S-807 Datasheet, PDF (39/42 Pages) Seiko Instruments Inc – HIGH-PRECISION VOLTAGE DETECTOR

HIGH-PRECISION VOLTAGE DETECTOR
S-807 Series
2. Power-on reset circuit
The Nch open-drain output products of the S-807 Series can be used to construct a power-on reset circuit. Following is an
example.
V_DD
R
Di
(R≤7.5kΩ) VIN
+
C
-
S-807XX
AN/SN
OUT
(Nch open-drain products)
V_SS
Note 1: R should be 7.5kΩ or less for purpose of protection against oscillation.
Note 2: “Di” momentarily discharges the charge received via “C” at the falling edge of power off. There
is no need to insert a diode, when there is no conflict with application circuit even if there is a
delay in the falling edge of OUT at the falling edge of power off.
V_DD
OUT
(V)
(V)
t (s)
t (s)
Figure 27
Note 3: When there is a sharp rise in power, the output voltage may go “H” momentarily in unstable range of
the output voltage (the output voltage is unstable below the minimum operating voltage) .
V_DD
(V)
OUT
(V)
t (s)
t (s)
Figure 28
38
Seiko Instruments Inc.