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LSO SERIES

28V Input, Single/Dual Output

Output Voltage Adjustment:

Output of LSO singles and duals can be adjusted to be

greater or less the nominal output voltage with an external

resistor. However, the ranges of the output voltages are

limited depending on the model as specified in Table 1 and

Table 2. An approximate value of the resistor can be

determined using the following formula.

For Single Output Model:

For Dual Output Model:

Where:

Power rating of the resistor shall be

≥ 0.125 W. Metal film

resistor with temperature coefficient of

≤ ± 50 ppm and

tolerance of

≤ 1% is recommended. However, the final

selection is dependent on specific design requirements.

A, B, C and D are unique constants depending on every

model as shown in Table 1 for single output models and

Table 2 for dual output models.

Placement of Radj: An external resistor must be added

in order to trim the output voltage of a LSO converter.

The placement of a Radj resistor must be connected as

shown in Fig. 7.

Singles: Radj is placed across Out Adj and

± Sense

pins. For output voltage greater than nominal voltage,

Radj is placed from Out Adj to –Sense. To have output

voltage less than nominal voltage, place Radj across Out

Adj and +Sense.

Duals: Radj is placed across Out Adj and

± Output pins

respectively.

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Fig. 7 - Output Voltage Adjustment

Output voltage

Low range

Output voltage

High range

Constants

3.135 to 3.300

3.300 to 3.465

A

B

C

9550

9550

D

31489

31489

Table 1. LSO2803R3S. Output Voltage Ranges and Constants

Table 2. LSO2805S. Output Voltage Ranges and Constants

Table 3. LSO2815S. Output Voltage Ranges and Constants

Table 4. LSO2805D. Output Voltage Ranges and Constants

Table 5. LSO2815D. Output Voltage Ranges and Constants

Output voltage

Low range

Output voltage

High range

Constants

4.750 to 5.000

5.000 to 5.250

A

B

C

7950

7950

D

39716

39717

Output voltage

Low range

Output voltage

High range

Constants

14.250 to 15.000

15.000 to 15.750

A

B

C

7950

6540

D

39716

39717

Output voltage

Low range

Output voltage

High range

Constants

r4.750 to r5.000

r5.000 to r5.250

A

B

C

6840

6840

D

68344

68344

Output voltage

Low range

Output voltage

High range

Constants

r14.250 to r15.000

r15.000 to r15.750

A

B

C

6260

6260

D

187646

187646

(B 2 V

)

out

A -

*

(C 2 V

)

*

out

D

-

*

*

(B V

)

out

A -

*

(C V

)

D

-