ADP3025

Rev. A | Page 6 of 24

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

13

18

14

12

11

10

9

8

1

2

3

4

7

6

5

19

17

16

15

20

29

28

27

32

31

30

38

37

36

35

34

33

23

22

21

26

25

24

TOP VIEW

(Not to Scale)

ADP3025

BST5

DRVH5

SW5

DRVL5

PGND1

SD

PGND2

INTVCC1

VIN

DRVL3

SW3

DRVH3

BST3

DRV2

FB2

COMP2/SD2

CPOR

PWRGD

CS5

FB5

EAN5

EAO5

PFI

SS5

CLSET5

REF

AGND

CLSET3

INTVCC2

SYNC

SS3

PFO

EAO3

EAN3

FB3

CS3

ADJ/FX3

ADJ/FX5

Figure 2. 38-Lead TSSOP Pin Configuration

Table 3. Pin Function Descriptions

Pin No.

Mnemonic

Function

1

CS5

Current Sense Input for the Top N-Channel MOSFET of the 5 V Buck Converter. Connect to the drain of the top

N-channel MOSFET.

2

FB5

Feedback Input for the 5 V Buck Converter. Connect to the output sense point in fixed output mode. Connect to

an external resistor divider in adjustable output mode.

3

EAN5

Inverting Input of the Error Amplifier of the 5 V Buck Converter. Use for external loop compensation only in

fixed output mode. In adjustable output mode, connect to the external resistor divider.

4

EAO5

Error Amplifier Output for the 5 V Buck Converter.

5

ADJ/FX5

TTL Logic Input. When ADJ/FX5 = 0 V, fixed output mode, connect FB5 to the output sense point. When

ADJ/FX5 = 5 V, adjustable output mode, connect FB5 to the external resistor divider.

6

SS5

Soft Start for the 5 V Buck Converter. Also used as an ON/OFF pin.

7

CLSET5

Current Limit Setting. A resistor can be connected from AGND to CLSET5. A minimum current limit is obtained

by leaving it open. A maximum current limit is obtained by connecting it to AGND.

8

REF

800 mV Reference. Bypass it with a capacitor (22 nF typical) to AGND. REF cannot be loaded externally.

9

AGND

Analog Signal Ground.

10

CLSET3

Current Limit Setting. A resistor can be connected from AGND to CLSET3. A minimum current limit is obtained

by leaving it open. A maximum current limit is obtained by connecting it to AGND.

11, 31

INTVCC2, 1

Linear Regulator Bypass for the Internal 5 V LDO. Bypass this pin with a 4.7 µF capacitor to AGND. Pins 11 and 31

must be connected for proper operation.

12

SYNC

SYNC = 5 V. The oscillator can be synchronized with an external source through the SYNC pin.

13

SS3

Soft Start for the 3.3 V Buck Converter. Also used as an ON/OFF pin.

14

ADJ/FX3

TTL Logic Input. When ADJ/FX3 = 0 V, fixed output mode, connect FB3 to the output sense point. When

ADJ/FX3 = 5 V, adjustable output mode, connect FB3 to the external resistor divider.

15

EAO3

Error Amplifier Output for the 3.3 V Buck Converter.

16

EAN3

Error Amplifier Inverting Input of the 3.3 V Buck Converter. Use for external loop compensation only in fixed

output mode. In adjustable output mode, connect to an external resistor divider.

17

FB3

Feedback Input for the 3.3 V Buck Converter. Connect to output sense point in fixed output mode. Connect to

an external resistor divider in adjustable output mode.

18

CS3

Current Sense Input for the Top N-Channel MOSFET of the 3.3 V Buck Converter. CS3 should be connected to

the drain of the N-channel MOSFET.