S8425 datasheet(12/45 Pages) SII

12 / 45 page

BATTERY BACKUP SWITCHING IC

S-8425 Series

Rev.3.1_01

2.2 RESET Voltage Detector

The RESET voltage detector monitors the output voltage VOUT (VOUT pin voltage). The detection voltage

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 VOUT pin voltage is 1.0 V or more.

The S-8425 Series incorporates a

RESET release delay circuit.

[RESET release delay time (tDELAY)]

The interval from when the VOUT pin voltage exceeds the RESET release voltage value (

+VDET2) until the

output of the RESET pin is actually inverted is called the RESET release delay time.

Figure 7 Definition of RESET Release Delay Time (tDELAY)

3. Switch Unit

The switch unit consists of the VSW1 and VSW2

detectors, a switch controller, voltage regulator 2,

and switch transistor M1 (see Figure 8 Switch

Unit

3.1 VSW1 Detector

The VSW1 detector monitors the power supply

voltage VIN and sends the results of detection to

the switch controller. The detection voltage

(VSW1) can be set to 77

±2% or 85 ±2% of the CS

release voltage

+VDET1.

Figure 8 Switch Unit

tDELAY

+VDET2

VOUT

VRESET

VOUT

VBAT

VIN

Switch

controller

VSW1

detector

VSW2

detector

REG2

S8425 Datasheet(PDF) 12 Page - Seiko Instruments Inc

S8425 Datasheet(HTML) 12 Page - Seiko Instruments Inc

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45

Datasheet Download

Link URL