s-8425 Seiko Instruments Inc., s-8425 Datasheet - Page 10

• Manufacturer Part Number: s-8425
• Description: Battery Backup Switching Ic
• Manufacturer: Seiko Instruments Inc.

3. Switch Unit
10
BATTERY BACKUP SWITCHING IC
S-8425 Series
2.2 RESET Voltage Detector
The RESET voltage detector monitors the output voltage V
can be selected from between 1.7 V and 3.4 V in 0.1 V steps. The result of detection is output at the
RESET pin: “Low” for a lower voltage than the detection level and “High” for a higher voltage than the
release level. RESET outputs the normal logic if the V OUT pin voltage is 1.0 V or more.
The S-8425 Series incorporates a RESET release delay circuit.
[RESET release delay time (t
The interval from when the VOUT pin voltage exceeds the RESET release voltage value ( + V
output of the RESET pin is actually inverted is called the RESET release delay time.
The switch unit consists of the V
detectors, a switch controller, voltage regulator 2,
and switch transistor M1 (see Figure 8 Switch
Unit ).
3.1 V
The V
voltage V
the switch controller. The detection voltage
(V
release voltage + V
SW1
SW1
) can be set to 77 ± 2% or 85 ± 2% of the CS
SW1
Detector
IN
detector monitors the power supply
and sends the results of detection to
DET1
Figure 7 Definition of RESET Release Delay Time (t
.
+ V
DET2
V
DELAY
SW1
)]
and V
Seiko Instruments Inc.
SW2
VIN
t
DELAY
V
OUT
OUT
(VOUT pin voltage). The detection voltage
controller
REG2
Switch
Figure 8 Switch Unit
VOUT
V
RESET
DELAY
t
detector
)
M1
V
SW1
VBAT
DET2
Rev.2.3
detector
V
) until the
SW2
_00