BWR-5/6-3.3/7-D12 Murata Power Solutions Inc, BWR-5/6-3.3/7-D12 Datasheet - Page 6

• Manufacturer Part Number: BWR-5/6-3.3/7-D12
• Description: DC/DC Power Supply Dual-OUT 5V/3.3V 6A/7A 33W 7-Pin Case C4
• Manufacturer: Murata Power Solutions Inc
• Type: Step Downr

Specifications of BWR-5/6-3.3/7-D12

• Package: 7Case C4
• Output Current: 6|7 A
• Output Voltage: 5|3.3 V
• Input Voltage: 12 V
• Number Of Outputs: 2
• Output Power: 33 W

Input Reverse-Polarity Protection
Upon applying a reverse-polarity voltage to the DC/DC converter, an internal
diode will be forward biased, drawing excessive current from the power
source. Therefore, it is required that the input current be limited be either an
appropriately rated input fuse or a current limited power source.
Input Fusing
Certain applications and/or safety agencies may require the installation of
fuses at the inputs of power conversion components. Fuses should also be
used if the possibility of a sustained, non-current-limited, input-voltage polarity
reversal exists. For DATEL BWR 33 Watt Series Converters, slow blow fuses are
recommended with values no greater than the following.
It is recommended that fuses be installed in the +Input line.
Trimming Output Voltages
These BWR converters have a trim capability (pin 8) that allow users to adjust
the output voltages ±5%. A trim adjustment will cause an equal percentage of
change in both outputs. Adjustments to the output voltages can be accom-
plished via a trim pot Figure 3 or a single fixed resistor as shown in Figures 4
and 5. A single fixed resistor can increase or decrease the output voltage
depending on its connection. Fixed resistors should be metal-film types with
absolute TCR’s less than 100ppm/°C to minimize sensitivity to changes in
temperature.
see Figure 4, will decrease the output voltages. A resistor connected from the
Trim Pin (pin 8) to Output Return (pin 6) will increase the output voltages.
1 through 5%.
converter’s performance and is not recommended.
A single resistor connected from the Trim Pin (pin 8) the +3.3V Output (pin 7),
Table 1 shows the typical Trim Resistor values for output voltage changes of
Trim adjustment greater than 5% can have an adverse affect on the
Table 1. Percentage of Output Voltage Change vs Trim Resistor Value (Ohms)
"D12" Models
"D24" Models
"D48" Models
V
IN
Range
0%
1%
2%
3%
4%
5%
Fuse Value
6 Amps
4 Amps
2 Amps
Trim Down
201.5k
92.5k
56.1k
38.0k
27.1k
Trim Up
123.7k
55.3k
32.6k
21.2k
14.3k
www.murata-ps.com
Figure 5. Increase Output Voltage Trim Connections Using A Fixed Resistor
Figure 4. Decrease Output Voltage Trim Connections Using A Fixed Resistor
resistor values, reference accuracy and factory-adjusted output
2
4
1
1
2
4
1
2
4
Note: Accuracy of adjustment is subject to the tolerances of
Dual Output BWR Models
+INPUT
–INPUT
ON/OFF
CONTROL
+INPUT
–INPUT
ON/OFF
CONTROL
+INPUT
–INPUT
ON/OFF
CONTROL
Figure 3. Trim Connections using a Trimpot
Technical enquiries email: [e-mail], tel:
accuracy. V
R
T
DOWN
R
T
(k ) =
+3.3V OUTPUT
UP
+3.3V OUTPUT
+3.3V OUTPUT
Mixed Voltage, 5V
+5V OUTPUT
+5V OUTPUT
+5V OUTPUT
(k ) =
O
OUTPUT
RETURN
OUTPUT
RETURN
OUTPUT
RETURN
(
= desired output voltage.
Trim Down
TRIM
Trim Up
TRIM
TRIM
3.55(V
(
MMDC_BWR 33W Models.A02
V
3.3 – V
4.51
O
33 Watt DC/DC Converters
– 3.3
O
7
7
7
5
6
8
5
8
5
8
6
6
– 1.273)
)
O
R TRIM
DOWN
– 13
+3.3V LOAD
+5V LOAD
)
20k
5-22
Turns
R TRIM
–13
UP
AND
+5V LOAD
+3.3V LOAD
+3.3V LOAD
+5V LOAD
3.3V, 2” x 2”
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