Datasheet

DRQ-12/42-D48 Series
500W Digital Fully Regulated
Intermediate DC-DC Bus Converter
MDC_DRQ-12/42-D48.A03 Page 22 of 24
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Soldering Guidelines
Murata Power Solutions recommends the specifi cations below when installing these
converters. These specifi cations vary depending on the solder type. Exceeding these
specifi cations may cause damage to the product. Be cautious when there is high atmo-
spheric humidity. We strongly recommend a mild pre-bake (100° C. for 30 minutes). 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 115° C.
Maximum Pot Temperature 270° C.
Maximum Solder Dwell Time 7 seconds
For Sn/Pb based solders:
Maximum Preheat Temperature 105° C.
Maximum Pot Temperature 250° C.
Maximum Solder Dwell Time 6 seconds
The remote Sense lines carry very little current. They are also capacitively
coupled to the output lines and therefore are in the feedback control loop to
regulate and stabilize the output. As such, they are not low impedance inputs
and must be treated with care in PC board layouts. Sense lines on the PCB
should run adjacent to DC signals, preferably Ground. In cables and discrete
wiring, use twisted pair, shielded tubing or similar techniques.
Any long, distributed wiring and/or signifi cant inductance introduced into the
Sense control loop can adversely affect overall system stability. If in doubt, test
your applications by observing the converter’s output transient response during
step loads. There should not be any appreciable ringing or oscillation. You
may also adjust the output trim slightly to compensate for voltage loss in any
external fi lter elements. Do not exceed maximum power ratings.
Please observe Sense inputs tolerance to avoid improper operation:
[Vout(+) −Vout(-)] − [Sense(+) −Sense(-)] ≤ 10% of Vout
Output overvoltage protection is monitored at the output voltage pin, not the
Sense pin. Therefore excessive voltage differences between Vout and Sense
together with trim adjustment of the output can cause the overvoltage protec-
tion circuit to activate and shut down the output.
Power derating of the converter is based on the combination of maximum
output current and the highest output voltage. Therefore the designer must
ensure:
(Vout at pins) x (Iout)
≤ (Max. rated output power)
Figure 5. Remote Sense Circuit Confi guration
LOAD
Contact and PCB resistance
losses due to IR drops
Contact and PCB resistance
losses due to IR drops
+VOUT
+SENSE
− SENSE
-VOUT
−V IN
ON/OFF
CONTROL
+
V IN
Sense Current
I OUT
Sense Return
I OUT Return