4

Package Pin Description

PACKAGE PIN #

PIN SYMBOL

FUNCTION

Typical Performance Characteristics

10k

30k

50k

100k

300k

500k

1.0M

4.0

6.0

8.0

10

12

14

16

15V

10k

30k

50k

100k

300k

500k

1.0M

38

40

42

44

46

48

50

Max. Output Duty Cycle vs. Oscillator Frequency

Timing Resistor vs. Oscillator Frequency

10k

100k

1.0k

10k

100k

1.0M

10M

f, FREQUENCY (Hz)

-20

0

20

40

60

80

100

GAIN

PHASE

180

150

120

90

60

30

0

0

1.0

2.0

3.0

4.0

5.0

7.0

ERROR AMP OUTPUT VOLTAGE (V)

0

0.2

0.4

0.6

0.8

1.0

1.2

6.0

Current Sense Input Threshold

vs. Error Amp Output Voltage

Error Amp Open-Loop Gain & Phase vs. Frequency

16 Lead SO Wide

1

SYNC

A positive going pulse applied to this input will synchronize the

oscillator. A DC voltage within the range of 2.4V to 5.5V will

inhibit the oscillator.

frequency.

Its value must be between 4.0kΩ and 16kΩ.

1

The inverting input of error amplifier 1. Normally it is connect-

ed to the switching power supply output.

5

The output of error amplifier 1, for loop compensation.

6

Output 1 pulse by pulse current limit.

1

Drives the power switch at output 1.

8

Gnd

Logic ground

9

Pwr Gnd

Power ground. Power device return is connected to this pin.

10

2

Drives the power switch at output 2.

11

Output 2 pulse by pulse current limit.

12

Output of error amplifier 2, for loop compensation.

13

2

Inverting input of error amplifier 2. Normally it is connected to

the switching power supply output.

14

15

5.0V reference output. It can source current in excess of 30mA.

16

The positive supply of the IC. The minimum operating voltage

after start-up is 8.8V.