ADDC02812DA/ADDC02815DA

REV. A

–9–

OUTPUT VOLTAGE – %

5

4

0

101

105

102

103

104

3

2

1

Figure 19. 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 both

pulled up and down by internal circuitry. Figures 20 and 21

show the typical source and sink capabilities of the status out-

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

effect on status trip point.

5

4

0

0.7

1.4

0.9

1.2

3

2

1

Figure 20. Source Capability of Status Output

1.0

0.8

0

119

4

7

101316

0.6

0.4

0.2

Figure 21. Sink Capability of Status Output

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

regulated 13 V to 15 V dc voltage supply for miscellaneous

system use. The maximum permissible current draw is 5 mA

and the voltage varies with the auxiliary load as shown in Figure

22.

13.75

13.70

13.50

0

6.5

1.63

2.1

3.1

4.1

5.6

13.65

13.60

13.55

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 internally 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 (15 ms max before the con-

verter is fully on). Pin 6 must be kept low for at least 2 milli-

seconds to initiate a full soft start. Shorter off times will result in

a partial soft start. Figure 23 shows the input characteristics of

Pin 6.