Rv5vh3 – Ricoh RV5VH User Manual
Page 44
RV5VH3
××
40
D
OUT
RV5VH3
××
Pull-up
Output Tr.
–
+
Vref
R1
R2
R3
Tr.1
3
8
V
DD
The Voltage Detector can operate by an input voltage to the V
DD
pin. The detector threshold and the reset voltage
are internally adjusted by trimmed resistors and the VD monitors V
DD
pin voltage.
The D
OUT
is Nch-opendrain output and a pull up resistor is necessary.
Oepration Diagram
The output is pulled up to V
DD
voltage
• Voltage Detector
A
B
Reset Voltage
Detector Threshold
GND
GND
Output Voltage
1
2
3
4
5
Hysteresis Range
+V
DET
–V
DET
Step
Step 1
Step 2
Step 3
Step 4
Step 5
Comparator(+) Pin
Input Voltage
A
B
B
B
A
Comparator Output
H
L
L
L
H
Tr. 1
OFF
ON
ON
ON
OFF
Output Tr.
OFF
ON
Indefinite
ON
OFF
Step 1. Output Voltage is equal to Pull-up Voltage
Step 2. When Input voltage(V
DD
) reaches to the state of V
REF
≥
V
DD
×
(R2+R3)/(R1+R2+R3) at point A, the output of the comparator is reversed, so that the
output voltage becomes to GND.
Step 3. Output Voltage becomes indefinite when Power Source Voltage (V
DD
) is smaller than Minimum Operating Voltage. When the output is pulIed up,
Output becomes pull-up voltage and GND.
Step 4. Output Voltage becomes to GND.
Step 5. When Input voltage(V
DD
) reaches to the state of V
REF
≤
V
DD
×
R2/(R1+R2) at point B, the output of the comparator is reversed, so that the output voltage
becomes to pull-up voltage.
A :
R2+R3
×
V
DD
R1+R2+R3
B :
R2
×
V
DD
R1+R2+R3