HEN-1.5/25-D12M-C Murata Power Solutions Inc, HEN-1.5/25-D12M-C Datasheet - Page 4

• Manufacturer Part Number: HEN-1.5/25-D12M-C
• Description: DC/DC Converters & Regulators 37.5W 12V-1.5V 25A Eighth-Brick
• Manufacturer: Murata Power Solutions Inc
• Series: HENr

Specifications of HEN-1.5/25-D12M-C

• Output Power: 38 W
• Input Voltage Range: 10.2 V to 13.8 V
• Number Of Outputs: 1
• Output Voltage (channel 1): 1.5 V
• Output Current (channel 1): 25 A
• Package / Case Size: Eighth Brick
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: HEN-1.5/25-D12M-C

External input capacitors serve primarily as energy-storage devices. They
minimize high-frequency variations in input voltage (usually caused by IR
drops in conductors leading to the DC/DC) as the switching converter draws
pulses of current. Input capacitors should be selected for bulk capacitance
(at appropriate frequencies), low ESR, and high rms-ripple-current ratings.
The switching nature of modern DC/DC's requires that the dc input voltage
source have low ac impedance and the frequencies of interest. Highly
inductive source impedances can greatly affect system stability. Your spe-
cific system configuration may necessitate additional considerations.
Output ripple/noise (also referred to as periodic and random deviations
or PARD) may be reduced below specified limits with the installation of
additional external output capacitors. Output capacitors function as true
filter elements and should be selected for bulk capacitance, low ESR, and
appropriate frequency response. Any scope measurements of PARD should
be made directly at the DC/DC output pins with scope probe ground less
than 0.5" in length.
All external capacitors should have appropriate voltage ratings and be
located as close to the converters as possible. Temperature variations for all
relevant parameters should be taken into consideration.
The most effective combination of external I/O capacitors will be a function
of your line voltage and source impedance, as well as your particular load
and layout conditions. Our Applications Engineers can recommend potential
solutions and discuss the possibility of our modifying a given device’s
internal filtering to meet your specific requirements. Contact our Applications
Engineering Group for additional details.
Input Fusing
Most applications and or safety agencies require the installation of fuses
at the inputs of power conversion components. HEN D12 Series DC/DC
converters are not internally fused. Therefore, input fusing is mandatory for
safety reasons, and safety agencies require a time delay fuse with a value
no greater than 40Amps, which should be installed within the ungrounded
input path to the converter.
As a rule of thumb however, we recommend to use a normal-blow or slow-
blow fuse with a typical value of about twice the maximum input current,
calculated at low line with the converters minimum efficiency.
Safety Considerations
HEN D12's are non-isolated DC/DC converters. In general, all DC/DC's
must be installed, including considerations for I/O voltages and spacing/
separation requirements, in compliance with relevant safety-agency speci-
fications (usually UL/IEC/EN60950).
In particular, for a non-isolated converter's output voltage to meet SELV
(safety extra low voltage) requirements, its input must be SELV compliant.
If the output needs to be ELV (extra low voltage), the input must be ELV.
Start-Up Time
The V
ramping input voltage crosses the lower limit of the specified input voltage
range (10.2 Volts) 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 capacitance, and the slew rate and
final value of the input voltage as it appears to the converter.
IN
to V
OUT
Start-Up Time is the interval between the time at which a
www.murata-ps.com
The On/Off to V
the On/Off Control with the nominal input voltage already applied to the
converter. The specification defines the interval between the time at which
the converter is turned on and the fully loaded output voltage enters and
remains within its specified accuracy band. See Typical Performance
Curves.
Remote Sense
HEN D12 Series DC/DC converters offer an output sense function on pin 10.
The sense function enables point-of-use regulation for overcoming moder-
ate IR drops in conductors and/or cabling. Since these are non-isolated
devices whose inputs and outputs usually share the same ground plane,
sense is provided only for the +Output.
The remote sense line is part of the feedback control loop regulating the
DC/DC converter’s output. The sense line carries very little current and
consequently requires a minimal cross-sectional-area conductor. As such,
it is not a low-impedance point and must be treated with care in layout and
cabling. Sense lines should be run adjacent to signals (preferably ground),
and in cable and/or discrete-wiring applications, twisted-pair or similar
techniques should be used. To prevent high frequency voltage differences
between V
close to the converter.
The sense function is capable of compensating for voltage drops between
the +Output and +Sense pins that do not exceed 10% of V
Power derating (output current limiting) is based upon maximum output
current and voltage at the converter's output pins. Use of trim and sense
functions can cause the output voltage to increase, thereby increasing
output power beyond the converter's specified rating. Therefore:
The internal 10Ω resistor between +Sense and +Output (see Figure 1)
serves to protect the sense function by limiting the output current flowing
through the sense line if the main output is disconnected. It also prevents
output voltage runaway if the sense connection is disconnected.
On/Off Control
The On/Off Control pin may be used for remote on/off operation. HEN D12
Note: If devices have the +Sense pin (pin 10) installed (no part-number
suffix) and the sense function is not used for remote regulation, +Sense
(pin 10) must be tied to +Output (pin 7, 9) at the DC/DC converter pins.
[V
(V
OUT
OUT
Single Output, Non Isolated, 12VIN, 0.8-5VOUT
OUT
(+) – Common] – [Sense(+) – Common] ≤ 10%V
at pins) x (I
and Sense, we recommend installation of a 1000pF capacitor
OUT
Start-Up Time assumes the converter is turned off via
Figure 2. Driving the On/Off Control Pin
ON/OFF pin open:
ON/OFF pin >2.8V:
Technical enquiries email: [e-mail], tel:
25 Amp, High di/dt DC/DC Converters
OUT
) ≤ rated output power
HEN D12 Models
Logic Low = DC/DC converter On
Logic High = DC/DC converter Off
MDC_HEN-D12.B01 Page 4 of 11
OUT
OUT
.
[phone]