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© 2010 Exar Corporation

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Rev. 1.0.3

PIN ASSIGNMENT

Fig. 3: XRP7708 Pin Assignment

PIN DESCRIPTION

Name

Pin Number

Description

VIN1

39

Power source for the internal linear regulators to generate VCCA, VDD and the Standby

LDO (LDOOUT). Place a decoupling capacitor close to the controller IC. Also used in

UVLO1 fault generation – if VIN1 falls below the user programmed limit, all channels

are shut down. The VIN1 pin needs to be tied to VIN2 on the board with a short trace.

VIN2

38

If the Vin2 pin voltage falls below the user programmed UVLO VIN2 level all channels

are shut down. The VIN2 pin needs to be tied to VIN1 on the board with a short trace.

VCCA

37

Output of the internal 5V LDO. This voltage is internally used to power analog blocks.

Note that a compensation capacitor should be used on this pin (see application note).

VCCD

26

Gate Drive input voltage. This is not an output voltage. This pin can be connected to

VCCA to provide power for the Gate Drive. VCCD should be connected to VCCA with the

shortest possible trace and decouple with a minimum 1µF capacitor. Alternatively,

VCCD could be connected to an external supply (not greater than 5V).

PGND1- PGND4

36,31,16,21

Power Ground. Ground connection for the low side gate driver.

AVDD

1

Output of the internal 1.8V LDO. A decoupling capacitor should be placed between

AVDD and AGND close to the chip (with short traces).