R3111x

14

 R3111E (TO-92) is the discontinued product as of April, 2017.

 Operation of R3111xxxxC

Vref

Ra

Rb

Rc

VDD

OUT

GND

Tr.1

Nch

Pch

Comparator

Block Diagram (R3111xxxxC)

tPLH

GND

GND

VDDL

-VDET

+VDET

Detector Threshold

Released Voltage

Minimum Operating Voltage

12

3

4

5

A

B

Detector Threshold

Hysteresis

Supply Voltage

(VDD)

Output Voltage

(VOUT)

Step

1

2

3

4

5

Comparator (+)

Pin Input Voltage

I

II

II

II

I

Comparator Output

H

L

Indefinite

L

H

Tr.1

OFF ON Indefinite ON OFF

Pch

ON OFF Indefinite OFF ON

Output Tr.

Nch

OFF ON Indefinite ON OFF

I

VDD

Rb

Rc

Ra

RbRc

II

VDD

Rb

Ra

Rb

Operation Diagram

 Explanation of operation

Step 1. The output voltage is equal to the supply voltage (VDD).

Step 2. At Point “A”, Vref  

 VDD(RbRc)/(RaRbRc) is true, as a result, the output of comparator is reversed

from "H" to "L", therefore the output voltage becomes the GND level. The voltage level of Point A

means a detector threshold voltage (

VDET).

Step 3. When the supply voltage is lower than the minimum operating voltage, the operation of the output

transistor becomes indefinite.

Step 4. The output Voltage is equal to the GND level.

Step 5. At Point “B”, Vref  

 VDDRb/(RaRb) is true, as a result, the output of comparator is reversed from "L" to

"H", then the output voltage is equal to the supply voltage (VDD). The voltage level of Point B means a

released voltage (

VDET).

) The difference between a released voltage and a detector threshold voltage is a detector threshold hysteresis.

Output

Delay Time