RN5VD RICOH electronics devices division, RN5VD Datasheet - Page 17

• Manufacturer Part Number: RN5VD
• Description: VOLTAGE DETECTOR WITH OUTPUT DELAY
• Manufacturer: RICOH electronics devices division

16
RN5VD
OPERATION
Supply Voltage
(V
Output Voltage
(OUT)
DD
Current Source
Step 1. Output Voltage is equal to Pull-up Voltage.
Step 2. When Input Voltage (V
Step 3. Output Voltage becomes indefinite when Power Source Voltage(V
Step 4. Output Voltage becomes equal to GND.
Step 5. When Input Voltage (V
)
reversed, so that Output Voltage becomes GND. Discharging is performed from C
output.
and the External Capacitor is charged through C
Minimum Operaing Voltage
GND
GND
Released Voltage +V
Detected Voltage –V
FIG. 2 Operation Diagram
Output Capacitor
DET
DET
1
Ra
DD
DD
Rb
Rc
) reaches the state of Vref≥V
) reaches the state of Vref≤V
Comparator
A
FIG. 1 Block Diagram
–
+
2
Tr.1
Detector Threshold Hysteresis
3
Tr.2
R
D
D
pin, so that Output Voltage becomes equal to Pulled-up Voltage after a delay time
4
B
DD
DD
Schmitt Trigger
C
· (Rb+Rc) / (Ra+Rb+Rc) at Point A (Detected Voltage –V
· Rb/ (Ra+Rb) at Point B (Released Voltage +V
D
5
Delay Time
DD
) is smaller than Minimum Operating Voltage. When the output is pulled up, V
Output Tr.
Comparator Output
Comparator (–) Pin
Input Voltage
Tr. 1, 2
D
Step
pin connected to External Capacitor. No delay time is generated.
Pch
Nch
I.
II.
Nch
Pch
V
OUT
GND
DD
Ra + Rb
Ra + Rb + Rc
Rb
Rb + Rc
Step 1 Step 2
OFF
OFF
ON
L
I
DET
) , the output of Comparator is reversed,
· V
OFF
ON
ON
II
H
DD
DET
· V
) , the output of Comparator is
Indefinite
Indefinite
Indefinite
Indefinite
DD
Step 3
II
t
D
(=0.69 10
Step 4
OFF
ON
ON
II
H
6
Step 5
OFF
OFF
ON
C
L
D
DD
I
) .
is