HA16108FP HITACHI [Hitachi Semiconductor], HA16108FP Datasheet - Page 11

• Manufacturer Part Number: HA16108FP
• Description: PWM Switching Regulator for High-performance Voltage Mode Control
• Manufacturer: HITACHI [Hitachi Semiconductor]

Undervoltage Lockout and PWM Output
The undervoltage lockout function turns off the PWM pulse output when the controller’s supply voltage
goes below a designated value. These ICs have two undervoltage lockout circuits. The UVL1 circuit
senses the supply voltage V
PWM output is turned on only when both voltages are above designated values. Otherwise, the IC operates
in standby mode.
The two built-in undervoltage lockout circuits make it possible to configure an extremely safe power
supply system. PWM output will shut down under a variety of abnormal conditions, such as if Vref is
shorted to ground while V
UVL1 (V
UVL2 (Vref and PWM output)
UVL1 and UVL2
OUT
Vref
I
IN
Vref
PWM output shut-down region
0
0
0
0
IN
and Vref)
9.5 V
V
Vref (UVL2)
PWM OUT
Standby mode
Note: Double circles indicate standby mode.
IN
10 V
10 V
10 V
10 V
*
IN
(UVL1)
2
4 V
is applied.
IN
. The UVL2 circuit senses the Vref voltage. A feature of these ICs is that
16.2 V
Operating region
5 V
20 V
20 V
20 V
20 V
L
L
L
6.45 V
6.45 V
30 V
30 V
30 V
30 V
L
H
L
34 V
OUT
H
H
*
1
HA16107P/FP, HA16108P/FP
V
V
V
V
IN
IN
IN
IN
L
H
L
Notes: 1.
2.
Breakdown voltage of
the internal Zener
diode (V
Hysteresis characteristic.
z
= 34 V typ).
11