UCP-12/4.2-D12 Murata Power Solutions Inc, UCP-12/4.2-D12 Datasheet - Page 5

• Manufacturer Part Number: UCP-12/4.2-D12
• Description: DC/DC Converter
• Manufacturer: Murata Power Solutions Inc
• Series: UCPr

Specifications of UCP-12/4.2-D12

• Dc / Dc Converter O/p Type: Fixed
• No. Of Outputs: 1
• Input Voltage: 10V To 18V
• Power Rating: 50W
• Output Voltage: 12V
• Output Current: 4.2A
• Approval Bodies: EN, UL
• Supply Voltage: 12V
• Product: Isolated
• Output Power: 50 W
• Input Voltage Range: 10 V to 18 V
• Input Voltage (nominal): 12 V
• Number Of Outputs: 1
• Output Voltage (channel 1): 12 V
• Output Current (channel 1): 4.2 A
• Isolation Voltage: 1.5 KV
• Package / Case Size: Half Brick
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Floating Outputs
Since these are isolated DC/DC converters, their outputs are "fl oating."
Designers will usually use the –Output (pin 9) as the ground/return of the
load circuit. You can, however, use the +Output (pin 5) as ground/return to
effectively reverse the output polarity.
Filtering and Noise Reduction
All UCP DC/DC Converters achieve their rated ripple and noise specifi cations
using the external input and output capacitors specifi ed in the Performance/
Functional Specifi cations 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. 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 will
be happy to recommend potential solutions and can discuss the possibility of
our modifying a given device’s internal fi ltering to meet your specifi c require-
ments. Contact our Applications Engineering Group for additional details.
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 UCP DC/DC Converters, you should use slow-
blow type fuses with values no greater than the following.
Start-Up Threshold and Undervoltage Shutdown
Under normal start-up conditions, devices will not begin to regulate until
the ramping-up input voltage exceeds the Start-Up Threshold Voltage (35V
for "D48" models). Once operating, devices will not turn off until the input
voltage drops below the Undervoltage Shutdown/Lockout limit (34V for "D48"
models). Subsequent re-start will not occur until the input is brought back
up to the Start-Up Threshold. This built-in hysteresis obviously avoids any
unstable on/off situations at a single voltage.
Start-Up Time
The V
a ramping input voltage crosses the turn-on threshold point and the fully-
loaded output voltage enters and remains within its specifi ed accuracy band.
Actual measured times will vary with input source impedance, external input
capacitance, and the slew rate and fi nal value of the input voltage as it
appears to the converter.
The On/Off to V
voltage applied but is turned off via the On/Off Control. The specifi cation
defi nes the interval between the time at which the converter is turned on
and the fully loaded output voltage enters and remains within its specifi ed
accuracy band.
T E C H N I C A L
IN
to V
D12 Models
D24 Models
D48 Models
V
OUT
IN
Range
start-up time is the interval between the time at which
OUT
start-up time assumes the converter has its nominal input
N O T E S
Fuse Value
7 Amps
6 Amps
3 Amps
www.murata-ps.com
On/Off Control (Standard)
The On/Off Control pin (pin 3) may be used for remote on/off operation.
As shown in Figure 5, the control pin is referenced to the –Input (pin 1) and
has an internal pull-up resistor (28.7k: 75k: and 100k: respectively for
D12, D24 and D48 models) to the +Input (pin 4). The standard UCP converter
is designed so that it is enabled when the control pin is left open and disabled
when the control pin is pulled low (to less than +0.8V relative to –Input).
When left open, pin 3 is pulled up to approximately 5V on "D24" models and
8V on "D48" models.
Dynamic control of the on/off function is best accomplished with a mechanical
relay or an open-collector/open-drain drive circuit (optically isolated if appro-
priate). The drive circuit should obviously be able to sink approximately 1mA
when activated and withstand more than 10 Volts when deactivated.
Applying an external voltage to pin 3 when no input power is applied to
the converter can cause permanent damage to the converter. The on/off
control function, however, is designed such that the converter can be disabled
(pin 3 pulled low) while input power is ramping up and then "released" once
the input has stabilized. Under these circumstances, it takes approximately
30ms for the output of the fully loaded DC/DC to ramp up and settle to within
rated accuracy.
For UCP converters confi gured with the negative-polarity option on the On/Off
Control pin ("N" suffi x added to part number), operation is exactly opposite
to that described above.
Input Reverse-Polarity Protection
Upon applying a reverse-polarity voltage to the DC/DC converter, an internal
diode will be forward biased and draw 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.
UL/EN Approved "Half-Brick" 40-75 Watt, DC/DC Converters
Technical enquiries email: [e-mail], tel:
Figure 5. Driving the On/Off Control Pin
4
3
1
+INPUT
ON/OFF
CONTROL
–INPUT
MDC_UCP40-75W.B03 Page 5 of 7
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