Maxim MAX8732AEEI, MAX8733AEEI, MAX8734AEEI Schematics

General Description

The MAX8732A/MAX8733A/MAX8734A dual step-down,
switch-mode power-supply (SMPS) controllers generate
logic-supply voltages in battery-powered systems. The
MAX8732A/MAX8733A/MAX8734A include two pulse­width modulation (PWM) controllers, adjustable from 2V to

5.5V or fixed at 5V and 3.3V. These devices feature two
linear regulators providing 5V and 3.3V always-on out­puts. Each linear regulator provides up to 100mA output
current with automatic linear-regulator bootstrapping to
the main SMPS outputs. The MAX8732A/MAX8733A/
MAX8734A include on-board power-up sequencing, a
power-good (PGOOD) output, digital soft-start, and inter­nal soft-stop output discharge that prevents negative volt­ages on shutdown. Additionally, the outputs are high
impedance when VCCfalls below its UVLO set point while
the outputs are enabled.

Maxim’s proprietary Quick-PWM™ quick-response, con­stant on-time PWM control scheme operates without
sense resistors and provides 100ns response to load tran­sients while maintaining a relatively constant switching fre­quency. The unique ultrasonic pulse-skipping mode
maintains the switching frequency above 25kHz, which
eliminates noise in audio applications. Other features
include pulse skipping, which maximizes efficiency in
light-load applications, and fixed-frequency PWM mode,
which reduces RF interference in sensitive applications.

The MAX8732A features a 200kHz/5V and 300kHz/3.3V
SMPS for highest efficiency, while the MAX8733A fea­tures a 400kHz/5V and 500kHz/3.3V SMPS for “thin and
light” applications. The MAX8734A provides a pin­selectable switching frequency, allowing either 200kHz/
300kHz or 400kHz/500kHz operation of the 5V/3.3V
SMPSs, respectively. The MAX8732A/MAX8733A/
MAX8734A are available in 28-pin QSOP packages and
operate over the extended temperature range
(-40°C to +85°C).

The MAX8732A/MAX8733A/MAX8734A are pin-for-pin
upgrades to the MAX1777/MAX1977/MAX1999.
The MAX1999 evaluation kit (EV kit) can be used to
evaluate the MAX8732A/MAX8733A/MAX8734A.

Applications

Notebook and Subnotebook Computers

PDAs and Mobile Communication Devices

3- and 4-Cell Li+ Battery-Powered Devices

Features

♦ No Current-Sense Resistor Needed (MAX8734A)
♦ Accurate Current Sense with Current-Sense

Resistor (MAX8732A/MAX8733A)

♦ 1.5% Output Voltage Accuracy
♦ 3.3V and 5V 100mA Bootstrapped Linear

Regulators

♦ Internal Soft-Start and Soft-Stop Output

Discharge

♦ Quick-PWM with 100ns Load Step Response
♦ 3.3V and 5V Fixed or Adjustable Outputs

(Dual Mode™)

♦ 4.5V to 24V Input Voltage Range
♦ Enhanced Ultrasonic Pulse-Skipping Mode

(25kHz min)

♦ Power-Good (PGOOD) Signal
♦ Overvoltage Protection Enable/Disable

MAX8732A/MAX8733A/MAX8734A

High-Efficiency, Quad-Output, Main Power-

Supply Controllers for Notebook Computers

________________________________________________________________ Maxim Integrated Products 1

Ordering Information

19-3711; Rev 0; 5/05

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

PART

TEMP RANGE

PIN-

5V/3.3V

SWITCHING

FREQUENCY

(kHz)

200/300

200/300

400/500

400/500

Quick-PWM and Dual Mode are trademarks of Maxim
Integrated Products, Inc.

Ordering Information continued at end of data sheet.

+Denotes lead-free package.

28

27

26

25

24

23

22

21

20

19

18

17

16

15

1

2

3

4

5

6

7

8

9

10

11

12

13

14

BST3

LX3

DH3

LDO3

DL3

GND

LX5

OUT3

OUT5

V+

DL5

LDO5

V

CC

DH5

BST5

TON

ILIM5

FB5

REF

FB3

ILIM3

ON5

ON3

PGOOD

N.C.

QSOP

TOP VIEW

MAX8734A

SHDN

PRO

SKIP

Pin Configurations

Pin Configurations continued at end of data sheet.

PA CKA GE

MAX8732AEEI+ -40°C to +85°C 28 QSOP

MAX8732AEEI -40°C to +85°C 28 QSOP

MAX8733AEEI+ -40°C to +85°C 28 QSOP

MAX8733AEEI -40°C to +85°C 28 QSOP

MAX8732A/MAX8733A/MAX8734A

High-Efficiency, Quad-Output, Main Power­Supply Controllers for Notebook Computers

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(Circuit of Figure 1 and Figure 2, no load on LDO5, LDO3, OUT3, OUT5, and REF, V+ = 12V, ON3 = ON5 = VCC, V

SHDN

= 5V,

T

A

= 0°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.)

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.

V+, SHDN to GND ..................................................-0.3V to +25V

BST_ to GND ..........................................................-0.3V to +30V

LX_ to BST_ ..............................................................-6V to +0.3V

CS_ to GND (MAX8732A/MAX8733A only) .................-2V to +6V

V

CC

, LDO5, LDO3, OUT3, OUT5, ON3, ON5, REF,

FB3, FB5, SKIP, PRO, PGOOD to GND ...............-0.3V to +6V

DH3 to LX3 ..............................................-0.3V to (V

BST3

+ 0.3V)

DH5 to LX5 ..............................................-0.3V to (V

BST5

+ 0.3V)

ILIM3, ILIM5 to GND...................................-0.3V to (V

CC

+ 0.3V)

DL3, DL5 to GND....................................-0.3V to (V

LDO5

+ 0.3V)

TON to GND (MAX8734A only) ................................-0.3V to +6V

LDO3, LDO5, REF Short Circuit to GND ....................Momentary

LDO3 Current (internal regulator) Continuous................+100mA

LDO3 Current (switched over to OUT3) Continuous ......+200mA

LDO5 Current (internal regulator) Continuous................+100mA

LDO5 Current (switched over to OUT5) Continuous ......+200mA

Continuous Power Dissipation (T

A

= +70°C)

28-Pin QSOP (derate 10.8mW/°C above +70°C).........860mW

Operating Temperature Range ...........................-40°C to +85°C

Junction Temperature......................................................+150°C

Storage Temperature Range .............................-65°C to +150°C

Lead Temperature (soldering, 10s) .................................+300°C

PARAMETER CONDITIONS

MIN

TYP

MAX

UNITS

MAIN SMPS CONTROLLERS

LDO5 in regulation 6 24

V+ Input Voltage Range

V+ = LDO5, V

OUT5

< 4.43V 4.5 5.5

V

3.3V Output Voltage in
Fixed Mode

V+ = 6V to 24V, FB3 = GND, V

SKIP

= 5V

V

V+ = 6V to 24V, FB5 = GND, V

SKIP

= 5V,

MAX8732A/MAX8734A (TON = V

CC

)

V+ = 7V to 24V, FB5 = GND, V

SKIP

= 5V,

MAX8733A/MAX8734A (TON = GND)

V

Output Voltage in
Adjustable Mode

V+ = 6V to 24V, either SMPS

V

Output Voltage Adjust Range Either SMPS 2.0 5.5 V

FB3, FB5 Adjustable-Mode
Threshold Voltage

Dual-Mode comparator 0.1 0.2 V

Either SMPS, V

SKIP

= 5V, 0 to 5A

Either SMPS, SKIP = GND, 0 to 5A

DC Load Regulation

Either SMPS, V

SKIP

= 2V, 0 to 5A

%

Line Regulation Either SMPS, 6V < V+ < 24V

%/V

Current-Limit Threshold
(Positive, Default)

ILIM_ = VCC, GND - CS_ (MAX8732A/MAX8733A),
GND - LX_ (MAX8734A)

93

107 mV

V

ILIM_

= 0.5V 40 50 60

V

ILIM_

= 1V 93

107

Current-Limit Threshold
(Positive, Adjustable)

GND - CS_
(MAX8732A/MAX8733A),
GND - LX_ (MAX8734A)

V

ILIM_

= 2V

215

mV

Zero-Current Threshold

SKIP = GND, ILIM_ = V

CC

, GND - CS_

(MAX8732A/MAX8733A), GND - LX_ (MAX8734A)

3mV

Current-Limit Threshold
(Negative, Default)

SKIP = ILIM_ = VCC, GND - CS_
(MAX8732A/MAX8733A), GND - LX_ (MAX8734A)

mV

Soft-Start Ramp Time Zero to full limit 1.7 ms

3.285 3.330 3.375

5V Output Voltage in Fixed Mode

4.975 5.050 5.125

1.975 2.00 2.025

0.005

185 200

-120

-0.1

-1.5

-1.7

100

100

MAX8732A/MAX8733A/MAX8734A

High-Efficiency, Quad-Output, Main Power-

Supply Controllers for Notebook Computers

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(Circuit of Figure 1 and Figure 2, no load on LDO5, LDO3, OUT3, OUT5, and REF, V+ = 12V, ON3 = ON5 = VCC, V

SHDN

= 5V,

T

A

= 0°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.)

PARAMETER CONDITIONS

MIN

TYP

MAX

UNITS

5V SMPS

MAX8732A or MAX8734A
(V

TON

= 5V), SKIP = V

CC

3.3V SMPS

5V SMPS

MAX8733A or MAX8734A
(V

TON

= 0), SKIP = V

CC 3.3V SMPS

Operating Frequency

SKIP = REF 25 36

kHz

V

OUT5

= 5.05V

MAX8732A or MAX8734A
(V

TON

= 5V)

V

OUT3

= 3.33V

V

OUT5

= 5.05V

On-Time Pulse Width

MAX8733A or MAX8734A
(V

TON

= 0)

V

OUT3

= 3.33V

µs

Minimum Off-Time

350 ns

V

OUT5

= 5.05V 94

MAX8732A or MAX8734A
(V

TON

= 5V)

V

OUT3

= 3.33V 91

V

OUT5

= 5.05V 88

Maximum Duty Cycle

MAX8733A or MAX8734A
(V

TON

= 0)

V

OUT3

= 3.33V 85

%

INTERNAL REGULATOR AND REFERENCE

LDO5 Output Voltage

V

LDO5 Short-Circuit Current LDO5 = GND

mA

LDO5 Undervoltage-Lockout
Fault Threshold

Falling edge of LDO5, hysteresis = 1% 3.7 4.0 4.3 V

LDO5 Bootstrap Switch Threshold

Falling edge of OUT5, rising edge at OUT5 regulation
point

V

LDO5 Bootstrap
Switch Resistance

LDO5 to OUT5, V

OUT5

= 5V 1.4 3.2 Ω

LDO3 Output Voltage

V

LDO3 Short-Circuit Current LDO3 = GND

mA

LDO3 Bootstrap Switch Threshold

Falling edge of OUT3, rising edge at OUT3 regulation
point

V

LDO3 Bootstrap Switch
Resistance

LDO3 to OUT3, V

OUT3

= 3.2V 1.5 3.5 Ω

REF Output Voltage No external load

V

REF Load Regulation 0 < I

LOAD

< 50µA 10 mV

REF Sink Current REF in regulation 10 µA

V+ Operating Supply Current LDO5 switched over to OUT5, 5V SMPS 25 50 µA

V+ Standby Supply Current V+ = 6V to 24V, both SMPSs off, includes I

SHDN

250 µA

V+ Shutdown Supply Current V+ = 4.5V to 24V 6 15 µA

Quiescent Power Consumption

Both SMPSs on, FB3 = FB5 = SKIP = GND, V

OUT3

=

3.5V, V

OUT5

= 5.3V

3 4.5 mW

FAULT DETECTION

Overvoltage Trip Threshold FB3 or FB5 with respect to nominal regulation point +8

+14 %

200

300

400

500

1.895 2.105 2.315

ON3 = ON5 = GND, 6V < V+ < 24V, 0 < I

ON3 = ON5 = GND, 6V < V+ < 24V, 0 < I

< 100mA 4.90 5.00 5.10

LDO5

< 100mA 3.28 3.35 3.42

LDO3

0.833 0.925 1.017

0.895 1.052 1.209

0.475 0.555 0.635

250 300

4.43 4.56 4.69

2.80 2.91 3.02

1.980 2.000 2.020

190

180

150

+11

MAX8732A/MAX8733A/MAX8734A

High-Efficiency, Quad-Output, Main Power­Supply Controllers for Notebook Computers

4 _______________________________________________________________________________________

ELECTRICAL CHARACTERISTICS (continued)

(Circuit of Figure 1 and Figure 2, no load on LDO5, LDO3, OUT3, OUT5, and REF, V+ = 12V, ON3 = ON5 = VCC, V

SHDN

= 5V,

T

A

= 0°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.)

PARAMETER CONDITIONS

UNITS

Overvoltage Fault
Propagation Delay

FB3 or FB5 delay with 50mV overdrive 10 µs

PGOOD Threshold

FB3 or FB5 with respect to nominal output, falling edge,
typical hysteresis = 1%

-12

-7 %

PGOOD Propagation Delay Falling edge, 50mV overdrive 10 µs

PGOOD Output Low Voltage I

SINK

= 4mA 0.3 V

PGOOD Leakage Current High state, forced to 5.5V 1 µA

Thermal-Shutdown Threshold

o

C

Output Undervoltage
Shutdown Threshold

FB3 or FB5 with respect to nominal output voltage 65 70 75 %

Output Undervoltage
Shutdown Blanking Time

From ON_ signal 10 22 35 ms

INPUTS AND OUTPUTS

V

FB3

= V

FB5

= 2.2V

nA

Low level 0.6

PRO Input Voltage

High level 1.5

V

Low level 0.8
Float level 1.7 2.3SKIP Input Voltage

High level 2.4

V

Low level 0.8

TON Input Voltage

High level 2.4

V

Clear fault level/SMPS off level 0.8

Delay start level 1.7 2.3ON3, ON5 Input Voltage

SMPS on level 2.4

V

V

PRO

or V

TON

= 0 or 5V -1 +1

V

ON_

= 0 or 5V -2 +2

V

SKIP

= 0 or 5V -1 +1

V

SHDN

= 0 or 24V -1 +1

V

CS_

= 0 or 5V -2 +2

Input Leakage Current

V

ILIM3

, V

ILIM5

= 0 or 2V

µA

Rising edge 1.2 1.6 2.0

SHDN Input Trip Level

Falling edge

V

DH_ Gate-Driver
Sink/Source Current

DH3, DH5 forced to 2V 2 A

DL_ Gate-Driver Source Current DL3 (source), DL5 (source), forced to 2V 1.7 A

DL_ Gate-Driver Sink Current DL3 (sink), DL5 (sink), forced to 2V 3.3 A
DH_ Gate-Driver On-Resistance BST - LX_ forced to 5V 1.5 4.0 Ω

DL_, high state (pullup) 2.2 5.0

DL_ Gate-Driver On-Resistance

DL_, low state (pulldown) 0.6 1.5

Ω

Feedback Input Leakage Current

MIN TYP MAX

-9.5

+160

-200 +40 +200

-0.2 +0.2

0.96 1.00 1.04

MAX8732A/MAX8733A/MAX8734A

High-Efficiency, Quad-Output, Main Power-

Supply Controllers for Notebook Computers

_______________________________________________________________________________________ 5

ELECTRICAL CHARACTERISTICS (continued)

(Circuit of Figure 1 and Figure 2, no load on LDO5, LDO3, OUT3, OUT5, and REF, V+ = 12V, ON3 = ON5 = VCC, V

SHDN

= 5V,

T

A

= 0°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.)

PARAMETER CONDITIONS

UNITS

OUT3, OUT5 Discharge-Mode
On-Resistance

12 40 Ω

OUT3, OUT5 Discharge-Mode
Synchronous Rectifier
Turn-On Level

0.2 0.3 0.4 V

ELECTRICAL CHARACTERISTICS

(Circuit of Figure 1 and Figure 2, no load on LDO5, LDO3, OUT3, OUT5, and REF, V+ = 12V, ON3 = ON5 = VCC, V

SHDN

= 5V,

T

A

= -40°C to +85°C, unless otherwise noted.) (Note 1)

PARAMETER CONDITIONS

UNITS

MAIN SMPS CONTROLLERS

LDO5 in regulation 6 24

V+ Input Voltage Range

V+ = LDO5, V

OUT5

< 4.41V 4.5 5.5

V

3.3V Output Voltage in
Fixed Mode

V+ = 6V to 24V, FB3 = GND, V

SKIP

= 5V

V

V+ = 6V to 24V, FB5 = GND, V

SKIP

= 5V,

MAX8732A/MAX8734A (TON = V

CC

)

5V Output Voltage in Fixed Mode

V+ = 7V to 24V, FB5 = GND, V

SKIP

= 5V,

MAX8733A/MAX8734A (TON = GND)

V

Output Voltage in
Adjustable Mode

V+ = 6V to 24V, either SMPS

V

Output Voltage Adjust Range Either SMPS 2.0 5.5 V

FB3, FB5 Adjustable-Mode
Threshold Voltage

Dual-Mode comparator 0.1 0.2 V

Current-Limit Threshold
(Positive, Default)

ILIM_ = VCC, GND - CS_ (MAX8732A/MAX8733A),
GND - LX_ (MAX8734A)

90 110 mV

V

ILIM_

= 0.5V 40 60

V

ILIM_

= 1V 90 110

Current-Limit Threshold
(Positive, Adjustable)

GND - CS_
(MAX8732A/MAX8733A),
GND - LX_ (MAX8734A)

V

ILIM_

= 2V

220

mV

V

OUT5

= 5.05V

MAX8732A or MAX8734A
(V

TON

= 5V)

V

OUT3

= 3.33V

V

OUT5

= 5.05V

On-Time Pulse Width

MAX8733A or MAX8734A
(V

TON

= 0)

V

OUT3

= 3.33V

µs

Minimum Off-Time

400 ns

INTERNAL REGULATOR AND REFERENCE

LDO5 Output Voltage

V

LDO5 Undervoltage-Lockout
Fault Threshold

Falling edge of LDO5, hysteresis = 1% 3.7 4.3 V

MIN TYP MAX

ON3 = ON5 = GND, 6V < V+ < 24V, 0 < I

< 100mA 4.90 5.10

LDO5

MIN TYP MAX

3.27 3.39

4.95 5.15

1.97 2.03

180

1.895 2.315

0.833 1.017

0.895 1.209

0.475 0.635

200

MAX8732A/MAX8733A/MAX8734A

High-Efficiency, Quad-Output, Main Power­Supply Controllers for Notebook Computers

6 _______________________________________________________________________________________

ELECTRICAL CHARACTERISTICS (continued)

(Circuit of Figure 1 and Figure 2, no load on LDO5, LDO3, OUT3, OUT5, and REF, V+ = 12.0.V, ON3 = ON5 = VCC, V

SHDN

= 5V,

T

A

= -40°C to +85°C, unless otherwise noted.) (Note 1)

PARAMETER CONDITIONS

UNITS

LDO5 Bootstrap Switch Threshold

Falling edge of OUT5, rising edge at OUT5 regulation
point

V

LDO5 Bootstrap Switch
Resistance

LDO5 to OUT5, V

OUT5

= 5V 3.2 Ω

LDO3 Output Voltage

V

LDO3 Bootstrap Switch Threshold

Falling edge of OUT3, rising edge at OUT3 regulation
point

V

LDO3 Bootstrap
Switch Resistance

LDO3 to OUT3, V

OUT3

= 3.2V 3.5 Ω

REF Output Voltage No external load

V

REF Load Regulation 0 < I

LOAD

< 50µA 10 mV

REF Sink Current REF in regulation 10 µA

V+ Operating Supply Current LDO5 switched over to OUT5, 5V SMPS 50 µA

V+ Standby Supply Current V+ = 6V to 24V, both SMPSs off, includes I

SHDN

300 µA

V+ Shutdown Supply Current V+ = 4.5V to 24V 15 µA

Quiescent Power Consumption

Both SMPSs on, FB3 = FB5 = SKIP = GND, V

OUT3

=

3.5V, V

OUT5

= 5.3V

4.5 mW

FAULT DETECTION

Overvoltage Trip Threshold FB3 or FB5 with respect to nominal regulation point +8 +14 %

PGOOD Threshold

FB3 or FB5 with respect to nominal output, falling edge,
typical hysteresis = 1%

-12 -7 %

PGOOD Output Low Voltage I

SINK

= 4mA 0.3 V

PGOOD Leakage Current High state, forced to 5.5V 1 µA

Output Undervoltage Shutdown
Threshold

FB3 or FB5 with respect to nominal output voltage 65 75 %

Output Undervoltage Shutdown
Blanking Time

From ON_ signal 10 40 ms

INPUTS AND OUTPUTS

Feedback Input Leakage Current

V

FB3

= V

FB5

= 2.2V

nA

Low level 0.6

PRO Input Voltage

High level 1.5

V

Low level 0.8

Float level 1.7 2.3

SKIP Input Voltage

High level 2.4

V

Low level 0.8

TON Input Voltage

High level 2.4

V

MIN TYP MAX

4.43 4.69

ON3 = ON5 = GND, 6V < V+ < 24V, 0 < I

< 100mA 3.27 3.43

LDO3

2.80 3.02

1.975 2.025

-200 +200

MAX8732A/MAX8733A/MAX8734A

High-Efficiency, Quad-Output, Main Power-

Supply Controllers for Notebook Computers

_______________________________________________________________________________________ 7

ELECTRICAL CHARACTERISTICS (continued)

(Circuit of Figure 1 and Figure 2, no load on LDO5, LDO3, OUT3, OUT5, and REF, V+ = 12.0.V, ON3 = ON5 = VCC, V

SHDN

= 5V,

T

A

= -40°C to +85°C, unless otherwise noted.) (Note 1)

PARAMETER CONDITIONS

MIN

TYP

MAX

UNITS

Clear fault level/SMPS off level 0.8

Delay start level 1.7 2.3ON3, ON5 Input Voltage

SMPS on level 2.4

V

V

PRO

or V

TON

= 0 or 5V -1 +1

V

ON_

= 0 or 5V -1 +1

V

SKIP

= 0 or 5V -2 +2

V

SHDN

= 0 or 24V -1 +1

V

CS_

= 0 or 5V -2 +2

Input Leakage Current

V

ILIM3

, V

ILIM5

= 0 or 2V

µA

Rising edge 1.2 2.0

SHDN Input Trip Level

Falling edge

V

DH_ Gate-Driver On-Resistance BST - LX_ forced to 5V 4.0 Ω

DL_, high state (pullup) 5.0

DL_ Gate-Driver On-Resistance

DL_, low state (pulldown) 1.5

Ω

OUT3, OUT5 Discharge-Mode
On-Resistance

40 Ω

OUT3, OUT5 Discharge-Mode
Synchronous Rectifier
Turn-On Level

0.2 0.4 V

Note 1: Specifications to -40°C are guaranteed by design, not production tested.

-0.2 +0.2

0.96 1.04

MAX8732A/MAX8733A/MAX8734A

High-Efficiency, Quad-Output, Main Power­Supply Controllers for Notebook Computers

8 _______________________________________________________________________________________

Typical Operating Characteristics

(Circuit of Figure 1 and Figure 2, no load on LDO5, LDO3, OUT3, OUT5, and REF, V+ = 12V, ON3 = ON5 = VCC, SHDN = V+,
R

CS

= 7mΩ, V

ILIM

_ = 0.5V, TA= +25°C, unless otherwise noted.)

100

0

0.001 0.01 0.1 1 10

MAX8732A

5V OUTPUT EFFICIENCY

vs. LOAD CURRENT

20

MAX8732A/3A/4A toc01

LOAD CURRENT (A)

EFFICIENCY (%)

40

60

80

70

50

30

10

90

VIN = 7V
ON5 = V

CC

ON3 = GND

PFM MODE

PWM MODE

ULTRASONIC MODE

100

0

0.001 0.01 0.1 1 10

MAX8732A

5V OUTPUT EFFICIENCY

vs. LOAD CURRENT

20

MAX8732A/3A/4A toc02

LOAD CURRENT (A)

EFFICIENCY (%)

40

60

80

70

50

30

10

90

VIN = 12V
ON5 = V

CC

ON3 = GND

PFM MODE

PWM MODE

ULTRASONIC MODE

100

0

0.001 0.01 0.1 1 10

MAX8732A

5V OUTPUT EFFICIENCY

vs. LOAD CURRENT

20

MAX8732A/3A/4A toc03

LOAD CURRENT (A)

EFFICIENCY (%)

40

60

80

70

50

30

10

90

VIN = 24V
ON5 = V

CC

ON3 = GND

PFM MODE

PWM MODE

ULTRASONIC MODE

100

0

0.001 0.01 0.1 1 10

MAX8733A

3.3V OUTPUT EFFICIENCY
vs. LOAD CURRENT

20

MAX8732A/3A/4A toc04

LOAD CURRENT (A)

EFFICIENCY (%)

40

60

80

70

50

30

10

90

ON5 = V

CC

ON3 = V

CC

VIN = 7V
V

IN

= 12V

V

IN

= 24V

PFM MODE

PWM MODE

ULTRASONIC MODE

1

10

100

0.1
7

10 13 16 19

22

25

MAX8732A

NO-LOAD BATTERY CURRENT

vs. INPUT VOLTAGE

MAX8732A/3A/4A toc05

INPUT VOLTAGE (V)

BATTERY CURRENT (mA)

PWM MODE

ULTRASONIC MODE

PFM MODE

1

10

100

0.1
7

10 13 16 19

22

25

MAX8733A

NO-LOAD BATTERY CURRENT

vs. INPUT VOLTAGE

MAX8732A/3A/4A toc06

INPUT VOLTAGE (V)

BATTERY CURRENT (mA)

PWM MODE

ULTRASONIC MODE

PFM MODE

170

176

174

172

180

178

188

186

184

182

190

7101316192225

STANDBY INPUT CURRENT

vs. INPUT VOLTAGE

MAX8732A/3A/4A toc07

INPUT VOLTAGE (V)

STANDBY INPUT CURRENT (µA)

MAX8732A

MAX8733A

5.0

6.5

6.0

5.5

7.5

7.0

9.5

9.0

8.5

8.0

10.0

7101316192225

SHUTDOWN INPUT CURRENT

vs. INPUT VOLTAGE

MAX8732A/3A/4A toc08

INPUT VOLTAGE (V)

SHUTDOWN INPUT CURRENT (µA)

MAX8733A

MAX8732A

MAX8732A

5V OUTPUT SWITCHING FREQUENCY

vs. LOAD CURRENT MAX8732A

MAX8732A/3A/4A toc09

LOAD CURRENT (A)

SWITCHING FREQUENCY (kHz)

10.10.01

25

50

75

100

125

150

175

200

225

250

0

0.001 10

VIN = 7V

PWM MODE

PFM MODE

ULTRASONIC MODE

Idle Mode is a trademark of Maxim Integrated Products, Inc.

MAX8732A/MAX8733A/MAX8734A

High-Efficiency, Quad-Output, Main Power-

Supply Controllers for Notebook Computers

_______________________________________________________________________________________ 9

Typical Operating Characteristics (continued)

(Circuit of Figure 1 and Figure 2, no load on LDO5, LDO3, OUT3, OUT5, and REF, V+ = 12V, ON3 = ON5 = VCC, SHDN = V+,
R

CS

= 7mΩ, V

ILIM

_ = 0.5V, TA= +25°C, unless otherwise noted.)

3.3V OUTPUT SWITCHING FREQUENCY
vs. LOAD CURRENT (MAX8732A)

MAX8732A/3A/4A toc10

LOAD CURRENT (A)

SWITCHING FREQUENCY (kHz)

10.10.01

40

80

120

160

200

240

280

320

360

0

0.001 10

VIN = 7V

PWM MODE

PFM MODE

ULTRASONIC MODE

250

0

0.001 0.01 0.1 1 10

MAX8732A

5V OUTPUT SWITCHING

FREQUENCY vs. LOAD CURRENT

50

MAX8732A/3A/4A toc11

LOAD CURRENT (A)

SWITCHING FREQUENCY (kHz)

100

150

200

175

125

75

25

225

PWM MODE

PFM MODE

VIN = 24V

ULTRASONIC MODE

360

0

0.001 0.01 0.1 1 10

MAX8732A

3.3V OUTPUT SWITCHING

FREQUENCY vs. LOAD CURRENT

80

MAX8732A/3A/4A toc12

LOAD CURRENT (A)

SWITCHING FREQUENCY (kHz)

160

240

320

280

200

120

40

PWM MODE

PFM MODE

VIN = 24V

ULTRASONIC MODE

450

0

0.001 0.01 0.1 1 10

MAX8733A

5V OUTPUT SWITCHING

FREQUENCY vs. LOAD CURRENT

100

MAX8732A/3A/4A toc13

LOAD CURRENT (A)

SWITCHING FREQUENCY (kHz)

200

300

400

350

250

150

50

VIN = 7V

PWM MODE

PFM MODE

ULTRASONIC MODE

110

0

100

200

400

300

500

550

0.001 0.01 0.1

MAX8733A

3.3V OUTPUT SWITCHING

FREQUENCY vs. LOAD CURRENT

MAX8732A/3A/4A toc14

LOAD CURRENT (A)

SWITCHING FREQUENCY (kHz)

450

350

250

150

50

PWM MODE

PFM MODE

VIN = 7V

ULTRASONIC MODE

450

0

0.001 0.01 0.1 1 10

MAX8733A

5V OUTPUT SWITCHING

FREQUENCY vs. LOAD CURRENT

100

MAX8732A/3A/4A toc15

LOAD CURRENT (A)

SWITCHING FREQUENCY (kHz)

200

300

400

350

250

150

50

PWM MODE

PFM MODE

VIN = 24V

ULTRASONIC MODE

110

0

100

200

400

300

500

550

0.001 0.01 0.1

MAX8733A

3.3V OUTPUT SWITCHING

FREQUENCY vs. LOAD CURRENT

MAX8732A/3A/4A toc16

LOAD CURRENT (A)

SWITCHING FREQUENCY (kHz)

450

350

250

150

50

PWM MODE

PFM MODE

VIN = 24V

ULTRASONIC MODE

MAX8732A

OUT5 VOLTAGE REGULATION

vs. LOAD CURRENT

MAX8732A/3A/4A toc17

LOAD CURRENT (A)

OUTPUT VOLTAGE (V)

10.10.01

5.07

5.09

5.11

5.13

5.15

5.17

5.19

5.05

0.001 10

ULTRASONIC

IDLE MODE

FORCED-PWM

MAX8732A

OUT3 VOLTAGE REGULATION

vs. LOAD CURRENT

MAX8732A/3A/4A toc18

LOAD CURRENT (A)

OUTPUT VOLTAGE (V)

10.10.01

3.34

3.35

3.36

3.37

3.38

3.39

3.41

3.40

3.33

0.001 10

ULTRASONIC

IDLE MODE

FORCED-PWM

MAX8732A/MAX8733A/MAX8734A

High-Efficiency, Quad-Output, Main Power­Supply Controllers for Notebook Computers

10 ______________________________________________________________________________________

Typical Operating Characteristics (continued)

(Circuit of Figure 1 and Figure 2, no load on LDO5, LDO3, OUT3, OUT5, and REF, V+ = 12V, ON3 = ON5 = VCC, SHDN = V+,
R

CS

= 7mΩ, V

ILIM

_ = 0.5V, TA= +25°C, unless otherwise noted.)

4.95

4.96

4.97

4.98

4.99

5.00

020304010 50 60 70 9080 100

LDO5 REGULATOR OUTPUT VOLTAGE

vs. OUTPUT CURRENT

MAX8732A/3A/4A toc19

LDO5 OUTPUT CURRENT (mA)

LDO5 OUTPUT VOLTAGE (V)

3.330

3.334

3.332

3.338

3.336

3.342

3.340

3.344

3.348

3.346

3.350

020304010 50 60 70 9080 100

LDO3 REGULATOR OUTPUT VOLTAGE

vs. OUTPUT CURRENT

MAX8732A/3A/4A toc20

LDO3 OUTPUT CURRENT (mA)

LDO3 OUTPUT VOLTAGE (V)

1.995

1.997

1.996

2.000

1.999

1.998

2.001

2.002

2.004

2.003

2.005

-10 10 20030405060708090100

REFERENCE VOLTAGE
vs. OUTPUT CURRENT

MAX8732A/3A/4A toc21

I

REF

(µA)

V

REF

(V)

0

0

0

10V

REF, LDO3, AND LDO5 POWER-UP

MAX8732A/3A/4A toc22

400µs/div

V+
10V/div

LDO5
2V/div

LDO3
2V/div

REF
1V/div

0

0

0

0

5V

DELAYED-START WAVEFORMS

(ON3 = REF)

MAX8732A/3A/4A toc23

100µs/div

ON5
5V/div

OUT5
2V/div

OUT3
2V/div

0

0

0

5V

DELAYED-START WAVEFORMS

(ON5 = REF)

MAX8732A/3A/4A toc24

100µs/div

ON3
5V/div

OUT5
2V/div

OUT3
2V/div

0

5A

0

3.3V

0

5A

SOFT-START WAVEFORMS

MAX8732A/3A/4A toc25

200µs/div

I

L5

5A/div

OUT3
5V/div

OUT5
5V/div

I

L3

5A/div

0

5V

0

3.3V
0

5V

0

5V

SHUTDOWN WAVEFORMS

MAX8732A/3A/4A toc26

10ms/div

ON3
5V/div

OUT5
5V/div

DL3
5V/div

OUT3
5V/div

0

5V

SWITCHING

0

4A

1A

5V

MAX8732A/MAX8734A (TON = VCC)

5V PWM-MODE

LOAD TRANSIENT RESPONSE

MAX8732A/3A/4A toc27

20µs/div

V

OUT

,
AC­COUPLED
100mV/div

INDUCTOR
CURRENT
2A/div

DL5
5V/div

5V

MAX8732A/MAX8733A/MAX8734A

High-Efficiency, Quad-Output, Main Power-

Supply Controllers for Notebook Computers

______________________________________________________________________________________ 11

0

4A

1A

5V

MAX8733A/MAX8734A (TON = GND)

5V PWM-MODE

LOAD TRANSIENT RESPONSE

MAX8732A/3A/4A toc28

10µs/div

V

OUT

,

AC­COUPLED
100mV/div

INDUCTOR
CURRENT
2A/div

DL5
5V/div

5V

0

4A

1A

3.3V

MAX8732A/MAX8734A (TON = VCC)

3.3V PWM-MODE

LOAD TRANSIENT RESPONSE

MAX8732A/3A/4A toc29

20µs/div

V

OUT

,
AC­COUPLED
100mV/div

INDUCTOR
CURRENT
2A/div

DL3
5V/div

5V

0

4A

1A

3.3V

MAX8733A/MAX8734A (TON = GND)

3.3V PWM-MODE

LOAD TRANSIENT RESPONSE

MAX8732A/3A/4A toc30

10µs/div

V

OUT

,
AC­COUPLED
100mV/div

INDUCTOR
CURRENT
2A/div

DL3
5V/div

5V

MAX8733A

5V OUTPUT EFFICIENCY

vs. LOAD CURRENT

MAX8732A/3A/4A toc31

LOAD CURRENT (A)

EFFICIENCY (%)

10.10.01

10

20

30

40

50

60

70

80

90

100

0

0.001 10

ON5 = V

CC

ON3 = GND
V

IN

= 7V

V

IN

= 12V

V

IN

= 24V

PFM MODE

PWM MODE

ULTRASONIC
MODE

MAX8733A

3.3V OUTPUT EFFICIENCY
vs. LOAD CURRENT

MAX8732A/3A/4A toc32

LOAD CURRENT (A)

EFFICIENCY (%)

10.10.01

10

20

30

40

50

60

70

80

90

100

0

0.001 10

ON5 = V

CC

ON3 = V

CC

VIN = 7V
V

IN

= 12V

V

IN

= 24V

PFM MODE

PWM MODE

ULTRASONIC
MODE

Typical Operating Characteristics (continued)

(Circuit of Figure 1 and Figure 2, no load on LDO5, LDO3, OUT3, OUT5, and REF, V+ = 12V, ON3 = ON5 = VCC, SHDN = V+,
R

CS

= 7mΩ, V

ILIM

_ = 0.5V, TA= +25°C, unless otherwise noted.)