MAXIM MAX1777, MAX1977, MAX1999 User Manual

General Description

The MAX1777/MAX1977/MAX1999 dual step-down,
switch-mode power-supply (SMPS) controllers generate
logic-supply voltages in battery-powered systems. The
MAX1777/MAX1977/MAX1999 include two pulse-width
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 MAX1777/MAX1977/MAX1999
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.

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 MAX1777 features a 200kHz/5V and 300kHz/3.3V
SMPS for highest efficiency, while the MAX1977 features
a 400kHz/5V and 500kHz/3.3V SMPS for “thin and light”
applications. The MAX1999 provides a pin-selectable
switching frequency, allowing either 200kHz/300kHz or
400kHz/500kHz operation of the 5V/3.3V SMPSs, respec­tively. The MAX1777/MAX1977/MAX1999 are available in
28-pin QSOP packages and operate over the extended
temperature range (-40°C to +85°C). The MAX1777/
MAX1977/MAX1999 are available in lead-free packages.

Applications

Notebook and Subnotebook Computers
PDAs and Mobile Communication Devices
3- and 4-Cell Li+ Battery-Powered Devices

Features

♦ No Current-Sense Resistor Needed (MAX1999)
♦ Accurate Current Sense with Current-Sense

Resistor (MAX1777/MAX1977)

♦ 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
♦ Ultrasonic Pulse-Skipping Mode (25kHz min)
♦ Power-Good (PGOOD) Signal
♦ Overvoltage Protection Enable/Disable

MAX1777/MAX1977/MAX1999

High-Efficiency, Quad Output, Main Power-

Supply Controllers for Notebook Computers

________________________________________________________________ Maxim Integrated Products 1

Ordering Information

19-2187; Rev 1; 9/04

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/3V

SWITCHING

FREQUENCY

MAX1777EEI

200k H z/300kH z

MAX1777EEI+

200k H z/300kH z

MAX1977EEI

400k H z/500kH z

MAX1977EEI+

400k H z/500kH z

MAX1999EEI

200k H z/300kH z or
400k H z/500kH z

MAX1999EEI+

200k H z/300kH z or
400k H z/500kH z

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

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

MAX1999

SHDN

PRO

SKIP

Pin Configurations

Pin Configurations continued at end of data sheet.

+Denotes lead-free package.

PACKAGE

-40°C to +85°C 28 QSOP

-40°C to +85°C 28 QSOP

-40°C to +85°C 28 QSOP

-40°C to +85°C 28 QSOP

-40°C to +85°C 28 QSOP

-40°C to +85°C 28 QSOP

MAX1777/MAX1977/MAX1999

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 (MAX1777/MAX1977 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 (MAX1999 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

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,

MAX1777/MAX1999 (TON = V

CC

)

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

SKIP

= 5V,

MAX1977/MAX1999 (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_ (MAX1777/MAX1977),
GND - LX_ (MAX1999)

93

107 mV

V

ILIM_

= 0.5V 40 50 60

V

ILIM_

= 1V 93

107

Current-Limit Threshold
(Positive, Adjustable)

GND - CS_
(MAX1777/MAX1977),
GND - LX_ (MAX1999)

V

ILIM_

= 2V

215

mV

Zero-Current Threshold

SKIP = GND, ILIM_ = V

CC

, GND - CS_

(MAX1777/MAX1977), GND - LX_ (MAX1999)

3mV

Current-Limit Threshold
(Negative, Default)

SKIP = ILIM_ = VCC, GND - CS_ (MAX1777/MAX1977),
GND - LX_ (MAX1999)

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

MAX1777/MAX1977/MAX1999

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

UNITS

5V SMPS

MAX1777 or MAX1999
(V

TON

= 5V), SKIP = V

CC

3.3V SMPS
5V SMPS

MAX1977 or MAX1999
(V

TON

= 0), SKIP = V

CC 3.3V SMPS

Operating Frequency

SKIP = REF 25 36

kHz

V

OUT5

= 5.05V

MAX1777 or MAX1999
(V

TON

= 5V)

V

OUT3

= 3.33V

V

OUT5

= 5.05V

On-Time Pulse Width

MAX1977 or MAX1999
(V

TON

= 0)

V

OUT3

= 3.33V

µs

Minimum Off-Time

350 ns

V

OUT5

= 5.05V 94

MAX1777 or MAX1999
(V

TON

= 5V)

V

OUT3

= 3.33V 91

V

OUT5

= 5.05V 88

Maximum Duty Cycle

MAX1977 or MAX1999
(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 %

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

MIN TYP MAX

200
300
400
500

1.895 2.105 2.315

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

MAX1777/MAX1977/MAX1999

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

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 2.3SKIP 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

MIN TYP MAX

-9.5

160

-200 +40 +200

-0.2 +0.2

0.96 1.00 1.04

MAX1777/MAX1977/MAX1999

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

MIN

TYP

MAX

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,

MAX1777/MAX1999 (TON = V

CC

)

5V Output Voltage in Fixed Mode

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

SKIP

= 5V,

MAX1977/MAX1999 (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_ (MAX1777/MAX1977),
GND - LX_ (MAX1999)

90 110 mV

V

ILIM_

= 0.5V 40 60

V

ILIM_

= 1V 90 110

Current-Limit Threshold
(Positive, Adjustable)

GND - CS_
(MAX1777/MAX1977),
GND - LX_ (MAX1999)

V

ILIM_

= 2V

220

mV

V

OUT5

= 5.05V

MAX1777 or MAX1999
(V

TON

= 5V)

V

OUT3

= 3.33V

V

OUT5

= 5.05V

On-Time Pulse Width

MAX1977 or MAX1999
(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

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

MAX1777/MAX1977/MAX1999

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

MAX1777/MAX1977/MAX1999

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

MAX1777/MAX1977/MAX1999

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

5V OUTPUT EFFICIENCY

vs. LOAD CURRENT (MAX1777)

20

MAX1777 toc01

LOAD CURRENT (A)

EFFICIENCY (%)

40

60

80
70

50

30

10

90

A: IDLE MODE, VIN = 7V
B: IDLE MODE, V

IN

= 12V

C: IDLE MODE, V

IN

= 24V

D: PWM MODE, V

IN

= 7V

E: PWM MODE, V

IN

= 12V

F: PWM MODE, V

IN

= 24V

A

B

C

D

E

F

100

0

0.001 0.01 0.1 1 10

5V OUTPUT EFFICIENCY

vs. LOAD CURRENT (MAX1977)

20

MAX1777 toc02

LOAD CURRENT (A)

EFFICIENCY (%)

40

60

80
70

50

30

10

90

A: IDLE MODE, VIN = 7V
B: IDLE MODE, V

IN

= 12V

C: IDLE MODE, V

IN

= 24V

D: PWM MODE, V

IN

= 7V

E: PWM MODE, V

IN

= 12V

F: PWM MODE, V

IN

= 24V

A

B

C

D

E

F

100

0

0.001 0.01 0.1 1 10

3.3V OUTPUT EFFICIENCY

vs. LOAD CURRENT (MAX1777)

20

MAX1777 toc03

LOAD CURRENT (A)

EFFICIENCY (%)

40

60

80
70

50

30

10

90

A: IDLE MODE, VIN = 7V
B: IDLE MODE, V

IN

= 12V

C: IDLE MODE, V

IN

= 24V

D: PWM MODE, V

IN

= 7V

E: PWM MODE, V

IN

= 12V

F: PWM MODE, V

IN

= 24V

A

B

C

D

E

F

100

0

0.001 0.01 0.1 1 10

3.3V OUTPUT EFFICIENCY

vs. LOAD CURRENT (MAX1977)

20

MAX1777 toc04

LOAD CURRENT (A)

EFFICIENCY (%)

40

60

80
70

50

30

10

90

A: IDLE MODE, VIN = 7V
B: IDLE MODE, V

IN

= 12V

C: IDLE MODE, V

IN

= 24V

D: PWM MODE, V

IN

= 7V

E: PWM MODE, V

IN

= 12V

F: PWM MODE, V

IN

= 24V

A

B

C

D

E

F

20

26
24
22

30
28

38
36
34
32

40

7

10 13 16 19

22

25

PWM NO-LOAD BATTERY CURRENT

vs. INPUT VOLTAGE

MAX1777 toc05

INPUT VOLTAGE (V)

BATTERY CURRENT (mA)

MAX1977

MAX1777

0.10

0.19

0.16

0.13

0.25

0.22

0.37

0.34

0.31

0.28

0.40

7101316192225

IDLE-MODE NO-LOAD BATTERY CURRENT

vs. INPUT VOLTAGE

MAX1777 toc06

INPUT VOLTAGE (V)

BATTERY CURRENT (mA)

MAX1977

MAX1777

170

176
174
172

180
178

188
186
184
182

190

7101316192225

STANDBY INPUT CURRENT

vs. INPUT VOLTAGE

MAX1777 toc07

INPUT VOLTAGE (V)

STANDBY INPUT CURRENT (µA)

MAX1777

MAX1977

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

MAX1777 toc08

INPUT VOLTAGE (V)

SHUTDOWN INPUT CURRENT (µA)

MAX1977

MAX1777

250

0

0.001 0.01 0.1 1 10

5V OUTPUT SWITCHING

FREQUENCY vs. LOAD CURRENT (MAX1777)

50

MAX1777 toc09

LOAD CURRENT (A)

SWITCHING FREQUENCY (kHz)

100

150

200
175

125

75

25

225

PWM MODE

IDLE MODE

VIN = 7V

MAX1777/MAX1977/MAX1999

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.)

400

0

0.001 0.01 0.1 1 10

3.3V OUTPUT SWITCHING

FREQUENCY vs. LOAD CURRENT (MAX1777)

80

MAX1777 toc10

LOAD CURRENT (A)

SWITCHING FREQUENCY (kHz)

160

240

320
280

200

120

40

360

PWM MODE

PFM MODE

VIN = 7V

ULTRASONIC MODE

250

0

0.001 0.01 0.1 1 10

5V OUTPUT SWITCHING

FREQUENCY vs. LOAD CURRENT (MAX1777)

50

MAX1777 toc11

LOAD CURRENT (A)

SWITCHING FREQUENCY (kHz)

100

150

200
175

125

75

25

225

PWM MODE

PFM MODE

VIN = 24V

ULTRASONIC MODE

400

0

0.001 0.01 0.1 1 10

3.3V OUTPUT SWITCHING

FREQUENCY vs. LOAD CURRENT (MAX1777)

80

MAX1777 toc12

LOAD CURRENT (A)

SWITCHING FREQUENCY (kHz)

160

240

320
280

200

120

40

360

PWM MODE

PFM MODE

VIN = 24V

ULTRASONIC MODE

500

0

0.001 0.01 0.1 1 10

5V OUTPUT SWITCHING

FREQUENCY vs. LOAD CURRENT (MAX1977)

100

MAX1777 toc13

LOAD CURRENT (A)

SWITCHING FREQUENCY (kHz)

200

300

400
350

250

150

50

450

PWM MODE

IDLE MODE

VIN = 7V

110

0

100

200

400

300

500

600

0.001 0.01 0.1

3.3V OUTPUT SWITCHING

FREQUENCY vs. LOAD CURRENT (MAX1977)

MAX1777 toc14

LOAD CURRENT (A)

SWITCHING FREQUENCY (kHz)

550

450

350

250

150

50

PWM MODE

PFM MODE

VIN = 7V

ULTRASONIC MODE

500

0

0.001 0.01 0.1 1 10

5V OUTPUT SWITCHING

FREQUENCY vs. LOAD CURRENT (MAX1977)

100

MAX1777 toc15

LOAD CURRENT (A)

SWITCHING FREQUENCY (kHz)

200

300

400
350

250

150

50

450

PWM MODE

PFM MODE

VIN = 24V

ULTRASONIC MODE

110

0

100

200

400

300

500

600

0.001 0.01 0.1

3.3V OUTPUT SWITCHING

FREQUENCY vs. LOAD CURRENT (MAX1977)

MAX1777 toc16

LOAD CURRENT (A)

SWITCHING FREQUENCY (kHz)

550

450

350

250

150

50

PWM MODE

IDLE MODE

VIN = 24V

ULTRASONIC MODE

5.15

5.05

0.001 0.01 0.1 1 10

OUT5 VOLTAGE REGULATION

vs. LOAD CURRENT

5.07

MAX1777 toc17

LOAD CURRENT (A)

OUTPUT VOLTAGE (V)

5.09

5.11

5.13

5.12

5.10

5.08

5.06

5.14

FORCED PWM

IDLE MODE

ULTRASONIC MODE

110

3.330

3.340

3.350

3.370

3.360

3.380

3.390

0.001 0.01 0.1

OUT3 VOLTAGE REGULATION

vs. LOAD CURRENT

MAX1777 toc18

LOAD CURRENT (A)

OUTPUT VOLTAGE (V)

3.385

3.375

3.365

3.355

3.345

3.335

FORCED PWM

IDLE MODE

ULTRASONIC

MAX1777/MAX1977/MAX1999

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

MAX1777 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

MAX1777 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 10 200 30405060708090100

REFERENCE VOLTAGE

vs. OUTPUT CURRENT

MAX1777 toc21

I

REF

(µA)

V

REF

(V)

0

2V

5V

0

3.3V

0

12V

REF, LDO3, AND LDO5 POWER-UP

MAX1777 toc22

4ms/div

V+
5V/div

LDO3
2V/div

LDO5
5V/div

REF
2V/div

0

0

5V

0

3.3V

0

5V

DELAYED START WAVEFORMS

(ON3 = REF)

MAX1777 toc23

200µs/div

ON5
2V/div

OUT3
2V/div

OUT5
2V/div

0

5V

0

3.3V

0

5V

DELAYED START WAVEFORMS

(ON5 = REF)

MAX1777 toc24

200µs/div

ON3
2V/div

OUT3
2V/div

OUT5
2V/div

0

5A

0

3.3V

0

5A

SOFT-START WAVEFORMS

MAX1777 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

MAX1777 toc26

10ms/div

ON3
5V/div

OUT5
5V/div

DL3
5V/div

OUT3
5V/div

0

5V

SWITCHING

0

4A

1A

5V

MAX1777/MAX1999 (TON = VCC)

5V PWM-MODE

LOAD TRANSIENT RESPONSE

MAX1777 toc27

20µs/div

V

OUT

,
AC­COUPLED
100mV/div

INDUCTOR
CURRENT
2A/div

DL5
5V/div

5V