uwr-3.3 C&D Technologies., uwr-3.3 Datasheet - Page 4

• Manufacturer Part Number: uwr-3.3
• Description: Single Output, High-density, 3.3vout And 5 Vout, 26-40 Watt, Dc/dc Converters
• Manufacturer: C&D Technologies.

Floating Outputs
with respect to the input. Designers will normally use the –Output (pin 7)
as the ground/return of the load circuit. You can, however, use the +Output
(pin 6) as ground/return to effectively reverse the output polarity.
Minimum Output Loading Requirements
UWR 26-40 Watt converters employ a synchronous-rectifier design topology.
All models regulate within spec and are stable under no-load conditions.
filtering and Noise Reduction
All UWR 26-40 Watt DC/DC Converters achieve their rated ripple and
noise specifications using the external output capacitor specified in the
Performance/Functional Specifications table. In critical applications, input/
output noise may be further reduced by installing additional external I/O caps.
Input capacitors should be selected for bulk capacitance, low ESR and
high rms-ripple-current ratings. Input capacitors serve as energy-storage
devices to minimize variations in line voltage caused by transient IR drops in
PCB conductors from backplane to the DC/DC. Output capacitors should be
selected for low ESR and appropriate frequency response. All caps should
have appropriate voltage ratings and be mounted as close to the converters
as possible.
The most effective combination of external I/O capacitors will be a function
of your particular load and layout conditions. Our Applications Engineers can
recommend potential solutions. Contact our Applications Engineering Group
for additional details.
Input Voltage:
On/Off Control (pin 4) Max. Voltages
Input Reverse-Polarity Protection
Output Current
Case Temperature
Storage Temperature
Lead Temperature (soldering, 10 sec.)
These are stress ratings. Exposure of devices to any of these conditions may adversely
affect long-term reliability. Proper operation under conditions other than those listed in the
Performance/Functional Specifications Table is not implied.
T E C h N I C A L
Since these are isolated DC/DC converters, their outputs are "floating,"
Continuous:
Transient (100msec):
Referenced to –Input (pin 2)
D12A Models
D24A Models
D48A Models
D12A Models
D24A Models
D48A Models
No Suffix
"N" Suffix
N O T E S
Absolute Maximum Ratings
18 Volts
36 Volts
75 Volts
25 Volts
50 Volts
100 Volts
+V
+V
Current must be <5 Amps. Brief
duration only. Fusing recommended.
Current limited. Devices can
withstand sustained output short
circuits without damage.
+100°C
–40 to +120°C
+300°C
IN
IN
www.murata-ps.com
Single Output, High-Density, 3.3V
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 sustained, non-current-limited, input-voltage polarity
reversals exists. For DATEL A-Series UWR 26-40 Watt DC/DC Converters,
you should use slow-blow type fuses with values no greater than the following.
Start-Up and Undervoltage Shutdown
Under normal start-up conditions, UWR 26-40W converters will not begin
to regulate properly until the ramping input voltage exceeds the Start-Up
Threshold. Once operating, devices will turn off when the applied voltage
droops below the Undervoltage Shutdown point. Devices will remain off as
long as the undervoltage condition continues. Units will automatically restart
when the applied voltage is brought back above the Start-Up Threshold.. The
hysteris is built into the function avoids an indeterminate on/off condition at
a single input voltage . See Performance/Functional Specifications table for
actual limits.
On/Off Control
to operate with either polarity. Positive-polarity devices (standard, no
part-number suffix) are enabled when pin 4 is left open or is pulled high
(+13V to V
polarity devices are disabled when pin 4 is pulled low (0-0.8V with respect
to –Input). Negative-polarity devices are off when pin 4 open or pulled high
(3.3V to +V
The input-side, remote On/Off Control function (pin 4) can be ordered
UWR-3.3/8-D12
UWR-3.3/9-D24
UWR-3.3/9-D48
UWR-5/7-D12
UWR-5/8-D24
UWR-5/8-D48
IN
IN
figure 2. Driving the Positive Polarity On/Off Control Pin
applied with respect to –Input, pin 2, (see Figure 2). Positive-
), and on when pin 4 is pulled low (0-0.8V). See Figure 3.
Model
1
4
2
Technical enquiries email: [e-mail], tel:
OUT
+INPUT
ON/OFF
CONTROL
–INPUT
and 5 V
UWR 26-40W Series
OUT
fuse Value
, 26-40 Watt, DC/DC Converters
7 Amps
4 Amps
2 Amps
8 Amps
5 Amps
3 Amps
MDC_UWR26-40W_B02 Page 4 of 10
13V CIRCUIT
5V CIRCUIT
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