VCD40 CUI INC, VCD40 Datasheet - Page 5

• Manufacturer Part Number: VCD40
• Description: Dc-dc Converter
• Manufacturer: CUI INC

PART NUMBER: VCD40 series
TRIM INFORMATION
20050 SW 112
(VCD40-D48-S5) by 5% to 5.25V, R trim-up is calculated as follows:
(VCD40-D48-S5) by 5% to 4.75V, R trim-down is calculated as follows :
For example, to trim-up the output voltage of 5.0V module
For example, to trim-down the output voltage of 5.0V module
Where: R trim-down is the external resistor in Kohm.
Vo,nom is the nominal output voltage.
Vo is the desired output voltage.
R1 ,Rt and Vr are internal to the unit and are defined in Table 1.
The value of R trim-down defined as:
Table 1 - Trim Resistor Values
Table 2 - Trim Resistor Values
Where: R trim-up is the external resistor in Kohm.
Vo,nom is the nominal output voltage.
Vo is the desired output voltage.
R1 ,Rt and Vr are internal to the unit and are defined in Table 1.
1. The value of Rtrim-up defined as:
R
trim
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 and between trim
pin and +Vo for trim-down. The output voltage trim range is ±10%. This is shown in Figures 1 and 2:
R
Vo – Vo,nom = 5.25 – 5.0 = 0.25V
R1 = 2.32 Kohm
Rt = 8.2 Kohm , Vr= 2.5
R
-
Vo,nom – Vo = 5.0 – 4.75 = 0.25 V
R1 = 2.32 Kohm
R t = 8.2 Kohm , Vr=2.5
R
trim
up
trim
trim
VCD40-D24-S3R3
VCD40-D48-S3R3
VCD40-D24-S12
VCD40-D48-S12
VCD40-D24-S15
VCD40-D48-S15
=
Model Number
-
-
-
up
(
VCD40-D24-S5
VCD40-D48-S5
down
down
Vo
Model Number
th
=
R
Ave. Tualatin, Oregon 97062
1
-
=
. 2
=
x
V
32
. 2
R
. 0
Vr
o
,
1
V
32
nom
25
x
x
o
,
2
Output Voltage(V)
x
(
nom
)
5 .
Vo
-
(
. 0
Output Voltage(V)
. 4
-
-
Rt
25
-
3.3V
12V
15V
75
Vo
8
Vr
2 .
5.0
(K
-
)
=
. 2
Ω
-
15
) 5
)
Rt
(K
-
R1 (Kohm)
(K
8
Ω
2 .
R1 (Kohm)
2.74
)
6.8
8.06
Ω
=
2.32
)
12
.
68
phone
phone [phone] fax
R2 (Kohm)
(K
Rt (Kohm)
1.8
2.4
2.4
Ω
DESCRIPTION: DC/DC converter
8.2
2. The output Voltage 3.3V,12V and 15V value of Rtrim are
defined as below:
)
Where: R trim-up is the external resistor in Kohm.
Vo,nom is the nominal output voltage.
Vo is the desired output voltage.
R1, R2, R3, Rt and Vr are internal to the unit and are defined in Table 2.
R
trim
R3 (Kohm)
R
-
0.27
2.32
trim
3.9
down
Figure 1. Trim-up Voltage Setup
Figure 2. Trim-down Voltage Setup
2.5
Vr
-
=
up
R
+Vin
-Vin
=
+Vin
-Vin
1
(
Rt (Kohm)
x
Vr
(
(
Vo
9.1
22
27
fax [phone]
(
x
V
R
o
-
,
1
nom
V
Vr
x
o
+Sense
,
(
+Sense
-Sense
-
-Sense
nom
+Vout
R
+Vout
x
-Vout
-Vout
Vo
Trim
Trim
2
R
)
1.24
2.5
2.5
Vr
x
+
1
)
x
R
R
R
) 3
2
2
)
-
R adj,down
-
R adj,up
) 1
Rt
R-Load
R-Load
-
(K
Rt
Ω
rev.
page
date
(K
)
Ω
)
10/2007
5 of 5