DRQ-12-50-L48 Datasheet, PDF (24/26 Pages) Murata Power Solutions Inc. – 600W Digital Fully Regulated Intermediate DC-DC Bus Converter

On/Off 1 can be configured by PMBus command MFR_PRIMARY_ON_OFF_
CONFIG (DDh); default configuration is not ignored; required On/Off 1 control
pin to be asserted to start the unit.
On/Off 2 can be configured by PMBUS command ON_OFF_CONFIG (02h);
default configuration is ignored; treat it as always ON.
DRQ's On/Off status is dependent on On/Off 1 control, On/Off 2 control, and
OPERATION (PMBus command) status; all three must be ON to turn DRQ on; if
one of them is OFF, unit will be turned off.
Output Capacitive Load
These converters do not require external capacitance added to achieve rated
specifications. Users should only consider adding capacitance to reduce
switching noise and/or to handle spike current load steps. Install only enough
capacitance to achieve noise objectives. Excess external capacitance may
cause degraded transient response and possible oscillation or instability.
Remote Sense Input
Use the Sense inputs with caution. Sense is normally connected at the load.
Sense inputs compensate for output voltage inaccuracy delivered at the load.
Contact and PCB resistance
losses due to IR drops
+VOUT
−VIN
I OUT
+SENSE
Sense Current
ON/OFF
CONTROL
Sense Return
LOAD
−SENSE
I OUT Return
+VIN
-VOUT
Contact and PCB resistance
losses due to IR drops
Figure 6. Remote Sense Circuit Configuration
DRQ-12/50-L48 Series
600W Digital Fully Regulated
Intermediate DC-DC Bus Converter
This is done by correcting IR voltage drops along the output wiring and the
current carrying capacity of PC board etch. This output drop (the difference
between Sense and Vout when measured at the converter) should not exceed
0.5V. Consider using heavier wire if this drop is excessive. Sense inputs also
improve the stability of the converter and load system by optimizing the control
loop phase margin.
Note: The Sense input and power Vout lines are internally connected through
low value resistors to their respective polarities so that the converter can
operate without external connection to the Sense. Nevertheless, if the Sense
function is not used for remote regulation, the user should connect +Sense to
+Vout and –Sense to –Vout at the converter pins.
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 significant 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 filter 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)
Soldering Guidelines
Murata Power Solutions recommends the specifications below when installing these
converters. These specifications vary depending on the solder type. Exceeding these
specifications 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
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MDC_DRQ-12/50-L48NK.B02 Page 24 of 26