BCP-15-15-D24 ETC1 [List of Unclassifed Manufacturers], BCP-15-15-D24 Datasheet - Page 6

• Manufacturer Part Number: BCP-15-15-D24
• Description: Dual Output Mixed Voltage, BCP Models
• Manufacturer: ETC1 [List of Unclassifed Manufacturers]

Output Trimming
Both the 5V and 3.3V outputs of the BCP Series can be independently
trimmed via a trimpot (Figure 3A) or a single fi xed resistor as shown (Figures
3B & 3C). The trimpot can be used to determine the value of a single fi xed
resistor. A single fi xed resistor can increase or decrease the output voltage
depending on its connection. Fixed resistors should be metal-fi lm types with
absolute TCR’s less than 100ppm/°C to ensure stability.
A resistor connected from the Trim Pin (pin 5 for 5V trim, pin 8 for 3.3V trim)
to the appropriate Return (pin 6 for 5V trim, pin 9 for 3.3V trim) will increase
the output voltage.
A single resistor connected from the Trim Pin (pin 5 for 5V trim, pin 8 for
3.3V trim) to its appropriate +Output (pin 7 for 5V trim, pin 10 for 3.3V trim)
will decrease the output voltage.
Figure 3C. Decrease Output Voltage Trim Connections Using a Fixed Resistor
Figure 3B. Increase Output Voltage Trim Connections Using a Fixed Resistor
XCP Series
1
4
1
4
1
4
–INPUT
+INPUT
Figure 3A. Trim Connections Using a Trimpot
–INPUT
+INPUT
–INPUT
+INPUT
+3.3V OUTPUT
+3.3V OUTPUT
+3.3V OUTPUT
3.3V RETURN
3.3V RETURN
3.3V RETURN
+5V OUTPUT
+5V OUTPUT
+5V OUTPUT
5V RETURN
5V RETURN
5V RETURN
3.3V TRIM
3.3V TRIM
3.3V TRIM
5V TRIM
5V TRIM
5V TRIM
10
8
9
7
5
6
10
10
8
9
7
5
6
8
9
7
5
6
TURNS
TURNS
DOWN
DOWN
20kΩ
20kΩ
+3.3V
TRIM
TRIM
+3.3V
TRIM
TRIM
5-22
5-22
+5V
+5V
UP
UP
7 5 W , D U A L O U T P U T , M I X E D - V O L T A G E D C / D C C O N V E R T E R S
+3.3V
LOAD
LOAD
+3.3V
LOAD
LOAD
+3.3V
LOAD
LOAD
+5V
+5V
+5V
6
The following equations mathematically depict:
V
Case Connection
BCP DC/DC's do not have their metal baseplate connected to one of the input
pins. The "uncommitted" baseplate is connected to pin 2 which, depending
upon your system confi guration, should be connected to either +Input (pin 4),
–Input (pin 1), Output Returns (pins 6 & 9), or earth ground.
V
Table 1 shows the typical fi xed Trim Resistor values for output voltage
changes of 0 through 10%. Trim adjustment greater than 10% can have an
adverse affect on the converter’s performance and is not recommended.
O
Table 1. Percentage of Output Voltage Change vs Trim Resistor Value (Ohms)
O
V
= 1.25
O
= 1.23
10%
to tolerances of resistor values and factory-adjusted output accuracy.
0%
1%
2%
3%
4%
5%
6%
7%
8%
9%
= 5.0 +
Output Voltage for a given Trim Resistor
Trim Resistor for a given Output Voltage
Note: Resistor values are in kΩ. Accuracy of adjustment is subject
V
O
= 3.30 +
0.38 +
1.23 +
0.30R
Trim Down
47.81k
22.32k
13.82k
5.320k
9.57k
7.02k
4.10k
3.19k
2.48k
1.92k
3.3V
R
R
T
R
–
T
DOWN
T
UP
T
DOWN
1.14
1
UP
(kΩ) + 1.5
2.07
(kΩ) + 2.37
(kΩ) + 4.99
(kΩ)+ 2.37
1
1
V
1
O
= desired output voltage.
3.3 Volt Trim Down
5 Volt Trim Down
Trim Up
3.3 Volt Trim Up
27.93k
12.78k
5 Volt Trim Up
7.73k
5.21k
3.69k
2.68k
1.96k
1.42k
1.00k
0.66k
+1
3.3V
+1
–
R
R
T
R
DOWN
T
UP
T
DOWN
R
(kΩ) =
(kΩ) =
T
UP
(kΩ) =
(kΩ) =
Trim Down
189.75k
91.06k
58.17k
41.72k
31.85k
25.27k
20.57k
17.05k
14.31k
12.12k
5V
(0.3V
–
(0.8V
V
1.23
1.14
O
O
V
2.07
) – 1.50
1
O
O
– 3.3
1
) – 1
1
–1
1
–2.37
–1.23
–0.38
Trim Up
61.68k
28.34k
17.23k
11.68k
–4.99
8.34k
6.12k
4.53k
3.34k
2.42k
1.68k
5V
–
–2.37
–4.99