Triple 1800 mA Buck Regulator with

Precision Enables and Power-Good Outputs

Data Sheet

ADP5135

Rev. 0

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FEATURES

Input voltage range: 3.0 V to 5.5 V

Three 1800 mA buck regulators

24-lead, 4 mm × 4 mm LFCSP package

Regulator accuracy: ±1.8%

Factory programmable or external adjustable VOUTx pins

Precision enables for easier power sequencing

Power-good pins for monitoring each regulator

3 MHz buck operation with forced PWM and auto PWM/PSM

modes

BUCK1/BUCK2/BUCK3: output voltage range from 0.8 V to 3.8 V

APPLICATIONS

Power for processors, application specific integrated circuits

(ASICs), field-programmable gate arrays (FPGAs), and

radio frequency (RF) chipsets

Portable instrumentation and medical devices

Space constrained devices

TYPICAL APPLICATION CIRCUIT

Figure 1.

GENERAL DESCRIPTION

The ADP5135 combines three high performance buck regulators

(BUCK1, BUCK2, and BUCK3). It is available in a 24-lead,

4 mm × 4 mm LFCSP.

The high switching frequency of the buck regulators enables tiny

multilayer external components and minimizes the board space.

When the MODE pin is set to high, the buck regulators operate in

forced pulse-width modulation (PWM) mode. When the

MODE pin is set to low, the buck regulators operate in PWM

mode only when the load is above a predefined threshold. When

the load current falls below this predefined threshold, the

regulator operates in power save mode (PSM), improving the

light load efficiency.

BUCK1 and BUCK2 operate in synchronization, and BUCK3

operates out of phase to reduce the input capacitor requirement.

Regulators in the ADP5135 are activated through dedicated

enable pins. The default output voltages can be externally set in

the adjustable version, or factory programmable to a wide range

of preset values in the fixed voltage version.

Table 1. Family Devices

Device

Channels

Max

Current

Package

ADP5023

2 buck regulators, 1 LDO

800 mA,

300 mA

LFCSP (CP-24-10)

ADP5024

2 buck regulators, 1 LDO

1.2 A,

300 mA

LFCSP (CP-24-10)

ADP5034

2 buck regulators, 2 LDOs

1.2 A,

300 mA

LFCSP (CP-24-10),

TSSOP (RE-28-1)

ADP5037

2 buck regulators, 2 LDOs

800 mA,

300 mA

LFCSP (CP-24-10)

ADP5033

2 buck regulators, 2 LDOs

with 2 ENx pins

800 mA,

300 mA

WLCSP (CB-16-8)

ADP5040

1 buck regulator, 2 LDOs

1.2 A,

300 mA

LFCSP (CP-20-10)

ADP5041

1 buck regulator, 2 LDOs

with supervisory circuit,

watchdog function, and

manual reset

1.2 A,

300 mA

LFCSP (CP-20-10)

ADP5133

2 buck regulators with

2 ENx pins

800 mA

WLCSP (CB-16-8)

ADP5134

2 buck regulators, 2 LDOs

with precision enable and

power good

1.2 A,

300 mA

LFCSP (CP-24-7)

PWM

AUTO

3.0V

TO

5.5V

MODE

BUCK1

1.8A

BUCK2

1.8A

BUCK3

1.8A

HOUSE-

KEEPING

POWER

GOOD

EN1

ON

OFF

12

EN2

ON

OFF

7

SW1

FB1

VOUT1

L1 1µH

C2

22µF

10

15

11

13

AVIN

17

AGND

18

C7

0.1µF

VIN1

16

PGND1

14

C1

10µF

VIN2

3

PGND2

5

C3

10µF

EN3

ON

OFF

24

VIN3

21

PGND3

19

C5

10µF

R2

R1

SW2

FB2

VOUT2

L2 1µH

C4

22µF

9

4

8

R4

R3

SW3

FB3

VOUT3

L3 1µH

C6

22µF

22

20

23

PG1

6

PG2

2

PG3

1

R6

R5

ADP5135

R9

100Ω

R8

100Ω

R7

100Ω