1.8

Resultant frequency f

≈

.0063 – 4

(

)

1

Resultant frequency f =

During the discharge time, the internal clock signal

maximum duty cycle. Charge and discharge times are

determined by the formulae:

LAB

SEME

IP1844A SERIES

IP1845A SERIES

Prelim. 2/95

Open–Loop Laboratory Test Fixture

APPLICATIONS INFORMATION

High peak current associated with capacitive loads necessitate careful grounding techniques. Timing and bypass capacitors should

be connected close to pin 5 in a single point ground. The transistor and 5K potentiometer are used to sample the oscillator wave

form and apply an adjustable ramp to pin 3.

0.1

µF

1k

Ω

1kW

1k

Ω

ERROR AMP

ADJUST

4.7k

Ω

5k

Ω

ADJUST

4.7k

Ω

100k

Ω

2N2222

I

SENSE

R

T

C

T

0.1

µF

OUTPUT

GROUND

1

2

45

7

8

36

I

SENSE

O/P

GND

COMP

R

Oscillator Waveforms and Maximum Duty Cycle

8

4

5

GND

R

T

C

T

REF

V

R

PIN4

V

(V

for 14 pin D package)

PIN7

INTERNAL CLOCK

INTERNAL CLOCK

OUTPUT – Max. Duty Cycle

PIN6

V

(V

for 14 pin D package)

PIN10

PIN4

V

(V

for 14 pin D package)

PIN7

OUTPUT – Max. Duty Cycle

PIN6

V

(V

for 14 pin D package)

PIN10

LARGE C

T

SMALL R

T

LARGE R

T

SMALL C

T