trim pin and +Vo for trim-down. The output voltage trim range is
10%. This is shown:
TEST SET-UP
The basic test set-up to measure parameters such as efficiency and
load regulation is shown below. When testing the modules under any
transient conditions please ensure that the transient response of the
source is sufficient to power the equipment under test.
We can calculate:
•
•
Efficiency
Load regulation and line regulation.
The value of efficiency is defined as:
Vo ×Io
η =
×100%
V ×Iin
in
Where:
Vo is output voltage,
Io is output current,
Vin is input voltage,
Iin is input current.
Trim-up Voltage Setup
The value of load regulation is defined as:
VFL − VNL
VNL
Load.reg =
×100%
Where:
VFL is the output voltage at full load
VNL is the output voltage at no load
The value of line regulation is defined as:
VHL − VLL
Line.reg =
×100%
VLL
Trim-down Voltage Setup
Where:
VHL is the output voltage of maximum input voltage at full load.
VLL is the output voltage of minimum input voltage at full load.
Vout (V)
5V
A
2.32
9.1
B
0
C
D
4.75
39
+Vo
A
4.75
5.8
6.1
6.4
6.5
6.6
+Vin
+Sense
12V
15V
24V
28V
48V
0.4
A
+
-
12
0.42
0.44
0.44
0.46
56
Vin
C1
Trim
V
V
Load
20
100
120
240
-Sense
-Vo
23.7
43.2
-Vin
QBR Series Test Setup
Trim Resistor Values
Output Voltage Adjustment
Output may be externally trimmed ( 10%) with a fixed resistor or an
external trim pot as shown (optional). Model specific formulas for
calculating trim resistors are available upon request as a separate
document.
The value of Rtrim_up defined as:
A ×
(
2.5 − B
)
− C
Rtrim_up
=
(
KΩ
)
Vo − Vo_nom
Where:
+SENSE(8)
+SENSE(8)
Rtrim_up is the external resistor in KΩ.
o_nom is the nominal output voltage.
TRIM DOWN
V
10K Ω
TRIMPOT
Vo is the desired output voltage.
A, B and C are internal components.
TRIM(7)
TRIM(7)
TRIM UP
-SENSE(6)
-SENSE(6)
For example, to trim-up the output voltage of 12V module
(QBR101S12-5) by 5% to 12.6V, Rtrim_up is calculated as follows:
In order to trim the voltage up or down, one needs to connect the trim
resistor either between the trim pin and -Vo for trim-up or between
September 18 2017 B.03
Page 10 of 15
DATEL [ DATEL, Inc. ]
