s-8426a Seiko Instruments Inc., s-8426a Datasheet - Page 12

• Manufacturer Part Number: s-8426a
• Description: Battery Backup Switching Ic
• Manufacturer: Seiko Instruments Inc.

12
BATTERY BACKUP SWITCHING IC
S-8426A Series
3. 4 Switch Transistor M1
Voltage regulator 2 is also used to switch from VIN pin to VOUT pin. Therefore, no reverse current flows from
VOUT pin to VIN pin when voltage regulator 2 is OFF. The output voltage of voltage regulator 2 can be
selected from between 2.3 V and 5.4 V in 0.1 V steps.
The on-resistance of switch transistor M1 is 60 Ω or lower (I
Therefore, when M1 is switched ON and VOUT pin is connected to VBAT pin, the voltage drop (V
M1 is 60 × I
When voltage regulator 2 is ON and M1 is OFF, the leakage current of M1 is kept below 0.1 µA max. (V
V, Ta = 25 °C) with the VBAT pin grounded (VSS pin).
VIN
OUT
(output current) at maximum., and V
REG2
Figure 15 Definition of V
Seiko Instruments Inc.
VOUT
BAT
V
M1
dif
– V
dif
OUT
(max.) is output to the VOUT pin at minimum.
dif
= 10 to 500 µA).
VBAT
Rev.1.0
dif
) caused by
IN
_00
= 6