TWR A-Series
20W, Triple Output DC-DC Converters
MDC_TWR20W.E02 Page 3 of 8
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Absolute Maximum Ratings
Performance/Functional Specifi cations
Typical @ TA = +25°C under nominal line voltage and “full-load” conditions, unless noted.
These converters require 10% min. loading on their primary output and 20% min.
loading on their auxiliary outputs to maintain specifi ed regulation. Operation under no-load
conditions will not damage the devices; however they may not meet all listed specifi cations. For
testing and specifi cation purposes, “full load” is defi ned as 2.75A on the primary +5V output and
±250/200mA on the auxiliary ±12/15V outputs. This corresponds to a total output power of 19.75W.
Application-specifi c internal input/output fi ltering can be recommended or perhaps added
internally upon request. Contact MPS Applications Engineering for details.
Applying a voltage to the Control pin when no input power is applied to the converter can
cause permanent damage to the converter.
D48A models have BASIC, D12A models have Functional insulation.Devices can be screened
or modifi ed for higher guaranteed isolation voltages. Contact MPS Applications Engineering
for details.
To avoid damage to the surface fi nish, please do not use certain cleaning agents such as Vigon.
Contact Murata Power Solutions for information.
Input
Input Voltage Range:
D12A Models 9-36 Volts (24V nominal)
D48A Models 18-75 Volts (48V nominal)
Input Current See Ordering Guide
Input Filter Type
Pi
Overvoltage Shutdown:
D12A Models 40 Volts
D48A Models 80 Volts
Reverse-Polarity Protection Yes (Instantaneous, 6A maximum)
On/Off (Sync.) Control (Pin 4)
TTL high = off, low (or open) = on
Output
Total Output Power 20W max., sum of all outputs
V
OUT Accuracy (50% loads):
+5V Output ±1%
±12V or ±15V Outputs ±3%
Temperature Coeffi cient ±0.02% per °C
Ripple/Noise (20MHz BW)
See Ordering Guide
Line/Load Regulation See Ordering Guide
Effi ciency See Ordering Guide
Isolation Voltage
1500Vdc, minimum
Isolation Capacitance 500pF
Current Limiting Power down to restart
Short Circuit Protection at 25ºC 5 min. max, 5V output
30 sec max.12/15V outputs
Overvoltage Protection Zener/transorb clamps, magnetic feed-
back
Dynamic Characteristics
Transient Response (50% load step) 300μsec max. to ±2% of fi nal value
Switching Frequency 165kHz (±15kHz)
Environmental
Operating Temperature (ambient):
Without Derating –40 to +55°C
With Derating to +100°C (See Derating Curve)
Storage Temperature –40 to +105°C
Physical
Dimensions 2" x 2" x 0.45" (51 x 51 x 11.4mm)
Shielding 5-sided
Case Connections:
D12A Models Pin 2 (–V
IN)
D48A Models Pin 1 (+V
IN)
Case Material Corrosion resistant steel with
non-conductive, epoxy-based, black
enamel fi nish and plastic baseplate
Pin Material Copper alloy with gold plate over nickel
underplate
Weight 2.7 ounces (77 grams)
Input Voltage:
“D12” Models 44 Volts
“D48” Models 88 Volts
Input Reverse-Polarity Protection Current must be <6A. Brief
duration only. Fusing recommended.
Output Overvoltage Protection
+5V Output 6.8 Volts, limited duration
±12V Outputs ±15 Volts, limited duration
±15V Outputs ±18 Volts, limited duration
Output Current Current limited.
Max. currents are
model dependent.
Storage Temperature –40 to +105°C
Lead Temperature (soldering, 10 sec.) +300°C
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 Specifi cations Table is not implied.
Filtering and Noise Reduction
All A-Series TWR 20 Watt DC/DC Converters achieve their rated ripple and
noise specifi cations without the use of external input/output capacitors. In
critical applications, input/output noise may be further reduced by installing
electrolytic capacitors across the input terminals and/or low-ESR tantalum or
electrolytic capacitors across the output terminals. Output capacitors should
be connected between their respective output pin (pin 5, 6 or 8) and Common
(pin 7). The caps should be located as close to the power converters as
possible. Typical values are listed below. In many applications, using values
greater than those listed will yield better results.
To Reduce Input Ripple
D12A Models 20μF, 50V
D48A Models 10μF, 100V
To Reduce Output Ripple
+5V Output 47μF, 10V, Low ESR
±12/15V Outputs 33μF, 20V, Low ESR
In critical, space-sensitive applications, MPS may be able to tailor the internal
input/output fi ltering of these units to meet your specifi c requirements. Con-
tact 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. For MPS A-Series TWR
20 Watt DC/DC Converters, you should use slow-blow type fuses with values
no greater than 4A for “D12A” models and 2A for “D48A” models.
On/Off Control
The On/Off Control pin (pin 4) may be used for remote on/off operation. A TTL
logic high (+2 to +5 Volts, 250μA max.) applied to pin 4 disables the converter.
A TTL logic low (0 to +0.8 Volts, 70μA max.), or no connection, enables the
converter. Control voltages should be referenced to pin 2 (–Input). Applying a
voltage to the Control pin when no input power is applied to the converter can
cause permanent damage to the converter.
Technical Notes
