QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
Applications
• Telecommunications
• Data communications
• Wireless communications
• Servers, Workstations
Benefits
• High efficiency – no heat sink required
• Higher current capability at 70 ºC than most
competitors’ 40 A half-bricks
Features
• RoHS lead-free solder and lead-solder-exempted
products are available
• Delivers up to 40 A
• Outputs available: 3.3, 2.5, 1.8, 1.5, 1.2 and 1.0 V
• Industry-standard quarter-brick pinout
• On-board input differential LC-filter
• Startup into pre-biased load
• No minimum load required
• Dimensions: 1.45” x 2.30” x 0.425”
(36.83 x 58.42 x 10.80 mm)
• Weight: 1.2 oz [34.2 g]
• Meets Basic Insulation requirements of EN60950
• Withstands 100 V input transient for 100 ms
• Fixed-frequency operation
• Fully protected
• Remote output sense
• Non-Latching / Latching OTP option
• Positive or negative logic ON/OFF option
• Output voltage trim range: +10%/20% with
industry-standard trim equations (±10% for 1.2 V
and 1.0 V)
• High reliability: MTBF = 13.9 million hours,
calculated per Telcordia TR-332, Method I Case 1
• UL60950 recognized in US and Canada and
DEMKO certified per IEC/EN60950 (pending)
• Designed to meet Class B conducted emissions per
FCC and EN55022 when used with external filter
• All materials meet UL94, V-0 flammability rating
Description
The QME48T40 DC-DC Series of converters provide outstanding thermal performance in high temperature
environments. This performance is accomplished through the use of patented/patent-pending circuits, packaging,
and processing techniques to achieve ultra-high efficiency, excellent thermal management, and a low-body profile.
The low-body profile and the preclusion of heat sinks minimize impedance to system airflow, thus enhancing
cooling for both upstream and downstream devices. The use of 100% automation for assembly, coupled with
advanced electronic circuits and thermal design, results in a product with extremely high reliability.
Operating from a 36-75 V input, the QME48T40 converters provide any standard output voltage from 3.3 V down
to 1.0 V that can be trimmed from –20% to +10% of the nominal output voltage (±10% for output voltages 1.2 V
and 1.0 V), thus providing outstanding design flexibility.
ZD-02057 Rev. 4.1 www.power-one.com Page 1 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
Electrical Specifications
Conditions: TA = 25 ºC, Airflow = 300 LFM (1.5 m/s), Vi n = 48 VDC, unless otherwise specified.
Parameter Notes Min Typ Max Units
Absolute Maximum Ratings
Input Voltage Continuous 0 80 VDC
Operating Ambient Temperature -40 85 °C
Storage Temperature -55 125 °C
Input Characteristics
Operating Input Voltage Range 36 48 75 VDC
Input Under Voltage Lockout
Turn-on Threshold 33 34 35 VDC
Turn-off Threshold 31 32 33 VDC
Input Voltage Transient 100 ms 100 VDC
Maximum Input Current 40 ADC Out @ 36 VDC In
V
OUT = 3.3 VDC 4.1 ADC
V
OUT = 2.5 VDC 3.2 ADC
V
OUT = 1.8 VDC 2.4 ADC
V
OUT = 1.5 VDC 2.0 ADC
V
OUT = 1.2 VDC 1.6 ADC
V
OUT = 1.0 VDC 1.4 ADC
Input Stand-by Current Vin = 48V, converter disabled 3 mA
Input No Load Current (0 load on the output) Vin = 48V, converter enabled
V
OUT = 3.3 VDC 50 mA
VOUT = 2.5 VDC 47 mA
VOUT = 1.8 VDC 45 mA
V
OUT = 1.5 VDC 44 mA
V
OUT = 1.2 VDC 43 mA
V
OUT = 1.0 VDC 43 mA
Input Reflected-Ripple Current, is Vin = 48V, 25 MHz bandwidth
VOUT = 3.3 VDC 10 mAPK-PK
V
OUT = 2.5 VDC 9 mAPK-PK
V
OUT = 1.8 VDC 9 mAPK-PK
V
OUT = 1.5 VDC 9 mAPK-PK
V
OUT = 1.2 VDC 8 mAPK-PK
V
OUT = 1.0 VDC 8 mAPK-PK
Input Voltage Ripple Rejection 120 Hz 60 dB
ZD-02057 Rev. 4.1 www.power-one.com Page 2 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
Electrical Specifications (continued)
Conditions: TA = 25 ºC, Airflow = 300 LFM (1.5 m/s), Vin = 48 VDC, unless otherwise specified.
Parameter Notes Min Typ Max Units
Output Characteristics
External Load Capacitance Plus full load (resistive)
40,000 µF
Output Current Range 0 40 ADC
Current Limit Inception Non-latching 42 47 52 ADC
Peak Short-Circuit Current Non-latching, Short = 10 m 50 60 A
RMS Short-Circuit Current Non-latching 9 Arms
Output Voltage Set Point (no load) VOUT = 3.3 VDC 3.267 3.300 3.333 VDC
VOUT = 2.5 VDC 2.475 2.500 2.525 VDC
VOUT = 1.8 VDC 1.782 1.800 1.818 VDC
VOUT = 1.5 VDC 1.485 1.500 1.515 VDC
VOUT = 1.2 VDC 1.188 1.200 1.212 VDC
VOUT = 1.0 VDC 0.990 1.000 1.010 VDC
Output Regulation Over Line ±2 ±5 mV
Output Regulation Over Load ±2 ±5 mV
Output Voltage Range Over line, load and temperature1-1.5 +1.5 %Vout
Output Ripple and Noise – 25 MHz bandwidth
VOUT = 3.3 VDC
Full load + 10 µF tantalum + 1 µF ceramic 55 110 mVPK-PK
VOUT = 1.0 VDC
Full load + 10 µF tantalum + 1 µF ceramic 35 70 mVPK-PK
Dynamic Response
Load Change 50%-75%-50% of Iout Max,
di/dt = 0.1 A/µs Co = 1 µF ceramic (Fig. 3.3V.9) 502 mV
di/dt = 5 A/µs Co = 470 µF POS + 1 µF ceramic 1302 mV
Settling Time to 1% of Vout 152 µs
Efficiency
100% Load VOUT = 3.3 VDC 91.0 %
V
OUT = 2.5 VDC 89.0 %
V
OUT = 1.8 VDC 86.5 %
V
OUT = 1.5 VDC 84.5 %
V
OUT = 1.2 VDC 82.0 %
V
OUT = 1.0 VDC 80.0 %
50% Load VOUT = 3.3 VDC 92.0 %
VOUT = 2.5 VDC 91.0 %
V
OUT = 1.8 VDC 88.5 %
V
OUT = 1.5 VDC 87.0 %
V
OUT = 1.2 VDC 85.0 %
V
OUT = 1.0 VDC 83.0 %
Additional Notes:
1 Operating ambient temperature range of -40 ºC to 85 ºC for converter.
2 See waveforms for dynamic response and settling time for different output voltages.
3 Vout can be increased up to 10% via the sense leads or 10% via the trim function. However, the total output voltage trim from all sources
should not exceed 10% of VOUT(NOM), in order to ensure specified operation of overvoltage protection circuitry
ZD-02057 Rev. 4.1 www.power-one.com Page 3 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
Electrical Specifications (continued)
Conditions: TA = 25 ºC, Airflow = 300 LFM (1.5 m/s), Vin = 48 VDC, unless otherwise specified.
Parameter Notes Min Typ Max Units
Isolation Characteristics
I/O Isolation 2000 VDC
Isolation Capacitance 2 nF
Isolation Resistance 10 M
Feature Characteristics
Switching Frequency 460 kHz
Output Voltage Trim Range3 Non-latching (3.3 - 1.5 V) -20 +10 %
Non-latching (1.2 V and 1.0 V) -10 +10 %
Remote Sense Compensation3 Percent of VOUT(NOM) +10 %
Output Overvoltage Protection Non-latching 117 128 140 %
Auto-Restart Period Applies to all protection features 200 ms
Turn-On Time 4 ms
ON/OFF Control (Positive Logic)
Converter Off (logic low) -20 0.8 VDC
Converter On (logic high) 2.4 20 VDC
ON/OFF Control (Negative Logic)
Converter Off (logic high) 2.4 20 VDC
Converter On (logic low) -20 0.8 VDC
ZD-02057 Rev. 4.1 www.power-one.com Page 4 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
Operations
Input and Output Impedance
These power converters have been designed to be
stable with no external capacitors when used in low
inductance input and output circuits.
In many applications, the inductance associated with
the distribution from the power source to the input of
the converter can affect the stability of the converter.
The addition of a 33 µF electrolytic capacitor with an
ESR < 1 across the input helps to ensure stability
of the converter. In many applications, the user has
to use decoupling capacitance at the load. The
power converter will exhibit stable operation with
external load capacitance up to 40,000 µF on 3.3 V –
1.0 V outputs.
Additionally, see the EMC section of this data sheet
for discussion of other external components which
may be required for control of conducted emissions.
ON/OFF (Pin 2)
The ON/OFF pin is used to turn the power converter
on or off remotely via a system signal. There are two
remote control options available, positive and
negative logic, with both referenced to Vin(-). A
typical connection is shown in Fig. A.
Rload
Vin
CONTROL
INPUT
Vin (+)
Vin (-)
ON/OFF
Vout (+)
Vout (-)
TRIM
SENSE (+)
SENSE (-)
(Top View)
Converter
QME Series
Fig. A: Circuit configuration for ON/OFF function.
The positive logic version turns on when the ON/OFF
pin is at a logic high and turns off when at a logic
low. The converter is on when the ON/OFF pin is left
open. See the Electrical Specifications for logic
high/low definitions.
The negative logic version turns on when the pin is
at a logic low and turns off when the pin is at a logic
high. The ON/OFF pin can be hardwired directly to
Vin(-) to enable automatic power up of the converter
without the need of an external control signal.
The ON/OFF pin is internally pulled up to 5 V
through a resistor. A properly debounced mechanical
switch, open-collector transistor, or FET can be used
to drive the input of the ON/OFF pin. The device
must be capable of sinking up to 0.2 mA at a low
level voltage of ≤ 0.8 V. An external voltage source
(±20 V maximum) may be connected directly to the
ON/OFF input, in which case it must be capable of
sourcing or sinking up to 1 mA depending on the
signal polarity. See the Startup Information section
for system timing waveforms associated with use of
the ON/OFF pin.
Remote Sense (Pins 5 and 7)
The remote sense feature of the converter
compensates for voltage drops occurring between
the output pins of the converter and the load. The
SENSE(-) (Pin 5) and SENSE(+) (Pin 7) pins should
be connected at the load or at the point where
regulation is required (see Fig. B).
100
10
Rw
Rw
Rload
Vin
Vin (+)
Vin (-)
ON/OFF
Vout (+)
Vout (+)
TRIM
SENSE (+)
SENSE (-)
(Top View)
Converter
QME Series
Fig. B: Remote sense circuit configuration.
CAUTION
If remote sensing is not utilized, the SENSE(-) pin must be
connected to the Vout(-) pin (Pin 4), and the SENSE(+) pin
must be connected to the Vout(+) pin (Pin 8) to ensure the
converter will regulate at the specified output voltage. If these
connections are not made, the converter will deliver an
output voltage that is slightly higher than the specified data
sheet value.
Because the sense leads carry minimal current,
large traces on the end-user board are not required.
However, sense traces should be run side by side
and located close to a ground plane to minimize
system noise and ensure optimum performance.
The converter’s output overvoltage protection (OVP)
senses the voltage across Vout(+) and Vout(-), and
not across the sense lines, so the resistance (and
resulting voltage drop) between the output pins of
the converter and the load should be minimized to
prevent unwanted triggering of the OVP.
When utilizing the remote sense feature, care must
be taken not to exceed the maximum allowable
output power capability of the converter, which is
equal to the product of the nominal output voltage
and the allowable output current for the given
conditions.
When using remote sense, the output voltage at the
converter can be increased by as much as 10%
above the nominal rating in order to maintain the
required voltage across the load. Therefore, the
designer must, if necessary, decrease the maximum
current (originally obtained from the derating curves)
by the same percentage to ensure the converter’s
ZD-02057 Rev. 4.1 www.power-one.com Page 5 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
actual output power remains at or below the
maximum allowable output power.
Output Voltage Adjust /TRIM (Pin 6)
The output voltage can be adjusted up 10% or down
20% for Vout 1.5 V, and ±10% for Vout = 1.2 V and
1.0 V relative to the rated output voltage by the
addition of an externally connected resistor.
The TRIM pin should be left open if trimming is not
being used. To minimize noise pickup, a 0.1 µF
capacitor is connected internally between the TRIM
and SENSE(-) pins.
To increase the output voltage, refer to Fig. C. A trim
resistor, RT-INCR, should be connected between the
TRIM (Pin 6) and SENSE(+) (Pin 7), with a value of:
10.22
1.225∆
626∆)V5.11(100
RNOMO
INCRT −
−+
=−
− [k],
for 3.3 – 1.5 V.
7.2
∆
84.6
RINCRT −=− [k] (1.2 V)
9
∆
120
RINCRT −=− [k] (1.0 V)
where,
=−INCRTRRequired value of trim-up resistor k]
=−NOMOVNominal value of output voltage [V]
100X
V
)V(V
∆
NOM- O
NOM-OREQ-O −
= [%]
=−REQOVDesired (trimmed) output voltage [V].
When trimming up, care must be taken not to exceed
the converter‘s maximum allowable output power.
See the previous section for a complete discussion
of this requirement.
Rload
Vin
Vin (+)
Vin (-)
ON/OFF
Vout (+)
Vout (-)
TRIM
SENSE (+)
SENSE (-)
RT-INCR
(Top View)
Converter
QME Series
Fig. C: Configuration for increasing output voltage.
To decrease the output voltage (Fig. D), a trim
resistor, RT-DECR, should be connected between the
TRIM (Pin 6) and SENSE(-) (Pin 5), with a value of:
10.22
|∆|
511
RDECRT −=− [k] (3.3 – 1.5 V)
15
|∆|
700
RDECRT −=− [k] (1.2 V)
17
|∆|
700
RDECRT −=− [k] (1.0 V)
where,
=−DECRTRRequired value of trim-down resistor [k]
and
∆
is defined above.
Note:
The above equations for calculation of trim resistor values match
those typically used in conventional industry-standard quarter-bricks
(except for 1.2 V and 1.0 V outputs).
Rload
Vin
Vin (+)
Vin (-)
ON/OFF
Vout (+)
Vout (-)
TRIM
SENSE (+)
SENSE (-)
RT-DECR
(Top View)
Converter
QME Series
Fig. D: Configuration for decreasing output voltage.
Trimming/sensing beyond 110% of the rated output
voltage is not an acceptable design practice, as this
condition could cause unwanted triggering of the
output overvoltage protection (OVP) circuit. The
designer should ensure that the difference between
the voltages across the converter’s output pins and its
sense pins does not exceed 10% of VOUT(NOM), or:
X NOM-O SENSESENSEOUTOUT 10%V)](V)([V)](V)([V
≤
−−+
−
−
−
+
[V]
This equation is applicable for any condition of output
sensing and/or output trim.
ZD-02057 Rev. 4.1 www.power-one.com Page 6 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
Protection Features
Input Undervoltage Lockout
Input undervoltage lockout is standard with this
converter. The converter will shut down when the
input voltage drops below a pre-determined voltage.
The input voltage must be typically 34 V for the
converter to turn on. Once the converter has been
turned on, it will shut off when the input voltage
drops typically below 32 V. This feature is beneficial
in preventing deep discharging of batteries used in
telecom applications.
Output Overcurrent Protection (OCP)
The converter is protected against overcurrent or
short circuit conditions. Upon sensing an overcurrent
condition, the converter will switch to constant
current operation and thereby begin to reduce output
voltage. When the output voltage drops below 60%
of the nominal value of output voltage, the converter
will shut down.
Once the converter has shut down, it will attempt to
restart nominally every 200 ms with a typical 3-5%
duty cycle. The attempted restart will continue
indefinitely until the overload or short circuit
conditions are removed or the output voltage rises
above 40-50% of its nominal value.
Once the output current is brought back into its
specified range, the converter automatically exits the
hiccup mode and continues normal operation.
Output Overvoltage Protection (OVP)
The converter will shut down if the output voltage
across Vout(+) (Pin 8) and Vout(-) (Pin 4) exceeds
the threshold of the OVP circuitry. The OVP circuitry
contains its own reference, independent of the output
voltage regulation loop. Once the converter has shut
down, it will attempt to restart every 200 ms until the
OVP condition is removed.
Overtemperature Protection (OTP)
The converter will shut down under an
overtemperature condition to protect itself from
overheating caused by operation outside the thermal
derating curves, or operation in abnormal conditions
such as system fan failure. After the converter has
cooled to a safe operating temperature, it will
automatically restart.
Safety Requirements
The converters meet North American and
International safety regulatory requirements per
UL60950 and EN60950 (pending). Basic Insulation is
provided between input and output.
To comply with safety agencies’ requirements, an
input line fuse must be used external to the
converter. The Table below provides the
recommended fuse rating for use with this family of
products.
Output Voltage Fuse Rating
3.3 V 7.5 A
2.5 V, 1.8 V 5 A
1.5 V, 1.2 V, 1.0 V 3 A
All QME converters are UL approved (pending) for a
maximum fuse rating of 15 Amps. To protect a group
of converters with a single fuse, the rating can be
increased from the recommended value above.
Electromagnetic Compatibility (EMC)
EMC requirements must be met at the end-product
system level, as no specific standards dedicated to
EMC characteristics of board mounted component
dc-dc converters exist. However, Power-One tests its
converters to several system level standards,
primary of which is the more stringent EN55022,
Information technology equipment - Radio
disturbance characteristics-Limits and methods of
measurement.
An effective internal LC differential filter significantly
reduces input reflected ripple current, and improves
EMC.
With the addition of a simple external filter, all
versions of the QME-Series of converters pass the
requirements of Class B conducted emissions per
EN55022 and FCC requirements. Please contact
Power-One Applications Engineering for details of
this testing.
ZD-02057 Rev. 4.1 www.power-one.com Page 7 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
Startup Information (using negative ON/OFF)
Scenario #1: Initial Startup From Bulk Supply
ON/OFF function enabled, converter started via application
of VIN. See Figure E.
Time Comments
t0ON/OFF pin is ON; system front end power is
toggled on, VIN to converter begins to rise.
t1VIN crosses undervoltage Lockout protection
circuit threshold; converter enabled.
t2Converter begins to respond to turn-on
command (converter turn-on delay).
t3Converter VOUT reaches 100% of nominal value.
For this example, the total converter startup time (t3- t1) is
typically 4 ms.
Scenario #2: Initial Startup Using ON/OFF Pin
With VIN previously powered, converter started via
ON/OFF pin. See Figure F.
Time Comments
t0VINPUT at nominal value.
t1Arbitrary time when ON/OFF pin is enabled
(converter enabled).
t2End of converter turn-on delay.
t3Converter VOUT reaches 100% of nominal value.
For this example, the total converter startup time (t3- t1) is
typically 4 ms.
Scenario #3: Turn-off and Restart Using ON/OFF Pin
With VIN previously powered, converter is disabled and
then enabled via ON/OFF pin. See Figure G.
Time Comments
t0VIN and VOUT are at nominal values; ON/OFF pin
ON.
t1ON/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.
t2ON/OFF pin is externally re-enabled.
If (t2- t1) ≤ 200 ms, external action of
ON/OFF pin is locked out by startup inhibit
timer.
If (t2- t1) > 200 ms, ON/OFF pin action is
internally enabled.
t3Turn-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.
t4End of converter turn-on delay.
t5Converter VOUT reaches 100% of nominal value.
For the condition, (t2- t1) ≤ 200 ms, the total converter
startup time (t5- t2) is typically 204 ms. For (t2- t1) > 200 ms,
startup will be typically 4 ms after release of ON/OFF pin.
VIN
ON/OFF
STATE
VOUT
t
t0t1t2t3
ON
OFF
Fig. E: Startup scenario #1.
ON/OFF
STATE
VOUT
t0t1t2t3
ON
OFF
VIN
t
Fig. F: Startup scenario #2.
Fig. G: Startup scenario #3.
ON/OFF
STATE OFF
ON
VOUT
t0t2
t1t5
VIN
t
t
3
4
t
200 ms
ZD-02057 Rev. 4.1 www.power-one.com Page 8 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A 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. x.1 and Fig. x.2 for vertical and
horizontal converter mountings. 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 (40 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
thermocouple locations shown in Fig. H should not
exceed 120 °C in order to operate inside the derating
curves.
Efficiency
Fig. x.3 shows the efficiency vs. load current plot for
ambient temperature of 25 ºC, airflow rate of 300 LFM
(1.5 m/s) with horizontal 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
horizontal mounting is shown in Fig. x.4.
Power Dissipation
Fig. x.5 shows the power dissipation vs. load current
plot for Ta = 25 ºC, airflow rate of 300 LFM (1.5 m/s)
with horizontal mounting and input voltages of 36 V,
48 V and 72 V. Also, a plot of power dissipation vs.
load current, as a function of ambient temperature
with Vin = 48 V, airflow rate of 200 LFM (1 m/s) with
horizontal mounting is shown in Fig. x.6.
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. x.7-8, respectively.
Ripple and Noise
Fig. x.11 show 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 x.12. The
corresponding waveforms are shown in Figs. x.13-14.
ZD-02057 Rev. 4.1 www.power-one.com Page 9 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
Ambient Tem
p
erature
[
°C
]
20 30 40 50 60 70 80 90
Load Current [Adc]
0
10
20
30
40
50
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)
NC - 30 LFM (0.15 m/s)
Fig. 3.3V.1: Available load current vs. ambient air
temperature and airflow rates for QME48T40033 converter
with G height pins mounted vertically with air flowing from
pin 1 to pin 3, MOSFET temperature ≤ 120 °C, Vin = 48 V.
Note: NC – Natural convection
Load Current [Adc]
0 8 16 24 32 40 48
Efficiency
0.75
0.80
0.85
0.90
0.95
72 V
48 V
36 V
Fig. 3.3V.3: Efficiency vs. load current and input voltage
for QME48T40033 converter mounted horizontally with air
flowing from pin 1 to pin 3 at a rate of 300 LFM (1.5 m/s)
and Ta = 25 °C.
A
mbient Tem
p
erature
[
°C
]
20 30 40 50 60 70 80 90
Load Current [Adc]
0
10
20
30
40
50
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)
NC - 30 LFM (0.15 m/s)
Fig. 3.3V.2: Available load current vs. ambient air
temperature and airflow rates for QME48T40033 converter
with G height pins mounted horizontally with air flowing
from pin 1 to pin 3, MOSFET temperature ≤ 120 °C,
Vin = 48 V.
Load Current [Adc]
0 8 16 24 32 40 48
Efficiency
0.75
0.80
0.85
0.90
0.95
70 C
55 C
40 C
Fig. 3.3V.4: Efficiency vs. load current and ambient
temperature for QME48T40033 converter mounted
horizontally with Vin = 48 V and air flowing from pin 1 to
pin 3 at a rate of 200 LFM (1.0 m/s).
ZD-02057 Rev. 4.1 www.power-one.com Page 10 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
Load Current [Adc]
0 5 10 15 20 25 30 35
P
ower
Di
ss
i
pa
ti
on
[W]
0.00
3.00
6.00
9.00
12.00
15.00
18.00
72 V
48 V
36 V
Fig. 3.3V.5: Power dissipation vs. load current and input
voltage for QME48T40033 converter mounted
horizontally with air flowing from pin 1 to pin 3 at a rate of
300 LFM (1.5 m/s) and Ta = 25 °C.
Fig. 3.3V.7: Turn-on transient at full rated load current
(resistive) with no output capacitor at Vin = 48 V,
triggered via ON/OFF pin. Top trace: ON/OFF signal
(5 V/div.). Bottom trace: output voltage (1 V/div.). Time
scale: 2 ms/div.
Load Current [Adc]
0 8 16 24 32 40 48
P
ower
Di
ss
i
pa
ti
on
[W]
0.00
3.00
6.00
9.00
12.00
15.00
18.00
70 C
55 C
40 C
Fig. 3.3V.6: Power dissipation vs. load current and
ambient temperature for QME48T40033 converter
mounted horizontally with Vin = 48 V and air flowing from
pin 1 to pin 3 at a rate of 200 LFM (1.0 m/s).
Fig. 3.3V.8: Turn-on transient at full rated load current
(resistive) plus 10,000 µF at Vin = 48 V, triggered via
ON/OFF pin. Top trace: ON/OFF signal (5 V/div.).
Bottom trace: output voltage (1 V/div.). Time scale:
2 ms/div.
ZD-02057 Rev. 4.1 www.power-one.com Page 11 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
Fig. 3.3V.9: Output voltage response to load current
step-change (20 A – 30 A – 20 A) at Vin = 48 V. Top
trace: output voltage (100 mV/div.). Bottom trace: load
current (10 A/div.). Current slew rate: 0.1 A/µs.
Co = 1 µF ceramic. Time scale: 0.2 ms/div.
Fig. 3.3V.11: Output voltage ripple (20 mV/div.) at full
rated load current into a resistive load with Co = 10 µF
tantalum + 1 µF ceramic and Vin = 48 V. Time scale:
1 µs/div.
Fig. 3.3V.10: Output voltage response to load current
step-change (20 A – 30 A – 20 A) at Vin = 48 V. Top
trace: output voltage (100 mV/div.). Bottom trace: load
current (10 A/div.). Current slew rate: 5 A/µs.
Co = 470 µF POS + 1 µF ceramic. Time scale:
0.2 ms/div.
Vout
Vsource
iSiC
1 µF
ceramic
capacitor
10 µH
source
inductance
DC/DC
Converter
33 µF
ESR <1
electrolytic
capacitor
ΩQME Series
Fig. 3.3V.12: Test setup for measuring input reflected
ripple currents, ic and is.
ZD-02057 Rev. 4.1 www.power-one.com Page 12 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
Fig. 3.3V.13: Input reflected ripple current, ic
(100 mA/div.), measured at input terminals at full rated
load current and Vin = 48 V. Refer to Fig. 3.3V.12 for
test setup. Time scale: 1 µs/div.
Fig. 3.3V.15: Output voltage vs. load current showing
current limit point and converter shutdown point. Input
voltage has almost no effect on current limit
characteristic.
Fig. 3.3V.14: Input reflected ripple current, is
(10 mA/div.), measured through 10 µH at the source at
full rated load current and Vin = 48 V. Refer to
Fig. 3.3V.12 for test setup. Time scale: 1 µs/div.
Fig. 3.3V.16: Load current (top trace, 20 A/div.,
50 ms/div.) into a 10 m short circuit during restart, at
Vin = 48 V. Bottom trace (20 A/div., 2 ms/div.) is an
expansion of the on-time portion of the top trace.
ZD-02057 Rev. 4.1 www.power-one.com Page 13 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
Ambient Tem
p
erature
[
°C
]
20 30 40 50 60 70 80 90
Load Current [Adc]
0
10
20
30
40
50
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)
NC - 30 LFM (0.15 m/s)
Fig. 2.5V.1: Available load current vs. ambient air
temperature and airflow rates for QME48T40025 converter
with G height pins mounted vertically with air flowing from
pin 1 to pin 3, MOSFET temperature ≤ 120 °C, Vin = 48 V.
Note: NC – Natural convection
Load Current [Adc]
0 8 16 24 32 40 48
Efficiency
0.70
0.75
0.80
0.85
0.90
0.95
72 V
48 V
36 V
Fig. 2.5V.3: Efficiency vs. load current and input voltage
for QME48T40025 converter mounted horizontally with air
flowing from pin 1 to pin 3 at a rate of 300 LFM (1.5 m/s)
and Ta = 25 °C.
A
mbient Tem
p
erature
[
°C
]
20 30 40 50 60 70 80 90
Load Current [Adc]
0
10
20
30
40
50
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)
NC - 30 LFM (0.15 m/s)
Fig. 2.5V.2: Available load current vs. ambient air
temperature and airflow rates for QME48T40025 converter
with G height pins mounted horizontally with air flowing
from pin 1 to pin 3, MOSFET temperature ≤ 120 °C,
Vin = 48 V.
Load Current [Adc]
0 8 16 24 32 40 48
Efficiency
0.70
0.75
0.80
0.85
0.90
0.95
70 C
55 C
40 C
Fig. 2.5V.4: Efficiency vs. load current and ambient
temperature for QME48T40025 converter mounted
horizontally with Vin = 48 V and air flowing from pin 1 to
pin 3 at a rate of 200 LFM (1.0 m/s).
ZD-02057 Rev. 4.1 www.power-one.com Page 14 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
Load Current [Adc]
0 8 16 24 32 40 48
P
ower
Di
ss
i
pa
ti
on
[W]
0.00
3.00
6.00
9.00
12.00
15.00
18.00
72 V
48 V
36 V
Fig. 2.5V.5: Power dissipation vs. load current and input
voltage for QME48T40025 converter mounted
horizontally with air flowing from pin 1 to pin 3 at a rate of
300 LFM (1.5 m/s) and Ta = 25 °C.
Fig. 2.5V.7: Turn-on transient at full rated load current
(resistive) with no output capacitor at Vin = 48 V,
triggered via ON/OFF pin. Top trace: ON/OFF signal
(5 V/div.). Bottom trace: output voltage (1 V/div.). Time
scale: 2 ms/div.
Load Current [Adc]
0 8 16 24 32 40 48
P
ower
Di
ss
i
pa
ti
on
[W]
0.00
3.00
6.00
9.00
12.00
15.00
18.00
70 C
55 C
40 C
Fig. 2.5V.6: Power dissipation vs. load current and
ambient temperature for QME48T40025 converter
mounted horizontally with Vin = 48 V and air flowing from
pin 1 to pin 3 at a rate of 200 LFM (1.0 m/s).
Fig. 2.5V.8: Turn-on transient at full rated load current
(resistive) plus 10,000 µF at Vin = 48 V, triggered via
ON/OFF pin. Top trace: ON/OFF signal (5 V/div.).
Bottom trace: output voltage (1 V/div.). Time scale:
2 ms/div.
ZD-02057 Rev. 4.1 www.power-one.com Page 15 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
Fig. 2.5V.9: Output voltage response to load current
step-change (20 A – 30 A – 20 A) at Vin = 48 V. Top
trace: output voltage (100 mV/div.). Bottom trace: load
current (10 A/div.). Current slew rate: 0.1 A/µs.
Co = 1 µF ceramic. Time scale: 0.2 ms/div.
Fig. 2.5V.11: Output voltage ripple (20 mV/div.) at full
rated load current into a resistive load with Co = 10 µF
tantalum + 1 µF ceramic and Vin = 48 V. Time scale:
1 µs/div.
Fig. 2.5V.10: Output voltage response to load current
step-change (20 A – 30 A – 20 A) at Vin = 48 V. Top
trace: output voltage (100 mV/div.). Bottom trace: load
current (10 A/div.). Current slew rate: 5A/µs.
Co = 470 µF POS + 1 µF ceramic. Time scale:
0.2 ms/div.
Vout
Vsource
iSiC
1 µF
ceramic
capacitor
10 µH
source
inductance
DC/DC
Converter
33 µF
ESR <1
electrolytic
capacitor
ΩQME Series
Fig. 2.5V.12: Test setup for measuring input reflected
ripple currents, ic and is.
ZD-02057 Rev. 4.1 www.power-one.com Page 16 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
Fig. 2.5V.13: Input reflected ripple current, ic
(100 mA/div.), measured at input terminals at full rated
load current and Vin = 48 V. Refer to Fig. 2.5V.12 for
test setup. Time scale: 1 µs/div.
Fig. 2.5V.15: Output voltage vs. load current showing
current limit point and converter shutdown point. Input
voltage has almost no effect on current limit
characteristic.
Fig. 2.5V.14: Input reflected ripple current, is
(10 mA/div.), measured through 10 µH at the source at
full rated load current and Vin = 48 V. Refer to
Fig. 2.5V.12 for test setup. Time scale: 1 µs/div.
Fig. 2.5V.16: Load current (top trace, 20 A/div.,
50 ms/div.) into a 10 m short circuit during restart, at
Vin = 48 V. Bottom trace (20 A/div., 2 ms/div.) is an
expansion of the on-time portion of the top trace.
ZD-02057 Rev. 4.1 www.power-one.com Page 17 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
Ambient Tem
p
erature
[
°C
]
20 30 40 50 60 70 80 90
Load Current [Adc]
0
10
20
30
40
50
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)
NC - 30 LFM (0.15 m/s)
Fig. 1.8V.1: Available load current vs. ambient air
temperature and airflow rates for QME48T40018 converter
with G height pins mounted vertically with air flowing from
pin 1 to pin 3, MOSFET temperature ≤ 120 °C, Vin = 48 V.
Note: NC – Natural convection
Load Current [Adc]
0 8 16 24 32 40 48
Efficiency
0.65
0.70
0.75
0.80
0.85
0.90
0.95
72 V
48 V
36 V
Fig. 1.8V.3: Efficiency vs. load current and input voltage
for QME48T40018 converter mounted horizontally with air
flowing from pin 1 to pin 3 at a rate of 300 LFM (1.5 m/s)
and Ta = 25 °C.
A
mbient Tem
p
erature
[
°C
]
20 30 40 50 60 70 80 90
Load Current [Adc]
0
10
20
30
40
50
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)
NC - 30 LFM (0.15 m/s)
Fig. 1.8V.2: Available load current vs. ambient air
temperature and airflow rates for QME48T40018 converter
with G height pins mounted horizontally with air flowing
from pin 1 to pin 3, MOSFET temperature ≤ 120 °C,
Vin = 48 V.
Load Current [Adc]
0 8 16 24 32 40 48
Efficiency
0.65
0.70
0.75
0.80
0.85
0.90
0.95
70 C
55 C
40 C
Fig. 1.8V.4: Efficiency vs. load current and ambient
temperature for QME48T40018 converter mounted
horizontally with Vin = 48 V and air flowing from pin 1 to
pin 3 at a rate of 200 LFM (1.0 m/s).
ZD-02057 Rev. 4.1 www.power-one.com Page 18 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
Load Current [Adc]
0 8 16 24 32 40 48
P
ower
Di
ss
i
pa
ti
on
[W]
0.00
3.00
6.00
9.00
12.00
15.00
72 V
48 V
36 V
Fig. 1.8V.5: Power dissipation vs. load current and input
voltage for QME48T40018 converter mounted
horizontally with air flowing from pin 1 to pin 3 at a rate of
300 LFM (1.5 m/s) and Ta = 25 °C.
Fig. 1.8V.7: Turn-on transient at full rated load current
(resistive) with no output capacitor at Vin = 48 V,
triggered via ON/OFF pin. Top trace: ON/OFF signal
(5 V/div.). Bottom trace: output voltage (1 V/div.). Time
scale: 2 ms/div.
Load Current [Adc]
0 8 16 24 32 40 48
P
ower
Di
ss
i
pa
ti
on
[W]
0.00
3.00
6.00
9.00
12.00
15.00
70 C
55 C
40 C
Fig. 1.8V.6: Power dissipation vs. load current and
ambient temperature for QME48T40018 converter
mounted horizontally with Vin = 48 V and air flowing from
pin 1 to pin 3 at a rate of 200 LFM (1.0 m/s).
Fig. 1.8V.8: Turn-on transient at full rated load current
(resistive) plus 10,000 µF at Vin = 48 V, triggered via
ON/OFF pin. Top trace: ON/OFF signal (5 V/div.).
Bottom trace: output voltage (1 V/div.). Time scale:
2 ms/div.
ZD-02057 Rev. 4.1 www.power-one.com Page 19 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
Fig. 1.8V.9: Output voltage response to load current
step-change (20 A – 30 A – 20 A) at Vin = 48 V. Top
trace: output voltage (100 mV/div.). Bottom trace: load
current (10 A/div.). Current slew rate: 0.1 A/µs. Co =
1 µF ceramic. Time scale: 0.2 ms/div.
Fig. 1.8V.11: Output voltage ripple (20mV/div.) at full
rated load current into a resistive load with Co = 10 µF
tantalum + 1 µF ceramic and Vin = 48 V. Time scale:
1 µs/div.
Fig. 1.8V.10: Output voltage response to load current
step-change (20 A – 30 A – 20 A) at Vin = 48 V. Top
trace: output voltage (100 mV/div.). Bottom trace: load
current (10 A/div.). Current slew rate: 5 A/µs. Co =
470 µF POS + 1 µF ceramic. Time scale: 0.2 ms/div.
Vout
Vsource
iSiC
1 µF
ceramic
capacitor
10 µH
source
inductance
DC/DC
Converter
33 µF
ESR <1
electrolytic
capacitor
ΩQME Series
Fig. 1.8V.12: Test setup for measuring input reflected
ripple currents, ic and is.
ZD-02057 Rev. 4.1 www.power-one.com Page 20 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
Fig. 1.8V.13: Input reflected ripple current, ic
(100 mA/div.), measured at input terminals at full rated
load current and Vin = 48 V. Refer to Fig. 1.8V.12 for
test setup. Time scale: 1 µs/div.
Fig. 1.8V.15: Output voltage vs. load current showing
current limit point and converter shutdown point. Input
voltage has almost no effect on current limit
characteristic.
Fig. 1.8V.14: Input reflected ripple current, is
(10 mA/div.), measured through 10 µH at the source at
full rated load current and Vin = 48 V. Refer to
Fig. 1.8V.12 for test setup. Time scale: 1 µs/div.
Fig. 1.8V.16: Load current (top trace, 20 A/div.,
50 ms/div.) into a 10 m short circuit during restart, at
Vin = 48 V. Bottom trace (20 A/div., 2 ms/div.) is an
expansion of the on-time portion of the top trace.
ZD-02057 Rev. 4.1 www.power-one.com Page 21 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
Ambient Tem
p
erature
[
°C
]
20 30 40 50 60 70 80 90
Load Current [Adc]
0
10
20
30
40
50
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)
NC - 30 LFM (0.15 m/s)
Fig. 1.5V.1: Available load current vs. ambient air
temperature and airflow rates for QME48T40015 converter
with G height pins mounted vertically with air flowing from
pin 1 to pin 3, MOSFET temperature ≤ 120 °C, Vin = 48 V.
Note: NC – Natural convection
Load Current [Adc]
0 8 16 24 32 40 48
Efficiency
0.60
0.65
0.70
0.75
0.80
0.85
0.90
0.95
72 V
48 V
36 V
Fig. 1.5V.3: Efficiency vs. load current and input voltage
for QME48T40015 converter mounted horizontally with air
flowing from pin 1 to pin 3 at a rate of 300 LFM (1.5 m/s)
and Ta = 25 °C.
A
mbient Tem
p
erature
[
°C
]
20 30 40 50 60 70 80 90
Load Current [Adc]
0
10
20
30
40
50
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)
NC - 30 LFM (0.15 m/s)
Fig. 1.5V.2: Available load current vs. ambient air
temperature and airflow rates for QME48T40015 converter
with G height pins mounted horizontally with air flowing
from pin 1 to pin 3, MOSFET temperature ≤ 120 °C,
Vin = 48 V.
Load Current [Adc]
0 8 16 24 32 40 48
Efficiency
0.60
0.65
0.70
0.75
0.80
0.85
0.90
0.95
70 C
55 C
40 C
Fig. 1.5V.4: Efficiency vs. load current and ambient
temperature for QME48T40015 converter mounted
horizontally with Vin = 48 V and air flowing from pin 1 to
pin 3 at a rate of 200 LFM (1.0 m/s).
ZD-02057 Rev. 4.1 www.power-one.com Page 22 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
Load Current [Adc]
0 8 16 24 32 40 48
P
ower
Di
ss
i
pa
ti
on
[W]
0.00
3.00
6.00
9.00
12.00
15.00
72 V
48 V
36 V
Fig. 1.5V.5: Power dissipation vs. load current and input
voltage for QME48T40015 converter mounted
horizontally with air flowing from pin 1 to pin 3 at a rate of
300 LFM (1.5 m/s) and Ta = 25 °C.
Fig. 1.5V.7: Turn-on transient at full rated load current
(resistive) with no output capacitor at Vin = 48 V,
triggered via ON/OFF pin. Top trace: ON/OFF signal
(5 V/div.). Bottom trace: output voltage (1 V/div.). Time
scale: 2 ms/div.
Load Current [Adc]
0 8 16 24 32 40 48
P
ower
Di
ss
i
pa
ti
on
[W]
0.00
3.00
6.00
9.00
12.00
15.00
70 C
55 C
40 C
Fig. 1.5V.6: Power dissipation vs. load current and
ambient temperature for QME48T40015 converter
mounted horizontally with Vin = 48 V and air flowing from
pin 1 to pin 3 at a rate of 200 LFM (1.0 m/s).
Fig. 1.5V.8: Turn-on transient at full rated load current
(resistive) plus 10,000 µF at Vin = 48 V, triggered via
ON/OFF pin. Top trace: ON/OFF signal (5 V/div.).
Bottom trace: output voltage (1 V/div.). Time scale:
2 ms/div.
ZD-02057 Rev. 4.1 www.power-one.com Page 23 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
Fig. 1.5V.9: Output voltage response to load current
step-change (20 A – 30 A – 20 A) at Vin = 48 V. Top
trace: output voltage (100 mV/div.). Bottom trace: load
current (10 A/div.). Current slew rate: 0.1 A/µs. Co =
1 µF ceramic. Time scale: 0.2 ms/div.
Fig. 1.5V.11: Output voltage ripple (20 mV/div.) at full
rated load current into a resistive load with Co = 10 µF
tantalum + 1 µF ceramic and Vin = 48 V. Time scale:
1 µs/div.
Fig. 1.5V.10: Output voltage response to load current
step-change (20 A – 30 A – 20 A) at Vin = 48 V. Top
trace: output voltage (100 mV/div.). Bottom trace: load
current (10 A/div.). Current slew rate: 5A/µs. Co =
470 µF POS + 1 µF ceramic. Time scale: 0.2 ms/div.
Vout
Vsource
iSiC
1 µF
ceramic
capacitor
10 µH
source
inductance
DC/DC
Converter
33 µF
ESR <1
electrolytic
capacitor
ΩQME Series
Fig. 1.5V.12: Test setup for measuring input reflected
ripple currents, ic and is.
ZD-02057 Rev. 4.1 www.power-one.com Page 24 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
Fig. 1.5V.13: Input reflected ripple current, ic
(100 mA/div.), measured at input terminals at full rated
load current and Vin = 48 V. Refer to Fig. 1.5V.12 for
test setup. Time scale: 1 µs/div.
Fig. 1.5V.15: Output voltage vs. load current showing
current limit point and converter shutdown point. Input
voltage has almost no effect on current limit
characteristic.
Fig. 1.5V.14: Input reflected ripple current, is
(10 mA/div.), measured through 10 µH at the source at
full rated load current and Vin = 48 V. Refer to
Fig. 1.5V.12 for test setup. Time scale: 1 µs/div.
Fig. 1.5V.16: Load current (top trace, 20 A/div.,
50 ms/div.) into a 10 m short circuit during restart, at
Vin = 48 V. Bottom trace (20 A/div., 2 ms/div.) is an
expansion of the on-time portion of the top trace.
ZD-02057 Rev. 4.1 www.power-one.com Page 25 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
Ambient Tem
p
erature
[
°C
]
20 30 40 50 60 70 80 90
Load Current [Adc]
0
10
20
30
40
50
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)
NC - 30 LFM (0.15 m/s)
Fig. 1.2V.1: Available load current vs. ambient air
temperature and airflow rates for QME48T40012 converter
with G height pins mounted vertically with air flowing from
pin 1 to pin 3, MOSFET temperature ≤ 120 °C, Vin = 48 V.
Note: NC – Natural convection
Load Current [Adc]
0 8 16 24 32 40 48
Efficiency
0.60
0.65
0.70
0.75
0.80
0.85
0.90
72 V
48 V
36 V
Fig. 1.2V.3: Efficiency vs. load current and input voltage
for QME48T40012 converter mounted horizontally with air
flowing from pin 1 to pin 3 at a rate of 300 LFM (1.5 m/s)
and Ta = 25 °C.
A
mbient Tem
p
erature
[
°C
]
20 30 40 50 60 70 80 90
Load Current [Adc]
0
10
20
30
40
50
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)
NC - 30 LFM (0.15 m/s)
Fig. 1.2V.2: Available load current vs. ambient air
temperature and airflow rates for QME48T40012 converter
with G height pins mounted horizontally with air flowing
from pin 1 to pin 3, MOSFET temperature ≤ 120 °C,
Vin = 48 V.
Load Current [Adc]
0 8 16 24 32 40 48
Efficiency
0.60
0.65
0.70
0.75
0.80
0.85
0.90
70 C
55 C
40 C
Fig. 1.2V.4: Efficiency vs. load current and ambient
temperature for QME48T40012 converter mounted
horizontally with Vin = 48 V and air flowing from pin 1 to
pin 3 at a rate of 200 LFM (1.0 m/s).
ZD-02057 Rev. 4.1 www.power-one.com Page 26 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
Load Current [Adc]
0 8 16 24 32 40 48
P
ower
Di
ss
i
pa
ti
on
[W]
0.00
3.00
6.00
9.00
12.00
15.00
72 V
48 V
36 V
Fig. 1.2V.5: Power dissipation vs. load current and input
voltage for QME48T40012 converter mounted
horizontally with air flowing from pin 1 to pin 3 at a rate of
300 LFM (1.5 m/s) and Ta = 25 °C.
Fig. 1.2V.7: Turn-on transient at full rated load current
(resistive) with no output capacitor at Vin = 48 V,
triggered via ON/OFF pin. Top trace: ON/OFF signal
(5 V/div.). Bottom trace: output voltage (1 V/div.). Time
scale: 2 ms/div.
Load Current [Adc]
0 8 16 24 32 40 48
P
ower
Di
ss
i
pa
ti
on
[W]
0.00
3.00
6.00
9.00
12.00
15.00
70 C
55 C
40 C
Fig. 1.2V.6: Power dissipation vs. load current and
ambient temperature for QME48T40012 converter
mounted horizontally with Vin = 48 V and air flowing from
pin 1 to pin 3 at a rate of 200 LFM (1.0 m/s).
Fig. 1.2V.8: Turn-on transient at full rated load current
(resistive) plus 10,000 µF at Vin = 48 V, triggered via
ON/OFF pin. Top trace: ON/OFF signal (5 V/div.).
Bottom trace: output voltage (1 V/div.). Time scale:
2 ms/div.
ZD-02057 Rev. 4.1 www.power-one.com Page 27 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
Fig. 1.2V.9: Output voltage response to load current
step-change (20 A – 30 A – 20 A) at Vin = 48 V. Top
trace: output voltage (100 mV/div.). Bottom trace: load
current (10 A/div.). Current slew rate: 0.1 A/µs. Co =
1 µF ceramic. Time scale: 0.2 ms/div.
Fig. 1.2V.11: Output voltage ripple (20 mV/div.) at full
rated load current into a resistive load with Co = 10 µF
tantalum + 1 µF ceramic and Vin = 48 V. Time scale:
1 µs/div.
Fig. 1.2V.10: Output voltage response to load current
step-change (20 A – 30 A – 20 A) at Vin = 48 V. Top
trace: output voltage (100 mV/div.). Bottom trace: load
current (10 A/div.). Current slew rate: 5 A/µs. Co =
470 µF POS + 1 µF ceramic. Time scale: 0.2 ms/div.
Vout
Vsource
iSiC
1 µF
ceramic
capacitor
10 µH
source
inductance
DC/DC
Converter
33 µF
ESR <1
electrolytic
capacitor
ΩQME Series
Fig. 1.2V.12: Test setup for measuring input reflected
ripple currents, ic and is.
ZD-02057 Rev. 4.1 www.power-one.com Page 28 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
Fig. 1.2V.13: Input reflected ripple current, ic
(100 mA/div.), measured at input terminals at full rated
load current and Vin = 48 V. Refer to Fig. 1.2V.12 for
test setup. Time scale: 1 µs/div.
Fig. 1.2V.15: Output voltage vs. load current showing
current limit point and converter shutdown point. Input
voltage has almost no effect on current limit
characteristic.
Fig. 1.2V.14: Input reflected ripple current, is
(10 mA/div.), measured through 10 µH at the source at
full rated load current and Vin = 48 V. Refer to
Fig. 1.2V.12 for test setup. Time scale: 1 µs/div.
Fig. 1.2V.16: Load current (top trace, 20 A/div.,
50 ms/div.) into a 10 m short circuit during restart, at
Vin = 48 V. Bottom trace (20 A/div., 5 ms/div.) is an
expansion of the on-time portion of the top trace.
ZD-02057 Rev. 4.1 www.power-one.com Page 29 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
Ambient Tem
p
erature
[
°C
]
20 30 40 50 60 70 80 90
Load Current [Adc]
0
10
20
30
40
50
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)
NC - 30 LFM (0.15 m/s)
Fig. 1.0V.1: Available load current vs. ambient air
temperature and airflow rates for QME48T40010 converter
with G height pins mounted vertically with air flowing from
pin 1 to pin 3, MOSFET temperature ≤ 120 °C, Vin = 48 V.
Note: NC – Natural convection
Load Current [Adc]
0 8 16 24 32 40 48
Efficiency
0.50
0.60
0.70
0.80
0.90
72 V
48 V
36 V
Fig. 1.0V.3: Efficiency vs. load current and input voltage
for QME48T40010 converter mounted horizontally with air
flowing from pin 1 to pin 3 at a rate of 300 LFM (1.5 m/s)
and Ta = 25 °C.
A
mbient Tem
p
erature
[
°C
]
20 30 40 50 60 70 80 90
Load Current [Adc]
0
10
20
30
40
50
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)
NC - 30 LFM (0.15 m/s)
Fig. 1.0V.2: Available load current vs. ambient air
temperature and airflow rates for QME48T40010 converter
with G height pins mounted horizontally with air flowing
from pin 1 to pin 3, MOSFET temperature ≤ 120 °C,
Vin = 48 V.
Load Current [Adc]
0 8 16 24 32 40 48
Efficiency
0.65
0.70
0.75
0.80
0.85
70 C
55 C
40 C
Fig. 1.0V.4: Efficiency vs. load current and ambient
temperature for QME48T40010 converter mounted
horizontally with Vin = 48 V and air flowing from pin 1 to
pin 3 at a rate of 200 LFM (1.0 m/s).
ZD-02057 Rev. 4.1 www.power-one.com Page 30 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
Load Current [Adc]
0 8 16 24 32 40 48
P
ower
Di
ss
i
pa
ti
on
[W]
0.00
3.00
6.00
9.00
12.00
15.00
72 V
48 V
36 V
Fig. 1.0V.5: Power dissipation vs. load current and input
voltage for QME48T40010 converter mounted
horizontally with air flowing from pin 1 to pin 3 at a rate of
300 LFM (1.5 m/s) and Ta = 25 °C.
Fig. 1.0V.7: Turn-on transient at full rated load current
(resistive) with no output capacitor at Vin = 48 V,
triggered via ON/OFF pin. Top trace: ON/OFF signal
(5 V/div.). Bottom trace: output voltage (1 V/div.). Time
scale: 2 ms/div.
Load Current [Adc]
0 8 16 24 32 40 48
P
ower
Di
ss
i
pa
ti
on
[W]
0.00
3.00
6.00
9.00
12.00
15.00
70 C
55 C
40 C
Fig. 1.0V.6: Power dissipation vs. load current and
ambient temperature for QME48T40010 converter
mounted horizontally with Vin = 48 V and air flowing from
pin 1 to pin 3 at a rate of 200 LFM (1.0 m/s).
Fig. 1.0V.8: Turn-on transient at full rated load current
(resistive) plus 10,000 µF at Vin = 48 V, triggered via
ON/OFF pin. Top trace: ON/OFF signal (5 V/div.).
Bottom trace: output voltage (1 V/div.). Time scale:
2 ms/div.
ZD-02057 Rev. 4.1 www.power-one.com Page 31 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
Fig. 1.0V.9: Output voltage response to load current
step-change (20 A – 30 A – 20 A) at Vin = 48 V. Top
trace: output voltage (100 mV/div.). Bottom trace: load
current (10 A/div.). Current slew rate: 0.1 A/µs. Co =
1 µF ceramic. Time scale: 0.2 ms/div.
Fig. 1.0V.11: Output voltage ripple (20 mV/div.) at full
rated load current into a resistive load with Co = 10 µF
tantalum + 1 µF ceramic and Vin = 48 V. Time scale:
1 µs/div.
Fig. 1.0V.10: Output voltage response to load current
step-change (20 A – 30 A – 20 A) at Vin = 48 V. Top
trace: output voltage (100 mV/div.). Bottom trace: load
current (10 A/div.). Current slew rate: 5 A/µs. Co =
470 µF POS + 1 µF ceramic. Time scale: 0.2 ms/div.
Vout
Vsource
iSiC
1 µF
ceramic
capacitor
10 µH
source
inductance
DC/DC
Converter
33 µF
ESR <1
electrolytic
capacitor
ΩQME Series
Fig. 1.0V.12: Test setup for measuring input reflected
ripple currents, ic and is.
ZD-02057 Rev. 4.1 www.power-one.com Page 32 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
Fig. 1.0V.13: Input reflected ripple current, ic
(100 mA/div.), measured at input terminals at full rated
load current and Vin = 48 V. Refer to Fig. 1.0V.12 for
test setup. Time scale: 1 µs/div.
Fig. 1.0V.15: Output voltage vs. load current showing
current limit point and converter shutdown point. Input
voltage has almost no effect on current limit
characteristic.
Fig. 1.0V.14: Input reflected ripple current, is
(10 mA/div.), measured through 10 µH at the source at
full rated load current and Vin = 48 V. Refer to
Fig. 1.0V.12 for test setup. Time scale: 1 µs/div.
Fig. 1.0V.16: Load current (top trace, 20 A/div.,
50 ms/div.) into a 10 m short circuit during restart, at
Vin = 48 V. Bottom trace (20 A/div., 5 ms/div.) is an
expansion of the on-time portion of the top trace.
ZD-02057 Rev. 4.1 www.power-one.com Page 33 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
Physical Information
QME48T Pinout (Through-hole)
SIDE VIEW
TOP VIEW
1
2
3
7
8
6
5
4
Pad/Pin Connections
Pad/Pin # Function
1 Vin (+)
2 ON/OFF
3 Vin (-)
4 Vout (-)
5 SENSE(-)
6 TRIM
7 SENSE(+)
8 Vout (+)
Height
O
p
tion
HT
(
Max. Hei
g
ht
)
CL
(
Min. Clea
r
ance
)
G 0.425 [10.80] 0.035 [0.89]
PL
Pin Len
g
th
Pin
Option ±0.005 [±0.13]
A 0.188 [4.78]
B 0.145 [3.68]
QME48T Platform Notes
• All dimensions are in inches [mm]
• Pins 1-3 and 5-7 are Ø 0.040” [1.02] with Ø 0.078”
[1.98] shoulder
• Pins 4 and 8 are Ø 0.062” [1.57] without shoulder
• Pin Material & Finish: Brass Alloy 360
with Matte Tin over Nickel
• Converter Weight: 1.2 oz [34.2 g] typical
ZD-02057 Rev. 4.1 www.power-one.com Page 34 of 35
QME48T40 DC-DC Series Data Sheet
36-75 VDC Input; 1.0-3.3 VDC @ 40A Output
Heatsink
O
p
tion
HT
(
Max. Hei
g
ht
)
CL
(
Min.
S1 0.99 [25.1] 0.039 [1.00]
PL
Pin Length
Pin
Option ±0.005 [±0.13]
B 0.145 [3.68]
Converter Part Numbering Ordering Information
Product
Series
Input
Voltage
Mounting
Scheme
Rated
Load
Current
Output
Voltage ON/OFF
Logic
Max
Height
[HT]
Pin
Length
[PL]
Special
Feature
s
RoHS Heatsink
QME 48 T 40 033 - N G B 0
Quarter-
Brick
Format
36-75 V
T ⇒
Through-
hole
40 ADC
010 ⇒1.0V
012 ⇒1.2V
015 ⇒1.5V
018 ⇒1.8V
025 ⇒2.5V
033 ⇒3.3V
N ⇒
Negative
P ⇒
Positive
Through
hole
G ⇒
0.425”
Through
hole
A ⇒
0.188”
B ⇒
0.145”
0 ⇒
STD
Non-
Latching
L ⇒
Latching
Option
No Suffix
⇒ RoHS
lead-solder-
exemption
compliant
G ⇒ RoHS
compliant
for all six
substances
No Suffix
⇒ No
heatsink
-S1 ⇒
Heatsink
as shown
Example: The example above describes P/N QME48T40033-NGB0: 36-75 V input, through-hole, 40 A @ 3.3 V output, negative ON/OFF
logic, a 0.145” solder tail and maximum height of 0.425”, standard (non-latching) protection, and Eutectic Tin/Lead solder. Consult factory for
the complete list of available options.
Attention: The heatsink option “S1” is only available with the model QME48T40033-NGBOG-S1
Notes:
1. NUCLEAR AND MEDICAL APPLICATIONS - Power-One products are not designed, intended for use in, or authorized for use as critical
components in life support systems, equipment used in hazardous environments, or nuclear control systems without the express written
consent of the respective divisional president of Power-One, Inc.
2. TECHNICAL REVISIONS - The appearance of products, including safety agency certifications pictured on labels, may change depending
on the date manufactured. Specifications are subject to change without notice.
ZD-02057 Rev. 4.1 www.power-one.com Page 35 of 35
