Delta Electronics S48SA Output Voltage Adjustment TRIM, Rtrim − down = ∆1690Vo% − 73.1ΚΩ, ∆ Vo%

Output Voltage Adjustment (TRIM)

To increase or decrease the output voltage set point, the modules may be connected with an external resistor between the TRIM pin and either the Vo+ or Vo -. The TRIM pin should be left open if this feature is not used.

Figure 15: Circuit configuration for trim-down (decrease output voltage)

If the external resistor is connected between the TRIM and Vo- pins, the output voltage set point decreases. The external resistor value required to obtain a percentage of output voltage change △Vo% is defined as:

Rtrim − down = ∆1690Vo% − 73.1[ΚΩ ]

Ex. When trim-down –10% (5V X 0.9 = 4.5V)

Rtrim − down = 169010 −73.1 = 95.9[ΚΩ ]

Figure 16: Circuit configuration for trim-up (increase output voltage)

If the external resistor is connected between the TRIM and Vo+the output voltage set point increases. The external resistor value required to obtain a percentage output voltage change △Vo% is defined as:

DS_S48SA05006_06022006

Rtrim − up =	69(100 + ∆Vo%) − 1690	− 73.1[ΚΩ]
	∆Vo%

Ex. When trim-up +10% (5V X 1.1 = 5.5V)

Rtrim − up = 69(100 + 10) −1690 − 73.1 = 516.9[ΚΩ] 10

Care should be taken to ensure that the maximum output power of the module remains at or below the maximum rated power.

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