent for more than two clock cycles, the device reverts
back to the internal clock.
System Enable (EN)
An enable control input (EN) activates the device from its
low-power shutdown mode. EN is compatible with inputs
from automotive battery level down to 3.5V. The high
voltage compatibility allows EN to be connected to SUP,
KEY/KL30, or the inhibit pin (INH) of a CAN transceiver.
EN turns on the internal regulator. Once VBIAS is above
the internal lockout threshold, VUVL = 3.15V (typ), the
controller activates and the output voltage ramps up
within 8ms.
A logic-low at EN shuts down the device. During shut-
down, the internal linear regulator and gate drivers turn
off. Shutdown is the lowest power state and reduces the
quiescent current to 5FA (typ). Drive EN high to bring the
device out of shutdown.
Spread-Spectrum Option
The devices have an internal spread-spectrum option to
optimize EMI performance. This is factory set and the
S-version of the device should be ordered. For spread-
spectrum-enabled ICs, the operating frequency is
varied ±6% centered on FOSC. The modulation signal is
a triangular wave with a period of 110µs at 2.2MHz.
Therefore, FOSC will ramp down 6% and back to 2.2MHz in
110µs and also ramp up 6% and back to 2.2MHz in 110µs.
The cycle repeats.
For operations at FOSC values other than 2.2MHz, the
modulation signal scales proportionally, e.g., at 400kHz,
the 110µs modulation period increases to 110µs x
2.2MHz/400kHz = 605µs.
The internal spread spectrum is disabled if the device is
synced to an external clock. However, the device does not
filter the input clock and passes any modulation (including
spread-spectrum) present on the driving external clock to the
SYNCOUT pin.
Automatic Slew-Rate Control on LX
The devices have automatic slew-rate adjustment that
optimizes the rise times on the internal HSFET gate
drive to minimize EMI. The IC detects the internal clock
frequency and adjusts the slew rate accordingly. When
the user selects the external frequency setting resistor
RFOSC such that the frequency is > 1.1MHz, the HSFET
is turned on in 4ns (typ). When the frequency is < 1.1MHz
the HSFET is turned on in 8ns (typ). This slew-rate control
optimizes the rise time on LX node externally to minimize
EMI while maintaining good efficiency.
Internal Oscillator (FOSC)
The switching frequency (fSW) is set by a resistor
(RFOSC) connected from FOSC to AGND. See Figure 3
to select the correct RFOSC value for the desired switch-
ing frequency. For example, a 400kHz switching fre-
quency is set with RFOSC = 73.2kI. Higher frequencies
allow designs with lower inductor values and less output
capacitance. Consequently, peak currents and I2R losses
are lower at higher switching frequencies, but core losses,
gate charge currents, and switching losses increase.
Synchronizing Output (SYNCOUT)
SYNCOUT is an open-drain output that outputs a 180N
out-of-phase signal relative to the internal oscillator.
Overtemperature Protection
Thermal-overload protection limits the total power
dissipation in the devices. When the junction tempera-
ture exceeds 175NC (typ), an internal thermal sensor
shuts down the internal bias regulator and the step-down
controller, allowing the device to cool. The thermal
sensor turns on the device again after the junction
temperature cools by 15NC.
Applications Information
Setting the Output Voltage
Connect FB to BIAS for a fixed +5V/+3.3 output voltage.
To set the output to other voltages between 1V and 10V,
connect a resistive divider from output (OUT) to FB to
AGND (Figure 2). Use the following formula to determine
the RFB2 of the resistive divider network:
RFB2 = RTOTAL x VFB/VOUT
where VFB = 1V, RTOTAL = selected total resistance of
RFB1, RFB2 in ω, and VOUT is the desired output in volts.
Figure 2. Adjustable Output-Voltage Setting
RFB2
RFB1
FB
VOUT
MAX16936
MAX16938
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MAX16936/MAX16938 36V, 220kHz to 2.2MHz Step-Down Converters
with 28µA Quiescent Current
Figure 3. Switching Frequency vs. R
Calculate RFB1 (OUT to FB resistor) with the following
equation:
OUT
FB1 FB2 FB
V
RR 1
V


= −





where VFB = 1V (see the Electrical Characteristics table).
FPWM/Skip Modes
The MAX16936/MAX16938 offer a pin selectable skip mode
or fixed-frequency PWM mode option. The IC has an internal
LS MOSFET that turns on when the FSYNC pin is connect-
ed to VBIAS or if there is a clock present on the FSYNC pin.
This enables the fixed-frequency-forced PWM mode opera-
tion over the entire load range. This option allows the user to
maintain fixed frequency over the entire load range in appli-
cations that require tight control on EMI. Even though the
devices have an internal LS MOSFET for fixed-frequency
operation, an external Schottky diode is still required to sup-
port the entire load range. If the FSYNC pin is connected
to GND, the skip mode is enabled on the device.
In skip mode of operation, the converter’s switching
frequency is load dependent. At higher load current, the
switching frequency does not change and the operating
mode is similar to the FPWM mode. Skip mode helps
improve efficiency in light-load applications by allowing
the converters to turn on the high-side switch only when
the output voltage falls below a set threshold. As such,
the converters do not switch MOSFETs on and off as
often as is the case in the FPWM mode. Consequently,
the gate charge and switching losses are much lower in
skip mode.
Inductor Selection
Three key inductor parameters must be specified
for operation with the devices: inductance value (L),
inductor saturation current (ISAT), and DC resistance
(RDCR). To select inductance value, the ratio of induc-
tor peak-to-peak AC current to DC average current (LIR)
must be selected first. A good compromise between size
and loss is a 30% peak-to-peak ripple current to average
current ratio (LIR = 0.3). The switching frequency, input
voltage, output voltage, and selected LIR then determine
the inductor value as follows:
OUT SUP OUT
SUP SW OUT
V (V V )
LV f I LIR
=
where VSUP, VOUT, and IOUT are typical values (so that
efficiency is optimum for typical conditions). The switching
frequency is set by RFOSC (see Figure 3).
Input Capacitor
The input filter capacitor reduces peak currents drawn
from the power source and reduces noise and voltage
ripple on the input caused by the circuit’s switching.
The input capacitor RMS current requirement (IRMS) is
defined by the following equation:
OUT SUP OUT
RMS LOAD(MAX) SUP
V (V V )
II V
=
IRMS has a maximum value when the input voltage equals
twice the output voltage (VSUP = 2VOUT), so IRMS(MAX)
= ILOAD(MAX)/2.
Choose an input capacitor that exhibits less than +10NC
self-heating temperature rise at the RMS input current for
optimal long-term reliability.
The input voltage ripple is composed of DVQ (caused
by the capacitor discharge) and DVESR (caused by the
ESR of the capacitor). Use low-ESR ceramic capacitors
with high ripple current capability at the input. Assume
the contribution from the ESR and capacitor discharge
equal to 50%. Calculate the input capacitance and ESR
required for a specified input voltage ripple using the fol-
lowing equations:
ESR
IN L
OUT
V
ESR I
I2
=
+
Figure 3. Switching Frequency vs. RFOSC
SWITCHING FREQUENCY vs. RFOSC
MAX16936 toc08
RFOSC (k)
SWITCHING FREQUENCY (MHz)
1027242
0.25
0.50
0.75
1.00
1.25
1.50
1.75
2.00
2.25
2.50
0
12 132
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MAX16936/MAX16938 36V, 220kHz to 2.2MHz Step-Down Converters
with 28µA Quiescent Current
Figure 4 Compensal/on Nerwork
where:
SUP OUT OUT
LSUP SW
(V V ) V
IV fL
−×
∆= ××
and:
OUT OUT
IN Q SW SUPSW
I D(1 D) V
C and D
Vf V
×−
= =
∆×
where IOUT is the maximum output current and D is the
duty cycle.
Output Capacitor
The output filter capacitor must have low enough ESR
to meet output ripple and load transient requirements.
The output capacitance must be high enough to absorb
the inductor energy while transitioning from full-load
to no-load conditions without tripping the overvoltage
fault protection. When using high-capacitance, low-ESR
capacitors, the filter capacitor’s ESR dominates the output
voltage ripple. So the size of the output capacitor depends
on the maximum ESR required to meet the output-voltage
ripple (VRIPPLE(P-P)) specifications:
RIPPLE(P P ) LOAD(MAX )
V ESR I LIR
=××
The actual capacitance value required relates to the phys-
ical size needed to achieve low ESR, as well as to the
chemistry of the capacitor technology. Thus, the capacitor
is usually selected by ESR and voltage rating rather than
by capacitance value.
When using low-capacity filter capacitors, such as ceramic
capacitors, size is usually determined by the capacity need-
ed to prevent voltage droop and voltage rise from causing
problems during load transients. Generally, once enough
capacitance is added to meet the overshoot requirement,
undershoot at the rising load edge is no longer a problem.
However, low capacity filter capacitors typically have high
ESR zeros that can affect the overall stability.
Rectifier Selection
The devices require an external Schottky diode rectifier
as a freewheeling diode when they are is configured for
skip-mode operation. Connect this rectifier close to the
device using short leads and short PCB traces. In FPWM
mode, the Schottky diode helps minimize efficiency loss-
es by diverting the inductor current that would otherwise
flow through the low-side MOSFET. Choose a rectifier
with a voltage rating greater than the maximum expected
input voltage, VSUPSW. Use a low forward-voltage-drop
Schottky rectifier to limit the negative voltage at LX. Avoid
higher than necessary reverse-voltage Schottky rectifiers
that have higher forward-voltage drops.
Compensation Network
The devices use an internal transconductance error ampli-
fier with its inverting input and its output available to the
user for external frequency compensation. The output
capacitor and compensation network determine the loop
stability. The inductor and the output capacitor are chosen
based on performance, size, and cost. Additionally, the
compensation network optimizes the control-loop stability.
The controller uses a current-mode control scheme that
regulates the output voltage by forcing the required
current through the external inductor. The devices use
the voltage drop across the high-side MOSFET to sense
inductor current. Current-mode control eliminates the
double pole in the feedback loop caused by the inductor
and output capacitor, resulting in a smaller phase shift and
requiring less elaborate error-amplifier compensation than
voltage-mode control. Only a simple single-series resistor
(RC) and capacitor (CC) are required to have a stable,
high-bandwidth loop in applications where ceramic capaci-
tors are used for output filtering (Figure 4). For other types
of capacitors, due to the higher capacitance and ESR, the
frequency of the zero created by the capacitance and ESR
is lower than the desired closed-loop crossover frequency.
To stabilize a nonceramic output capacitor loop, add
another compensation capacitor (CF) from COMP to GND
to cancel this ESR zero.
The basic regulator loop is modeled as a power
modulator, output feedback divider, and an error
amplifier. The power modulator has a DC gain set by
gm O RLOAD, with a pole and zero pair set by RLOAD,
the output capacitor (COUT), and its ESR. The follow-
ing equations allow to approximate the value for the
gain of the power modulator (GAINMOD(dc)), neglecting
the effect of the ramp stabilization. Ramp stabilization is
Figure 4. Compensation Network
R2
R1
VREF
VOUT
RC
CC
CF
COMP
gm
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13
MAX16936/MAX16938 36V, 220kHz to 2.2MHz Step-Down Converters
with 28µA Quiescent Current
necessary when the duty cycle is above 50% and is
internally done for the device.
MOD(dc) m LOAD
GAIN g R= ×
where RLOAD = VOUT/ILOUT(MAX) in I and gm = 3S.
In a current-mode step-down converter, the output capaci-
tor, its ESR, and the load resistance introduce a pole at
the following frequency:
= π× ×
pMOD OUT LOAD
f 1(2 C R )
The output capacitor and its ESR also introduce a zero at:
zMOD OUT
1
f2 ESR C
=π× ×
When COUT is composed of “n” identical capacitors in
parallel, the resulting COUT = n O COUT(EACH), and
ESR = ESR(EACH)/n. Note that the capacitor zero for a
parallel combination of alike capacitors is the same as for
an individual capacitor.
The feedback voltage-divider has a gain of GAINFB =
VFB/VOUT, where VFB is 1V (typ). The transconduc-
tance error amplifier has a DC gain of GAINEA(dc) =
gm,EA O ROUT,EA, where gm,EA is the error amplifier
transconductance, which is 700FS (typ), and ROUT,EA is
the output resistance of the error amplifier 50MI.
A dominant pole (fdpEA) is set by the compensation
capacitor (CC) and the amplifier output resistance
(ROUT,EA). A zero (fzEA) is set by the compensation
resistor (RC) and the compensation capacitor (CC).
There is an optional pole (fpEA) set by CF and RC to
cancel the output capacitor ESR zero if it occurs near
the cross over frequency (fC, where the loop gain equals
1 (0dB)). Thus:
dpEA C O U T ,E A C
zEA CC
pEA FC
1
f2 C (R R )
1
f2C R
1
f2CR
=π× × +
=π× ×
=π× ×
The loop-gain crossover frequency (fC) should be set
below 1/5th of the switching frequency and much higher
than the power-modulator pole (fpMOD):
SW
pMOD C
f
ff
5
<< ≤
The total loop gain as the product of the modulator gain,
the feedback voltage-divider gain, and the error amplifier
gain at fC should be equal to 1. So:
FB
MOD(fC) EA(fC)
OUT
V
GAIN GAIN 1
V
×× =
EA(fC) m, EA C
pMOD
MOD(fC) MOD(dc) C
GAIN g R
f
GAIN GAIN f
= ×
= ×
Therefore:
FB
MOD(fC) m,EA C
OUT
V
GAIN g R 1
V
× × ×=
Solving for RC:
OUT
Cm,EA FB MOD(fC)
V
Rg V GAIN
=××
Set the error-amplifier compensation zero formed by RC
and CC (fzEA) at the fpMOD. Calculate the value of CC a
follows:
CpMOD C
1
C2f R
=π× ×
If fzMOD is less than 5 x fC, add a second capacitor,
CF, from COMP to GND and set the compensation pole
formed by RC and CF (fpEA) at the fzMOD. Calculate the
value of CF as follows:
FzMOD C
1
C2f R
=π× ×
As the load current decreases, the modulator pole
also decreases; however, the modulator gain increases
accordingly and the crossover frequency remains the
same.
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14
MAX16936/MAX16938 36V, 220kHz to 2.2MHz Step-Down Converters
with 28µA Quiescent Current
l «m;
PCB Layout Guidelines
Careful PCB layout is critical to achieve low switching
losses and clean, stable operation. Use a multilayer board
whenever possible for better noise immunity and power
dissipation. Follow these guidelines for good PCB layout:
1) Use a large contiguous copper plane under the IC
package. Ensure that all heat-dissipating components
have adequate cooling. The bottom pad of the IC must
be soldered down to this copper plane for effective
heat dissipation and for getting the full power out of the
IC. Use multiple vias or a single large via in this plane
for heat dissipation.
2) Isolate the power components and high current path
from the sensitive analog circuitry. Doing so is essential
to prevent any noise coupling into the analog signals.
Implementing an RC filter on the SUP pin decreases
switching noise from entering the logic supply. Refer
to the MAX16936 EV kit data sheet for details on filter
configuration and PCB layout for the SUP and SUPSW
input capacitors. Do not route the OUT or feedback
signal next to the inductor. Make sure components used
on FOSC, COMP, and BIAS are connected to analog
ground.
3) Keep the high-current paths short, especially at the
ground terminals. This practice is essential for stable,
jitter-free operation. The high-current path composed
of the input capacitor, high-side FET, inductor, and the
output capacitor should be as short as possible.
4) Keep the power traces and load connections short. This
practice is essential for high efficiency. Use thick copper
PCBs (2oz vs. 1oz) to enhance full-load efficiency.
5) The analog signal lines should be routed away from
the high-frequency planes. Doing so ensures integrity
of sensitive signals feeding back into the IC.
6) The ground connection for the analog and power section
should be close to the IC. This keeps the ground current
loops to a minimum. In cases where only one ground is
used, enough isolation between analog return signals
and high power signals must be maintained.
D1 COUT
22µF
CIN2
4.7µF
CIN3
4.7µF
RIN3
0I
RCOMP
20kIRPGOOD
10kI
RSYNCOUT
100I
RFOSC
12kI
L1
2.2µH VOUT
5V AT 2.5A
CBST
0.1µF
LX
BST
VOUT VBIAS
OUT
VBAT
FB
VBIAS
VOUT
PGOOD
SYNCOUT
FOSC
CBIAS
1µF
CCOMP2
12pF
BIAS
CCOMP1
1000pF
COMP
FSYNC
OSC SYNC PULSE
EN
SUPSWSUP
CIN1
POWER-GOOD OUTPUT
180° OUT-OF-PHASE OUTPUT
AGNDPGND
MAX16936
MAX16938
Typical Application Circuit
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15
MAX16936/MAX16938 36V, 220kHz to 2.2MHz Step-Down Converters
with 28µA Quiescent Current
/V denotes an automotive qualified part.
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
**Future productcontact factory for availability.
PACKAGE
TYPE
PACKAGE
CODE
OUTLINE
NO.
LAND
PATTERN NO.
16 TSSOP-EP U16E+3 21-0108 90-0120
16 TQFN-EP T1655+4 21-0140 90-0121
PART
VOUT
SPREAD
SPECTRUM TEMP RANGE PIN-PACKAGE
ADJUSTABLE
(FB CONNECTED TO
RESISTIVE DIVIDER) (V)
FIXED
(FB
CONNECTED
TO BIAS) (V)
MAX16936RAUEA/V+ 1 to 10 5 Off -40°C to +125°C 16 TSSOP-EP*
MAX16936RAUEB/V+ 1 to 10 3.3 Off -40°C to +125°C 16 TSSOP-EP*
MAX16936SAUEA/V+ 1 to 10 5 On -40°C to +125°C 16 TSSOP-EP*
MAX16936SAUEB/V+ 1 to 10 3.3 On -40°C to +125°C 16 TSSOP-EP*
MAX16936RATEA/V+ 1 to 10 5 Off -40°C to +125°C 16 TQFN-EP*
MAX16936RATEB/V+ 1 to 10 3.3 Off -40°C to +125°C 16 TQFN-EP*
MAX16936SATEA/V+ 1 to 10 5 On -40°C to +125°C 16 TQFN-EP*
MAX16936SATEB/V+ 1 to 10 3.3 On -40°C to +125°C 16 TQFN-EP*
MAX16938AUERA/V+** 1 to 10 5 Off -40°C to +125°C 16 TSSOP-EP*
MAX16938AUERB/V+** 1 to 10 3.3 Off -40°C to +125°C 16 TSSOP-EP*
MAX16938AUESA/V+** 1 to 10 5 On -40°C to +125°C 16 TSSOP-EP*
MAX16938AUESB/V+** 1 to 10 3.3 On -40°C to +125°C 16 TSSOP-EP*
MAX16938ATERA/V+ 1 to 10 5 Off -40°C to +125°C 16 TQFN-EP*
MAX16938ATERB/V+ 1 to 10 3.3 Off -40°C to +125°C 16 TQFN-EP*
MAX16938ATESA/V+ 1 to 10 5 On -40°C to +125°C 16 TQFN-EP*
MAX16938ATESB/V+ 1 to 10 3.3 On -40°C to +125°C 16 TQFN-EP*
Ordering Information/Selector Guide
Package Information
For the latest package outline information and land patterns (foot-
prints), go to www.maximintegrated.com/packages. Note that
a “+”, “#”, or “-” in the package code indicates RoHS status only.
Package drawings may show a different suffix character, but the
drawing pertains to the package regardless of RoHS status.
Chip Information
PROCESS: BiCMOS
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16
MAX16936/MAX16938 36V, 220kHz to 2.2MHz Step-Down Converters
with 28µA Quiescent Current
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
0 3/13 Initial release
1 4/13 Added non-automotive OPNs to Ordering Information/Selector Guide 16
2 8/13
Updated FPWM and Skip Mode output voltages in Electrical Characteristics, Internal
Oscillator (FOSC) and Compensation Network sections, and removed the non-
automotive parts from the Ordering Information/Selector Guide
2, 3, 11, 13, 16
3 11/13 Removed future product references from the Ordering Information/Selector Guide 16
4 2/14 Changed the BST capacitor value from 0.22µF to 0.1µF in Pin Descriptions and
Typical Application Circuit; updated the Linear Regulator Output (BIAS) section 8, 9, 15
5 3/14 Added lead-free designation to TQFN package code 16
6 1/15
Updated SUP pin in Pin Descriptions table, added Maximum Duty-Cycle Operation
section, updated guideline #2 in PCB Layout Guidelines section, and added an RC
filter in the Typical Application Circuit
9, 14, 15
7 2/15 Updated the Benefits and Features section 1
8 3/15 Added new Note 1 to Absolute Maximum Ratings and renumbered the remaining
notes in Package Thermal Characteristics section and Electrical Characteristics 2–4
9 6/15 Added the MAX16938 to data sheet as a future product 1–17
10 6/15 Corrected MAX16938 variants in Ordering Information/Selector Guide 16
11 7/15 Corrected typo in Pin Configurations diagram; corrected exposed pad and future
product designations and corrected typo in Ordering Information/Selector Guide 8,16
12 3/16 Updated 3rd sub-bullet under 1st main bullet in Benefits and Features section
(changed Accuracy (5V) to (5V/3.3V) 1
13 4/16 Added new bullet in Benefits and Features section; removed future product
references 1, 16
14 6/16 Changed part number from MAX16939 to MAX16938 in last bullet in Benefits and
Features section 1
15 1/17 Added 3.3V option for Supply Current and changed maximum Skip-Mode Output
Voltage from 3.34V to 3.4V in Electrical Characteristics table 2, 3
16 7/17 Added a new Note 3 in/after Electrical Characteristics table and renumbered the
remaining four notes accordingly 2, 4
17 10/17 Deleted Note 3 in/after Electrical Characteristics table and renumbered the
remaining four notes accordingly 2, 4
18 3/18 Changed AGND to PGND for LX pin in the Pin Descriptions table 9
Revision History
Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses
are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits)
shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. © 2018 Maxim Integrated Products, Inc.
17
MAX16936/MAX16938 36V, 220kHz to 2.2MHz Step-Down Converters
with 28µA Quiescent Current
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.

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