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Revision 0.6

3

W83301R

Preliminary

4.Pin Description

SYMBOL

PIN

FUNCTION

Mode A: BT Current Source. Connect this pin to the gate of a suitable N-channel

MOSFET for driving bus termination regulator output.

1

Mode B: STR2 Driver. Connect this pin to the gate of a suitable N-channel

MOSFET for driving STR2 output.

Mode A: BT Sense. Connect this pin to the bus termination regulator output.

2

Mode B: STR2 Sense. Connect this pin to the STR2 output.

Mode A: BT Current Sink. This pin is used to drive a N-channel MOSFET to sink

the redundant current in the high-speed bus.

3

Mode B: STR3 Driver. Connect this pin to the gate of a suitable N-channel

MOSFET for driving STR3 output.

Mode A: Function Reserved. Pull up this pin to +5VSB through a 1.5 Kohm

resistor.

4

Mode B: STR3 Sense. Connect this pin to the STR3 output.

GND

5

Power Ground. Connect this pin to ground.

Vcc

6

Power Vcc. Input 5VSB supply.

C1

7

Charge Pump Cap. Attach flying capacitor between this pin and C2 to generate

internally used high voltage from 5V power supply.

C2

8

Charge Pump Cap. Attach flying capacitor between this pin and C1 to generate

internally used high voltage from 5V power supply.

ChrPmp

9

Charge Pump output. This pin produces voltage doubled 5V supply by charge-

pumping. Bypass with a 0.1uF capacitor.

10

S5#

11

S5 Status. Control signal governing the soft off state S5. Pull-up internally.

S3#

12

S3 Status. Control signal governing the soft off state S3. Pull-up internally.

13

Voltage Selection 1. Combine with VSET2 to select operation mode and output

voltages of STR regulators.

14

Voltage Selection 0. Combine with VSET1 to select operation mode and output

voltages of STR regulators.

15

5VSB Output Control. Connect this pin to the gate of a N-MOSFET to output

16

5V Output Control. Connect this pin to the gate of a N-MOSFET to output 5V

PWOK

17

Power OK. Open collector input/output. Used to indicate the ready of 5Vin supply. If

any STR supply (only STR1 in mode A) occurs over current and induce under-

voltage, PWOK will be pull down.

SS

18

Soft-Start. Attach a capacitor (0.033u) to this pin to determine the softstart rate. A

ramp generated by charging this capacitor with internal soft-start current (18uA) is

avoids too much rush current during voltage setup.

19

STR1 Sense. Connect this pin to the STR1 output.

20

STR1 Driver. Connect this pin to the gate of a suitable N-channel MOSFET for

driving STR1 output.