The QmaXTM Series of high current single output DC-DC converters from
Power Bel Solutions sets new standards for thermal performance and power
density in the quarter brick package.
The 40A QM48S converters of the QmaXTM Series provide thermal
performance in high temperature environments that is comparable to or
exceeds the industry’s leading 40A half bricks. This is accomplished through
the use of patent pending circuit, packaging and processing techniques to
achieve ultra-high efficiency, excellent thermal management and a very low
body profile.
The QM48S40 converters have a power density of up to 130 W/in3, more
than twice that of competitors’ 40A half bricks. Over 1 square inch of board
space can be saved for every slot in which a 40A half brick is replaced with a
QM48S40 converter from Power Bel Solutions.
Low body profile and the preclusion of heat sinks minimize impedance to
system airflow, thus enhancing cooling for downstream devices. The use of
100% automation for assembly, coupled with Power Bel Solutions advanced
electric and thermal design, results in a product with extremely high reliability.
Operating from a 36-75 V input, the QmaXTM Series converters provide
standard output voltage for 3.3 V. Output can be trimmed from –20% to +10%
of the nominal output voltage, thus providing outstanding design flexibility.
Delivers up to 40 A (132 W)
Industry-standard SM quarter brick pinout
Higher current capability at 70 ºC than most competitors’ 40 A half
bricks
On-board input differential LC-filter
High efficiency – no heat sink required
Start up into pre-biased output
No minimum load required
Low profile: 0.28” [7.1 mm]
Low weight: 1.06 oz [30 g] typical
Meets Basic Insulation requirements of EN60950
Withstands 100 V input transient for 100 ms
Fixed-frequency operation
Fully protected
Remote output sense
Output voltage trim range: +10%/−20% with Industry-standard trim
equations
High reliability: MTBF of 2.6 million hours, calculated per Telcordia TR-
332, Method I Case 1
Positive or negative logic ON/OFF option
Approved to the following Safety Standards: UL/CSA60950-1,
EN60950-1, and IEC60950-1
Meets conducted emissions requirements of FCC Class B and EN
55022 Class B with external filter
All materials meet UL94, V-0 flammability rating
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Conditions: TA = 25ºC, Airflow = 300 LFM (1.5 m/s), Vin = 48 VDC, unless otherwise specified.
PARAMETER
CONDITIONS / DESCRIPTION
MIN
TYP
UNITS
Absolute Maximum Ratings
Input Voltage
Continuous
0
Vdc
Operating Ambient Temperature
-40
°C
Storage Temperature
-55
°C
Input Characteristics
Operating Input Voltage Range
36
48
Vdc
Input Under Voltage Lockout
Non-latching
Turn-on Threshold
33
34
Vdc
Turn-off Threshold
31
32
Vdc
Input Voltage Transient
100 ms
Vdc
Isolation Characteristics
I/O Isolation
2000
Vdc
Isolation Capacitance
1.4
nF
Isolation Resistance
10
MΩ
Feature Characteristics
Switching Frequency
415
kHz
Output Voltage Trim Range1
Industry-std. equations on page 4
-20
%
Remote Sense Compensation1
Percent of VOUT(nom)
%
Output Over-Voltage Protection
Non-latching
117
128
%
Auto-Restart Period
Applies to all protection features
100
ms
Turn-On Time
4
ms
ON/OFF Control (Positive Logic)
Converter Off
-20
Vdc
Converter On
2.4
Vdc
ON/OFF Control (Negative Logic)
Converter Off
2.4
Vdc
Converter On
-20
Vdc
Input Characteristics
Maximum Input Current
40 Adc, 3.3 Vdc Out @ 36 Vdc In
Adc
Input Stand-by Current
Vin = 48 V, converter disabled
3
mAdc
Input No Load Current (0 load on the output)
Vin = 48 V, converter enabled
63
mAdc
Input Reflected-Ripple Current
25MHz bandwidth
7.5
mAPK-PK
Input Voltage Ripple Rejection
120Hz
64
dB
Output Characteristics
Output Voltage Set Point (no load)
3.267
3.300
Vdc
Output Regulation
Over Line
±2
mV
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Over Load
±2
mV
Output Voltage Range
Over line, load and temperature2
3.250
Vdc
Output Ripple and Noise - 25MHz bandwidth
Full load + 10 μF tantalum + 1 μF ceramic
30
mVPK-PK
External Load Capacitance
Plus full load (resistive)
μF
Output Current Range
0
Adc
Current Limit Inception
Non-latching
42
47
Adc
Peak Short-Circuit Current
Non-latching. Short=10mΩ.
50
A
RMS Short-Circuit Current
Non-latching
10
Arms
Dynamic Response
Load Change 25% of Iout Max, di/dt = 1 A/μS
Co = 470 μF tantalum + 1 μF ceramic
120
mV
Setting Time to 1%
80
µs
Efficiency
100% Load
90.5
%
50% Load
92.5
%
1) Vout can be increased up to 10% via the sense leads or up to 10% via the trim function, however total output voltage trim
from all sources should not exceed 10% of VOUT(nom), in order to insure specified operation of over-voltage protection
circuitry.
2) -40ºC to 85ºC
2.1
These power converters have been designed to be stable with no external capacitors when used in low inductance input
and output circuits.
However, 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 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.
2.2
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 logic and negative logic and both are referenced to Vin(-). Typical connections are shown in
Fig. 1.
Rload
Vin
CONTROL
INPUT
Vin (+)
Vin (-)
ON/OFF
Vout (+)
Vout (-)
TRIM
SENSE (+)
SENSE (-)
(Top View)
Converter
QmaXTM Series
Figure 1. 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.
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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 hard wired directly to Vin (-) to enable automatic power up of the converter without the need of an external control
signal.
ON/OFF pin is internally pulled-up to 5 V through a resistor. A 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 Start-up Information section for
system timing waveforms associated with use of the ON/OFF pin.
2.3
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. 2).
100
10
Rw
Rw
Rload
Vin
Vin (+)
Vin (-)
ON/OFF
Vout (+)
Vout (-)
TRIM
SENSE (+)
SENSE (-)
(Top View)
Converter
QmaXTM Series
Figure 2. Remote sense circuit configuration
If remote sensing is not required, 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 value.
Because the sense leads carry minimal current, large traces on the end-user board are not required. However, sense traces
should be located close to a ground plane to minimize system noise and insure optimum performance. When wiring
discretely, twisted pair wires should be used to connect the sense lines to the load to reduce susceptibility to noise.
The converter’s output over-voltage 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, 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 actual
output power remains at or below the maximum allowable output power.
2.4
The output voltage can be adjusted up 10% or down 20% relative to the rated output voltage by the addition of an externally
connected resistor. Trim up to 10% is guaranteed only at Vin ≥ 40 V, and it is marginal (8% to 10%) at Vin = 36 V.
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. 3. A trim resistor, RT-INCR, should be connected between the TRIM (Pin 6) and
SENSE(+) (Pin 7), with a value of:
10.22
1.225Δ
626Δ)V5.11(100
RNOMO
INCRT
[kΩ]
where,
RT-INCR = Required value of trim-up resistor k]
VO-NOM = Nominal value of output voltage [V]
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100X
V)V(V
ΔNOM- O
NOM-OREQ-O
[kΩ]
Vo-REQ = Desired (trimmed) output voltage [V].
When trimming up, care must be taken not to exceed the converter‘s maximum allowable output power. See 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
SeriesQmaXTM
Figure 3. Configuration for increasing output voltage.
To decrease the output voltage (Fig. 4), a trim resistor, RT-DECR, should be connected between the TRIM (Pin 6) and SENSE
(-) (Pin 5), with a value of:
10.22
|Δ|
511
RDECRT
[kΩ]
where,
RT-DECR Required value of trim-down resistor [k]
and
Δ
is as defined above.
Note:
The above equations for calculation of trim resistor values match those typically used in conventional industry-standard
quarter bricks. For more information see Application Note 103.
Rload
Vin
Vin (+)
Vin (-)
ON/OFF
Vout (+)
Vout (-)
TRIM
SENSE (+)
SENSE (-) RT-DECR
(Top View)
Converter
Series
QmaXTM
QmaXQmaXTM
Figure 4. 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 over-voltage 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 0.33 V, or:
SENSESENSEOUTOUT 0.33)](V)([V)](V)([V
[V]
This equation is applicable for any condition of output sensing and/or output trim.
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Input under-voltage 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 34V for the converter to turn on. Once the converter has been turned on, it will shut off
when the input voltage drops typically below 32V. This feature is beneficial in preventing deep discharging of batteries used
in telecom applications.
The converter is protected against overcurrent or short circuit conditions. Upon sensing an over-current condition, the
converter will switch to constant current operation and thereby begin to reduce output voltage. When the output voltage
drops below 50% 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 100 ms with a typical 1-2% duty cycle. The
attempted restart will continue indefinitely until the overload or short circuit conditions are removed or the output voltage
rises above 50% of its nominal value.
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 100 ms until the OVP condition is removed.
The converter will shut down under an over temperature 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.
The converters meet North American and International safety regulatory requirements per UL60950 and EN60950. 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. A 7.5-A fuse is
recommended for use with this product.
Modules are UL approved for maximum fuse rating of 15-A. To protect a group of modules with a single fuse, the rating can
be increased from the recommended values above.
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 Bel Solutions 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.
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 QmaX™ Series of converters pass the requirements of Class
B conducted emissions per EN55022 and FCC, and meet at a minimum, Class A radiated emissions per EN 55022 and Class
B per FCC Title 47CFR, Part 15-J. Please contact Power Bel Solutions Applications Engineering for details of this testing.
Figure 5. Location of the thermocouple for thermal testing.
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Scenario #1: Initial Startup From Bulk Supply
ON/OFF function enabled, converter started via application of
VIN. See Figure 6.
Time
Comments
t0
ON/OFF pin is ON; system front-end power is
toggled on, VIN to converter begins to rise.
t1
VIN crosses Under-Voltage Lockout protection circuit
threshold; converter enabled.
t2
Converter begins to respond to turn-on command
(converter turn-on delay).
t3
Converter VOUT reaches 100% of nominal value
For this example, the total converter startup time (t3- t1) is
typically 4 ms.
Figure 6. Start-up scenario #1.
Scenario #2: Initial Startup Using ON/OFF Pin
With VIN previously powered, converter started via ON/OFF pin.
See Figure 7.
Time
Comments
t0
VINPUT at nominal value.
t1
Arbitrary time when ON/OFF pin is enabled (converter
enabled).
t2
End of converter turn-on delay.
t3
Converter VOUT reaches 100% of nominal value.
For this example, the total converter startup time (t3- t1) is
typically 4 ms.
Figure 7. Startup scenario #2.
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 8.
Time
Comments
t0
VIN and VOUT are at nominal values; ON/OFF pin ON.
t1
ON/OFF pin arbitrarily disabled; converter output falls
to zero; turn-on inhibit delay period (100 ms typical) is
initiated, and ON/OFF pin action is internally inhibited.
t2
ON/OFF pin is externally re-enabled.
If (t2- t1) ≤ 100 ms, external action of ON/OFF
pin is locked out by startup inhibit timer.
If (t2- t1) > 100 ms, ON/OFF pin action is
internally enabled.
t3
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 7.
t4
End of converter turn-on delay.
t5
Converter VOUT reaches 100% of nominal value.
For the condition, (t2- t1) ≤ 100 ms, the total converter startup time
(t5- t2) is typically 104 ms. For (t2- t1) > 100 ms, startup will be
typically 4 ms after release of ON/OFF pin.
Figure 8. Startup scenario #3.
VIN
ON/OFF
STATE
VOUT
t
t0t1t2t3
ON
OFF
ON/OFF
STATE
VOUT
t0t1t2t3
ON
OFF
VIN
t
ON/OFF
STATE OFF
ON
VOUT
t0t2t1t5
VIN
t
t4t3
100 ms
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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 mounting, efficiency, start-up 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.
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, comprising 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 Power Bel Solutions vertical and horizontal wind tunnel facilities 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. Power Bel Solutions recommends the use of AWG #40 gauge thermocouples to ensure
measurement accuracy. Careful routing of the thermocouple leads will further minimize measurement error. Refer to Figure
5 for optimum measuring thermocouple location.
Load current vs. ambient temperature and airflow rates are given in Figs. 17 and 18 for vertical and horizontal converter
mounting. 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 (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 than or equal to 120°C should not be
exceeded. Temperature on the PCB at the thermocouple location shown in Fig. 5 should not exceed 118°C in order to
operate inside the derating curves.
4.4
Fig. 11 shows the efficiency vs. load current plot for ambient temperature of 25ºC, 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. 12.
Fig. 13 shows the power dissipation vs. load current plot for Ta = 25ºC, 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 power dissipation 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. 14.
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 Fig. 15 and Fig. 16, respectively.
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Fig. 18 shows 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 F ceramic capacitor.
The input reflected ripple current waveforms are obtained using the test setup shown in Fig. 19. The corresponding
waveforms are shown in Fig. 20 and Fig. 21.
Ambient Temperature [°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)
30 LFM (0.15 m/s)
Figure 9. Available load current vs. ambient air temperature
and airflow rates for QM48S40033 converter mounted
vertically with air flowing from pin 3 to pin 1, MOSFET
temperature 120 C, Vin = 48 V.
Ambient Temperature [°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)
30 LFM (0.15 m/s)
Figure 10. Available load current vs. ambient air temperature
and airflow rates for QM48S40033 converter mounted
horizontally with air flowing from pin 3 to pin 1, MOSFET
temperature 120 C, Vin = 48 V.
Load Current [Adc]
010 20 30 40 50
Efficiency
0.65
0.70
0.75
0.80
0.85
0.90
0.95
72 V
48 V
36 V
Figure 11. Efficiency vs. load current and input voltage for
converter mounted vertically with air flowing from pin 3 to pin 1
ºC.
Load Current [Adc]
010 20 30 40 50
Efficiency
0.65
0.70
0.75
0.80
0.85
0.90
0.95
70 C
55 C
40 C
Figure 12. 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).
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Load Current [Adc]
010 20 30 40 50
Power Dissipation [W]
0.00
4.00
8.00
12.00
16.00
72 V
48 V
36 V
Figure 13. Power dissipation 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
ºC.
Load Current [Adc]
010 20 30 40 50
Power Dissipation [W]
0.00
4.00
8.00
12.00
16.00
70 C
55 C
40 C
Figure 14. Power dissipation 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).
Figure 15. Turn-on transient at full rated load current (resistive)
with no out-put 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.
Figure 16. Turn-on transient at full rated load current (resistive)
plus 40,000 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.
Figure 17. 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: 1 A/µs. Co = 470 µF tantalum + 1 µF
ceramic. Time scale: 0.2 ms/div.
Figure 18. Output voltage ripple (20 mV/div.) at full rated load
current into a resistive load with Co = 10 µF tantalum + 1µF
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Vout
Vsource
iSiC
1 F
ceramic
capacitor
10 H
source
inductance DC/DC
Converter
33 F
ESR <1
electrolytic
capacitor
QmaXSeries
QmaXTM
Figure 19. Test setup for measuring input reflected ripple currents, ic and is.
Figure 20. Input reflected ripple current, is (10 mA/div),
current and Vin = 48 V. Refer to Fig. 19 for test setup. Time
Figure 21. Input reflected ripple current, ic (100 mA/div),
measured at in-put terminals at full rated load current and Vin
= 48 V. Refer to Fig. 19 for test setup. Time scale: 1 µs/div.
Figure 22. Output voltage vs. load current showing current
limit point and converter shutdown point. Input voltage has
almost no effect on current limit characteristic.
Figure 23. Load current (top trace, 20 A/div, 20 ms/div) into a
10 m
Ω
short circuit during restart, at Vin = 48 V. Bottom trace
(20 A/div, 1 ms/div) is an expansion of the on-time portion of
the top trace.
Iout [Adc]
15 60
4.0
Vout [Vdc]
0
0
2.0
1.0
30 45
3.0
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• All dimensions are in inches [mm]
• Connector Material: Copper
• Connector Finish: Gold over
Nickel
• Converter Weight: 1.06oz [30 g]
• Recommended Surface-Mount
Pads:
• Min. 0.080” X 0.112” [2.03 x 2.84]
• Max. 0.092” X 0.124” [2.34 x 3.15]
PAD/PIN CONNECTIONS
Pad/Pin #
Function
1
Vin (+)
2
ON/OFF
3
Vin (-)
4
Vout (-)
5
SENSE (-)
6
TRIM
7
SENSE (+)
8
Vout (+)
Product
Series
Input
Voltage
Mounting
Scheme
Rated
Load
Current
Output
Voltage
ON/OFF
Logic
Maximum
Height [HT]
Pin
Length [PL]
Special
Features
RoHS
QM
48
S
40
033
-
N
S
0
0
G
Quarter-
Brick
Format
36-75 V
Surface
Mount
40 A
033 3.3 V
N
Negative
P
Positive
S 0.295”
0 0.00”
0 STD
No Suffix
RoHS
lead-solder-
exemption
compliant
G RoHS
compliant
for all six
substances
The example above describes P/N QM48S40033-NS00G: 36-75 V input, surface mount, 40 A @ 3.3 V output, negative ON/OFF logic, maximum
height of 0.295” and RoHS compliant for all six substances. Please consult factory regarding availability of a specific version.
NUCLEAR AND MEDICAL APPLICATIONS - Products are not designed or intended for use as critical components in life support systems,
equipment used in hazardous environments, or nuclear control systems.
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.