MB3790 Datasheet, PDF (4/21 Pages) Fujitsu Component Limited. – Battery Backup IC

MB3790
s PIN DESCRIPTION
Pin number
Symbol
I/O
16P 20P
Name and function
1
1
N.C.
— Non connection
2
2
VBATI
I This pin connects to the primary battery.
3, 4
3, 4
VOUT
O These pins supply the output voltage. (Range of output current value
IOUT ≤ 200 mA)
5
5
VBAT2
I/O This pin connects to the secondary battery. When the power supply
voltage is greater than or equal to the detection level (i.e., VINH), the
secondary battery is recharged using the constant-voltage method of
charging.
—
6, 7
N.C.
— Non connection
6
8
ALARM1
O This is an open-collector output pin for a primary battery alarm
signal. When the power supply voltage is greater than or equal to
VINH, it monitors the primary battery voltage. If the power supply
voltage is less than VINL, it does not monitor the primary battery
voltage. If VBAT1 is less than or equal to 2.65 V, its output voltage is
forced to a Low level.
7
9
ALARM2
O This is an open-collector output pin for a primary battery alarm
signal. When the power supply voltage is greater than or equal to
VINH, it monitors the primary battery voltage. If the power supply
voltage is less than VINL, it does not monitor the primary battery
voltage. If VBAT1 is less than or equal to 2.37 V, its output voltage is
forced to a Low level.
8
10
GND
— This pin connects to the ground (0 V).
9
11
RESET
O This pin outputs a reset signal. When the power supply voltage is
less than or equal to VINL, it outputs a High level.
If the power supply voltage of SRAM is less than the designated
range, it directly controls the CE or CS of SRAM to disable writes and
thereby protect the data in memory.
10
12
RESET
O This pin outputs an inverted signal of RESET.
11
13
CT
— This pin is used to set the reset pulse width.
Insert a capacitor between this pin and GND to set the pulse width.
— 14, 15
N.C.
— Non connection
12
16
VSENSE
I This pin accepts comparator input for detecting the power supply
voltage level. For details, refer to APPLICATION in this data sheet.
13, 14 17, 18
VIN
I These pins accept the input voltage for the device.
15
19
N.C.
— Non connection
16
20 CONTROL I This pin is used for output control. For details, refer to APPLICATION
in this data sheet.
4