Datasheet

DS_DNT12SMD03_07182012
8
FEATURE DESCRIPTIONS (CON.)
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.
Table 1
VO (V)
Rtrim (KΩ)
0.7525
Open
1.2
22.464
1.5
13.047
1.8
9.024
2.5
5.009
3.3
3.122
5.0
1.472
5.5
1.210
Table 2
VO (V)
Vtrim (V)
0.7525
Open
1.2
0.670
1.5
0.650
1.8
0.630
2.5
0.583
3.3
0.530
5.0
0.4167
5.5
0.3840
FEATURE DESCRIPTIONS (CON.)
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, Rmargin-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.
Vo
On/Off
Vin
GND
Trim
Q2
Q1
Rmargin-up
Rmargin-down
Rtrim
Figure 26: Circuit configuration for output voltage margining
PS1
PS1
PS2
PS2
+△V