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TPS65161

SLVS617 – APRIL 2006

TERMINAL FUNCTIONS

TERMINAL

I/O

DESCRIPTION

NAME

NO.

This is the supply pin of the positive charge pump driver and can be connected to the input supply Vin or the

SUP

8

I

output of the main boost converter Vs. This depends mainly on the desired output voltage VGH and numbers of

charge pump stages.

Frequency adjust pin. This pin allows setting the switching frequency with a logic level to 500 kHz = low and

FREQ

12

I

750 kHz = high.

Analog input voltage of the device. This is the input for the analog circuits of the device and should be bypassed

AVIN

22

I

with a 1-

µF ceramic capacitor for good filtering.

VINB

20, 21

I

Power input voltage pin for the buck converter.

This is the enable pin of the buck converter and negative charge pump. When this pin is pulled high, the buck

EN1

16

I

converter starts up, and after a delay time set by DLY1, the negative charge pump comes up. This pin must be

terminated and not be left floating. A logic high enables the device and a logic low shuts down the device.

The boost converter starts only with EN1 = high, after the step-down converter is enabled. EN2 is the enable pin

of the boost converter and positive charge pump. When this pin is pulled high, the boost converter and positive

EN2

9

I

charge pump starts up after the buck converter is within regulation and a delay time set by DLY2 has passed by.

This pin must be terminated and not be left floating. A logic high enables the device and a logic low shuts down

the device.

DRN

11

O

Drive pin of the negative charge pump.

FBN

13

I

Feedback pin of negative charge pump.

REF

24

O

Internal reference output typically 1.213 V

PGND

6, 7

Power ground

SS

28

O

connected to this pin to set the soft-start time.

DLY1

25

O

converter output high) to VGL during start-up.

DLY2

26

O

This is the compensation pin for the main boost converter. A small capacitor and, if required, a resistor is

COMP

2

connected to this pin.

FBB

15

I

Feedback pin of the buck converter

SWB

18

O

Switch pin of the buck converter

NC

19

Not connected

N-channel MOSFET gate drive voltage for the buck converter. Connect a capacitor from the switch node SWB to

BOOT

17

I

this pin.

FBP

14

I

Feedback pin of positive charge pump.

DRP

10

O

Drive pin of the positive charge pump.

This is the gate drive pin which can be used to control an external MOSFET switch to provide input to output

GD

27

latched low as soon as the boost converter is within 8% of its nominal regulated output voltage. GD goes high

impedance when the EN2 input voltage is cycled low.

GND

23

Analog ground

Output sense pin. The OS pin is connected to the internal rectifier switch and overvoltage protection comparator.

This pin needs to be connected to the output of the boost converter and cannot be connected to any other voltage

OS

3

I

rail. Connect a 470-nF capacitor from OS pin to GND to avoid noise coupling into this pin. The PCB trace of the

OS pin needs to be wide because it conducts high current.

FB

1

I

SW

4, 5

I

PowerPAD

The PowerPAD needs to be connected and soldered to power ground (PGND).

6

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