BD9536FV ROHM Co. Ltd., BD9536FV Datasheet - Page 10

• Manufacturer Part Number: BD9536FV
• Description: 2ch Switching Regulators For Desktop Pc
• Manufacturer: ROHM Co. Ltd.

●Timing Chart
EN/UVLO
・Over current protection circuit
・Timer Latch Type Short Circuit Protection
・Output Over Voltage Protection
V
SCP
OUT
HG
HG
LG
LG
SCP
I
L
FB
t
ON
T
SCP
REF×0.8
t
ON
REF×1.2
Switching
Delay setting voltage
t
ON
Delay setting voltage
1.2V
1.2V
t
ON
10/17
Short protection engages when output falls to or below
REF x 0.8. When the programmed time period elapses,
output is latched off to prevent damage to the IC. Output
voltage can be restored either by reconnecting the EN pin
or disabling UVLO. Short circuit protection time is
determined via formula (4) below.
When output voltage rises to or above REF x 1.2, output
over-voltage protection engages after the set time T
has elapsed. During this protection period, the low-side
FET opens completely for maximum reduction of output
voltage (LG = high, HG = low). Output voltage can be
restored either by reconnecting the EN pin or disabling
UVLO.
During normal operation, when VOUT falls below REF,
HG switches high during for the period of time t
However, if the current through the inductor exceeds the
I
After the MAX ON TIME period elapses, HG switches
high again if the output voltage is lower than the
specified voltage level, and if I
level.
Short protection time setting
LIMIT
Tscp=
threshold, HG will switch off.
1.2(V)×C
2 µA(typ)
SCP
[sec] ・・・(4)
L
is lower than the I
ON
(P8).
SCP
LIMIT
/8