Datasheet

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Input Fusing
Certain applications and/or safety agencies may require fuses at the inputs of
power conversion components. Fuses should also be used when there is the
possibility of sustained input voltage reversal which is not current-limited. For
greatest safety, we recommend a fast blow fuse installed in the ungrounded
input supply line with a value which is approximately twice the maximum line
current, calculated at the lowest input voltage.
The installer must observe all relevant safety standards and regulations. For
safety agency approvals, install the converter in compliance with the end-user
safety standard.
Input Under-Voltage Shutdown and Start-Up Threshold
Under normal start-up conditions, converters will not begin to regulate properly
until the rising input voltage exceeds and remains at the Start-Up Threshold
Voltage (see Specifi cations). Once operating, converters will not turn off until
the input voltage drops below the Under-Voltage Shutdown Limit. Subsequent
restart will not occur until the input voltage rises again above the Start-Up
Threshold. This built-in hysteresis prevents any unstable on/off operation at a
single input voltage.
Users should be aware however of input sources near the Under-Voltage
Shutdown whose voltage decays as input current is consumed (such as capaci-
tor inputs), the converter shuts off and then restarts as the external capacitor
recharges. Such situations could oscillate. To prevent this, make sure the
operating input voltage is well above the UV Shutdown voltage AT ALL TIMES.
Start-Up Delay
Assuming that the output current is set at the rated maximum, the Vin to Vout
Start-Up Time (see Specifi cations) is the time interval between the point when
the rising input voltage crosses the Start-Up Threshold and the fully loaded
regulated output voltage enters and remains within its specifi ed regulation
band. Actual measured times will vary with input source impedance, external
input capacitance, input voltage slew rate and fi nal value of the input voltage
as it appears at the converter.
These converters include a soft start circuit to moderate the duty cycle of the
PWM controller at power up, thereby limiting the input inrush current.
The On/Off Remote Control interval from inception to Vout regulated
assumes that the converter already has its input voltage stabilized above the
Start-Up Threshold before the On command. The interval is measured from the
On command until the output enters and remains within its specifi ed regulation
band. The specifi cation assumes that the output is fully loaded at maximum
rated current.
UEE 150W Series
Isolated, High-Density, Eighth-Brick
DOSA Low Profi le DC-DC Converters
MDC_UEE 150W_Series.A02 Page 30 of 35
TECHNICAL NOTES
THROUGH-HOLE SOLDERING GUIDELINES
Murata Power Solutions recommends the specifi cations below when install-
ing these converters. These specifi cations vary depending on the solder
type. Exceeding these specifi cations may cause damage to the product. Your
production environment may differ; therefore please thoroughly review these
guidelines with your process engineers.
Wave Solder Operations for through-hole mounted products (THMT)
For Sn/Ag/Cu based solders:
Maximum Preheat Temperature 115ºC.
Maximum Pot Temperature 270ºC.
Maximum Solder Dwell Time 7 seconds
For Sn/Pb based solders:
Maximum Preheat Temperature 105ºC.
Maximum Pot Temperature 250ºC.
Maximum Solder Dwell Time 6 seconds
SMT REFLOW SOLDERING GUIDELINES
The surface-mount refl ow solder profi le shown below is suitable for SAC305
type lead-free solders. This graph should be used only as a guideline. Many
other factors infl uence the success of SMT refl ow soldering. Since your pro-
duction environment may differ, please thoroughly review these guidelines with
your process engineers.