22
Under Voltage Lockout
Feature. (Discussion applies to
HCPL-3120, HCPL-J312, and
HCNW3120)
fully-charged IGBT gate voltage)
to drop below a level necessary to
keep the IGBT in a low resistance
state. When the HCPL-3120
output is in the high state and the
supply voltage drops below the
HCPL-3120 VUVLO– threshold
(9.5 < VUVLO– < 12.0) the opto-
coupler output will go into the
low state with a typical delay,
UVLO Turn Off Delay, of 0.6 µs.
When the HCPL-3120 output is in
the low state and the supply
voltage rises above the HCPL-
3120 VUVLO+ threshold (11.0 <
VUVLO+ < 13.5) the optocoupler
output will go into the high state
(assumes LED is “ON”) with a
typical delay, UVLO Turn On
Delay of 0.8 µs.
The HCPL-3120 contains an
under voltage lockout (UVLO)
feature that is designed to protect
the IGBT under fault conditions
which cause the HCPL-3120
supply voltage (equivalent to the
14
12
(12.3, 10.8)
10
(10.7, 9.2)
8
6
4
2
(10.7, 0.1)
(12.3, 0.1)
15
0
0
5
10
20
(V
- V
) – SUPPLY VOLTAGE – V
EE
CC
Figure 34. Under Voltage Lock Out.
ETC [ ETC ]
