UCQ-3.3/30-D48N-C Murata Power Solutions Inc, UCQ-3.3/30-D48N-C Datasheet - Page 10

• Manufacturer Part Number: UCQ-3.3/30-D48N-C
• Description: DC/DC Converters & Regulators 48V 3.3Vout 30A 99W Negative polarity
• Manufacturer: Murata Power Solutions Inc
• Series: UCQr

Specifications of UCQ-3.3/30-D48N-C

• Output Power: 99 W
• Input Voltage Range: 36 V to 75 V
• Number Of Outputs: 1
• Output Voltage (channel 1): 3.3 V
• Output Current (channel 1): 30 A
• Isolation Voltage: 2.25 KV
• Package / Case Size: Quarter Brick
• Product: Isolated
• Dc / Dc Converter O/p Type: Quarter-Brick
• No. Of Outputs: 1
• Input Voltage: 36V To 75V
• Power Rating: 99W
• Output Voltage: 3.3V
• Output Current: 30A
• Approval Bodies: EN / IEC / UL
• Supply Voltage: 48V
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Floating Outputs
Since these are isolated DC/DC converters, their outputs are “floating” with
respect to their input. Designers will normally use the –Output (pin 4) as the
ground/return of the load circuit. You can however, use the +Output (pin 8) as
ground/return to effectively reverse the output polarity.
Minimum Output Loading Requirements
UCQ converters employ a synchronous-rectifier design topology and all models
regulate within spec and are stable under no-load to full load conditions.
Operation under no-load conditions however might slightly increase the output
ripple and noise.
Thermal Shutdown
The UCQ converters are equipped with thermal-shutdown circuitry. If environ-
mental conditions cause the temperature of the DC/DC converter to rise above
the designed operating temperature, a precision temperature sensor will power
down the unit. When the internal temperature decreases below the threshold
of the temperature sensor, the unit will self start. See Performance/Functional
Specifications.
Output Over-Voltage Protection
The UCQ output voltage is monitored for an over-voltage condition using a com-
parator. The signal is optically coupled to the primary side and if the output volt-
age rises to a level which could be damaging to the load, the sensing circuitry
will power down the PWM controller causing the output voltage to decrease.
Following a time-out period the PWM will restart, causing the output voltage
to ramp to its appropriate value. If the fault condition persists, and the output
voltage again climbs to excessive levels, the over-voltage circuitry will initiate
another shutdown cycle. This on/off cycling is referred to as “hiccup” mode.
Current Limiting
As soon as the output current increases to approximately 130% of its rated
value, the DC/DC converter will go into a current-limiting mode. In this condi-
tion, the output voltage will decrease proportionately with increases in output
current, thereby maintaining somewhat constant power dissipation. This is
between the power supply and its load. In order to minimize measurement
errors, scope measurements should be made using BNC connectors, or the
probe ground should be less than ½ inch and soldered directly to the fixture.
In Figure 3, the two copper strips simulate real-world PCB impedances
+OUTPUT
–OUTPUT
+SENSE
–SENSE
Figure 3. Measuring Output Ripple/Noise (PARD)
C1 = 1µF CERAMIC
C2 = 10µF TANTALUM
LOAD 2-3 INCHES (51-76mm) FROM MODULE
7
8
4
5
C1
COPPER STRIP
COPPER STRIP
C2
SCOPE
www.murata-ps.com
R
LOAD
should be used. Output over-voltage protection is monitored at the output volt-
age pin, not the Sense pin. Therefore, excessive voltage differences between
V
commonly referred to as power limiting. Current limit inception is defined
as the point at which the full-power output voltage falls below the specified
tolerance. See Performance/Functional Specifications. If the load current, being
drawn from the converter, is significant enough, the unit will go into a short
circuit condition as described below.
Short Circuit Condition
When a converter is in current-limit mode, the output voltage will drop as the
output current demand increases. If the output voltage drops too low, the mag-
netically coupled voltage used to develop primary side voltages will also drop,
thereby shutting down the PWM controller. Following a time-out period, the
PWM will restart causing the output voltage to begin ramping to their appropri-
ate value. If the short-circuit condition persists, another shutdown cycle will be
initiated. This on/off cycling is referred to as “hiccup” mode. The hiccup cycling
reduces the average output current, thereby preventing internal temperatures
from rising to excessive levels. The UCQ Series is capable of enduring an
indefinite short circuit output condition.
Remote Sense
Note: The Sense and V
resistors. Nevertheless, if the sense function is not used for remote regulation
the user should connect the +Sense to +V
DC converter pins. UCQ series converters employ a sense feature to provide
point of use regulation, thereby overcoming moderate IR drops in PCB conduc-
tors or cabling. The remote sense lines carry very little current and therefore
require minimal cross-sectional-area conductors. The sense lines, which are
capacitively coupled to their respective output lines, are used by the feedback
control-loop to regulate the output. As such, they are not low impedance points
and must be treated with care in layouts and cabling. Sense lines on a PCB
should be run adjacent to dc signals, preferably ground.
OUT
In cables and discrete wiring applications, twisted pair or other techniques
and Sense in conjunction with trim adjustment of the output voltage can
[V
Single Output UCQ Models
OUT
(+)-V
Figure 4. Remote Sense Circuit Configuration
Technical enquiries email: [e-mail], tel:
OUT
Low-Profile, Quarter Brick, 8.3-40 Amp
OUT
(–)] – [Sense(+)-Sense(–)] ≤ 10%V
lines are internally connected through low-value
Isolated DC/DC Converters
OUT
MDC_UCQ Models.B06 Page 10 of 16
and –Sense to –V
OUT
OUT
[phone]
at the DC/