NCP392C

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7

Figure 5. External Connection to GND of OVLO

INPUT

VREF

SEL

OVLO

GND

Fault &

EN

ACOK

If OVLO pin is not grounded, and by adding external

bridge resistor on OVLO pin, between IN and GND,

overvoltage protection can be adjusted as following:

Figure 6. External Connection to Resistor Bridge of

OVLO

INPUT

VREF

SEL

OVLO

GND

Fault &

EN

ACOK

NEW_OVLO

OVLO

EXT

R

R

2

(eq. 1)

Reference)

Example:

R1

+ R2

OVLO

1.221

* 1 + R2

12

1.221

* 1 + 8.828

R2

(eq. 2)

Taking into account external input bridge doesn’t have

excessive current consumption, and 1% is recommended:

R2 arbitrarilly fixed at 1.05 M

W.

R1 = 9.269 M

W (9.31 MW standard value)

Obtained typical OVLO = 12.04 V

EN Input

To enable normal operation, the EN pin has to be at low

level. There is neither internal pull up, nor internal pull down

connected to EN pin. If not externally driven, this pin and so

NCP392C switch are undefined state.

A high level on the pin, disconnects OUT pin from IN pin.

Table 4. CONTROL LOGIC MODES

OVP State

NCP392Cx

OVLO EXT

Low

High

EN

Low

ON

OFF

High

OFF

OFF