ULTRA-SMALL PACKAGE HIGH-PRECISION VOLTAGE DETECTOR
S-808xxC Series
Rev.3.2_00
3. Change of Detection Voltage
In Nch open-drain output products of the S-808xxC series, detection voltage can be changed using
resistance dividers or diodes as shown in Figures 30 to 31. In Figure 30, hysteresis width also changes.
VDD
VDD
Vf1
Vf2
*1
RA
(RA≤75 kΩ)
S-
S-
VIN
VIN
808xxCN
OUT
OUT
808xxCN
+
−
(Nch open-drain
output product)
RB
(Nch open-drain
output products)
VSS
Detection voltage=Vf1+Vf2+(−VDET
VSS
Detection voltagae = RA + RB • −VDET
)
RB
Hysterisis width = RA + RB • VHYS
RB
*1. RA should be 75 kΩ or less to prevent oscillation.
Caution If RA and RB are large, the hysteresis
width may aloso be larger than the value
given by the above equation due to the
through-type current (which flows
slightly in an Nch open-drain product).
Figure 30
Figure 31
Caution The above connection diagram and constants do not guarantee correct operation. Perform
sufficient evaluation using the actual application to set the constants.
34
Seiko Instruments Inc.
SII [ SEIKO INSTRUMENTS INC ]
