OMO ElectronicOMO Electronic
Expand menu
Hello, Sign inMy Account
0 Cart

QM48T14120-NBB0G

P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P20
ZD-00376 Rev. 1.1.1, 19-Feb-10 Page 7 of 20 www.power-one.com
QM48T/S14120 DC-DC Converter Data Sheet
36-75 VDC Input; 12 VDC @ 14 A Output
Startup Information (using negative ON/OFF)
Scenario #1: Initial Startup From Bulk Supply
ON/OFF function enabled, converter started via application
of V
IN
. See Figure E.
Time Comments
t
0
ON/OFF pin is ON; system front end power is
toggled on, V
IN
to converter begins to rise.
t
1
V
IN
crosses undervoltage Lockout protection
circuit threshold; converter enabled.
t
2
Converter begins to respond to turn-on
command (converter turn-on delay).
t
3
Converter V
OUT
reaches 100% of nominal value.
For this example, the total converter startup time (t
3
- t
1
) is
typically 4 ms.
Scenario #2: Initial Startup Using ON/OFF Pin
With V
IN
previously powered, converter started via
ON/OFF pin. See Figure F.
Time Comments
t
0
V
INPUT
at nominal value.
t
1
Arbitrary time when ON/OFF pin is enabled
(converter enabled).
t
2
End of converter turn-on delay.
t
3
Converter V
OUT
reaches 100% of nominal value.
For this example, the total converter startup time (t
3
- t
1
) is
typically 4 ms.
Scenario #3: Turn-off and Restart Using ON/OFF Pin
With V
IN
previously powered, converter is disabled and
then enabled via ON/OFF pin. See Figure G.
Time Comments
t
0
V
IN
and V
OUT
are at nominal values; ON/OFF pin
ON.
t
1
ON/OFF pin arbitrarily disabled; converter
output falls to zero; turn-on inhibit delay period
(200 ms typical) is initiated, and ON/OFF pin
action is internally inhibited.
t
2
ON/OFF pin is externally re-enabled.
If (t
2
- t
1
) ≤ 100 ms, external action of
ON/OFF pin is locked out by startup inhibit
timer.
If (t
2
- t
1
) > 100 ms, ON/OFF pin action is
internally enabled.
t
3
Turn-on inhibit delay period ends. If ON/OFF pin
is ON, converter begins turn-on; if off, converter
awaits ON/OFF pin ON signal; see Figure F.
t
4
End of converter turn-on delay.
t
5
Converter V
OUT
reaches 100% of nominal value.
For the condition, (t
2
- t
1
) ≤ 100 ms, the total converter
startup time (t
5
- t
2
) is typically 104 ms. For (t
2
- t
1
) > 100 ms,
startup will be typically 4 ms after release of ON/OFF pin.
VIN
ON/OFF
STATE
V
OUT
t
t
0 t1 t2 t3
ON
OFF
Fig. E: Startup scenario #1.
ON/OFF
STATE
VOUT
t0 t1 t2 t3
ON
OFF
VIN
t
Fig. F: Startup scenario #2.
ON/OFF
STATE
OFF
ON
V
OUT
t0 t2t1 t5
VIN
t
t4t3
100 ms
Fig. G: Startup scenario #3.
ZD-00376 Rev. 1.1.1, 19-Feb-10 Page 8 of 20 www.power-one.com
QM48T/S14120 DC-DC Converter Data Sheet
36-75 VDC Input; 12 VDC @ 14 A Output
Characterization
General Information
The converter has been characterized for many
operational aspects, to include thermal derating
(maximum load current as a function of ambient
temperature and airflow) for vertical and horizontal
mountings, efficiency, startup and shutdown
parameters, output ripple and noise, transient
response to load step-change, overload, and short
circuit.
The following pages contain specific plots or
waveforms associated with the converter. Additional
comments for specific data are provided below.
Test Conditions
All data presented were taken with the converter
soldered to a test board, specifically a 0.060” thick
printed wiring board (PWB) with four layers. The top
and bottom layers were not metalized. The two inner
layers, comprised of two-ounce copper, were used to
provide traces for connectivity to the converter.
The lack of metalization on the outer layers as well
as the limited thermal connection ensured that heat
transfer from the converter to the PWB was
minimized. This provides a worst-case but consistent
scenario for thermal derating purposes.
All measurements requiring airflow were made in the
vertical and horizontal wind tunnel using Infrared (IR)
thermography and thermocouples for thermometry.
Ensuring components on the converter do not
exceed their ratings is important to maintaining high
reliability. If one anticipates operating the converter
at or close to the maximum loads specified in the
derating curves, it is prudent to check actual
operating temperatures in the application.
Thermographic imaging is preferable; if this
capability is not available, then thermocouples may
be used. The use of AWG #40 gauge thermocouples
is recommended to ensure measurement accuracy.
Careful routing of the thermocouple leads will further
minimize measurement error. Refer to Fig. H for the
optimum measuring thermocouple locations.
Fig. H: Locations of the thermocouple for thermal testing.
Thermal Derating
Load current vs. ambient temperature and airflow
rates are given in Fig. 1 and Fig. 2 for vertical and
horizontal converter mountings for through-hole
version. Ambient temperature was varied between
25 °C and 85 °C, with airflow rates from 30 to
500 LFM (0.15 to 2.5 m/s).
For each set of conditions, the maximum load current
was defined as the lowest of:
(i) The output current at which any FET junction
temperature does not exceed a maximum specified
temperature of 120 °C as indicated by the
thermographic image, or
(ii) The nominal rating of the converter (14 A).
During normal operation, derating curves with
maximum FET temperature less or equal to 120 °C
should not be exceeded. Temperature on the PCB at
the thermocouple location shown in Fig. H should not
exceed 118 °C in order to operate inside the derating
curves.
Efficiency
Fig. 3 shows the efficiency vs. load current plot for
ambient temperature of 25 ºC, airflow rate of 300 LFM
(1.5 m/s) with vertical mounting and input voltages of
36 V, 48 V and 72 V. Also, a plot of efficiency vs. load
current, as a function of ambient temperature with
Vin = 48 V, airflow rate of 200 LFM (1 m/s) with
vertical mounting is shown in Fig. 4.
Startup
Output voltage waveforms, during the turn-on
transient using the ON/OFF pin for full rated load
currents (resistive load) are shown without and with
external load capacitance in Figs. 7-8, respectively.
Ripple and Noise
The output voltage ripple waveform, measured at full
rated load current with a 10 µF tantalum and 1 µF
ceramic capacitor across the output. Note that all
output voltage waveforms are measured across a 1
µF ceramic capacitor.
The input reflected ripple current waveforms are
obtained using the test setup shown in Fig I. The
corresponding waveforms are shown in plot section.
Vout
Vsource
i
S
i
C
1 F
ceramic
capacitor
10 H
source
inductance
DC/DC
Converter
33 F
ESR <1
electrolytic
capacitor
QmaX
Series
QmaX
TM
Fig. I: Test Setup for measuring input reflected-ripple
currents, i
c
and i
s
.
ZD-00376 Rev. 1.1.1, 19-Feb-10 Page 9 of 20 www.power-one.com
QM48T/S14120 DC-DC Converter Data Sheet
36-75 VDC Input; 12 VDC @ 14 A Output
QM48T/S14120-wxy0 (Non-parallelable version)
Ambient Temperature [°C]
20 30 40 50 60 70 80 90
Load Current [Adc]
0
4
8
12
16
500 LFM (2.5 m/s)
400 LFM (2.0 m/s)
300 LFM (1.5 m/s)
200 LFM (1.0 m/s)
100 LFM (0.5 m/s)
30 LFM (0.15 m/s)
Fig. 1: Available load current vs. ambient air temperature and
airflow rates for converter with B height pins mounted
vertically with air flowing from pin 3 to pin 1, MOSFET
temperature 120 C, Vin = 48 V.
Load Current [Adc]
03691215
Efficiency
0.60
0.70
0.80
0.90
1.00
72 V
48 V
36 V
Fig. 3: Efficiency vs. load current and input voltage for
converter mounted vertically with air flowing from pin 3 to pin
1 at a rate of 300 LFM (1.5 m/s) and Ta = 25 C.
Ambient Temperature [°C]
20 30 40 50 60 70 80 90
Load Current [Adc]
0
4
8
12
16
500 LFM (2.5 m/s)
400 LFM (2.0 m/s)
300 LFM (1.5 m/s)
200 LFM (1.0 m/s)
100 LFM (0.5 m/s)
30 LFM (0.15 m/s)
Fig. 2: Available load current vs. ambient air temperature and
airflow rates for converter with B height pins mounted
horizontally with air flowing from pin 3 to pin 1, MOSFET
temperature 120 C, Vin = 48 V.
Load Current [Adc]
03691215
Efficiency
0.60
0.70
0.80
0.90
1.00
70 C
55 C
40 C
Fig. 4: Efficiency vs. load current and ambient temperature
for converter mounted vertically with Vin = 48 V and air
flowing from pin 3 to pin 1 at a rate of 200 LFM (1.0 m/s).
P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P20

QM48T14120-NBB0G

Mfr. #:
Buy QM48T14120-NBB0G
Manufacturer:
Bel
Description:
DC DC CONVERTER 12V
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
T/T Paypal Visa MoneyGram Western Union

Products related to this Datasheet