MB3790 Datasheet, PDF (16/21 Pages) Fujitsu Component Limited. – Battery Backup IC

MB3790
3. Outputting Reset Signal Forcibly
The reset signal can be output forcibly by bringing the VSENSE pin of the MB3790 to a Low level (< 1.24). The reset
signal is held on until the capacitator CT is charged up after the VSENSE pin is released open.
Forced Reset Method 1
V IN
V IN
47KΩ
SW
VSENSE
CT
CT
GND
Forced Reset Method 2
SW: Turned on (VRESET = High)
V IN
V IN
Control signal
input pin
10KΩ
10KΩ
47KΩ
Q1
VSENSE
CT
CT
GND
When the voltage enough to turn on Q1 (≥ approx. 1.2 V) gives to the Control signal input pin,
VRESET is equal to High level.
[Reset Pulse Width Calculation Formula]
Reset Pulse Width tPO (sec) = CT (F) ×10⁶ (where CT = capacitance)
Example: When CT = 1000 pF, tPO = 1 ms (Typ)
16