an8027 Panasonic Corporation of North America, an8027 Datasheet - Page 6

• Manufacturer Part Number: an8027
• Description: Ac-dc Switching Power Supply Control Ic With Standby Mode
• Manufacturer: Panasonic Corporation of North America

AN8027, AN8037
6
Pin No. Pin name
Pin Descriptions (continued)
6
7
8
9
V
Out
SD
FB
CC
I/O
O
I
I
Output used to directly drive a power MOSFET.
A totem pole structure is adopted in this
output circuit.
The absolute maximum ratings for the output
current are:
Power supply.
This pin monitors supply voltage and has the
threshold for the start, stop, OVP, and OVP
reset levels.
This pin is used in RM (remote), OVP (over-
voltage protection), and timer latch.
RM:
The IC is in remote operation if this pin is
short-circuited to the ground and the output
of the IC is turned off.
OVP:
When overvoltage signal of the power sup-
ply is detected and high is inputted to the ter-
minal, it turns off the internal circuit. At the
same time, it holds that condition (latch).
Timer latch:
It detects the output voltage fall due to the
overcurrent condition of the power supply
output through the current level inputted to
FB. When the I
of certain value, the charge current flows in
the capacitor which is connected to this ter-
minal. Then, when the capacitor is charged
up to the threshold voltage of the OVP, the
OVP works so that the IC could keep the op-
eration stop condition.
Connection for the photocoupler used for the
power supply output error-voltage feedback.
This input can decrease the photocoupler dark
current by about 200 A.
Peak: 1 A
DC: 150 mA
FB
Explanation
decreases under the current
V
OVP
V
RM
CC
V
CC
V
REF
Comp.
Comp.
FB
Equivalent Circuit
Voltage Regulators
3.9 V
0.1 V
I
FB
7
9
25 A
I
TIM
8
6