
Product Specification
Power Supply Supervisor + PWM
PIN DESCRIPTIONS
Name
Pin
SG6108
System General Corp.
Version 1.0.1 (IAO33.0048.B0)
- 3 -
www.sg.com.tw www.fairchildsemi.com
September 26, 2007
Type
Function
Remote On/Off logic input for
the CPU or the controller. Turns the PWM output on/off following a 45
msec / 16 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.
3.3V over-voltage/under-voltage control sense input.
5V over-voltage/under-voltage control sense input.
Over-power sense input. This pin is connected to the driver transformer or the output of the current
transformer. When not in use, this pin should be grounded.
AC fail-detection. This detects main AC voltage under-voltage and/or failure.
The protection input for negative outputs, such as –12V and/or –5V. Trip voltage = 2.1V.
12V over-voltage/under-voltage control sense input.
The totem-pole output drivers of a push-pull PWM. The outputs are enabled (low) only when the
NAND gate inputs are high. The maximum duty cycle on an output (OP1 or OP2) is 48%.
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.
Second 12V over-voltage/under-voltage control sense input.
12V over current protection sense input. The sink current = 8 x IRI
5V over current protection sense input. The sink current = 8 x IRI
3.3V over current protection sense input. The sink current = 8 x IRI
Ground.
The error amplifier output and the input of the PWM comparator.
The negative input of the error amplifier. The positive input of the error amplifier is a 2.5V reference
voltage.
Soft-start. This can be set through the external capacitor. The current source output at this pin is 8uA
and the voltage is clamped at 2.5V.
This is connected to the external resistor to provide a reference setting. It determines the PWM
frequency, and also the OCP current setting. Setting RI = 75k
will result in a PWM frequency of
65kHz. Do not attach a capacitor to this pin. For OCP current settings please refer to the Over Current
Protection section on page 13.
Supply voltage. 4.5V ~ 5.5V. It is connected to the 5V-standby.
PSON
1
Logic Input
V33
V5
2
3
Analog Input
Analog Input
OPP
4
Analog Input
UVAC
NVP
VS12
5
6
7
Analog Input
Analog Input
Analog Input
OP2/OP1
8/9
Analog Output
PG
10
Logic Output
VS12B
IS12
IS5
IS33
GND
COMP
11
12
13
14
15
16
Analog Input
Analog Input
Analog Input
Analog Input
Supply
Analog Output
IN
17
Analog Input
SS
18
Analog Input
RI
19
Program.
Analog Input
VCC
20
Supply