ACT30

Rev 5, 05-Jun-09

Active-Semi

Innovative Power

TM

- 8 -

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Copyright © 2009 Active-Semi, Inc.

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Application Example

The application circuit in Figure 5 provides a

5V/0.75A constant voltage/constant current output.

The performance of this circuit is summarized in

Table 2.

Table 2:

System Performance of Circuit in Figure 5

Layout Considerations

The following should be observed when doing

layout for the ACT30:

1) Use a "star point" connection at the GND pin of

ACT30 for the VDD bypass components (C5 and

C6 in Figure 5), the input filter capacitor (C2 in

Figure 5) and other ground connections on the

primary side.

2) Keep the loop across the input filter capacitor,

the transformer primary windings, and the high

voltage transistor, and the ACT30 as small as

possible.

3) Keep ACT30 pins and the high voltage transistor

pins as short as possible.

4) Keep the loop across the secondary windings,

the output diode, and the output capacitors as

small as possible.

5) Allow enough copper area under the high voltage

transistor, output diode, and current shunt

resistor for heat sink.

110VAC

220VAC

Standby Power

0.09W

0.15W

Current Limit

0.75A

0.75A

Full Load Efficiency

65%

67%