Ricoh RV5VH Manual Do Utilizador

××

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.

The output is pulled up to V

DD

voltage

A

B

Reset Voltage
Detector Threshold  

GND 

GND 

Output Voltage

1 

2 

3 

4 

5 

Hysteresis Range

+V

DET

 

–V

DET

  

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