NCP1124, NCP1126, NCP1129

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2

Figure 1. Typical Application

Table 2. PIN FUNCTION DESCRIPTION

Pin No.

Pin Name

Pin Description

1

VCC

This pin is connected to an external auxiliary voltage and supplies the controller. When above a certain

level, the part fully latches off.

2

FB

Feedback input. Hooking an optocoupler collector to this pin will allow regulation.

3

CS

This pin monitors the primary peak current but also offers a means to introduce ramp compensation.

4

Source

Source of the internal MOSFET. This pin is typically connected to the source of a grounded sense resistor.

5

Drain

The drain of the internal MOSFET. These pins connect to the transformer terminal and can withstand up to

650 V.

6

Drain

7

−

Removed for creepage distance.

8

GND

Ground reference.

Table 3. OPTIONS

Switcher

Package

Frequency

Short−Circuit Protection

NCP1124AP65G

PDIP−7

65 kHz

Latch

NCP1124BP65G

PDIP−7

65 kHz

Auto−Recovery

NCP1124AP100G

PDIP−7

100 kHz

Latch

NCP1124BP100G

PDIP−7

100 kHz

Auto−Recovery

NCP1126AP65G

PDIP−7

65 kHz

Latch

NCP1126BP65G

PDIP−7

65 kHz

Auto−Recovery

NCP1126AP100G

PDIP−7

100 kHz

Latch

NCP1126BP100G

PDIP−7

100 kHz

Auto−Recovery

NCP1129AP65G

PDIP−7

65 kHz

Latch

NCP1129BP65G

PDIP−7

65 kHz

Auto−Recovery

NCP1129AP100G

PDIP−7

100 kHz

Latch

NCP1129BP100G

PDIP−7

100 kHz

Auto−Recovery