S-807 Datasheet, PDF (26/42 Pages) Seiko Instruments Inc – HIGH-PRECISION VOLTAGE DETECTOR

HIGH-PRECISION VOLTAGE DETECTOR
S-807 Series
5. Oscillation
In applications where a resistor is connected to the voltage detector input (Figure 11 and 12), the through-type current
generated when the output goes from low to high (release) causes a voltage drop equal to [through-type current]×[input
resistance] across the resistor. When the input voltage resultantly drops below the detection voltage -V_DET, the output
voltage returns to its low level. In this state, the through-type current -- and its resultant voltage drop -- have disappeared,
and the output goes back from low to high. Again, a through-type current is generated, a voltage drop appears, and the
process repeats. Oscillation refers to this unstable condition.
• Power reset mis-implementation
• Mis-implementation with input voltage
divider
V_DD
R
Di
V_IN
C
S-
(CMOS output)
807XXAL
/SL
OUT
V_SS
Figure 11
V_DD
RA
V_IN
S-
(CMOS output)
807XXAL
/SL
OUT
RB
V_SS
Figure 12
Seiko Instruments Inc.
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