AN8026
Voltage Regulators
■ Terminal Equivalent Circuits (continued)
Pin No.
Equivalent circuit
Description
I/O
3
TON:
VCC
Terminal for connecting the capacitor for deter-
mining the maximum on-period (high) of the IC
output (VOUT). An equation for approximate
calculation of the maximum on-period (TON) is
as follows:
VREF
Comp.
FB
0.7 V
TON = 6 500 × C
3
C: External capacitance
4
CLM:
I
Input terminal for detection of the pulse-by-
pulse overcurrent protection.
Normally, it is recommended that a filter be
attached externally.
Comp.
(+)
4
5
6
GND:
5
Grounding terminal.
VOUT
:
O
VCC
Output terminal for directly driving the power
MOSFET.
It uses the totem pole type output.
The maximum rating of the output current:
Peak: ±1 A
6
DC: ±150 mA
7
8
VCC:
Terminal for applying power supply voltage.
It monitors the supply voltage and has the op-
eration threshold of start/stop/OVP reset.
7
OVP:
I
When overvoltage of the power supply output is
detected and high is inputted to the terminal, it
turns off the internal circuit. At the same time, it
holds that condition (latch).
8
Comp.
To reset the OVP latch, the terminal voltage should
be decreased to low, or the VCC should be decreased
to a voltage lower than the release voltage.
9
FB:
I
VCC
Terminal for connecting the photocoupler for
error voltage feedback of the power supply out-
put.
It is possible to cancel about 150 µA of the dark
current of photocoupler.
9
TON
4
PANASONIC [ PANASONIC ]
