LP38798

SNOSCT6B – MARCH 2013 – REVISED DECEMBER 2014

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7.5 Programming

7.5.1 Programming the Output Voltage

Current sourced from the SET pin, through R1 and R2, must be kept to less than 100 µA. The minimum allowed

value for R2 is 12.9 k

Ω.

(4)

(5)

(6)

The values for R1 and R2 may be adjusted as needed to achieve the desired output voltage as long as the value

for R2 is no less than 12.9 k

Ω. The maximum recommended value for R2 is 100 kΩ.

Equation 7 is used to determine the output voltage:

(7)

Alternately, Equation 8 can be used to determine the appropriate R1 value for a given R2 value:

(8)

1.200V. This is not a definitive list, as other combinations exist that will provide similar, possibly better,

performance.

Table 1. Typical R1 and R2 Values for Assorted Output Voltages

R1

R2

1.5 V

4.22 k

Ω

16.9 k

Ω

1.5 V

1.8 V

10.5 k

Ω

21.0 k

Ω

1.8 V

2.0 V

10.0 k

Ω

15.0 k

Ω

2.0 V

2.5 V

16.2 k

Ω

15.0 k

Ω

2.496 V

3.0 V

21.0 k

Ω

14.0 k

Ω

3.0 V

3.3 V

23.2 k

Ω

13.3 k

Ω

3.293 V

5.0 V

47.5 k

Ω

15.0 k

Ω

5.0 V

16

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