ADDC02828SA

REV. 0

–8–

OUTPUT VOLTAGE – %

5

4

0

101

105

102

103

104

3

2

1

Figure 17. External Resistor Value for Increasing Output

Voltage

With regard to the range that the output voltage can be adjusted

by the user, there are two concerns. As the output voltage is

raised it may become difficult to maintain regulation at full

power and low input voltage. As the output voltage is lowered,

it may become difficult to maintain regulation at minimum

power and high input line.

Pin 4 (STATUS)

Pin 4 is active high referenced to –SENSE (Pin 1), indicating

that the output voltage is typically within

± 5%. The pin is

pulled both up and down by internal circuitry. Figures 18 and

19 show the typical source and sink capabilities of the status

output. Refer to the paragraphs describing Pin 3 (ADJUST) for

effect on status trip point.

5

4

0.2

0.4

0.6

0.8

1

1.2

1.4

3

2

0

1

Figure 18. Source Capability of Status Output

1.0

0.8

0.0

1.0

19.0

4.0

7.0

10.0

13.0

16.0

0.6

0.4

0.2

Figure 19. Sink Capability of Status Output

Pin 5 is referenced to the input return and provides a semi-

regulated 11 V to 14 V dc voltage supply for miscellaneous

system use. The maximum permissible current draw is 5 mA

and the voltage varies with the output load of the converter as

shown in Figure 20.

CONVERTER OUTPUT CURRENT – Amps

14

01

2

3

4

13

12

10

11

Pin 6 (INHIBIT)

Pin 6 is active low and is referenced to the input return of the

converter. Connecting it to the input return will turn the

converter off. For normal operation, the inhibit pin is inter-

nally pulled up to 12 V. Use of an open collector circuit is

recommended.

When Pin 6 is disconnected from input return, the converter

will restart in the soft-start mode. Pin 6 must be kept low for at

least 2 milliseconds to initiate a full soft start. Shorter off times

will result in a partial soft start. Figure 21 shows the input

characteristics of Pin 6.

OBSOLETE