REV. 0

ADP3170

–4–

PIN FUNCTION DESCRIPTIONS

Pin No.

Mnemonic

Function

1–5

VID3, VID2,

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

VID1, VID0,

providing a logic one if left open. The DAC output programs the FB regulation voltage from

VID25

1.05 V to 1.825 V.

6

PWRGD

Open drain output that signals when the output voltage is in the proper operating range.

7

REF

3.0 V Reference Output.

8

SD

Regulator Shutdown. Pulling this pin high turns off both MOSFETs of the switching

regulator. SD has no effect on the linear regulator controller.

9

FB

Feedback Input. Error amplifier input for remote sensing of the output voltage.

10

CS–

Current Sense Negative Node. Negative input for the current comparator.

11

CS+

Current Sense Positive Node. Positive input for the current comparator. The output current is

sensed as a voltage at this pin with respect to CS–.

12

CT

External capacitor connected from CT to ground sets the OFF-Time of the device.

13

COMP

Error Amplifier Output and Compensation Point. The voltage at this output programs the

output current control level between CS+ and CS–.

14

LRDRV

Gate Drive for the 1.8 V linear regulator N-channel MOSFET.

15

LRFB

Feedback Connections for the 1.8 V linear regulator controller.

16

VCC

Supply Voltage for the ADP3170.

17

DRVL

Low-Side MOSFET Drive. Gate drive for the synchronous rectifier N-channel MOSFET.

The voltage at DRVL swings from GND to VCC.

18

DRVH

High-Side MOSFET Drive. Gate drive for the buck switch N-channel MOSFET. The voltage

at DRVH swings from GND to VCC.

19

PGND

Power Ground. PGND should have a low impedance path to the source of the synchronous

MOSFET.

20

GND

Small-Signal Ground. This ground reference can be used in conjunction with FB to provide

remote sensing of the output voltage at the CPU pins.

PIN CONFIGURATION

RU-20

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

ADP3170

FB

SD

REF

PWRGD

CT

COMP

PGND

DRVH

DRVL

LRDRV

LRFB

VCC

VID3

GND

VID2

VID1

VID0

VID25

CS+

CS–