Application Notes

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PT6620 Series

Adjusting the Output Voltage of the

PT6620 6 A, 12-V Bus Converter Series

The output voltage of the Power Trends PT6620 Series

ISRs may be adjusted higher or lower than the factory

trimmed pre-set voltage with the addition of a single

external resistor. Table 1 accordingly gives the allowable

adjustment range for each model in the series as

Adjust Up:

An increase in the output voltage is obtained

GND (pins 7-10).

Adjust Down:

Refer to Figure 1 and Table 2 for both the placement and value

Notes:

location. Place the resistor as close to the ISR as possible.

3. If the Remote Sense feature is being used, connecting the

(pin 1) can benefit load regulation.

4. The minimum input voltage required by the part is

Figure 1

C

in

+

C

out

+

(R1)

Adj Down

R2

Adjust

Up

Vo

COM

COM

Vin

PT6620

11,12,13

14

7,8,9,10

4,5,6

Vin

V o

GND

Vo(adj)

STBY

3

Vsense

1

L

O

A

D

also be calculated using the following formulae.

=

=

Table 1

PT6620 ADJUSTMENT AND FORMULA PARAMETERS

Series Pt #

PT6622

PT6623

PT6621

PT6624

PT6625

PT6626

Vo (nom)

1.5 V

2.5 V

3.3 V

3.6 V

5 V

9.0 V

Va (min)

1.4 V

1.9 V

2.3 V

2.5 V

2.9 V

5.2 V

Va (max)

2.7 V

3.7 V

4.5 V

4.8 V

6.5 V

10 V

Ro (k

Ω

Ω

Ω

Ω

Ω)

4.99

10.0

12.1

12.1

16.2

12.1

Rs (k

Ω

Ω

Ω

Ω

Ω)

2.49

4.99

12.1

12.1

12.1

12.1