DNT12S0A0S03NFA_13 Datasheet, PDF (8/12 Pages) Delta Electronics, Inc. – Delphi series DNT12 Non-Isolated Point of Load DC/DC Power Modules: 8.3~14Vin

FEATURES DESCRIPTIONS (CON.)
For example, to program the output voltage of the DNT
module to 3.3Vdc, Rtrim is calculated as follows:
Rtrim
:=

10500
2.5475
−
1000^ ⋅Ω

Rtrim = 3.122 kΩ
DNT can also be programmed by applying a voltage
between the TRIM and GND pins (Figure 25). The
following equation can be used to determine the value of
Vtrim needed for a desired output voltage Vo:
Vtrim := 0.7 − _(Vo − 0.7525) ⋅0.0667_
Vtrim is the external voltage in V
Vo is the desired output voltage
For example, to program the output voltage of a DNT
module to 3.3 Vdc, Vtrim is calculated as follows
Vtrim := 0.7 − (2.5475⋅0.0667)
Vtrim = 0.530V
Figure 24: Circuit configuration for programming output voltage
using an external resistor
Figure 25: Circuit Configuration for programming output voltage
using external voltage source
Table 1 provides Rtrim values required for some common
output voltages, while Table 2 provides value of external
voltage source, Vtrim, for the same common output
voltages. By using a 1% tolerance trim resistor, set point
tolerance of ±2% can be achieved as specified in the
electrical specification.
DS_DNT12SIP03_03292013
Table 1
VO (V)
0.7525
1.2
1.5
1.8
2.5
3.3
5.0
Rtrim (KΩ)
Open
22.464
13.047
9.024
5.009
3.122
1.472
Table 2
VO (V)
0.7525
1.2
1.5
1.8
2.5
3.3
5.0
Vtrim (V)
Open
0.670
0.650
0.630
0.583
0.530
0.4167
The amount of power delivered by the module is the
voltage at the output terminals multiplied by the output
current. When using the trim feature, the output voltage
of the module can be increased, which at the same
output current would increase the power output of the
module. Care should be taken to ensure that the
maximum output power of the module must not exceed
the maximum rated power (Vo.set x Io.max ≤ P max).
Voltage Margining
Output voltage margining can be implemented in the
DNT modules by connecting a resistor, Rmargin-up, from
the Trim pin to the ground pin for margining-up the
output voltage and by connecting a resistor, R , margin-down
from the Trim pin to the output pin for margining-down.
Figure 26 shows the circuit configuration for output
voltage margining. If unused, leave the trim pin
unconnected. A calculation tool is available from the
evaluation procedure, which computes the values of
Rmargin-up and Rmargin-down for a specific output voltage and
margin percentage.
Vin
Vo
On/Off Trim
Rtrim
GND
Rmargin-down
Q1
Rmargin-up
Q2
Figure 26: Circuit configuration for output voltage margining
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