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TPS68000

SLVS524 – OCTOBER 2005

PIN ASSIGNMENTS (continued)

Terminal Functions (continued)

TERMINAL

I/O

DESCRIPTION

NAME

NO.

PH

4

I

Phase delay programming input. A voltage between 0 V and 2 V applied to that pin programs the

phase delay of the operating frequency compared to the synchronizing frequency. Applying V5 (5.0

V) programs the device as a master regarding the main oscillator frequency (see SYNC). The

voltage applied to that pin is also used to determine the phase delay in a distributed dimming

configuration

SA

28

Source connection of switch A

SC

18

Source connection of switch C

SET

2

I

Operating frequency programming input. A resistor connected to this pin programs the internal

operating frequency.

STC

3

I

Startup capacitor. A capacitor connected to that pin determines the the time the device waits in

voltage regulation for the lamp to strike.

SYNC

1

I/O

Synchronization input or operating frequency output. If the device is configured as master (see PH)

the pin is used to provide the synchronization frequency for the slaves. Otherwise the device works

as slave and uses the applied frequency at that pin for synchronizing the operating frequency.

V5

23

O

Input/Output of the internal 5 V regulator for Gate drive supply. A capacitor must be connected to

that pin to decouple switching noise caused by the gate drivers.

V5A

26

O

Supply input for the gate driver of the high-side switch A. A capacitor must be connected to that pin

to supply the gate driver during switching (bootstrap).

V5C

20

O

Supply input for the gate driver of the high side switch C. A capacitor must be connected to that pin

to supply the gate driver during switching (bootstrap).

VA-

10

I

Voltage amplifier negative input. This input is used to connect the compensation capacitor for

compensating the voltage loop.

VAO

9

O

Voltage amplifier output. This is the output for the voltage amplifier. It is used to connect the

compensation capacitor for the voltage loop.

VCC

24

I

Device supply voltage

VREF

30

O

Voltage reference. Output of the internal 3.3-V reference for use with all the analog control inputs.

VSEN

11

I

Voltage sense. Measuring input for the lamp voltage. This voltage is used for lamp voltage

regulation (open lamp regulation) and overvoltage protection. Sensed AC voltages can be applied

directly. They are rectified internally.

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