MB3885
s OVERVOLTAGE PROTECTION CIRCUIT VOTAGE SETTING
Overvoltage conditions in the DC/DC converter output voltage can be detected by connecting external resistance
from the DC/DC converter output voltage to the +INC terminal (pin 9) on the respective overvoltage protection
comparator circuits (OVP comp.) .
When the output voltage of the DC/DC converter rises above the detection voltage, the overvoltage protection
comparator (OVP Comp.) output goes to “H” level, setting a latch and shutting off.
Detection voltage
VOVP (V) =: 1.47 × (R3 + R4) /R4
Once the protection circuit has been activated, it can be reset by lowering the VCC voltage below the reset
voltage (1.7 V Min.) .
VO
R3
9
+INC1
R4
VCC
OVP
+ Comp.
−
RQ
S
1.47 V
20