UHE Datasheet, PDF (12/16 Pages) Murata Manufacturing Co., Ltd. – Isolated, High Effi ciency, 1.6" × 2" 2-10 Amp, 12-30 Watt DC/DC Converters

UHE Series
Isolated, High Efficiency, 1.6" × 2"
2-10 Amp, 12-30 Watt DC/DC Converters
Absolute Maximum Ratings
Input Voltage:
Continuous:
D12 Models
D24/Q12 Models
D48/Q48 Models
Transient (100msec):
D12 Models
D24/Q12 Models
D48/Q48 Models
On/Off Control (pin 4) Max. Voltages
Referenced to –Input (pin 2)
No Suffix
"N" Suffix
Input Reverse-Polarity Protection
Output Current
Case Temperature
Storage Temperature
Lead Temperature (soldering, 10 sec.)
23 Volts
42 Volts
81 Volts
25 Volts
50 Volts
100 Volts
+15 Volts
+7 Volts
Current must be <5 Amps. Brief
duration only. Fusing recommended.
Current limited. Devices can
withstand sustained output short
circuits without damage.
+100°C
–55 to +125°C
See soldering specifications
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.
Input Undervoltage Shutdown and Start-Up Threshold
Under normal start-up conditions, devices will not begin to regulate until
the ramping-up input voltage exceeds the Start-Up Threshold Voltage. Once
operating, devices will not turn off until the input voltage drops below the
Undervoltage Shutdown limit. Subsequent re-start will not occur until the input
is brought back up to the Start-Up Threshold. This built in hysteresis prevents
any unstable on/off situations from occurring at a single input voltage.
Start-Up Time
The VIN to VOUT Start-Up Time is the interval of time between the point at which
the ramping input voltage crosses the Start-Up Threshold and the fully loaded
output voltage enters and remains within its specified accuracy band. Actual
measured times will vary with input source impedance, external input/output
capacitance, and load. The UHE Series implements a soft start circuit that limits
the duty cycle of its PWM controller at power up, thereby limiting the input
inrush current.
The On/Off Control to VOUT start-up time assumes the converter has its
nominal input voltage applied but is turned off via the On/Off Control pin. The
specification defines the interval between the point at which the converter is
turned on and the fully loaded output voltage enters and remains within its
specified accuracy band. Similar to the VIN to VOUT start-up, the On/Off Control
to VOUT start-up time is also governed by the internal soft start circuitry and
external load capacitance.
The difference in start up time from VIN to VOUT and from On/Off Control to
VOUT is therefore insignificant.
TECHNICAL NOTES
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 MPS’s UHE 12-30 Watt DC/DC Converters, you should use
slow-blow type fuses, installed in the ungrounded input supply line, with values
no greater than the following.
Model
Output/Input
1.2 VOUT
1.5 VOUT
1.8 VOUT
2.5 VOUT
3.3 VOUT
5 VOUT
12 VOUT
15 VOUT
Fuse Values in Amps
D12 Q12 D24 Q48 D48
3
--
2
--
1
4
--
2
--
1
5
--
2.5
--
1
5
--
2.5
--
1
--
7.5
-
3
1.5
--
5
-
3
2
6
3
3
5
2
6
3
3
5
2
All relevant national and international safety standards and regulations must be
observed by the installer. For system safety agency approvals, the converters
must be installed in compliance with the requirements of the end-use safety
standard, e.g. IEC/EN/UL60950-1.
Input Overvoltage Shutdown
All D12/Q12 and D24 Models of the UHE DC/DC converters are equipped with
Input Overvoltage Protection. Input voltages exceeding the input overvoltage
shutdown specification listed in the Performance/Functional Specifications will
cause the device to shutdown. A built-in hysteresis for all models will not allow
the converter to restart until the input voltage is sufficiently reduced.
All 48VIN models have this overvoltage shutdown function disabled because
of requirements for withstanding brief input surges to 100V for up to 100μsec
without output voltage interruption.
Please contact MPS to have input overvoltage shutdown for D48/Q48
models enabled.
Input Source Impedance
UHE converters must be driven from a low ac-impedance input source. The
DC/DC's performance and stability can be compromised by the use of highly
inductive source impedances. The input circuit shown in Figure 2 is a practical
solution that can be used to minimize the effects of inductance in the input
traces. For optimum performance, components should be mounted close to
the DC/DC converter. If the application has a high source impedance, low VIN
models can benefit of increased external input capacitance.
I/O Filtering, Input Ripple Current, and Output Noise
All models in the UHE 12-30 Watt DC/DC Converters are tested/specified for in-
put reflected ripple current and output noise using the specified external input/
output components/circuits and layout as shown in the following two figures.
External input capacitors (CIN in Figure 2) serve primarily as energy-storage
elements, minimizing line voltage variations caused by transient IR drops
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