UCC25705, UCC25706, UCC35705, UCC35706

HIGHSPEED VOLTAGE MODE PULSE WIDTH MODULATOR

SLUS473A – NOVEMBER 1999 – REVISED MARCH 2001

7

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FUNCTIONAL DESCRIPTION

component selection for oscillator with duty cycle clamp (MODE = 1)

For a power converter with the following specifications:

In this mode, the on-time is approximately:

15

= 1.20 V

R

V

IN min

T

V

FF min

C

T

R

30

R

T

1

)

V

FF(min)

V

IN(min)

R

T

C

T

T

OFF(min)

must be decreased.

R

V

FF(min)

R

DISCH

2

V

The nearest 1% standard value to the calculated value is 13.7 k.