General Description
The MAX5096/MAX5097 easy-to-use, Dual Mode™,
DC-DC converters operate as LDO (low dropout) or
switch-mode buck converters. At a high output load,
the converters operate as high-efficiency pulse-width-
modulated (PWM) switch-mode converters and reduce
the power dissipation. The devices switch to a low-qui-
escent-current (IQ) LDO mode of operation at light load.
During the key-off condition, the system’s microcon-
troller drives the LDO/BUCK input on the fly and forces
the MAX5096/MAX5097 into LDO Mode, thereby reduc-
ing the quiescent current significantly.
In Buck Mode, the MAX5096/MAX5097 operate from a 5V
to 40V input voltage range and deliver up to 600mA of
load current with excellent load and line regulation. The
fixed-switching frequency versions of 135kHz and
330kHz are available. The MAX5096/MAX5097 DC-DC
internal oscillator can be synchronized to an external
clock. External compensation and a current-mode control
scheme make it easy to design with.
In LDO Mode, the MAX5096/MAX5097 operate from a
4V to 40V input voltage. The LDO Mode operation is
intended for a lower output load current of up to
100mA. The quiescent current at 100µA load in LDO
Mode is only 41µA (typ).
The MAX5096/MAX5097 feature an enable input that
shuts down the device, reducing the current consump-
tion to 6µA (typ). Additional features include a power-on
reset output with a capacitor-adjustable timeout period,
programmable soft-start, output tracking, output over-
load, short-circuit and thermal shutdown protections.
The MAX5096/MAX5097 operate over the -40°C to
+125°C automotive temperature range and are avail-
able in thermally enhanced 20-pin TSSOP or 16-pin
TQFN packages.
Applications
Automotive
Industrial
Features
High-Efficiency Switcher Mode (Buck Mode) or
Low-Quiescent-Current Linear Regulator
(LDO Mode) Operation
Wide Operating Input Voltage Range
+5V to +40V Buck Mode
+4V to +40V LDO Mode
Fixed 3.3V or 5V and Adjustable (1.24V to 11V)
Output Voltage Versions
6μA (typ) Shutdown Current
Fixed 135kHz or 330kHz Switching Frequency
External Frequency Synchronization
Programmable Soft-Start
Integrated Microprocessor Reset (RESET) Circuit
with Programmable Timeout Period
Thermal and Short-Circuit Protection
-40°C to +125°C Automotive Temperature Range
Thermally-Enhanced Package Dissipates
2.6W at TA= +70°C (16-Pin TQFN)
1.7W at TA= +70°C (20-Pin TSSOP)
MAX5096/MAX5097
40V, 600mA Buck Converters with Low-
Quiescent-Current Linear Regulator Mode
________________________________________________________________ Maxim Integrated Products 1
19-0603; Rev 2; 9/07
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
EVALUATION KIT
AVAILABLE
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
PKG
CODE
MAX5096AATE+
-40°C to +125°C 16 TQFN-EP*
T1655-2
MAX5096BATE+
-40°C to +125°C 16 TQFN-EP*
T1655-2
MAX5096AAUP+
-40°C to +125°C 20 TSSOP-EP*
U20E-4
MAX5096BAUP+
-40°C to +125°C 20 TSSOP-EP*
U20E-4
MAX5097AATE+
-40°C to +125°C 16 TQFN-EP*
T1655-2
MAX5097BATE+
-40°C to +125°C 16 TQFN-EP*
T1655-2
MAX5097AAUP+
-40°C to +125°C 20 TSSOP-EP*
U20E-4
MAX5097BAUP+
-40°C to +125°C 20 TSSOP-EP*
U20E-4
TQFN
+
LX
16
1
2
3
4
12
11
10
9
15 14 13
5678
IN
IN
LX
EN
OUT
ADJ
LDO/BUCK
SGND
RESET
BP
SYNC
SS
CT
COMP
PGND
MAX5096
MAX5097
TOP VIEW
20
19
18
17
16
15
14
1
2
3
4
5
6
7
LX
LX
N.C.
ENPGND
IN
IN
IN
TOP VIEW
MAX5096
MAX5097
OUT
ADJ
N.C.BP
138N.C.
129 COMPSYNC
1110 CTSS
SGND
TSSOP
LDO/BUCK
RESET
+
Pin Configurations
+Denotes lead-free package.
*EP = Exposed pad.
Dual Mode is a trademark of Maxim Integrated Products, Inc.
MAX5096/MAX5097
40V, 600mA Buck Converters with Low-
Quiescent-Current Linear Regulator Mode
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation 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.
(All voltages referenced to PGND, unless otherwise noted.)
IN (transient, 1ms) ..................................................-0.3V to +45V
SGND ....................................................................-0.3V to +0.3V
LX....................................................................-1V to (VIN + 0.3V)
LX Current ................................................................................2A
EN ................................................................-0.3V to (VIN + 0.3V)
BP, SYNC, LDO/BUCK, RESET to SGND...............-0.3V to +12V
BP, RESET Output Current..................................................25mA
CT, SS, ADJ, COMP to SGND ....................-0.3V to (VBP + 0.3V)
OUT ........................................................................-0.3V to +11V
OUT Short-Circuit Duration ........................................Continuous
Continuous Power Dissipation (TA= +70°C)*
16-Pin TQFN (derate 33.3mW/°C above +70°C) ........2666mW
20-Pin TSSOP (derate 21.7mW/°C above +70°C) ......1739mW
Thermal Resistance:
(θJA, 16-Pin TQFN)* ...................................................30.0°C/W
(θJC, 16-Pin TQFN).......................................................1.7°C/W
(θJA, 20-Pin TSSOP)* .................................................46.0°C/W
(θJC, 20-Pin TSSOP)........................................................2°C/W
Operating Temperature Range .........................-40°C to +125°C
Junction Temperature......................................................+150°C
Storage Temperature Range .............................-60°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
ELECTRICAL CHARACTERISTICS
(VIN = +14V, IOUT = 1mA, CIN = 100µF, COUT = 22µF, L = 22µH, CBP = 1µF, VEN = +2.4V (Figure 2), SGND = PGND = 0V, TA= TJ=
-40°C to +125°C, unless otherwise noted. Typical values are at TA= TJ= +25°C.) (Note 1)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
SYSTEM INPUT
Input Voltage Range (LDO Mode)
VIN_LDO
LDO/BUCK = high 4 40 V
Input Voltage Range (Buck
Mode)
VIN_BUCK
LDO/BUCK = low 5 40 V
Internal Input Undervoltage
Lockout VUVLO VBP rising 3.5
3.65
3.9 V
Internal Input Undervoltage
Lockout Hysteresis
VUVLO_HYS
VBP falling 0.2 V
BP (Internal Regulator) Output
Voltage VBP VIN = +4.5V, IBP = 100µA
3.75
4
4.20
V
IQ
LDO/BUCK = high,
measured at input supply
return, VOUT = 5V,
IOUT = 100µA
TA = -40°C to
+125°C 38 70
Quiescent Supply Current
(LDO Mode)
IQ
LDO/BUCK = high,
measured at input supply
return, VOUT = 5V,
IOUT = 100mA
TA = -40°C to
+125°C 44 100
µA
Buck Converter No-Load Supply
Current
IQ_BUCK
VIN = 14V, VOUT = 5V, IOUT = 0
680
µA
TA = -40°C to
+125°C 619
Shutdown Supply Current ISHDN VEN = 0V, measured
from VIN TA = -40°C to
+85°C 612
µA
*As per JEDEC 51 Standard—Multilayer Board.
MAX5096/MAX5097
40V, 600mA Buck Converters with Low-
Quiescent-Current Linear Regulator Mode
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(VIN = +14V, IOUT = 1mA, CIN = 100µF, COUT = 22µF, L = 22µH, CBP = 1µF, VEN = +2.4V (Figure 2), SGND = PGND = 0V, TA= TJ=
-40°C to +125°C, unless otherwise noted. Typical values are at TA= TJ= +25°C.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN TYP MAX
UNITS
BUCK MODE
Supply Current
(Buck Converter On) IS
LDO/BUCK = low,
VADJ = 1.4V, MAX5096,
no switching
135kHz
version
693
980 µA
Supply Current
(Buck Converter On) IS
LDO/BUCK = low,
VADJ = 1.4V, MAX5097,
no switching
330kHz
Version
720 1000
µA
5V version, 5.5V VIN 40V, no load
4.85
5
5.12
Fixed Output Voltage VOUT 3.3V version, 5.5V VIN 40V, no load
3.196
3.3
3.391
V
ADJ Set Point VFB 50% duty cycle, no load
1.21 1.235 1.27
V
ADJ Input Bias Current IFB VADJ = 1.5V 5 100 nA
VADJTH_R
ADJ rising
125
Dual Mode ADJ Threshold
VADJTH_F
ADJ falling 62 mV
Maximum Duty Cycle DMAX VADJ = 0.5V
100
%
Error Amplifier Transconductance
GmEA VCOMP = VADJ, ICOMP = ±10µA 55
136
210 µS
Adjustable Output Voltage Range
VADJ
1.235 11.000
V
Minimum Output Current IOUT VIN = 6.5V to 40V
600
mA
Switch Current Limit
ISW_LIM
VIN = 6V to 40V
1.15
1.5
1.90
A
Internal Switch On-Resistance
RDS
(
ON
)
VIN = 14V, IDRAIN = 100mA 0.9 2.1 Ω
Switch Leakage Current ISW_L VEN = 0V
0.05
A
VIN = 14V, VOUT = 5V, IOUT = 400mA 85
Efficiency ηVIN = 14V, VOUT = 3.3V, IOUT = 400mA 81 %
MAX5096
120 135
148 kHz
Switching Frequency fSW MAX5097
300 330
350 kHz
MAX5096
120
500 kHz
Synchronization SYNC Input fSYNC MAX5097
300
500 kHz
SYNC Input High Threshold
VSYNCH
VBP = 4V 2.0 V
SYNC Input Low Threshold
VSYNCL
VBP = 4V 0.8 V
SYNC Input Minimum High Pulse
Width
250
ns
SYNC Input Leakage VSYNC =11V 1 µA
LDO MODE
Guaranteed Output Current IOUT (Note 2)
100
mA
MAX5096/MAX5097
40V, 600mA Buck Converters with Low-
Quiescent-Current Linear Regulator Mode
4 _______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS (continued)
(VIN = +14V, IOUT = 1mA, CIN = 100µF, COUT = 22µF, L = 22µH, CBP = 1µF, VEN = +2.4V (Figure 2), SGND = PGND = 0V, TA= TJ=
-40°C to +125°C, unless otherwise noted. Typical values are at TA= TJ= +25°C.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN TYP MAX
UNITS
5V version, MAX5096B/MAX5097B,
5.5V VIN 40V, IOUT = 10mA
4.89
5
5.09
V
Output Voltage VOUT 3.3V version, MAX5096A/MAX5097A,
4V VIN 40V, IOUT = 10mA
3.219
3.3
3.378
V
ADJ Set Point VADJ IOUT = 10mA
1.21 1.2375 1.26
V
ADJ Input Bias Current IFB VADJ = 4V 0.5
100
nA
Adjustable Output Voltage Range
VADJ IOUT = 10mA
1.237 11.000
V
Dropout Voltage ΔVDO
IOUT = 100mA,
VOUT = 0.98 x VOUT(NOMINAL) (5V version
only), MAX5096B/MAX5097B
0.37
V
Startup Response Time
Rising edge of EN to
VOUT = 10% VOUT(NOMINAL),
RL = 500Ω, VADJ = SGND,
LDO/BUCK = 4V, CSS = 2nF
300 µs
5V version,
+5.5V VIN +40V, IOUT = 100mA
0.125
Line Regulation ΔVOUT /
ΔVIN 3.3V version,
+4V VIN +40V, IOUT = 100mA
0.093
mV/V
TJ = +25°C
0.242 0.374
5V version,
IOUT = 100µA to
100mA, VIN = +14V TJ = -40°C to +125°C 0.242
1
TJ = +25°C
0.164 0.237
Load Regulation ΔVOUT /
ΔIOUT 3.3V version,
IOUT = 100µA to
100mA, VIN = +14V TJ = -40°C to +125°C 0.164
1
mV/mA
Power-Supply Rejection Ratio PSRR IOUT = 10mA, f = 100Hz, 500mVP-P,
VOUT = +5V, VIN = +14V 60 dB
Short-Circuit Current ISC VIN = 6V 150 330
500
mA
BUCK MODE (LDO MODE TRANSITION)
LDO/BUCK High Threshold 2.0 V
LDO/BUCK Low Threshold 0.8 V
LDO/BUCK Input Leakage LDO/BUCK = 11V 1 µA
Transition Timing from LDO Mode
to Buck Mode
Falling edge of LDO/BUCK to buck
converter on 32
Clock
Periods
Transition Timing from Buck
Mode to LDO Mode
Rising edge of LDO/BUCK to LDO
operation 100 µs
SOFT-START, ENABLE (EN) AND RESET
Soft-Start Charge Current ISS VSS = 0.1V 3 5 7 µA
Soft-Start Reference Voltage
VSS-REF
VOUT = VOUT(NOMINAL) - 20% 0.9
0.99
1.1 V
EN High-Voltage Threshold VENH EN = high, regulator on 1.4 V
MAX5096/MAX5097
40V, 600mA Buck Converters with Low-
Quiescent-Current Linear Regulator Mode
_______________________________________________________________________________________ 5
ELECTRICAL CHARACTERISTICS (continued)
(VIN = +14V, IOUT = 1mA, CIN = 100µF, COUT = 22µF, L = 22µH, CBP = 1µF, VEN = +2.4V (Figure 2), SGND = PGND = 0V, TA= TJ=
-40°C to +125°C, unless otherwise noted. Typical values are at TA= TJ= +25°C.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN TYP MAX
UNITS
EN Low-Voltage Threshold VENL Regulator off 0.4 V
EN Input Pulldown VEN = 2V, LDO/BUCK = 4V 0.5 µA
RESET Voltage Threshold High
VRESET_H
VOUT rising 89 92 94
% VOUT
RESET Voltage Threshold Low
VRESET_L
VOUT falling 87 90 92
% VOUT
RESET Output-Low Voltage VRL ISINK = 1mA 0.2 V
RESET Output-High Leakage
Current IRH VRESET = 5V, VADJ = 1.5V 1 µA
RESET Output Minimum Timeout
Period CCT = 0 25 µs
VOUT to RESET Delay VOUT falling 10mV/µs, CCT = 0 6 µs
Delay Comparator Threshold VCT_TH VCT rising
1.18 1.2374 1.29
V
Delay Comparator Threshold
Hysteresis
100
mV
CT Charge Current ICH
0.74
1
1.20
µA
CT Discharge Current IDISCH VCT = 1V
13.8
mA
THERMAL SHUTDOWN
Thermal Shutdown Temperature
TJ
(
SHDN
)
Temperature rising
+165
°C
Thermal Shutdown Hysteresis
ΔTJ
(
SHDN
)
20 °C
Note 1: Limits to -40°C are guaranteed by design.
Note 2: The continuous maximum output current from LDO is limited by package power dissipation.
MAX5096/MAX5097
40V, 600mA Buck Converters with Low-
Quiescent-Current Linear Regulator Mode
6 _______________________________________________________________________________________
Typical Operating Characteristics
(VIN = +14V, VEN = +2.4V, MAX5097AATE+, Figures 2 and 4, TA= +25°C, unless otherwise specified.)
OUTPUT VOLTAGE vs. INPUT VOLTAGE
(LDO MODE)
MAX5096 toc01
INPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
10
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
0
1 100
IOUT = 50mA
OUTPUT VOLTAGE vs. INPUT VOLTAGE
(BUCK MODE)
MAX5096 toc02
INPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
10
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
0
1100
IOUT = 600mA
0
10
70
30
20
40
50
60
80
-40 -10 5 20-25 35 50 9580 11065 125
QUIESCENT SUPPLY CURRENT
vs. TEMPERATURE (LDO MODE)
MAX5096 toc03
TEMPERATURE (°C)
QUIESCENT SUPPLY CURRENT (μA)
VIN = 14V
VOUT = 3.3V
IOUT = 100mA
IOUT = 100μA
IOUT = 0
640
660
650
680
670
700
690
710
NO-LOAD SUPPLY CURRENT
vs. TEMPERATURE (BUCK MODE)
MAX5096 toc04
VIN = 14V
VOUT = 3.3V
-40 -10 5 20-25 35 50 9580 11065 125
TEMPERATURE (°C)
NO-LOAD SUPPLY CURRENT (μA)
0
4
2
8
6
12
10
14
SHUTDOWN CURRENT
vs. TEMPERATURE
MAX5096 toc05
-40 -10 5 20-25 35 50 9580 11065 125
TEMPERATURE (°C)
SHUTDOWN CURRENT (μA)
VEN = 0V
VIN = 14V
3.0
3.1
3.2
3.3
3.4
3.5
OUTPUT VOLTAGE vs. TEMPERATURE
(LDO MODE)
MAX5096 toc06
OUTPUT VOLTAGE (V)
-40 -10 5 20-25 35 50 9580 11065 125
TEMPERATURE (°C)
VOUT = 3.3V
IOUT = 10mA IOUT = 100μA
IOUT = 10mA
3.24
3.28
3.26
3.32
3.30
3.36
3.34
3.38
OUTPUT VOLTAGE
vs. TEMPERATURE (BUCK MODE)
MAX5096 toc07
-40 -10 5 20-25 35 50 9580 11065 125
TEMPERATURE (°C)
OUTPUT VOLTAGE (V)
VOUT = 3.3V
IOUT = 100μA
IOUT = 100mA IOUT = 600mA
0
0.04
0.02
0.10
0.08
0.06
0.16
0.14
0.12
0.18
04020 60 80 100
DROPOUT VOLTAGE
vs. OUTPUT CURRENT (LDO MODE)
MAX5096 toc08
OUTPUT CURRENT (mA)
DROPOUT VOLTAGE (V)
VOUT = 5V
0
30
20
10
40
50
60
70
80
90
100
0.01 0.1 1
EFFICIENCY vs. LOAD CURRENT
(VOUT = 3.3V)
MAX5096 toc09
LOAD CURRENT (A)
EFFICIENCY (%)
VIN = 5V
VIN = 14V
VIN = 24V
VIN = 40V
fSW = 330kHz
MAX5096/MAX5097
40V, 600mA Buck Converters with Low-
Quiescent-Current Linear Regulator Mode
_______________________________________________________________________________________ 7
Typical Operating Characteristics (continued)
(VIN = +14V, VEN = +2.4V, MAX5097AATE+, Figures 2 and 4, TA= +25°C, unless otherwise specified.)
0
30
20
10
40
50
60
70
80
90
100
0.01 0.1 1
EFFICIENCY vs. LOAD CURRENT
(VOUT = 5V)
MAX5096 toc10
LOAD CURRENT (A)
EFFICIENCY (%)
VIN = 40V
VIN = 5.5V VIN = 24V
VIN = 14V
2ms/div
LOAD-TRANSIENT RESPONSE
(LDO MODE)
IOUT
50mA/div
VOUT
50mV/div
MAX5096 toc11
VIN = 14V
IOUT = 100μA to 50mA
1ms/div
LOAD-TRANSIENT RESPONSE
(BUCK MODE)
IOUT
200mA/div
VOUT
AC-COUPLED
100mV/div
MAX5096 toc12
VIN = 14V
ISTEP = 300mA to 600mA
10ms/div
VIN STARTUP RESPONSE
(LDO MODE)
VIN
10V/div
RESET
5V/div
MAX5096 toc13
VIN = 14V
IOUT = 0A
CCT = 0.047μF
VEN
10V/div
VOUT
2V/div
10ms/div
ENABLE STARTUP RESPONSE
(LDO MODE)
VIN
10V/div
RESET
5V/div
MAX5096 toc14
VIN = 14V
IOUT = 100mA
CCT = 0.047μF
VEN
5V/div
VOUT
2V/div
10ms/div
VIN STARTUP RESPONSE
(BUCK MODE)
VIN
10V/div
RESET
5V/div
MAX5096 toc15
VIN = 14V
IOUT = 0A
CCT = 0.047μF
VEN
5V/div
VOUT
2V/div
10ms/div
ENABLE STARTUP RESPONSE
(BUCK MODE)
VIN
10V/div
RESET
5V/div
MAX5096 toc16
VIN = 14V
IOUT = 600mA
CCT = 0.047μF
VEN
5V/div
VOUT
2V/div
100ms/div
SHUTDOWN RESPONSE THROUGH
VIN (LDO MODE)
VIN
10V/div
RESET
5V/div
MAX5096 toc17
IOUT = 50mA
VEN
10V/div
VOUT
2V/div
100ms/div
SHUTDOWN RESPONSE THROUGH
VIN (BUCK MODE)
VIN
10V/div
RESET
5V/div
MAX5096 toc18
IOUT = 50mA
VEN
10V/div
VOUT
2V/div
MAX5096/MAX5097
40V, 600mA Buck Converters with Low-
Quiescent-Current Linear Regulator Mode
8 _______________________________________________________________________________________
Typical Operating Characteristics (continued)
(VIN = +14V, VEN = +2.4V, MAX5097AATE+, Figures 2 and 4, TA= +25°C, unless otherwise specified.)
2μs/div
LX VOLTAGE AND INDUCTOR CURRENT
MAX5096 toc19
IOUT = 0A
VLX
5V/div
INDUCTOR
CURRENT
200mA/div
1μs/div
LX VOLTAGE AND INDUCTOR CURRENT
MAX5096 toc20
IOUT = 600mA
VLX
10V/div
INDUCTOR
CURRENT
500mA/div
1μs/div
LX VOLTAGE, SYNC INPUT,
AND INDUCTOR CURRENT
MAX5096 toc21
VLX
10V/div
INDUCTOR
CURRENT
500mA/div
SYNC INPUT
5V/div
400μs/div
TRANSITION FROM BUCK
MODE TO LDO MODE
MAX5096 toc22
LDO/BUCK
5V/div
IOUT
100mA/div
VOUT
AC-COUPLED
200mV/div
VIN = 14V
IOUT = 100mA
100μs/div
TRANSITION FROM LDO MODE
TO BUCK MODE
MAX5096 toc23
LDO/BUCK
3V/div
IOUT
100mA/div
VOUT
AC-COUPLED
200mV/div
VIN = 14V
IOUT = 100mA
MAX5096/MAX5097
40V, 600mA Buck Converters with Low-
Quiescent-Current Linear Regulator Mode
_______________________________________________________________________________________ 9
Pin Description
PIN
TQFN TSSOP NAME FUNCTION
1 4 PGND
Power Ground. Return path for p-channel power MOSFET driver. Connect the input
capacitor return, freewheeling diode anode, and output capacitor return terminals to
PGND.
2 5 SGND
Signal Ground. Connect SGND to PGND near the input bypass capacitor return terminal.
36RESET
Open-Drain, Active-Low Reset Output. RESET asserts low when OUT drops below the
reset threshold. When output rises above 92% of the programmed level, RESET
becomes high impedance after the reset timeout period. Connect a pullup resistor from
RESET to the converter output to create a logic output.
47BP
4V Internal Regulator Output. Bypass BP to SGND with a 1µF or greater ceramic
capacitor.
5 9 SYNC Synchronization Input. Connect SYNC to an external clock for synchronization. Connect
SYNC to SGND when not used.
610SS
Soft-Start Timer Input. Connect an external capacitor from SS to SGND to adjust the soft-
start timeout period (see the Soft-Start (SS) section).
711CT
Reset Timeout Period. Connect a capacitor from CT to SGND to set the reset timeout
period (see the Power-On Reset Output
RESET
section).
8 12 COMP
Buck Converter (Buck Mode) Control Loop Compensation. See the Compensation
Network section for compensation network design. LDO mode does not need external
compensation.
913
LDO/BUCK
LDO Mode/Buck Mode Select. Drive LDO/BUCK low to select the Buck Mode. The Buck
Mode activates after 32 internal/external clock cycles. Force the LDO/BUCK high (> 2V),
to select LDO Mode. The Buck Mode stops and LDO Mode is activated with a 100µs
delay.
10 15 ADJ
Regulator Output Feedback Point. Connect ADJ to SGND for a fixed 3.3V
(MAX5096A/MAX5097A) or 5V (MAX5096B/MAX5097B). For adjustable output voltage,
use an external resistive divider to set VOUT. VADJ regulating set point is 1.237V.
11 16 OUT
Converter Output. OUT must always be connected to the regulator output. Connect at
least a 22µF low-ESR (equivalent series resistance) capacitor from OUT to PGND for
stable operation.
12 17 EN Enable Input. EN is internally pulled to ground. Drive EN high to turn on the regulator.
Force EN low or leave unconnected to place the device in shutdown mode.
13, 14 19, 20 LX Drain Connection of Internal p-Channel High-Side Switch
15, 16 1, 2, 3 IN Regulator Input. Bypass IN to PGND with a parallel combination of low-ESR ceramic and
aluminum capacitor to handle the input ripple current.
8, 14, 18 N. C. No Connection. Not internally connected.
EP EP EP Exposed Pad. Connect externally to a large ground plane (SGND) for improved heat
dissipation. Do not use EP as an electrical ground connection.
MAX5096/MAX5097
40V, 600mA Buck Converters with Low-
Quiescent-Current Linear Regulator Mode
10 ______________________________________________________________________________________
+
-
-
+
-
-
+
+
-
-+
gm
VREF
0.9Ω
CURRENT
LIMITER
RESET
INTERNAL
4V LDO
BP
IN
ADJ
LX
RESET
GATE
DRIVER
MUX
EN
PGND
LDO/BUCK
LVOUT
CIN
PWM
COUT
SYNC
CT
SS
0.12V
FEEDBACK
SELECTOR
BUCK MODE GM
AMPLIFIER
FB
LDO/ BUCK
SELECTOR
PWM
COMPARATOR
DC-DC ENABLE
OSCILLATOR
AND RAMP
GENERATOR
MODE
SELECTOR
SS
OUT
LDO MODE
AMPLIFIER
SS
DC
CURRENT
SENSE
COMP
RC
CC
VOUT
SGND
VIN
FB
SYNCRO
CBP
R2
RPU
R1
CSS
CCT
BIAS SOFT-
START
INTERNAL
BANDGAP
UVLO
THERMAL
PROTECTION
VREF
MAX5096
MAX5097
CP
Figure 1. Simplified Diagram
Detailed Description
The MAX5096/MAX5097 are easy-to-use, high-efficien-
cy, PWM current-mode, step-down switching convert-
ers in normal operation. The MAX5096/MAX5097 have
an internal high-side p-channel 0.9Ωswitch and use a
low forward-drop freewheeling diode for rectification. In
Buck Mode, the p-channel switches at the 135kHz or
330kHz frequency. Buck Mode uses a current-mode
control architecture that offers excellent line-transient
response, easier frequency compensation, and cycle-
by-cycle current limiting. The buck converter is com-
pensated externally for a selected value/type of output
inductor and capacitor.
The internal p-channel switch acts as a pass element
when operating in the low-quiescent-current LDO
Mode.
The LDO Mode can be selected on the fly through the
LDO/BUCK input. During the key-off condition, the sys-
tem’s microcontroller drives the LDO/BUCK input high
and forces the MAX5096/MAX5097 into LDO Mode,
reducing the quiescent current to 1µA (typ). When in
LDO Mode, the device is capable of delivering up to
100mA, which may be limited by the device power dis-
sipation. The LDO and switcher share the same pass
element and the reference; however, the error ampli-
fiers are different with their own compensation
schemes.
The MAX5096/MAX5097 include an integrated micro-
processor reset circuit with an adjustable reset timeout
period. The internal reset circuit monitors the regulator
output voltage and asserts RESET low when the regula-
tor output falls below the reset threshold voltage. Other
features include an enable input, externally program-
mable soft-start, optimized current-limit protection in
both LDO and Buck Modes, and thermal shutdown.
Enable Input (EN)
EN is a logic-level enable input that turns the device on
or off. The logic-high and logic-low voltages for the EN
input are 1.4V and 0.4V, respectively. Drive EN high to
turn on the device, and drive it low to place the device
in shutdown. Leaving EN unconnected disables the
device since the EN is internally pulled low with a 0.5µA
current, however, a forced pulldown of EN improves the
noise immunity. The MAX5096/MAX5097 draw 6µA
(typ) of supply current when in shutdown. EN with-
stands up to +40V, allowing EN to be connected direct-
ly to IN for always-on operation. The converter may be
turned on and off while in both Buck and LDO Modes.
Each time the EN is toggled, the output rises with a pro-
grammed soft-start period.
Internal Regulator (BP)/
Undervoltage Lockout
The MAX5096/MAX5097 include an internal 4V auxiliary
regulator to power internal circuitry. Bypass the auxil-
iary regulator output (BP) to SGND with a 1µF ceramic
capacitor physically located close to the device. The
regulator is not intended to supply the external circuit
other than pulling up the LDO/BUCK input or RESET.
Do not load BP externally by more than 2mA. The regu-
lator output is regulated to 4V with 7% accuracy during
steady state. During turn-on, the BP voltage stabilizes
after 250µs with a 1µF capacitor at BP. Drive EN high to
turn on the internal regulator. The internal UVLO with
hysteresis ensures stable operation, resulting in the
monotonic rise of the output voltage. The UVLO circuit
monitors the output of the regulator. The rising UVLO
threshold is internally set to 3.65V (BP rising) with a
185mV hysteresis (BP falling). The 3.65V UVLO at the
no-load BP output guarantees operation at VIN lower
than 4V.
Soft-Start (SS)
Soft-start provides for the monotonic, glitch-free turn-on
of the converter. Soft-start limits the input inrush current
which may cause a glitch, especially if the source
impedance is high. The soft-start period required also
depends on the output capacitance and the closed-
loop bandwidth of converter. The soft-start period for
the MAX5096/MAX5097 is externally programmable
using a single capacitor (CSS). The soft-start is
achieved by the controlled ramping up of the error
amplifier reference input. At startup, after VIN is applied
and the UVLO threshold is reached, the device enters
soft-start. During soft-start, 5µA is sourced into the
capacitor (CSS) connected from SS to SGND (Figure 2)
causing the reference voltage to ramp up slowly. When
VSS reaches 1.237V, the output becomes fully active.
Set the soft-start time (tSS) using following equation:
where VSS is 1.237V, ISS is 5µA, tSS is in seconds, and
CSS is in Farads.
Pulling EN low quickly discharges the CSS capacitor,
making it ready for the next soft-start period.
tV
IC
SS SS
SS SS
MAX5096/MAX5097
40V, 600mA Buck Converters with Low-
Quiescent-Current Linear Regulator Mode
______________________________________________________________________________________ 11
MAX5096/MAX5097
Output Voltage Tracking/Sequencing
The output voltages of multiple MAX5096/MAX5097
converters can be made to track by using the SS pin
during turn-on and turn-off (see Figure 3). SS is pulled
up using a 5µA current source and connecting SS of
multiple MAX5096/MAX5097s, raising the references
with the same slope. Tracking the converters reduces
the differential voltages between the core and I/O volt-
ages during turn-on, turn-off, and brownout. If any one
converter output drops due to shutdown or an overload
fault situation, the SS drops, pulling down all the con-
verters simultaneously. The rate of fall of output volt-
ages, however, depends on the output capacitance
and load of the individual converter.
Multiple voltage sequencing can be done by daisy-
chaining several MAX5096/MAX5097s. The RESET of
the first converter can be connected to EN of the sec-
ond converter. This allows the first converter to come
up first every time the system is powered up.
Power-On Reset Output (
RESET
)
A supervisor circuit is integrated in the MAX5096/
MAX5097. RESET is an open-drain output. RESET pulls
low as soon as VOUT drops below 90% of its nominal
regulation voltage. Once the output voltage rises above
92% of the set output voltage, the RESET output enters
a high-impedance state after the active timeout period
(tRP). The active timeout period is externally program-
mable using a single capacitor from CT to ground. Use
the following equation to calculate the required timeout
period for the power-on reset:
where VCT-TH is 1.237V, ICH is 1µA, tRP is in seconds,
and CCT is in Farads.
To obtain a logic-voltage output, connect a pullup
resistor from RESET to a logic-supply voltage. The
internal open-drain MOSFET can sink 1mA while provid-
ing a TTL logic-low signal. If unused, ground RESET or
leave it unconnected.
The power-on reset behavior is the same in both the
LDO and Buck Modes of operation.
Oscillator/Synchronization Input (SYNC)
The MAX5096/MAX5097 internal oscillator generates a
factory-preset frequency of either 135kHz (MAX5096)
or 330kHz (MAX5097). The 135kHz version keeps the
maximum fundamental frequency below 150kHz, which
keeps the third harmonic below 450kHz and under the
tV
IC
RP CT TH
CH CT
40V, 600mA Buck Converters with Low-
Quiescent-Current Linear Regulator Mode
12 ______________________________________________________________________________________
PGND
OUT
LX
VIN
GND
BP
VIN
VOUT
ADJ
22μH
COUT
22μF
(CER.)
COMP
SYNC D1*
B260/
MURS105
CIN
100μF
LDO/BUCK
RESET
EN
CT
SS
CP
22pF
CSS
0.047μFCCT
0.01μF
100kΩ
+
1.0μF
MAX5096
MAX5097
RC
100kΩ
CC
1.2nF
*USE MURS105 IN APPLICATIONS
WHERE LDO MODE QUIESCENT
CURRENT IS CRITICAL.
RESET
Figure 2. Fixed Output Voltage Configuration
lower end of the AM band. The MAX5096 is suitable for
noise-sensitive applications like AM radio power sup-
ply. For an application where size is more important,
use the MAX5097, which runs at 330kHz frequency.
The high-frequency operation reduces the size and
cost of the external inductor and capacitor. The
MAX5096/MAX5097 can be synchronized using an
external signal. The MAX5096 can be synchronized
from 120kHz to 500kHz, while the MAX5097 is capable
of synchronizing from 300kHz to 500kHz. The external
synchronization feature makes frequency hopping pos-
sible depending on the selected AM channel. Connect
SYNC to ground, if not used.
Thermal Protection
When the junction temperature exceeds TJ= +165°C,
an internal thermal sensor signals the shutdown logic,
which turns off the regulator (both in Buck Mode and
LDO Mode), and discharges the soft-start capacitor
allowing the IC to cool. The thermal sensor turns the
regulator on again after the IC’s junction temperature
cools by 20°C, resulting in a cycled output during con-
tinuous thermal-overload conditions. The thermal hys-
teresis and a soft-start period limit the average power
dissipation into the device during continuous fault con-
dition. During operation, do not exceed the absolute
maximum junction temperature rating of TJ= +150°C.
Applications Information
Output Voltage Selection
The MAX5096/MAX5097 can be configured as either a
preset fixed output voltage or an adjustable output volt-
age device. Connect ADJ to ground to select the facto-
ry-preset output voltage option (Figure 2). The
MAX5096A/MAX5097A and MAX5096B/MAX5097B
provide a fixed output voltage equal to 3.3V and 5V,
respectively (see the Selector Guide). The MAX5096/
MAX5097 become an adjustable version as soon as the
devices detect about 125mV at the ADJ pin. The resis-
tor-divider at ADJ increases the ADJ voltage above
125mV and also adjusts the output voltage depending
upon the resistor values. In adjustable mode, select an
output between +1.273V and +11V using two external
resistors connected as a voltage-divider to ADJ (Figure
4). Set the output voltage using the following equation:
where VADJ = 1.273V and R2 is chosen to be approxi-
mately 100kΩ.
Connect ADJ to GND if adjustable mode is not used.
Inductor Selection
Three key inductor parameters must be specified for
proper operation with the MAX5096/MAX5097: induc-
tance value (L), peak inductor current (IPEAK), and
inductor saturation current (ISAT). The minimum
required inductance is a function of operating frequen-
cy, input-to-output voltage differential, and the peak-to-
peak inductor current (ΔIP-P). Higher ΔIP-P allows for a
lower inductor value, while a lower ΔIP-P requires a
higher inductor value. A lower inductor value minimizes
size and cost and improves large-signal and transient
response, but reduces efficiency due to higher peak
currents and higher peak-to-peak output voltage ripple
for the same output capacitor. On the other hand, high-
er inductance increases efficiency by reducing the rip-
ple current. Resistive losses due to extra wire turns can
exceed the benefit gained from lower ripple current lev-
els, especially when the inductance is increased while
keeping the dimension of the inductor constant. A good
compromise is to choose ΔIP-P equal to 40% of the full
load current. Calculate the inductor value using the fol-
lowing equation:
LVVV
Vf I
OUT IN OUT
IN SW P P
=
××
()
Δ
VV R
R
OUT ADJ
+
11
2
MAX5096/MAX5097
40V, 600mA Buck Converters with Low-
Quiescent-Current Linear Regulator Mode
______________________________________________________________________________________ 13
VOUT3
VOUT2
VOUT1
SOFT-START STOP
RATIOMETRIC TRACKING OUTPUTS
SEQUENCED OUTPUTS
STOP
SOFT-START
VOUT3
VOUT2
VOUT1
Figure 3. Output Voltage Tracking/Sequencing
MAX5096/MAX5097
use typical values of VIN and fSW so that efficiency is opti-
mum for typical conditions. The switching frequency (fSW)
is fixed at 135kHz (MAX5096) and 330kHz (MAX5097).
fSW can also be varied from 120kHz to 500kHz
(MAX5096) and from 300kHz to 500kHz (MAX5097) when
synchronized to an external clock (see the Oscillator/
Synchronization Input (SYNC) section). The peak-to-peak
inductor current, which reflects the peak-to-peak output
ripple, is worst at the maximum input voltage. See the
Output Capacitor Selection section to verify that the
worst-case output ripple is acceptable. The inductor satu-
rating current (ISAT) is also important to avoid runaway
current during continuous output short circuit. Select an
inductor with an ISAT specification higher than the maxi-
mum peak current limit of 1.9A.
The Buck Mode operation determines the inductor and
output capacitor values. However, the values of the
inductor, its DCR, and the output capacitance/ESR
affect the closed-loop transfer function both in Buck
and LDO Modes. The internal compensation of the
MAX5096/MAX5097 in LDO Mode limits the values of
these external components. Make sure that the combi-
nation of output inductor, capacitor, and ESR falls with-
in the range specified in following Table 1.
Output Capacitor Selection
The allowable output voltage ripple and the maximum
deviation of the output voltage during load steps deter-
mine the output capacitance and its ESR. The output
40V, 600mA Buck Converters with Low-
Quiescent-Current Linear Regulator Mode
14 ______________________________________________________________________________________
PGND
OUT
LX
VIN
GND
BP
5V TO 40V
VIN
VOUT
ADJ
22μH
COUT
22μF
COMP
SYNC
D1*
B260/
MURS105
CIN
100μF
LDO/BUCK
RESET
EN
RC
CC
CT
SS
CP
RPU
+
1.0μF
MAX5096
MAX5097
R1
R2
CCT
CSS
RESET
*USE MURS105 IN APPLICATIONS
WHERE LDO MODE QUIESCENT
CURRENT IS CRITICAL.
Figure 4. Adjustable Output Voltage Configuration
INDUCTOR
OUTPUT CAPACITOR (COUT)
22µF, ESR = 5m to 20m (ceramic)
47µF, ESR = 40m to 150m
100µF, ESR = 30m to 100m
22µH
470µF / ESR = 60Ω to 400mΩ
22µF, ESR = 5mΩ to 20mΩ (ceramic)
47µF / ESR = 40mΩ to 150mΩ
100µF / ESR = 30m to 100m
47µH
470µF / ESR = 60m to 400m
22µF, ESR = 5m to 20m (ceramic)
47µF / ESR = 40m to 150m
100µF / ESR = 30m to 100m
100µH
470µF / ESR = 60m to 400m
Table 1. Inductor/Output Capacitor
Selection
ripple is mainly composed of ΔVQ(caused by the
capacitor discharge) and ΔVESR (caused by the volt-
age drop across the ESR of the output capacitor).
Normally, a good approximation of the output voltage
ripple is ΔVRIPPLE ≈ΔVESR + ΔVQ. If using ceramic
capacitors, assume the contribution to the output volt-
age ripple from the ESR and the capacitor discharge to
be equal to 20% and 80%, respectively. If using alu-
minum electrolyte capacitors, assume the contribution
to the output voltage ripple from the ESR and the
capacitor discharge to be equal to 90% and 10%,
respectively.
Use the following equations for calculating the output
capacitance and its ESR for required peak-to-peak out-
put voltage ripple.
ΔIP-P is the peak-to-peak inductor current and fSW is
the converter’s switching frequency.
The allowable deviation of the output voltage during
fast load transients also determines the output capaci-
tance, its ESR, and its equivalent series inductance
(ESL). The output capacitor supplies the load current
during a load step until the controller responds with a
greater duty cycle. The response time (tRESPONSE)
depends on the closed-loop bandwidth of the converter
(see the Compensation Network section). The resistive
drop across the output capacitor’s ESR, the drop
across the capacitor’s ESL, and the capacitor dis-
charge, causes a voltage drop during the load step.
Use a combination of low-ESR tantalum/aluminum elec-
trolytic and ceramic capacitors for better transient load
and voltage ripple performance. Non-leaded capaci-
tors and/or multiple parallel capacitors help reduce the
ESL. Keep the maximum output voltage deviation
below the tolerable limits of the electronics being pow-
ered. Use the following equations to calculate the
required ESR, ESL, and capacitance value during a
load step:
where ISTEP is the load step, tSTEP is the rise time of the
load step, and tRESPONSE is the response time of the
controller. The response time of the converter is
approximately one third of the inverse of its closed-loop
bandwidth and also depends on the phase margin.
Rectifier Selection
The MAX5096/MAX5097 require an external Schottky/
fast-recovery diode rectifier as a freewheeling diode.
Connect this rectifier close to the device using short
leads and short PC board traces. Choose a rectifier
with a continuous current rating greater than the high-
est output current-limit threshold (1.9A) and with a volt-
age rating greater than the maximum expected input
voltage, VIN. 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. Use a 60V (max)
Schottky rectifier with a 2A current rating. The Schottky
rectifier leakage current at high temperature significant-
ly increases the quiescent current in LDO Mode. In
applications where LDO Mode quiescent current is
important, use an ultra-fast switching diode to limit the
leakage current. In this type of application, use
MURS105, MURS120 for their fast-switching and low-
leakage features.
Input Capacitor Selection
The discontinuous input current of the buck converter
causes large input ripple currents and therefore, the
input capacitor must be carefully chosen to keep the
input voltage ripple within design requirements. The
input voltage ripple is comprised of ΔVQ(caused by
the capacitor discharge) and ΔVESR (caused by the
ESR of the input capacitor). The total voltage ripple is
the sum of ΔVQand ΔVESR. Calculate the input capaci-
tance and ESR required for a specified ripple using the
following equations (continuous mode):
IOUT_MAX is the maximum output current and D is the
duty cycle.
ESR V
II
CIDD
Vf
where
IVV V
Vf L and
DV
V
ESR
OUT MAX PP
IN OUT MAX
QSW
PP IN OUT OUT
IN SW
OUT
IN
=
+
=×
×
=×
××
=
Δ
Δ
Δ
Δ
_
_()
()
2
1
ESR V
I
CIt
V
ESL Vt
I
ESR
STEP
OUT STEP RESPONSE
Q
ESL STEP
STEP
=
=×
=×
Δ
Δ
Δ
Δ
CI
Vf
ESR V
I
OUT PP
QSW
ESR
PP
=××
=
Δ
Δ
Δ
Δ
16
MAX5096/MAX5097
40V, 600mA Buck Converters with Low-
Quiescent-Current Linear Regulator Mode
______________________________________________________________________________________ 15
MAX5096/MAX5097
Compensation Network
The MAX5096/MAX5097 in LDO Mode are compensat-
ed internally with a compensation network around the
LDO error amplifier. When in Buck Mode, the DC-DC
gMamplifier must be externally compensated using a
network connected from COMP to ground. The current-
mode control architecture reduces the compensation
network to a single pole-zero. The RC and C network,
connected from the internal transconductance amplifier
output to SGND, can provide a single pole-zero pair.
Choose all the power components like the inductor,
output capacitor, and ESR first and design the com-
pensation network around them. Choose the closed-
loop bandwidth (fC) to be approximately 1/10 of the
switching frequency. See the following equations to cal-
culate the compensation values for the low-ESR output
capacitor with ESR zero frequency, approximately a
decade higher than fC.
Calculate the dominant pole due to the output capaci-
tor (COUT) and the load (ROUT):
where ROUT = VOUT / ILOAD.
Calculate the RCusing following equation:
where gMC is the control to output gain of the
MAX5096/MAX5097 buck converter and is equal to
1.06. VADJ is the feedback set point equal to 1.237V
and gm(transconductance amplifier gain) is equal to
136µS. See Figure 2.
Place a zero (fZ) at 0.9 x fPO:
Finally, place a high-frequency pole at the frequency
equal to half of the converter switching frequency (fSW).
Place the compensation network physically close to the
MAX5096/MAX5097.
Switching Between LDO Mode
and Buck Mode
The MAX5096/MAX5097 switch between the Buck
Mode and LDO Mode on the fly. However, care must
be taken to reduce output glitch or overshoot during
the switching.
Buck Mode to LDO Mode
The LDO Mode is intended for the low 100mA output
current while the buck converter delivers up to 600mA
output current. It is important to first reduce the output
load below 100mA before switching to the LDO Mode.
If the output load is higher than 100mA, the
MAX5096/MAX5097 may go into the current limit and
the output will drop significantly. Whenever the mode is
changed, output is expected to glitch because the loop
dynamics change due to different error amplifiers when
operating in the LDO and Buck Modes. The output volt-
age undershoot can be minimized by reducing the out-
put load during switching and using larger output
capacitance.
LDO Mode to Buck Mode
When switching from the LDO Mode to Buck Mode, a
fixed amount of delay (32 cycles) is applied so that the
buck converter control loop and oscillator reach their
steady-state conditions. The 32-cycle delay translates
to approximately 250µs and 100µs for 150kHz and
330kHz switching frequency versions, respectively. It is
recommended that the output load of 600mA must be
delayed by at least this much time to allow the
MAX5096/MAX5097 to switch to high-current Buck
Mode. This ensures that the output does not drop due
to the LDO current-limit protection mechanism.
PC Board Layout Guidelines
1) Proper PC board layout is essential. Minimize
ground noise by connecting the anode of the free-
wheeling rectifier, the input bypass capacitor
ground lead, and the output filter capacitor ground
lead to a large PGND plane.
2) Minimize lead lengths to reduce stray capacitance,
trace resistance, and radiated noise. In particular,
place the Schottky/fast recovery rectifier diode right
next to the device.
CRf
PCSW
=××
1
π
CRf
CCFPO PO
=×× ×
1
2π
RVf
gR gV f
COC
MC OUT m ADJ PO
=×
××××
fCR
PO OUT OUT
=×× ×
1
2π
40V, 600mA Buck Converters with Low-
Quiescent-Current Linear Regulator Mode
16 ______________________________________________________________________________________
MAX5096/MAX5097
40V, 600mA Buck Converters with Low-
Quiescent-Current Linear Regulator Mode
______________________________________________________________________________________ 17
PART
OUTPUT
VOLTAGE
(V)
SWITCHING
FREQUENCY
(kHz)
MAX5096A_ _ _
+3.3/Adjustable
135
MAX5096B_ _ _
+5.0/Adjustable
135
MAX5097A_ _ _
+3.3/Adjustable
330
MAX5097B_ _ _
+5.0/Adjustable
330
Selector Guide
Chip Information
PROCESS: BiCMOS
3) Connect the exposed pad of the IC to the SGND
plane. Do not make a direct connection between the
exposed pad plane and SGND (pin 2) under the IC.
Connect the exposed pad and pin 2 to the SGND
plane separately. Connect the ground connection of
the feedback resistive divider, the soft-start capaci-
tor, the adjustable reset timeout capacitor, and the
compensation network to the SGND plane. Connect
the SGND plane and PGND plane at one point near
the input bypass capacitor at VIN.
4) Use the large SGND plane as a heatsink for the
MAX5096/MAX5097. Use large PGND and LX
planes as heatsinks for the rectifier diode and the
inductor.
MAX5096/MAX5097
40V, 600mA Buck Converters with Low-
Quiescent-Current Linear Regulator Mode
18 ______________________________________________________________________________________
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
QFN THIN.EPS
MAX5096/MAX5097
40V, 600mA Buck Converters with Low-
Quiescent-Current Linear Regulator Mode
______________________________________________________________________________________ 19
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
MAX5096/MAX5097
40V, 600mA Buck Converters with Low-
Quiescent-Current Linear Regulator Mode
20 ______________________________________________________________________________________
TSSOP 4.4mm BODY.EPS
AA AA
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
MAX5096/MAX5097
40V, 600mA Buck Converters with Low-
Quiescent-Current Linear Regulator Mode
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 21
© 2007 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.
Boblet
Revision History
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
0 7/06 Initial release
1 6/07 Updated Electrical Characteristics table 1, 2, 3, 5, 20
2 9/07 Removed future product asterisks from Ordering Information table, Updated
Electrical Characteristics table and TSSOP package outline 1, 4, 18, 19, 20