MB3790 Datasheet, PDF (17/21 Pages) Fujitsu Component Limited. – Battery Backup IC

MB3790
4. Adjusting the Supply Voltage Detection Level Set time
The MB3790 outputs a reset signal when the power supply momentarily goes down or its voltage sags for 5 µs or
more. The set time before this reset signal is output can be extended by connecting a capacitor to the VSENSE pin.
Adjusting the Supply Voltage Detection Level Set Time
5V
4V
t PI
V IN
C
V IN
VSENSE
GND
5. Compatibility with JEIDA Memory Card Guideline Ver. 4
The MB3790 has its ALM1 and ALM2 pin specifications matched to the BVD2 and BVD1 pin specifications of the
JEIDA Memory Card Guideline Ver. 4. Therefore, the ALM1 and ALM2 pins can be connected directly to the BVD2
and BVD1 pins.
• Alarm Pin Detection Voltage Levels
Pin Name
ALM1
ALM2
VBAT1 ≤ 2.37 V
Low level
Low level
2.37 V < VBAT1 ≤ 2.65V
Low level
High level
2.65 V ≤ VBAT1
High level
High level
Connected Pin
BVD2
BVD1
VBAT1: Primary battery voltage
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