REV. A

ADP3155

–3–

PIN FUNCTION DESCRIPTIONS

Pin No.

Mnemonic

Function

1–4, 20

VID1–VID4,

Voltage Identification DAC Inputs. These pins are pulled up to an internal reference, providing a

VID0

Logic 1 if left open. The DAC output programs the SENSE– regulation voltage from 1.3 V to 3.5 V.

Leaving all five DAC inputs open results in placing the ADP3155 into shutdown.

5

AGND

Analog Ground. All internal signals of the ADP3155 are referenced to this ground.

6

SD

Shutdown. A logic high will place the ADP3155 in shutdown and disable both outputs. This pin is

internally pulled down.

7, 14

FB1, FB2

These pin are the feedback connections for the linear controllers. Connect each pin to the resistor

divider from each respective linear regulator output to set its output voltage.

8, 13

Gate drives for the respective linear regulator N-channel MOSFETs.

9

SENSE–

Connects to the internal resistor divider that senses the output voltage. This pin is also the reference

input for the current comparator.

10

SENSE+

The (+) input for the current comparator. The output current is sensed as a voltage at this pin with

respect to SENSE–.

11

12

CMP

Error Amplifier output and compensation point. The voltage at this output programs the output cur-

rent control level between the SENSE pins.

15

PWRGD

Power Good. An open drain signal indicates that the output voltage is within a

±5% regulation band.

16

Supply Voltage to ADP3155.

17

DRIVE2

Gate Drive for the (bottom) synchronous rectifier N-channel MOSFET. The voltage at DRIVE2

18

DRIVE1

Gate Drive for the buck switch N-channel MOSFET. The voltage at DRIVE1 swings from ground to

19

PGND

Power Ground. The drivers turn off the buck and synchronous MOSFETs by discharging their gate

capacitances to this pin. PGND should have a low impedance path to the source of the synchronous

MOSFET.

PIN CONFIGURATION

TOP VIEW

(Not to Scale)

20

19

18

17

16

15

14

13

12

11

1

2

3

4

5

6

7

8

9

10

ADP3155

SENSE+

SENSE–

VID2

VID3

VID4

FB1

SD

AGND

CMP

PGND

DRIVE1

DRIVE2

FB2

PWRGD

VID1

VID0

ABSOLUTE MAXIMUM RATINGS*

Shutdown Input Voltage . . . . . . . . . . . . . . . . –0.3 V to +16 V

Operating Ambient Temperature Range . . . . . 0

°C to +70°C

Junction Temperature Range . . . . . . . . . . . . . 0

°C to +150°C

θ

JA

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110

°C/W

Storage Temperature Range . . . . . . . . . . . . –65

°C to +150°C

Lead Temperature (Soldering, 10 sec) . . . . . . . . . . . +300

°C

*This is a stress rating only; operation beyond these limits can cause the device to

be permanently damaged.

ORDERING GUIDE

Temperature

Package

Package

Model

Range

Description

Option

ADP3155JRU

0

°C to +70°C

Thin Shrink Small RU-20

Outline (TSSOP)

CAUTION

ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily

accumulate on the human body and test equipment and can discharge without detection.

Although the ADP3155 features proprietary ESD protection circuitry, permanent damage may

occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD

precautions are recommended to avoid performance degradation or loss of functionality.

WARNING!

ESD SENSITIVE DEVICE