NCS2001

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12

The non−inverting input threshold levels are set so that

the capacitor voltage oscillates between 1/3 and 2/3 of

equal value. The following formula can be used to

approximate the output frequency.

470 k

470 k

470 k

470 k

1.0 nF

0.9 V

470 k

1N4148

−

+

−

+

0.9 V

f

O+

1

1.39 R

0

Output Voltage

Timing Capacitor

Voltage

470 k

1N4148

10 k

10 k

1.0 M

cw

470 k

1.0 nF

0

Output Voltage

Timing Capacitor

Voltage

0

Output Voltage

Timing Capacitor

Voltage

signal can be programmed by adjusting the value of the trimpot. The ca-

resistors at the non−inverting input are of equal value.

Clock−wise, Low Duty Cycle

Counter−Clock−wise, High Duty Cycle

Figure 34. 0.9 V Square Wave Oscillator

Figure 35. Variable Duty Cycle Pulse Generator

cww