Delta Electronics DNM - Manual (Page 8)

8
8.2.4 Output Voltage Set-point Programming
(1) Output Voltage Set-Point Adjustment by external resistor
Output Voltage Set-point Programming can be carried out by using the external program
resistor connect between TRIM pin to ground to set output voltage set-point from 0.75Vdc to
5Vdc, the location can refer to the Evaluation Board Schematic (please refer to the data sheet
for more the detailed specification). These test functions are divided into two types,
Rset of DNM04S and DNL04S series can be calculated by using the following equation:




−
−
= 5110
7525 . 0
21070
Vo
R
set
Ω
For example, to program the output voltage of the DNL04S module to 1.8Vdc, below is the
calculation of Rtrim:
15004 5110
7525 . 0 8 . 1
21070
=




−
−
=
set
R Ω
The table 1 provides the Rset value required for some standard output and the location on the
Evaluation board is R33.
Table 1.
Vo,set Rset (k Ω ) R33 Recommend Value, R//R
0.7525 Open Open
1.2 41.973 44.2k//825k
1.5 23.077 23.7k//825k
1.8 15.004 15.4k//590k
2.5
6.947 7.15k//243k
3.3 3.160 3.16k//Open
Rset of the DNM12S and DNL12S series can be calculated by using the following equation:




−
−
= 1000
7525 . 0
10500
Vo
R
set
Ω
For example, to program the output voltage of the DNL12S module to 3.3Vdc, below is the
calculation of Rset:
3122 1000
7525 . 0 3 . 3
10500
=




−
−
=
set
R Ω
The table 2 provides the Rset value required for some standard output. The location on the
Evaluation board is R33.