January 1999 TOKO, Inc.

Page 7

TK11830

CIRCUIT OPERATION

The TK11830 operates with a continuous mode oscillator. The circuit operates by detecting the difference between the

set output voltage and the internal bandgap reference. This is used to vary the oscillator frequency in response to load

current. The output voltage is regulated by controlling the power transistor switch current; this maintains a constant

charge on the output capacitor.

Frequency goes up when the load current goes down.

~VOUT

~VIN

Time

Start

Low Load

Current

High Load

Current

Set Output Voltage

ILPK(MAX)

Power - Transistor Maximum