Product Specification

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ORDERING INFORMATION

Part Number

Package

STC6105

20-Pin DIP

PIN DESCRIPTIONS

Name

Pin

Type

Function

VCC

20

Supply

Supply voltage. 4.5V ~ 5.5V. It is connected to 5V-standby.

PG

10

Logic output

Power Good logic output, 0 or 1 (open-collector). PG = 1 means that the power is good for operation.

The PG delay is 300 msec.

V33

2

Analog input

3.3V over-voltage/under-voltage control sense input.

V5

3

Analog input

5V over-voltage/under-voltage control sense input.

V12

7

Analog input

12V over-voltage/under-voltage control sense input.

OPP

4

Analog input

Over-power sense input. This pin is connected to driver transformer or the output of current

transformer. When not in use, this pin should be grounded.

PSON

1

Logic input

Remote On/Off logic input for CPU or controller. Turn on/off the PWM Output after the 7.5 msec / 26

msec delay.

PSON = 0 means that the main SMPS is operational.

PSON =1 means that the main SMPS is off and the latch is reset.

NVP

6

Analog input

The protection input for negative output, such as –12V and/or –5V. Trip voltage = 2.1V.

UVAC

5

Analog input

AC fail detection, detect main AC voltage under-voltage and/or failure.

COMP

16

Analog output

Error amplifier output and the input of the PWM comparator.

IN

17

Analog input

The negative input of error amplifier. The positive input of error amplifier is a 2.5V reference voltage.

SS

18

Analog input

The soft-start. It is settable through external capacitor. The current source output at this pin is 8uA and

the voltage is clamped at 2.5V.

OP1/OP2

9/8

Analog output

The totem-pole output drivers of push-pull PWM. The output are enabled (low) only when the NAND

gate inputs are high, the maximum duty cycle on an output (OP1 or OP2) is 46%.

FB1

14

Analog output

Output for first converter regulation loop.

VREF1

13

Analog input

Reference comparison input for first converter regulation loop. 2.5V.

FB2

11

Analog output

Output for second converter regulation loop.

VREF2

12

Analog input

Reference comparison input for second converter regulation loop. 2.5V.

RI

19

Program.

Analog input

Connected to external resistor for the reference setting.

RI = 75k ohms.

GND

15

Supply

Ground.

STC6105

Power Supply Supervisor + Regulator + PWM