Embedded Power for

Business-Critical Continuity

Technical Reference Note

Rev. 12.07.09

LGA C Series

6 of 28

Setting Output Voltage (cont'd)

ThetrimequationforthepotentiometerconfigurationshowinFigure7.

0.591

Vout=

(Rtrim2 + Rpot)Rtrim1 *

(2Rtrim2 + 2Rpot + Rtrim1Rtrim2 + Rtrim1Rpot + 2Rtrim1)

WhereVoutisthedesiredoutputvoltage,Rtrim1(kΩ)andRtrim2(kΩ)aretheresistorsinFigure7and

Rpotistheresistanceofthepotentiometer.

Undervoltage Lockout

TheseEPD'shavebuilt-inundervoltagelockouttoensurereliableoutputpower.Thelockoutpreventsthe

unitfromoperatingwhentheinputvoltageistoolow.TheUVLOfortheLGA03/06/10Ccanbeadjusted

withthefollowingequation:

Ruvlo(kΩ)=

14.8 * 6.81

6.81 * Vturn_on - 18.16

TheUVLOfortheLGA20Ccanbeadjustedwiththefollowingequation:

Ruvlo(kΩ)=

30.1 * 4.22

8.577 * Vturn_on - 34.32

Applications(cont'd)

Figure 7 - Output Voltage Trim -

withPotentiometer

Figure 8 - Typical Trim Curves

Remote

ON/OFF

Vout

LGA C Series

Trim

Vin

-Sense

Rtrim1

Rtrim2

Rpot

10

100

1000

10000

100000

1000000

0

1

2

3

4

5

DESIRED OUTPUT VOLTAGE SETPOINT (V)