Product # MCOTS-C-48-05-QT Phone 1-888-567-9596 www.synqor.com Doc.# 005-0005326 Rev. A 11/03/09
Page 1
MCOTS-C-48-05-QT
Single Output
Quarter-brick
The
MilQor series of Mil-COTS DC/DC converters brings
SynQor’s field proven high-efficiency synchronous
rectification technology to the Military/Aerospace
industry. SynQor’s ruggedized encased packaging
approach ensures survivability in demanding
environments. Compatible with the industry standard
format, these converters operate at a fixed frequency,
and follow conservative component derating guidelines.
They are designed and manufactured to comply with a
wide range of military standards.
Full Power Operation: -55°C to +100°C
Mil-COTS
MILITARY COTS DC/DC CONVERTER
Designed and Manufactured in the USA
34-75V 34-100V 5V 25A 92% @ 12.5A / 90% @ 25A
Continuous Input Transient Input Output Output Efciency
Protection Features
•Input under-voltage lockout
•Output current limit and short circuit protection
•Active back bias limit
•Output over-voltage protection
•Thermal shutdown
Screening/Qualification
MCOTS-C-48-05-QT-N-M
DC/DC CONVERTER
48V
IN 5.0V
OUT @ 25A
• AS9100 and ISO 9001:2000 certied facility
• Qualication consistent with MIL-STD-883
•Available with S-Grade or M-Grade screening
•Pre-cap inspection per IPC-610, Class III
• Temperature cycling per MIL-STD-883, Method 1010,
Condition B, 10 cycles
•Burn-In at 100C baseplate temperature
• Final visual inspection per MIL-STD-2008
•Full component traceability
Operational Features
Mechanical Features
Control Features
Safety Features
• High efciency, 90% at full rated load current
• Operating input voltage range: 34-75V
•Fixed frequency switching provides predictable EMI
•No minimum load requirement
•On/Off control referenced to input return
•Remote sense for the output voltage
• Output voltage trim range of +10%, -20%
• 2250V, 30 MΩ input-to-output isolation
• Certied 60950-1 requirement for basic insulation
(see Standards and Qualications page)
• Industry standard quarter-brick pin-out conguration
•Size: 1.54” x 2.39” x 0.50”
(39.0 x 60.6 x 12.7 mm)
• Total weight: 3.02 oz. (85.7 g)
•Flanged baseplate version available
MCOTS-C-48-05-QT
Single Output
Quarter-brick
Output:
Current:
Technical Specification
Product # MCOTS-C-48-05-QT Phone 1-888-567-9596 www.synqor.com Doc.# 005-0005326 Rev. A 11/03/09
Page 2
MCOTS-C-48-05-QT
5V
25A
BLOCK DIAGRAM
TYPICAL CONNECTION DIAGRAM
Vin
External
Input
Filter
Trim
Vin(+)
Iload
Cload
Vout(+)
Rtrim-up
or
Rtrim-down
Vsense(+)
ON/OFF
Vin(_)Vout(_)
Vsense(_)
Electrolytic
Capacitor
−
SENSE
ISOLATION STAGEREGULATION STAGE
8
4
UVLO
OVSD
SECONDARY
CONTROL
GATE CONTROL
PRIMARY
CONTROL
POSITIVE
INPUT
INPUT
RETURN
ON/OFF
6
7
5
1
3
2
POSITIVE
OUTPUT
OUTPUT
RETURN
TRIM
+ SENSE
GATE DRIVERS
ISOLATION BARRIER
T1 T1T2 T2
CURRENT
LIMIT
CURRENT
SENSE
OPTO-ISOLATION
DATA COUPLING
MCOTS-C-48-05-QT
Single Output
Quarter-brick
MCOTS-C-48-05-QT
Output:
Current:
Technical Specification
Product # MCOTS-C-48-05-QT Phone 1-888-567-9596 www.synqor.com Doc.# 005-0005326 Rev. A 11/03/09
Page 3
MCOTS-C-48-05-QT
5V
25A
MCOTS-C-48-05-QT ELECTRICAL CHARACTERISTICS
Ta = 25 °C, Vin = 48Vdc unless otherwise noted; full operating temperature range is -55 °C to +100 °C baseplate temperature with appropriate power
derating. Specications subject to change without notice.
Parameter Min. Typ. Max. Units Notes & Conditions
ABSOLUTE MAXIMUM RATINGS
Input Voltage
Non-Operating 80 V Continuous
Operating 75 V Continuous
Operating Transient Protection 100 V100 ms
Isolation Voltage
Input to Output 2250 V dc
Input to Base-Plate 2250 V dc
Output to Base-Plate 2250 V dc
Operating Temperature -55 100 °C Baseplate temperature
Storage Temperature -65 135 °C
Voltage at ON/OFF input pin -2 18 V
INPUT CHARACTERISTICS
Operating Input Voltage Range 34 48 75 V
Input Under-Voltage Lockout
Turn-On Voltage Threshold 32.2 33.0 33.8 V
Turn-Off Voltage Threshold 30.225 31 31.775 V
Lockout Voltage Hysteresis 2.0 V
Recommended External Input Capacitance 100 µF Typical ESR 0.1-0.2Ω
Input Filter Component Values (L\C) 4.7\6.6 µH\µF Internal values; see Figure E
Maximum Input Current 5.3 A Vin min; trim up; in current limit
No-Load Input Current 70 90 mA
Disabled Input Current 2 4mA
Response to Input Transient 0.25 V 500V/ms; see Figure 6
Input Terminal Ripple Current 320 mA RMS
Recommended Input Fuse 15 A Fast acting external fuse recommended
OUTPUT CHARACTERISTICS
Output Voltage Set Point 4.95 5 5.05 V
Output Voltage Regulation
Over Line ±0.1 ±0.3 %
Over Load ±0.1 ±0.3 %
Over Temperature -75 75 mV
Total Output Voltage Range 4.875 5.125 V Over sample, line, load, temperature & life
Output Voltage Ripple and Noise 20MHz bandwidth; see Note 1
Peak-to-Peak 0 60 120 mV Full load
RMS 20 40 mV Full load
Operating Output Current Range 0 25 A Subject to thermal derating
Output DC Current-Limit Inception 27.5 30 32.5 A Output voltage 10% Low
Output DC Current-Limit Shutdown Voltage 2.4 V
Back-Drive Current Limit while Enabled 1 A Negative current drawn from output
Back-Drive Current Limit while Disabled 10 mA Negative current drawn from output
Maximum Output Capacitance 8000 µF Vout nominal at full load (resistive load)
Output Voltage during Load Current Transient
Step Change in Output Current (0.1A/µs) 240 mV 50% to 75% to 50% Iout max
Settling Time 400 µs To within 1% Vout nom
Output Voltage Trim Range -20 10 % Across Pins 8&4; Figure C; See Note 2
Output Voltage Remote Sense Range 10 % Across Pins 8&4
Output Over-Voltage Protection 5.9 6.1 6.4 V Over full temp range
EFFICIENCY
100% Load 90 % See Figure 1 for efciency curve
50% Load 92 % See Figure 1 for efciency curve
Note 1: Output is terminated with 1 µF ceramic and 22 µF low-ESR tantalum capacitors. For applications requiring reduced output voltage ripple and
noise, consult SynQor applications support (e-mail: mqnbofae@synqor.com)
Note 2: Trim-up range is limited below 10% at low line and full load. Contact SynQor applications support for more detail (e-mail: mqnbofae@synqor.
com)
Output:
Current:
Technical Specification
Product # MCOTS-C-48-05-QT Phone 1-888-567-9596 www.synqor.com Doc.# 005-0005326 Rev. A 11/03/09
Page 4
MCOTS-C-48-05-QT
5V
25A
MCOTS-C-48-05-QT ELECTRICAL CHARACTERISTICS
Ta = 25 °C, Vin = 48Vdc unless otherwise noted; full operating temperature range is -55 °C to +100 °C baseplate temperature with appropriate power
derating. Specications subject to change without notice.
Parameter Min. Typ. Max. Units Notes & Conditions
DYNAMIC CHARACTERISTICS
Turn-On Transient
Turn-On Time 10 ms Full load, Vout=90% nom.
Start-Up Inhibit Time 200 230 250 ms Figure F
Output Voltage Overshoot 0% Maximum Output Capacitance
ISOLATION CHARACTERISTICS
Isolation Voltage (dielectric strength) See Absolute Maximum Ratings
Isolation Resistance 30 MΩ
Isolation Capacitance (input to output) 1000 pF See Note 1
TEMPERATURE LIMITS FOR POWER DERATING CURVES
Semiconductor Junction Temperature 125 °C Package rated to 150°C
Board Temperature 125 °C UL rated max operating temp 130°C
Transformer Temperature 125 °C
Maximum Baseplate Temperature, Tb 100 °C
FEATURE CHARACTERISTICS
Switching Frequency 250 kHz
ON/OFF Control
Off-State Voltage 2.4 18 V
On-State Voltage -2 0.8
ON/OFF Control Application notes Figures A & B
Pull-Up Voltage 5 V
Pull-Up Resistance 50 kΩ
Over-Temperature Shutdown OTP Trip Point 125 °C Average PCB Temperature
Over-Temperature Shutdown Restart Hysteresis 10 °C
RELIABILITY CHARACTERISTICS
Calculated MTBF (Telcordia) TR-NWT-000332 2.5 106 Hrs. 80% load, 200LFM, 40°C Ta
Calculated MTBF (MIL-217) MIL-HDBK-217F 1.8 106 Hrs. 80% load, 200LFM, 40°C Ta
Field Demonstrated MTBF TBD 106 Hrs. See our website for details
Note 1: Higher values of isolation capacitance can be added external to the module
STANDARDS COMPLIANCE
Parameter Notes & Conditions
STANDARDS COMPLIANCE
UL 60950-1:2003 Basic Insulation
CAN/CSA-C22.2 No. 60950-1:2003
EN60950-1:2001
Note: An external input fuse must always be used to meet these safety requirements. Contact SynQor for ofcial safety certicates on new releases or
download from the SynQor website.
MCOTS-C-48-05-QT
Output:
Current:
Technical Specification
Product # MCOTS-C-48-05-QT Phone 1-888-567-9596 www.synqor.com Doc.# 005-0005326 Rev. A 11/03/09
Page 5
MCOTS-C-48-05-QT
5V
25A
60
65
70
75
80
85
90
95
100
0 5 10 15 20 25
Load Current (A)
Efficiency (%)
34 Vin
48 Vin
75 Vin
Figure 1: Efficiency at nominal output voltage vs. load current for
minimum, nominal, and maximum input voltage at 25
°
C.
Figure 2: Efficiency at nominal output voltage and 60% rated power vs.
case temperature for minimum, nominal, and maximum input voltage.
Figure 3: Power dissipation at nominal output voltage vs. load current
for minimum, nominal, and maximum input voltage at T
CASE=25
°
C.
Figure 4: Power dissipation at nominal output voltage and 60% rated
power vs. case temperature for minimum, nominal, and maximum input
voltage.
Figure 6: Output voltage vs. load current showing typical current limit
curves. See Current Limit section in the Application Notes.
60
65
70
75
80
85
90
95
100
-55ºC 25ºC 100ºC
Efficiency (%)
34 Vin
48 Vin
75 Vin
0
3
6
9
12
15
18
-55ºC 25ºC 100ºC
Case Temperature (ºC)
Power Dissipation (W)
34 Vin
48 Vin
75 Vin
0
3
6
9
12
15
18
0 5 10 15 20 25
Load Current (A)
Power Dissipation (W)
34 Vin
48 Vin
75 Vin
0
20
40
60
80
100
120
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
Load Current (%)
Output Voltage (%)
16 Vin
28 Vin
40 Vin
Typical Current Limit Inception Point
Typical Output Voltage at Shutdown
Figure 5: Load current (10A/div) as a function of time (1ms/div and 50ms/div)
when the converter attempts to turn on into a 10 mΩ short circuit.
Output:
Current:
Technical Specification
Product # MCOTS-C-48-05-QT Phone 1-888-567-9596 www.synqor.com Doc.# 005-0005326 Rev. A 11/03/09
Page 6
MCOTS-C-48-05-QT
5V
25A
Figure 9: Input terminal current ripple, iC, at full rated output current and
nominal input voltage with SynQor MCOTS lter module (200 mA/div).
Bandwidth: 20MHz. See Figure 17.
Figure 10: Output voltage ripple, Vout, at nominal input voltage and rated
load current (10 mV/div). Load capacitance: 1µF ceramic capacitor and 10µF
tantalum capacitor. Bandwidth: 10 MHz. See Figure 17.
Figure 12: Output voltage response to step-change in input voltage (250V/ms).
Load cap: 100 µF electrolytic output capacitance. Ch 1: Vout (200mV/div), Ch
2: Vin (20V/div).
Figure 11: Output voltage response to step-change in load current (50%-
75%-50% of Iout(max); dI/dt = 0.1 A/µs). Load cap: 1 µF ceramic and 15 µF
tantalum capacitors. Ch 1: Vout (500mV/div), Ch 2: Iout (5A/div).
Figure 8: Turn-on transient at full resistive load and zero output capacitance
initiated by Vin. ENA1 and ENA2 both previously high. Ch 1: Vout (50V/div).
Ch 3: Vin (2V/div).
Figure 7: Typical startup waveform. Input voltage pre-applied, ON/OFF Pin on
Ch 1.
MCOTS-C-48-05-QT
Output:
Current:
Technical Specification
Product # MCOTS-C-48-05-QT Phone 1-888-567-9596 www.synqor.com Doc.# 005-0005326 Rev. A 11/03/09
Page 7
MCOTS-C-48-05-QT
5V
25A
Figure 13: Magnitude of incremental output impedance (Zout = vout/
iout) for minimum, nominal, and maximum input voltage at full rated
power.
Figure 14: Magnitude of incremental forward transmission (FT = vout/
vin) for minimum, nominal, and maximum input voltage at full rated
power.
Figure 15: Magnitude of incremental reverse transmission (RT = iin/
iout) for minimum, nominal, and maximum input voltage at full rated
power.
Figure 16: Magnitude of incremental input impedance (Zin = vin/iin)
for minimum, nominal, and maximum input
voltage at full rated power.
Figure 17: Test set-up diagram showing measurement points for Input Terminal
Ripple Current (Figure 9) and Output Voltage Ripple (Figure 10).
DC/DC
Converter
VSOURCE
iCVOUT
0.0001
0.001
0.01
0.1
1
10 100 1,000 10,000 100,000
Hz
Output Impedance (ohms)
48Vin
75Vin
34Vin
0.1
1
10
100
1000
10
100 1,000 10,000 100,000
Hz
Input Impedance (Ohms)
48Vin
75Vin
34Vin
-70
-60
-50
-40
-30
-20
-10
0
10 100 1,000 10,000 100,000
Hz
Forward Transmission (dB)
48Vin
75Vin
34Vin
-50
-40
-30
-20
10 100 1,000 10,000 100,000
Hz
Reverse Transmission (dB)
48Vin
75Vin
34Vin
4.7 µH
source impedance
100 µF,
0.2Ω ESR
electrolytic capacitor
10 µF,
100mΩ ESR
tantalum capacitor
1 µF
ceramic capacitor
Output:
Current:
Technical Specification
Product # MCOTS-C-48-05-QT Phone 1-888-567-9596 www.synqor.com Doc.# 005-0005326 Rev. A 11/03/09
Page 8
MCOTS-C-48-05-QT
5V
25A
Figure A: Various circuits for driving the ON/OFF pin. Figure B: Internal ON/OFF pin circuitry
BASIC OPERATION AND FEATURES
This Mil-COTS converter series uses a two-stage power
conversion topology. The first stage is a buck-converter that
keeps the output voltage constant over variations in line, load,
and temperature. The second stage uses a transformer to
provide the functions of input/output isolation and voltage step-
up or step-down to achieve the output voltage required.
Both the first stage and the second stage switch at a fixed
frequency for predictable EMI performance. Rectification of the
transformer’s output is accomplished with synchronous rectifiers.
These devices, which are MOSFETs with a very low on-state
resistance, dissipate far less energy than Schottky diodes. This
is the primary reason that the converter has such high efficiency,
even at very low output voltages and very high output currents.
These converters are offered totally encased to withstand harsh
environments and thermally demanding applications. Dissipation
throughout the converter is so low that it does not require a
heatsink for operation in many applications; however, adding
a heatsink provides improved thermal derating performance in
extreme situations.
This series of converters use the industry standard footprint and
pin-out configuration.
CONTROL FEATURES
REMOTE ON/OFF (Pin 2): The ON/OFF input, Pin 2, permits
the user to control when the converter is on or off. This input
is referenced to the return terminal of the input bus, Vin(-).
The ON/OFF signal is active low (meaning that a low turns the
converter on). Figure A details four possible circuits for driving
the ON/OFF pin. Figure B is a detailed look of the internal ON/
OFF circuitry.
REMOTE SENSE(+) (Pins 7 and 5): The SENSE(+) inputs
correct for voltage drops along the conductors that connect the
converter’s output pins to the load.
Pin 7 should be connected to Vout(+) and Pin 5 should be
connected to Vout(-) at the point on the board where regulation
is desired. A remote connection at the load can adjust for a
voltage drop only as large as that specified in this datasheet,
that is
[Vout(+) - Vout(-)] – [Vsense(+) - Vsense(-)] <
Sense Range % x Vout
Pins 7 and 5 must be connected for proper regulation of
the output voltage. If these connections are not made, the
converter will deliver an output voltage that is slightly higher
than its specified value.
Note: the output over-voltage protection circuit senses the
voltage across the output (pins 8 and 4) to determine when
it should trigger, not the voltage across the converter’s sense
leads (pins 7 and 5). Therefore, the resistive drop on the board
should be small enough so that output OVP does not trigger,
even during load transients.
Open Collector Enable Circuit
Remote Enable Circuit
Direct Logic Drive
Negative Logic
(Permanently Enabled)
Vin(_)
ON/OFF
ON/OFF
Vin(_)
ON/OFF
5V
Vin(_)
Vin(_)
TTL
5V
50k
50k
ON/OFF
Vin(_)
100pF
TTL/
CMOS
ON/OFF
MCOTS-C-48-05-QT
Output:
Current:
Technical Specification
Product # MCOTS-C-48-05-QT Phone 1-888-567-9596 www.synqor.com Doc.# 005-0005326 Rev. A 11/03/09
Page 9
MCOTS-C-48-05-QT
5V
25A
OUTPUT VOLTAGE TRIM (Pin 6): The TRIM input permits the
user to adjust the output voltage across the sense leads up or
down according to the trim range specifications.
To decrease the output voltage, the user should connect a
resistor between Pin 6 and Pin 5 (SENSE(-) input). For a desired
decrease of the nominal output voltage, the value of the resistor
should be
R
trim-down
=
(
511
)
- 10.22
(kW)
D%
where
D%
=
V
nominal
– V
desired
x
100%
V
nominal
To increase the output voltage, the user should connect a
resistor between Pin 6 and Pin 7 (SENSE(+) input). For a desired
increase of the nominal output voltage, the value of the resistor
should be
Trim graphs show the relationship between the trim resistor
value and Rtrim-up and Rtrim-down, showing the total range the
output voltage can be trimmed up or down.
Note: the TRIM feature does not affect the voltage at which the
output over-voltage protection circuit is triggered. Trimming the
output voltage too high may cause the over-voltage protection
circuit to engage, particularly during transients.
It is not necessary for the user to add capacitance at the Trim
pin. The node is internally bypassed to eliminate noise.
Total DC Variation of V
OUT
: For the converter to meet its full
specifications, the maximum variation of the dc value of V
OUT
, due
to both trimming and remote load voltage drops, should not be
greater than that specified for the output voltage trim range.
PROTECTION FEATURES
Input Under-Voltage Lockout: The converter is designed
to turn off when the input voltage is too low, helping avoid an
input system instability problem, described in more detail in
the application note titled “
Input System Instability
” on our
website. The lockout circuitry is a comparator with dc hysteresis.
When the input voltage is rising, it must exceed the typical Turn-
On Voltage Threshold value (listed on the specifications page)
before the converter will turn on. Once the converter is on,
the input voltage must fall below the typical Turn-Off Voltage
Threshold value before the converter will turn off.
Output Current Limit: The maximum current limit remains
constant as the output voltage drops. However, once the
impedance of the load across the output is small enough to make
the output voltage drop below the specified Output DC Current-
Limit Shutdown Voltage, the converter turns off.
The converter then enters a “hiccup mode” where it repeatedly
turns on and off at a 5 Hz (nominal) frequency with a 5% duty
cycle until the short circuit condition is removed. This prevents
excessive heating of the converter or the load board.
Output Over-Voltage Limit: If the voltage across the output
pins exceeds the Output Over-Voltage Protection threshold, the
converter will immediately stop switching. This prevents damage
to the load circuit due to 1) excessive series resistance in output
current path from converter output pins to sense point, 2) a
release of a short-circuit condition, or 3) a release of a current
limit condition. Load capacitance determines exactly how high
the output voltage will rise in response to these conditions. After
200 ms the converter will automatically restart.
Over-Temperature Shutdown: A temperature sensor on
the converter senses the average temperature of the module.
The thermal shutdown circuit is designed to turn the converter
off when the temperature at the sensed location reaches the
Over-Temperature Shutdown value. It will allow the converter
to turn on again when the temperature of the sensed location
falls by the amount of the Over-Temperature Shutdown Restart
Hysteresis value.
R
trim-up
(k
W)
where V
out
= Nominal Output Voltage
511
_
10.22
5.11V
OUT x
(100+
D%)
1.225
D
%
D
%
)
=
(
_
Figure C: Trim graph for trim-up, trim down.
10
100
1,000
10,000
100,000
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Trim Resistance (kΩ)
% Increase in Vout % Decrease in Vout
Output:
Current:
Technical Specification
Product # MCOTS-C-48-05-QT Phone 1-888-567-9596 www.synqor.com Doc.# 005-0005326 Rev. A 11/03/09
Page 10
MCOTS-C-48-05-QT
5V
25A
APPLICATION CONSIDERATIONS
Figure D: Typical application circuit (negative logic unit, permanently enabled).
Figure E: Internal Input Filter Diagram
Vin
External
Input
Filter
Trim
Vin(+)
Iload
Cload
Vout(+)
Rtrim-up
or
Rtrim-down
Vsense(+)
ON/OFF
Vin(_)Vout(_)
Vsense(_)
Electrolytic
Capacitor
Input System Instability: This
condition can occur because
any dc-dc converter appears incrementally as a negative
resistance load. A detailed application note titled “Input System
Instability” is available on the SynQor website which provides
an understanding of why this instability arises, and shows the
preferred solution for correcting it.
Application Circuits: Figure D provides a typical circuit diagram
which details the input filtering and voltage trimming.
Input Filtering and External Capacitance:
Figure E
provides
a diagram showing the internal input filter components. This filter
dramatically reduces input terminal ripple current, which otherwise
could exceed the rating of the converter's external electrolytic
input capacitor. The recommended external input capacitance
is specified in the Input Characteristics section on the
Electrical
Characteristics page.
More detailed information is available in
the application note titled “
EMI Characteristics
” on the
SynQor
website.
L
Vin(+)
Vin(_)
C
Vout(+)
Vout(-)
Internal
Input
Filter
Converter
MCOTS-C-48-05-QT
Output:
Current:
Technical Specification
Product # MCOTS-C-48-05-QT Phone 1-888-567-9596 www.synqor.com Doc.# 005-0005326 Rev. A 11/03/09
Page 11
MCOTS-C-48-05-QT
5V
25A
Startup Inhibit Period: The Startup Inhibit Period ensures that
the converter will remain off for approximately 200 ms when it is
shut down for any reason. When an output short is present, this
generates a 5 Hz “hiccup mode,” which prevents the converter
from overheating. In all, there are seven ways that the converter
can be shut down, initiating a Startup Inhibit Period:
• Input Under-Voltage Lockout
• Input Over-Voltage Shutdown
• Output Over-Voltage Protection
• Over Temperature Shutdown
• Current Limit
• Short Circuit Protection
• Turned off by the ON/OFF input
Figure F shows three turn-on scenarios, where a Startup Inhibit
Period is initiated at t
0
, t
1
, and t
2
:
Before time t
0
, when the input voltage is below the UVL threshold,
the unit is disabled by the Input Under-Voltage Lockout feature.
When the input voltage rises above the UVL threshold, the Input
Under-Voltage Lockout is released, and a Startup Inhibit Period is
initiated. At the end of this delay, the ON/OFF pin is evaluated,
and since it is active, the unit turns on.
At time t
1
, the unit is disabled by the ON/OFF pin, and it cannot be
enabled again until the Startup Inhibit Period has elapsed.
When the ON/OFF pin goes high after t
2
, the Startup Inhibit Period
has elapsed, and the output turns on within the typical Turn-On
Time.
Thermal Considerations: The maximum operating base-plate
temperature, T
B
, is 100 ºC. As long as the user’s thermal system
keeps T
B
< 100 ºC, the converter can deliver its full rated power.
A power derating curve can be calculated for any heatsink that is
attached to the base-plate of the converter. It is only necessary
to determine the thermal resistance, RTH
BA
, of the chosen heatsink
between the base-plate and the ambient air for a given airflow
rate. This information is usually available from the heatsink
vendor. The following formula can the be used to determine the
maximum power the converter can dissipate for a given thermal
condition if its base-plate is to be no higher than 100 ºC.
Pmax = 100 ºC - T
A
diss RTH
BA
This value of power dissipation can then be used in conjunction
with the data shown in Figure 2 to determine the maximum load
current (and power) that the converter can deliver in the given
thermal condition.
Figure F: Startup Inhibit Period (turn-on time not to scale)
Under-Voltage
Lockout Turn-
On Threshold
ON/OFF
(neg logic)
Vout
Vin
200ms 200ms
200ms
(typical start-up
inhibit period)
t0t1t2
t
ON ON ON
OFF OFF
(typical turn on time)
10ms
Output:
Current:
Technical Specification
Product # MCOTS-C-48-05-QT Phone 1-888-567-9596 www.synqor.com Doc.# 005-0005326 Rev. A 11/03/09
Page 12
MCOTS-C-48-05-QT
5V
25A
Top View
1.536 ±0.020 (39.01 ±0.5)
1. 030 (26.16)
0.600 (15.24)
0.450 (11.43)
0.300 (7.62)
0.150 (3.81)
123
8 7 5 46
2.386
± 0.020
(60.6± 0.5)
2.00
(50.8) 1.86
(47.2)
M3 Threaded Inserts
4 Places
See Notes
0.300 (7.62)
0.600 (15.24)
0.500±0.025
(12.7±0.63)
Overall Height
0.263±0.020
(6.68±0.5)
0.253±0.020 (6.4±0.5)
0.18±0.010
(4.57±0.25)
Side View
0.183±.020
(4.65)±0.5
0.468±0.020 (11.89±0.5)
Mechanical Drawing – Normal Heatsink Option
NOTES
1) Applied torque per screw should not exceed 6in-lb (0.7 Nm).
2) Baseplate flatness tolerance is 0.004" (.10mm) TIR for surface.
3) Pins 1-3, 5-7 are 0.040” (1.02mm) diameter, with 0.080” (2.03mm)
diameter standoff shoulders.
4) Pins 4 and 8 are 0.062” (1.57 mm) diameter with 0.100" (2.54 mm)
diameter standoff shoulders.
5) All Pins: Material – Copper Alloy; Finish – Matte Tin over Nickel plate
6) Undimensioned components are shown for visual reference only.
7) Weight: 3.02 oz. (85.7 g) typical
8) All dimensions in inches (mm)
Tolerances: x.xx +/-0.02 in. (x.x +/-0.5mm)
x.xxx +/-0.010 in. (x.xx +/-0.25mm)
9) Workmanship: Meets or exceeds IPC-A610 Class II
10) Recommended pin length is 0.03” (0.76mm) greater than the PCB
thickness.
PIN DESIGNATIONS
Pin Name Function
1 Vin(+) Positive input voltage
2 ON/OFF TTL input to turn converter on and off,
referenced to Vin(–), with internal pull up.
3 Vin(–) Negative input voltage
4 Vout(–) Negative output voltage
5 SENSE(–) Negative remote sense1
6 TRIM Output voltage trim2
7 SENSE(+) Positive remote sense3
8 Vout(+) Positive output voltage
Notes:
1) SENSE(–) should be connected to Vout(–) either remotely or
at the converter.
2) Leave TRIM pin open for nominal output voltage.
3) SENSE(+) should be connected to Vout(+) either remotely or
at the converter.
MCOTS-C-48-05-QT
Output:
Current:
Technical Specification
Product # MCOTS-C-48-05-QT Phone 1-888-567-9596 www.synqor.com Doc.# 005-0005326 Rev. A 11/03/09
Page 13
MCOTS-C-48-05-QT
5V
25A
2.200 ±.020 [ 55.88 ±0.5]
1.536 ±.020 [ 39.01 ±0.5 ]
.01 [0.2]
OVERALL HEIGHT
.500 ±.025
[12.7 ±0.63]
.18
[ 4.6 ]
SEE NOTE 5 .15 [ 3.8 ]
.30 [ 7.6 ]
.45 [ 11.4 ]
.60 [ 15.2 ]
8
7
6
1
2
3
.30 [ 7.6 ]
.60 [ 15.2 ]
2.386
2.00
[ 50.8 ]
±.020
[ 60.6 ±0.5 ]
BOTTOMSIDE CLEARANCE
±.020 .010
[0.51 0.25]
1.30
[ 33 ]
.70
[ 17.8 ]
.800 ±.020
[ 20.32 ±0.5 ]
2.07
[ ]
.13
[ 3.2 ]
1
.02 [ 0.6 ]
.183 ±.020
[ 4.65 ±0.5 ]
.36
[ 9.1 ]
1.01
[ 25.7 ]
1.66
[ 42.2 ]
TOP VIEW BOTTOM VIEW
52.5
5
4
R .065
1,65[ ]
Mechanical Drawing – Flanged Heatsink Option
NOTES
1) Applied torque per screw should not exceed 5in-lb (3in-lb
recommended).
2) Baseplate flatness tolerance is 0.01” (.25mm) TIR for surface.
3) Pins 1-3, 5-7 are 0.040” (1.02mm) diameter, with 0.080” (2.03mm)
diameter standoff shoulders.
4) Pins 4 and 8 are 0.062” (1.57 mm) diameter with 0.100" (2.54 mm)
diameter standoff shoulders.
5) All Pins: Material – Copper Alloy; Finish – Matte Tin over Nickel plate
6) Weight: 3.12 oz (88.5 g) typical
7) Undimensioned components are shown for visual reference only.
8) All dimensions in inches (mm)
Tolerances: x.xx +/-0.02 in. (x.x +/-0.5mm)
x.xxx +/-0.010 in. (x.xx +/-0.25mm)
9) Workmanship: Meets or exceeds IPC-A610 Class II
10) Recommended pin length is 0.03” (0.76mm) greater than the PCB
thickness.
11) A thermal interface material is required to assure proper heat
transfer from the flanged baseplate to the cooling surface. Thermal
grease, conductive pads, compounds, and other similar products are
available from many heatsink manufacturers.
PIN DESIGNATIONS
Pin Name Function
1 Vin(+) Positive input voltage
2 ON/OFF TTL input to turn converter on and off,
referenced to Vin(–), with internal pull up.
3 Vin(–) Negative input voltage
4 Vout(–) Negative output voltage
5 SENSE(–) Negative remote sense1
6 TRIM Output voltage trim2
7 SENSE(+) Positive remote sense3
8 Vout(+) Positive output voltage
Notes:
1) SENSE(–) should be connected to Vout(–) either remotely or
at the converter.
2) Leave TRIM pin open for nominal output voltage.
3) SENSE(+) should be connected to Vout(+) either remotely or
at the converter.
Output:
Current:
Technical Specification
Product # MCOTS-C-48-05-QT Phone 1-888-567-9596 www.synqor.com Doc.# 005-0005326 Rev. A 11/03/09
Page 14
MCOTS-C-48-05-QT
5V
25A
Test Name Details #Tested
(# Failed)
Consistent with
MIL-STD-883F
Method
Consistent with
MIL-STD-883F
Method 5005
Life Testing
Visual, mechanical and electrical test-
ing before, during and after 1000 hour
burn-in @ full load
15
(0) Method 1005.8
Shock-Vibration
Visual, mechanical and electrical test-
ing before, during and after shock and
vibration tests
5
(0)
MIL-STD-202, Method
1
Humidity +85˚C, 85% RH, 1000 hours, 2 min-
utes on/6 hours off
8
(0) Method 1004.7
Temperature Cycling 500 cycles of -55˚C to +100˚C (30
minute dwell at each temperature
10
(0) Method 1010.8 Condition A
Solderability 15 pins 15
(0) Method 2003
DMT -65˚C to +110˚C across full line and
load specications in 5˚C steps
7
(0)
Mil-COTS Qualication
Mil-COTS Screening
Screening Process Description S-Grade M-Grade
Baseplate Operating Temperature -55˚C to +100˚C -55˚C to +100˚C
Storage Temperature -65˚C to +135˚C -65˚C to +135˚C
Pre-Cap Inspection IPC-610, Class III ● ●
Temperature Cyclling Method 1010, Condition B,
10 Cycles ●
Burn-In 100˚C Baseplate 12 Hours 96 Hours
Final Electrical Test 100% 25˚C -55˚C, +25˚C, +100˚C
Final Visual Inspection MIL-STD-2008 ● ●
MCOTS-C-48-05-QT
Output:
Current:
Technical Specification
Product # MCOTS-C-48-05-QT Phone 1-888-567-9596 www.synqor.com Doc.# 005-0005326 Rev. A 11/03/09
Page 15
MCOTS-C-48-05-QT
5V
25A
Warranty
SynQor offers a two (2) year limited warranty. Complete warranty
information is listed on our website or is available upon request from
SynQor.
Information furnished by SynQor is believed to be accurate and reliable.
However, no responsibility is assumed by SynQor for its use, nor for any
infringements of patents or other rights of third parties which may result
from its use. No license is granted by implication or otherwise under any
patent or patent rights of SynQor.
Contact SynQor for further information:
Phone: 978-849-0600
Toll Free: 888-567-9596
Fax: 978-849-0602
E-mail: mqnbofae@synqor.com
Web:
www.synqor.com
Address: 155 Swanson Road
Boxborough, MA 01719
USA
Family Product Input
Voltage Output Voltage Package Heatsink
Option
Screening
Level
MCOTS C: Converter
F: Filter
28: 16-40V
48: 34-75V
270: 155-425V
1R2: 1.2V
1R5: 1.5V
1R8: 1.8V
2R5: 2.5V
3R3: 3.3V
05: 5V
07: 7V
12: 12V
15: 15V
24: 24V
28: 28V
40: 40V
48: 48V
50: 50V
P: Passive
T: Active
FT: Full Brick
HP: Half Brick Peta
HZ: Half Brick Zeta
QT: Quarter Brick
EG: Eighth Brick
SM: Sixteenth Brick
N: Normal
Threaded
D: Normal
Non-Threaded
F: Flanged
S: S-Grade
M: M-Grade
Example MCOTS-C-48-05-QT-N-S
Not all combinations make valid part numbers, please contact SynQor for availability. See
product summary page
for details.
APPLICATION NOTES
A variety of application notes and technical white papers can be downloaded
in pdf format from our website.
Ordering Information/ Part Numbering
PATENTS
SynQor holds the following U.S. patents, one or more of which
apply to each product listed in this brochure. Additional patent
applications may be pending or led in the future.
5,999,417 6,222,742 6,545,890 6,577,109 6,594,159
6,731,520 6,894,468 6,896,526 6,927,987 7,050,309
7,072,190 7,085,146 7,119,524 7,269,034 7,272,021
7,272,023 7,558,083 7,564,702