R

3 V

(10 mA)

C

1.6

D

MAX

R

T

f

(1)

UDG−95102

R

C

IR

3 V

IC−IR

CLK

ID = 10 mA

LEB

1 k

10 k

70

75

80

85

90

95

100

100 k

MAXIMUM DUTY CYCLE

vs

TIMING RESISTANCE

10 M

1 M

100 k

10 k

1 k

10 k

100 k

OSCILLATOR FREQUENCY

vs

TIMING RESISTANCE

UC2825A-EP

www.ti.com

SGLS305D – JULY 2005 – REVISED SEPTEMBER 2010

APPLICATION INFORMATION

The oscillator of the UC2825A-EP is a sawtooth. The rising edge is governed by a current controlled by the RT

Selection of RT should be done first, based on desired maximum duty cycle. CT then can be chosen, based on

Figure 1. Oscillator

Figure 2.

Figure 3.

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