The new high performance 40A SQE48T40015 DC-DC converter provides a
high efficiency single output, in an eighth brick package that is only 62% the
size of the industry-standard quarter-brick. Specifically designed for operation
in systems that have limited airflow and increased ambient temperatures, the
SQE48T40015 converter utilize the same pinout and functionality of the
industry-standard quarter-bricks.
The SQE48T40015 converter provides thermal performance in high
temperature environments that exceeds most 40A quarter-bricks in the
market. 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.
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 36-75V input, the SQE48T40015 converter provides a 1.5V
output voltage that can be trimmed from –20% to +10% of the nominal output
voltage, thus providing outstanding design flexibility.
With standard pinout and trim equations, the SQE48T40015 converter is a
perfect drop-in replacement for existing 40A quarter-brick designs. Inclusion
of this converter in a new design can result in significant board space and cost
savings. The designer can expect reliability improvement over other available
converters because of the SQE48T40015’s optimized thermal efficiency.
36-75 VDC Input; 1.5 VDC @ 40 A Output
Industry-standard eighth-brick pinout
On-board input differential LC-filter
Start-up into pre-biased load
No minimum load required
Withstands 100 V input transient for 100 ms
Fixed-frequency operation
Fully protected
Remote output sense
Positive or negative logic ON/OFF option
Output voltage trim range: +10%/−20% with industry-standard trim
equations
High reliability: MTBF = 15.4 million hours, calculated per Telcordia SR332, Method I Case 1
Approved to the latest edition of the following standards:
UL/CSA60950-1, IEC60950-1 and EN60950-1
RoHS lead-free solder & lead-solder-exempted products are available
Asia-Pacific
+86 755 298 85888
Europe, Middle East
+353 61 225 977
© 2015 Bel Power Solutions, Inc.
North America
+1 866 513 2839
BCD.00726_AA
2
Conditions: TA = 25 ºC, Airflow = 300 LFM (1.5 m/s), Vin = 48 VDC, Cin = 33 µF, unless otherwise specified.
PARAMETER
CONDITIONS / DESCRIPTION
MIN
Continuous
-0.3
TYP
MAX
UNITS
80
VDC
Absolute Maximum Ratings
Input Voltage
Operating Ambient Temperature
-40
85
°C
3000
m
3001
10000
m
-55
125
°C
Iout = 40 A
Operating Altitude
Iout ≤ 32 A
Storage Temperature
Isolation Characteristics
I/O Isolation
Standard Product:
Option 0
(refer to Ordering Information)
Isolation Capacitance
Isolation Resistance
I/O Isolation
2250
160
Isolation Resistance
pF
10
MΩ
1500
VDC
Option K
(refer to Ordering Information)
Isolation Capacitance
VDC
200
1500
10
pF
MΩ
Feature Characteristics
Switching Frequency
440
1
Output Voltage Trim Range
Remote Sense Compensation
Industry-std. equations
1
-20
Percent of VOUT(nom)
117
122
kHz
+10
%
+10
%
Output Overvoltage Protection
Non-latching
130
%
Overtemperature Shutdown (PCB)
Non-latching
125
°C
Operating Humidity
Non-condensing
95
%
Storage Humidity
Non-condensing
95
%
Peak Back-drive Output Current
(Sinking current from external source)
during startup into pre-biased output
Back-drive Output Current
(Sinking Current from external source)
Peak amplitude
1
ADC
Peak duration
50
µs
Converter OFF;
external voltage 5 VDC
10
Auto-Restart Period
Applies to all protection features
200
Turn-On Time
See Figures E, F, and G
3
50
mADC
ms
15
ms
Converter Off (logic low)
-20
0.8
VDC
Converter On (logic high)
2.4
20
VDC
ON/OFF Control (Positive Logic)
Converter Off (logic high)
2.4
20
VDC
Converter On (logic low)
-20
0.8
VDC
ON/OFF Control (Negative Logic)
Input Characteristics
Operating Input Voltage Range
75
VDC
Turn-on Threshold
36
33
48
35.5
VDC
Turn-off Threshold
32.5
34.5
VDC
Input Undervoltage Lockout
1
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.
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Lockout Hysteresis Voltage
2.0
VDC
100
VDC
Input Voltage Transient Rate
7
V/ms
Input Current Transient Rate
0.1
A2s
2.0
ADC
Input Voltage Transient
1.0
100 ms
Maximum Input Current
40 ADC Out @ 36 VDC In, VOUT = 1.5 VDC
Input Stand-by Current
Vin = 48 V, converter disabled
2
Input No Load Current
(0 A load on the output)
Vin = 48 V, converter enabled, VOUT = 1.5 VDC
30
50
mA
Input Reflected-Ripple Current, is
Vin = 48 V, 25 MHz bandwidth, VOUT = 1.5VDC
8
30
mAPK-PK
Input Voltage Ripple Rejection
120 Hz, VOUT = 1.5 VDC
60
mA
dB
Output Characteristics
External Load Capacitance
Plus full load (resistive)
Output Current Range
Current Limit Inception
Non-latching
Peak Short-Circuit Current
Non-latching, Short = 10 mΩ
RMS Short-Circuit Current
Non-latching
20000
µF
0
40
ADC
42
48
ADC
50
A
+1
%Vout
±2
±5
mV
±2
±5
mV
+3.0
%Vout
12
Output Voltage Set Point (no load)2
Arms
-1
Over Line
Output Regulation
Over Load
2
Output Voltage Range
Over line, load and temperature
Output Ripple and Noise
(25 MHz bandwidth)
Full load + 10µF tantalum + 1µF ceramic VOUT
= 1.5 VDC
-3.0
35
mVPK-PK
Co = 1 µF ceramic (Figure 8)
30
mV
100
µs
150
mV
20
µs
Dynamic Response
Load Change 50%-75%-50% of Iout Max,
di/dt = 0.1 A/μs
Settling Time to 1% of Vout
di/dt = 2.5 A/μs
Co = 470 µF POS + 1µF ceramic (Figure 9)
Settling Time to 1% of Vout
Efficiency
100% Load
VOUT = 1.5 VDC
86.7
%
50% Load
VOUT = 1.5 VDC
90
%
25.1
g
5-9
5
9-200
1
10
Hz
mm/s
Hz
g
g
Mechanical
Weight
Freq. Velocity IEC 68-2-6
Vibration IEC Class 3M5
Freq. Accelerat. IEC 68-2-6
Shocks IEC Class 3M5
Accelerat. IEC 68-2-29
MIL-STD-202F
Method 213B Cond. F
Reliability
Telcordia SR-332, Method I Case 1
50% electrical stress, 40°C ambient
MTBF
2
15.4
MHrs
Operating ambient temperature range of -40 ºC to 85 ºC for converter.
tech.support@psbel.com
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These power converters have been designed to be stable with no external capacitors when used in low inductance input
and output circuits.
However, in some applications, the inductance associated with the distribution from the power source to the input of the
converter can affect the stability of the converter. A 33 µF electrolytic capacitor with an ESR < 1Ω across the input is
recommended to ensure stability of the converter over the wide range of input source impedance.
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 20000 µF.
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.
Vin (+)
SQE48 Converter
(Top View)
Vout (+)
SENSE (+)
ON/OFF
Vin
TRIM
Rload
SENSE (-)
Vin (-)
Vout (-)
CONTROL
INPUT
Figure 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 the pin is 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 hard wired 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 5V through a resistor. A properly de-bounced 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 0.2mA at
a low level voltage of 0.8V. An external voltage source (±20V maximum) may be connected directly to the ON/OFF input,
in which case it must be capable of sourcing or sinking up to 1mA depending on the signal polarity. See the Startup
Information section for system timing waveforms associated with use of the ON/OFF pin.
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).
SQE48 Converter
Vin (+)
(Top View)
Rw
Vout (+)
100
SENSE (+)
Vin
ON/OFF
TRIM
Rload
SENSE (-)
10
Vin (-)
Vout (-)
Rw
Figure B. Remote sense circuit configuration.
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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 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 actual
output power remains at or below the maximum allowable output power.
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.
The TRIM pin should be left open if trimming is not being used. To minimize noise pickup, a 0.1µF 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:
RTINCR
5.11(100 Δ)V ONOM 626
10.22
1.225Δ
[kΩ],
where,
RTINCR Required value of trim-up resistor kΩ]
VONOM Nominal value of output voltage [V]
Δ
(VO-REQ VO-NOM )
X 100
VO -NOM
[%]
VOREQ
Desired (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.
Vin (+)
SQE48 Converter
Vout (+)
(Top View)
SENSE (+)
Vin
ON/OFF
R T-INCR
TRIM
Rload
SENSE (-)
Vin (-)
Vout (-)
Figure 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:
RTDECR
511
10.22
|Δ|
[kΩ]
where,
tech.support@psbel.com
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RTDECR Required value of trim-down resistor [kΩ] and Δ
is defined above.
Note:
The above equations for calculation of trim resistor values match those typically used in conventional industry-standard quarter-bricks.
Vin (+)
SQE48 Converter
Vout (+)
(Top View)
SENSE (+)
Vin
ON/OFF
TRIM
Rload
RT-DECR
SENSE (-)
Vin (-)
Vout (-)
Figure 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:
[VOUT() VOUT()] [VSENSE() VSENSE()] VO - NOM X 10% [V]
This equation is applicable for any condition of output sensing and/or output trim.
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 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 33V. 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 overcurrent condition, the
converter will switch to constant current operation and thereby begin to reduce output voltage.
If the converter is equipped with the special OCP version designated by the suffix K in the part number, the converter will
shut down in approximately 15 ms after entering the constant current mode of operation. The standard version (suffix 0) will
continue operating in the constant current mode until the output voltage drops below 60% at which point the converter will
shut down as shown in Figure 14.
Once the converter has shut down, it will attempt to restart nominally every 200 ms with a typical 3-5% duty cycle as shown
in Figure 15. 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.
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 200ms until the OVP condition is removed.
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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. Converter with the nonlatching option will automatically restart after it has cooled to a safe operating temperature.
The converters meet North American and International safety regulatory requirements per UL60950 and EN60950. Basic
Insulation is provided between input and output.
The converters have no internal fuse. If required, the external fuse needs to be provided to protect the converter from
catastrophic failure. Refer to the “Input Fuse Selection for DC/DC converters” application note on belpowersolutions.com
for proper selection of the input fuse. Both input traces and the chassis ground trace (if applicable) must be capable of
conducting a current of 1.5 times the value of the fuse without opening. The fuse must not be placed in the grounded input
line.
Abnormal and component failure tests were conducted with the input protected by a TBD fuse. If a fuse rated greater than
TBD A is used, additional testing may be required. To protect a group of converters with a single fuse, the rating can be
increased from the recommended value 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, Bel Power 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.
An effective internal LC differential filter significantly reduces input reflected ripple current, and improves EMC.
With the addition of a simple external filter, the SQE48T40015 converter passes the requirements of Class B conducted
emissions per EN55022 and FCC requirements. All materials meet UL94, V-0 flammability rating.
Contact Bel Power Solutions Applications Engineering for details of this testing.
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Scenario #1: Initial Startup From Bulk Supply
ON/OFF function enabled, converter started via application of
VIN. See Figure E.
Time
Comments
ON/OFF pin is ON; system front-end power is toggled
t0
on, VIN to converter begins to rise.
VIN crosses undervoltage Lockout protection circuit
t1
threshold; converter enabled.
Converter begins to respond to turn-on command
t2
(converter turn-on delay).
t3
Converter VOUT reaches 100% of nominal value.
For this example, the total converter startup time (t3- t1) is
typically 3 ms.
VIN
ON/OFF
STATE
OFF
ON
VOUT
t0
t1 t2
t
t3
Figure E. Startup scenario #1.
Scenario #2: Initial Startup Using ON/OFF Pin
With VIN previously powered, converter started via ON/OFF pin.
See Figure F.
Time
VIN
Comments
t0
VINPUT at nominal value.
t1
t2
Arbitrary time when ON/OFF pin is enabled (converter
enabled).
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 3 ms.
ON/OFF
STATE OFF
ON
VOUT
t0
t1 t2
t
t3
Figure F. 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 G.
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 (200 ms typical) is
initiated, and ON/OFF pin action is internally inhibited.
t2
ON/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.
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 F.
t4
End of converter turn-on delay.
t5
Converter VOUT reaches 100% of nominal value.
For the condition, (t2- t1) ≤ 200 ms, the total converter startup
time (t5- t2) is typically 203 ms. For (t2- t1) > 200 ms, startup will
be typically 3 ms after release of ON/OFF pin.
V IN
200 ms
ON/OFF
STATE OFF
ON
V OUT
t0
t1
t2
t3 t4
t5
t
Figure G. Startup scenario #3.
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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, 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.
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: Location of the thermocouple for thermal testing.
Load current vs. ambient temperature and airflow rates are given in Figure 1. 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)
(ii)
(iii)
The output current at which any FET junction temperature does not exceed a maximum temperature of 120 °C as
indicated by the thermographic image, or
The temperature of the transformer does not exceed 120 °C, or
The nominal rating of the converter (40 A at 1.5 V).
During normal operation, derating curves with maximum FET temperature less or equal to 120 °C should not be exceeded.
Temperature at both thermocouple locations shown in Fig. H should not exceed 120 °C in order to operate inside the derating
curves.
Figure 2 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, 54 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 Figure 3.
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Figure 4 shows the power dissipation vs. load current plot for Ta = 25 ºC, airflow rate of 300 LFM (1.5 m/s) with vertical
mounting and input voltages of 36 V, 48 V, 54 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 Figure 5.
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 Figure 6 and Figure 7, respectively.
40
95
35
90
Efficiency, %
Load Current, A
Figure 10 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 µF ceramic capacitor.
The input reflected-ripple current waveforms are obtained using the test setup shown in Figure 11. The corresponding
waveforms are shown in Figure 12 and Figure 13.
30
NC ~ 30 LFM (0.15 m/s)
100 LFM (0.5 m/s)
200 LFM (1 m/s)
300 LFM (1.5 m/s)
400 LFM (2 m/s)
500 LFM (2.5 m/s)
25
30
40
36V
48V
80
54V
72V
75
20
20
85
50
60
70
80
0
90
10
Ambient Temperature, C
Figure 1. Available load current vs. ambient air temperature
and airflow rates for SQE48T40015 converter mounted
vertically with air flowing from pin 3 to pin 1,
MOSFET temperature 120 C, Vin = 48 V.
Note: NC – Natural convection
30
40
Figure 2. Efficiency vs. load current and input voltage for
SQE48T40015 converter mounted vertically with air flowing
from pin 3 to pin 1 at 300 LFM (1.5 m/s) and Ta=25C.
90
10
Power Dissipation, W
Efficiency, %
20
Load Current, A
85
40C
55C
70C
85C
80
7.5
5
36V
48V
54V
72V
2.5
0
75
0
10
20
Load Current, A
30
40
Figure 3. Efficiency vs. load current and ambient temperature
for SQE48T40015 converter mounted vertically with Vin=48V
and air flowing from pin 3 to pin 1 at 200LFM (1.0m/s).
0
10
20
Load Current, A
30
40
Figure 4. Power dissipation vs. load current and input voltage
for SQE48T40015 converter mounted vertically with air flowing
from pin 3 to pin 1 at a rate of 300 LFM (1.5 m/s) and
Ta = 25C.
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Power Dissipation, W
10
7.5
5
40C
55C
70C
85C
2.5
0
0
10
20
Load Current, A
30
40
Figure 5. Power dissipation vs. load current and ambient
temperature for SQE48T40015 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 6. 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 (0.5 V/div.). Time scale: 5 ms/div.
Figure 7. 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
(0.5 V/div.). Time scale: 5 ms/div.
Figure 8. 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: 0.2ms/div.
Figure 9. Output voltage response to load current step-change
(20 A – 30 A –20A) at Vin = 48 V. Top trace: output voltage
(200 mV/div.). Bottom trace: load current (10 A/div.). Current
slew rate: 2.5 A/µs. Co = 470 µF POS + 1 µF ceramic. Time
scale: 0.2 ms/div.
Figure 10. 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.
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iS
10 H
source
inductance
Vsource
iC
33 F
ESR < 1
electrolytic
capacitor
SQE48
DC-DC
Converter
1 F
ceramic
Vout
capacitor
Figure 11. Test setup for measuring input reflected ripple currents, ic and is.
Figure 12. 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 Figure 11 for test setup. Time
scale: 1 µs/div.
Figure 13. Input reflected ripple-current, iC (100 mA/div.),
measured at input terminals at full rated load current and
Vin = 48 V. Refer to Figure 11 for test setup.
Time scale: 1 µs/div.
Figure 14. Output voltage vs. load current showing current limit
point and converter shutdown point. Input voltage has almost
no effect on current limit characteristic.
Figure 15. Load current (top trace, 50 A/div., 50 ms/div.) into a
10 mΩ short circuit during restart, at Vin = 48 V. Bottom trace
(50 A/div., 5 ms/div.) is an expansion of the on-time portion of
the top trace.
tech.support@psbel.com
13
2.300±0.020 [58.42±0.51]
0.896±0.020 [22.76±0.51]
8
7
6
5
4
1
0.300 [7.62]
TOP VIEW
2
0.300 [7.62]
3
0.600 [15.24]
0.450 [11.43]
0.300 [7.62]
0.150 [3.81]
0.148 [3.76]
2.000 [50.80]
0.148±0.020 [3.76±0.51]
0.140±0.020 [3.56±0.51]
SQE48T Pinout (Through-Hole)
SQE48T 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 a shoulder
•
Pin Material: Brass Alloy 360
•
Pin Finish: Tin over Nickel
•
Weight: 0.88 oz [25.1g]
Height
Option
HT
(Max. Height)
CL
(Min. Clearance)
+0.000 [+0.00]
-0.038 [- 0.97]
+0.016 [+0.41]
-0.000 [- 0.00]
0.374 [9.5]
0.045 [1.14]
D
Mounting
Scheme
Rated
Load
Current
Output
Voltage
SQE
48
T
40
015
1/8th
Brick
Format
36-75 V
T
Throughhole
40
40 A
015
1.5 V
Function
1
Vin (+)
2
ON/OFF
3
Vin (-)
4
Vout (-)
±0.005 [±0.13]
5
SENSE(-)
A
0.188 [4.77]
6
TRIM
B
0.145 [3.68]
7
SENSE(+)
0.110 [2.79]
8
Vout (+)
C
Input
Voltage
Pad/Pin #
PL
Pin Length
Pin
Option
Product
Series1
PAD/PIN CONNECTIONS
-
ON/OFF
Logic
Maximum
Height
[HT]
Pin
Length
[PL]
Special
Features
N
D
A
K
G
0 2250VDC
isolation, no
CM cap
No Suffix
RoHS
lead-solderexemption
compliant
N
Negative
P
Positive
D 0.374”
Through
hole
A 0.188”
B 0.145”
C 0.110”
K 1500VDC
isolation, CM
cap, and
special OCP
RoHS
G RoHS
compliant
for all six
substances
The example above describes P/N SQE48T40015-NDAKG: 36-75 V input, through-hole, 40A @ 1.5V output, negative ON/OFF logic, maximum
height of 0.374”, 0.188” pins, 1500VDC isolation, common mode capacitor, special OCP, and RoHS compliant for all 6 substances. Consult
factory for availability of other options.
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.
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