R3130N RICOH [RICOH electronics devices division], R3130N Datasheet - Page 17

• Manufacturer Part Number: R3130N
• Description: Low Voltage Detector with Built-in Delay Circuit
• Manufacturer: RICOH [RICOH electronics devices division]

•
Operation Diagram
Supply
Voltage
(V
Output
Voltage
(OUT)
DD
1 Output voltage becomes equal to GND level.
2When supply voltage is down to the detector threshold level (Point A), Vref
3 When supply voltage is lower than minimum operating voltage, Output of transistor is indefinite, therefore
4 Output voltage is equal to supply voltage. (Nch open drain output type; equal to pull-up voltage.)
5 When supply voltage is higher than released voltage (Point B), Vref
∗ There is no hysteresis range between detector threshold and released voltage.
Operation of R3131N Series
In the above diagram,
Vref
)
output of the comparator is reversed, thus output voltage becomes equal to supply voltage (Nch open drain
output type; equal to pull-up Voltage).
output is also indefinite.(Nch open drain output type; Output voltage level is equal to pull-up voltage.)
of the comparator is reversed, thus output voltage becomes equal to GND level after the output delay time.
Ra
Rb
1
A
+
-
Comparator
Block Diagram
2
Circuit
Delay
3
4
B
5
Minimum Operating
Voltage(V
Detector Threshold(V
GND
Tdelay
GND
=Released Voltage
Pch
Nch
DDL
V
OUT
GND
)
DD
⋅
⋅
< =
OUT pin is connected to the drain of
Nch Tr. and Pch Tr. in this IC.
OUT pin is connected to the drain of
Nch Tr. in this IC. (OUT pin should be
pulled up to V
level.)
DET)
CMOS output type
Nch open drain output type: I
V
DD
× Rb/(Ra+Rb) is true. Then output
> =
V
DD
× Rb/(Ra+Rb) is true. Then,
DD
or an external voltage
R3130N/R3131N
17