ML4823

5

FUNCTIONAL DESCRIPTION

OSCILLATOR

voltage reaches the upper threshold (Ramp Peak), the

comparator changes state and the capacitor discharges to

the lower threshold (Ramp Valley) through Q1. While the

capacitor is discharging, Q2 provides a high pulse.

The oscillator period can be described by the following

relationship:

and:

+

–

5.1V

Q1

400

µA

3V

CLOCK

OUT

CLOCK OUT

RAMP PEAK

RAMP VALLEY

Figure 2. Oscillator Timing Resistance vs Frequency

30

25

20

15

10

5

0

0.47

1.0

2.2

4.7

10.0

22

47

100

160

140

120

100

80

10k

100k

1M

FREQ (Hz)

1.0nF

470pF

Figure 3. Oscillator Deadtime vs Frequency

Figure 1. Oscillator Block Diagram

100k

10k

1k

0.1k

1k

10k

100k

1M

10M

FREQ (Hz)

100nF

47nF

22nF

10nF

4.7nF

2.2nF

1nF

470pF