Analog Integrated Circuit Device Data

Freescale Semiconductor

3

34712

PIN CONNECTIONS

PIN CONNECTIONS

Figure 3. 34712 Pin Connections

Table 1. 34712 Pin Definitions

A functional description of each pin can be found in the Functional Pin Description section beginning on page 10.

Pin Number

Pin Name

Pin Function

Formal Name

Definition

1

GND

Ground

Signal Ground

Analog signal ground of IC

2

FREQ

Passive

Frequency Adjustment

Buck converter switching frequency adjustment pin

3

NC

None

No Connect

No internal connections to this pin

4

PG

Output

Power Good

Active-low (open drain) power-good status reporting pin

5

STBY

Input

Standby

Standby mode input control pin

6

SD

Input

Shutdown

Shutdown mode input control pin

7

VREFIN

Input

Voltage-Tracking-

Reference Input

Voltage-Tracking-Reference voltage input

8

VREFOUT

Output

Reference Voltage

Output

Buffered output equal to 1/2 of voltage-tracking reference

9

COMP

Passive

Compensation

Buck converter external compensation network pin

10

INV

Input

Error Amplifier

Inverting Input

Buck converter error amplifier inverting input pin

11

VOUT

Output

Output Voltage

Discharge FET

Discharge FET drain connection (connect to buck converter output

capacitors)

12,13,14

PGND

Ground

Power Ground

Ground return for buck converter and discharge FET

15,16,17

SW

Power

Switching Node

Buck converter power switching node

18,19,20

PVIN

Supply

Power-Circuit Supply

Input

Buck converter main supply voltage input

21

BOOT

Passive

Bootstrap

Bootstrap switching node (connect to bootstrap capacitor)

GND

FREQ

STBY

PG

NC

SD

SW

PGND

PGND

SW

SW

PVIN

Transparent

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

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