25A/300W

MCOTS-C-270-12-HT
Single Output
Half-brick
MILITARY COTS DC-DC CONVERTER
155-425V
Continuous Input
155-475V
Transient Input
12V
Output
25A
Output
88% @ 12.5A / 87% @ 25A
Efficiency
Operation: -55°C to +100°C
Mil-COTS
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.
N-S-F
-12-HT
-C-270
MCOTS ONVERTER
C
V T@
V)IN 12 OU
DC/DC
55-425
270V (1
25A
Safety Features
• 4250V dc, 100 MΩ input-to-output isolation
• (see Standards and Qualifications page)
Designed and Manufactured in the USA
Operational Features
•
•
•
•
Mechanical Features
• Industry standard half-brick pin-out configuration
• Size:
2.49” x 2.39” x 0.50”
(63.1 x 60.6 x 12.6 mm)
• Total weight: 4.7 oz (134 g)
• Flanged baseplate version available
Control Features
Protection Features
•
•
•
•
•
Input under-voltage lockout/over-voltage shutdown
Output current limit and short circuit protection
Active back bias limit
Output over-voltage protection
Thermal shutdown
Specification Compliance
MCOTS series converters (with an MCOTS filter) are designed to meet:
• MIL-HDBK-704 (A-F)
• RTCA/DO-160E Section 16
• MIL-STD-1275 (B,D)
• DEF-STAN 61-5 (Part 6)/(5 or 6)
• MIL-STD-461 (C, D, E, F)
Product # MCOTS-C-270-12-HT
Phone 1-888-567-9596
High efficiency, 87% at full rated load current
Operating input voltage range: 155-425 V
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%
Active current sharing (full feature option)
Clock synchronization (full feature option)
Start synchronization (full feature option)
Screening/Qualification
•
•
•
•
•
AS9100 and ISO 9001:2008 certified facility
Qualified to MIL-STD-810
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
www.synqor.com
Doc.# 005-0005517
Rev. C
02/27/15
Page 1
MCOTS-C-270-12-HT
Output: 12V
Current: 25A
Technical Diagrams
BLOCK DIAGRAM
REGULATION STAGE
ISOLATION STAGE
CURRENT
SENSE
1
POSITIVE
INPUT
8
T1
T1
3
T2
POSITIVE
OUTPUT
T2
NEGATIVE
INPUT
ISOLATION BARRIER
4
GATE DRIVERS
UVLO
OVSD
CURRENT
LIMIT
2
ON/OFF
OPTO-ISOLATION
PRIMARY
CONTROL
A
NEGATIVE
OUTPUT
GATE CONTROL
6
TRIM
SECONDARY
CONTROL
7
+ SENSE
Clock Sync (Full Feature Option)
B
5
Start Sync (Full Feature Option)
− SENSE
DATA COUPLING
C
IShare (Full Feature Option)
TYPICAL CONNECTION DIAGRAM
Vin(+)
Vin
External
Input
Filter
Electrolytic
Capacitor
Vout(+)
Vsense(+)
ON/OFF
Trim
Vsense(_)
Vin(_)
Product # MCOTS-C-270-12-HT
Phone 1-888-567-9596
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Rtrim-up
or
Rtrim-down
Cload
Iload
Vout(_)
Doc.# 005-0005517
Rev. C
02/27/15
Page 2
MCOTS-C-270-12-HT
Output: 12V
Current: 25A
Technical Specification
MCOTS-C-270-12-HT ELECTRICAL CHARACTERISTICS
Tb = 25 °C, Vin = 270dc unless otherwise noted; full operating temperature range is -55 °C to +100 °C baseplate temperature with appropriate power
derating. Specifications subject to change without notice.
Parameter
Min.
ABSOLUTE MAXIMUM RATINGS
Input Voltage
Non-Operating
Operating
Operating Transient Protection
Isolation Voltage
Input to Output
Input to Base-Plate
Output to Base-Plate
Operating Temperature
Storage Temperature
Voltage at ON/OFF input pin
INPUT CHARACTERISTICS
Operating Input Voltage Range
Input Under-Voltage Turn-On Threshold
Input Under-Voltage Turn-Off Threshold
Input Over-Voltage Turn-Off Threshold
Input Over-Voltage Turn-On Threshold
Recommended External Input Capacitance
Input Filter Component Values (L\C)
Maximum Input Current
No-Load Input Current
Disabled Input Current
Response to Input Transient
Input Terminal Ripple Current
Recommended Input Fuse
OUTPUT CHARACTERISTICS
Output Voltage Set Point
Output Voltage Regulation
Over Line
Over Load
Over Temperature
Total Output Voltage Range
Output Voltage Ripple and Noise
Peak-to-Peak
RMS
Operating Output Current Range
Output DC Current-Limit Inception
Output DC Current-Limit Shutdown Voltage
Back-Drive Current Limit while Enabled
Back-Drive Current Limit while Disabled
Maximum Output Capacitance
Output Voltage during Load Current Transient
Step Change in Output Current (0.1 A/µs)
Settling Time
Output Voltage Trim Range
Output Voltage Remote Sense Range
Output Over-Voltage Protection
EFFICIENCY
100% Load
50% Load
Typ.
Max.
Units
Notes & Conditions
600
425
475
V
V
V
Continuous
Continuous
1 s transient, square wave
4250
2300
2300
+100
+135
18
V dc
V dc
V dc
°C
°C
V
425
155
147
525
475
5
V
V
V
V
V
µF
µH\µF
A
mA
mA
V
mA
A
12.0
12.120
V
±0.1
±0.1
±0.3
±0.3
51
12.25
%
%
mV
V
182
48.6
25
34.8
5000
mV
mV
A
A
V
A
mA
µF
10
10
15.8
mV
µs
%
%
V
50% to 75% to 50% Iout max
To within 1% Vout nom
Across Pins 8&4; Figure C; see Note 3
Across Pins 8&4
Over full temp range
%
%
See Figure 1 for efficiency curve
See Figure 1 for efficiency curve
-1
-55
-65
-2
155
145
133
475
430
270
150
140
500
453
3.3
28/0.41
44
5
0.55
82
11.880
-51
11.7
72
11.9
26.77
31.25
6
7
5
3.0
56
10
480
250
-20
13.8
15
87
88
Baseplate temperature
475V transient for 1 s
Typical ESR 8 Ω see Note1
Internal values; see Figure E
Vin min; trim up; in current limit
Peak, see Figure 12
RMS, full load, 20MHz bandwidth
Fast acting external fuse recommended
Over sample, line, load, temperature & life
20 MHz bandwidth; see Note 2
Full load
Full load
Subject to thermal derating
Output voltage 10% Low
Negative current drawn from output
Negative current drawn from output
Vout nominal at full load (resistive load)
Note 1: An input capacitor with series resistance is necessary to provide system stability.
Note 2: Output is terminated with 1 µF ceramic and 15 µF low-ESR tantalum capacitors. For applications requiring reduced output voltage ripple and
noise, consult SynQor applications support (e-mail: [email protected])
Note 3: Trim-up range is limited below 10% at low line and full load.Applying 6.2V between trim pin and Vout(-) may damge the unit.
Product # MCOTS-C-270-12-HT
Phone 1-888-567-9596
www.synqor.com
Doc.# 005-0005517
Rev. C
02/27/15
Page 3
MCOTS-C-270-12-HT
Output: 12V
Current: 25A
Technical Specification
MCOTS-C-270-12-HT ELECTRICAL CHARACTERISTICS
Tb = 25 °C, Vin = 270dc unless otherwise noted; full operating temperature range is -55 °C to +100 °C baseplate temperature with appropriate power
derating. Specifications subject to change without notice.
Parameter
Min.
Typ.
Max.
Units
DYNAMIC CHARACTERISTICS
Turn-On Transient
Turn-On Time
42
ms
Start-Up Inhibit Time
360
400
440
ms
Output Voltage Overshoot
0
%
ISOLATION CHARACTERISTICS
Isolation Voltage (dielectric strength)
4250
V dc
Isolation Resistance
100
MΩ
Isolation Capacitance (input to output)
N/A
pF
TEMPERATURE LIMITS FOR POWER DERATING CURVES
Semiconductor Junction Temperature
125
°C
Board Temperature
125
°C
Transformer Temperature
125
°C
Maximum Baseplate Temperature, Tb
100
°C
FEATURE CHARACTERISTICS
Switching Frequency
506
550
594
kHz
ON/OFF Control
Off-State Voltage
2.4
18
V
On-State Voltage
-1
0.8
ON/OFF Control
Pull-Up Voltage
5
V
Pull-Up Resistance
68.1
kΩ
Over-Temperature Shutdown OTP Trip Point
125
°C
Over-Temperature Shutdown Restart Hysteresis
10
°C
FULL FEATURE OPTION
Clock Sync
600
615
630
kHz
Current Share
2
V
RELIABILITY CHARACTERISTICS
Calculated MTBF per MIL-HDBK-217F
4.1
MHrs.
Calculated MTBF per MIL-HDBK-217F
0.971
MHrs.
Note 1: Higher values of isolation capacitance can be added external to the module.
Note 2: Do not apply a clock signal lower than specified frequency, also do not apply clock sync or
CLK sync. should be between 30%-70%
Notes & Conditions
Full load, Vout=90% nom.
See Figure F
Maximum Output Capacitance
See Absolute Maximum Ratings
See Note 1
Package rated to 150 °C
UL rated max operating temp 130 °C
Isolation stage switching freq. is half this
Application notes Figures A & B
Average PCB Temperature
See Note 2
Half load
Ground Benign, 70°C Tb
Ground Mobile, 70°C Tb
change frequency while unit is running. Duty cycle of
STANDARDS COMPLIANCE
Parameter
Notes & Conditions
STANDARDS COMPLIANCE
UL 60950-1/R2011-12
Reinforced Insulation
CAN/CSA-C22.2 No. 60950-1/A1:2011
EN 60950-1/A12:2011
CE Marked
2006/95/EC Low Voltage Directive
IEC 61000-4-2
ESD test, 8 kV - NP, 15 kV air - NP (Normal Performance)
Note: An external input fuse must always be used to meet these safety requirements. Contact SynQor for official safety certificates on new releases or
download from the SynQor website.
Product # MCOTS-C-270-12-HT
Phone 1-888-567-9596
www.synqor.com
Doc.# 005-0005517
Rev. C
02/27/15
Page 4
MCOTS-C-270-12-HT
Output: 12V
Current: 25A
Technical Charts
95
95
90
90
Efficiency (%)
Efficiency (%)
85
80
75
85
80
75
70
155 Vin
155 Vin
270 Vin
65
270 Vin
70
425 Vin
425 Vin
65
-55ºC
60
0
5
10
15
20
Load Current (A)
25
50
50
40
40
30
20
30
20
155 Vin
10
155 Vin
10
100ºC
Figure 2: Efficiency at nominal output voltage and 60% rated power vs.
case temperature for minimum, nominal, and maximum input voltage.
Power Dissipation (W)
Power Dissipation (W)
Figure 1: Efficiency at nominal output voltage vs. load current for
minimum, nominal, and maximum input voltage at 25°C.
25ºC
Case Temperature (ºC)
270 Vin
270 Vin
425 Vin
425 Vin
0
-55ºC
0
0
5
10
15
20
Load Current (A)
25
Figure 3: Power dissipation at nominal output voltage vs. load current
for minimum, nominal, and maximum input voltage at TCASE =25°C.
14.0
12.0
25
Output Voltage (V)
20
Iout (A)
100ºC
Figure 4: Power dissipation at nominal output voltage and 60% rated
power vs. case temperature for minimum, nominal, and maximum input
voltage.
30
15
10
10.0
8.0
6.0
4.0
155 Vin
Vin = 155V
5
0
25ºC
Case Temperature (ºC)
270 Vin
2.0
Vin = 270V
425 Vin
Vin = 425V
50
60
70
80
90
100
110
0.0
0
Base Plate Temperature (°C)
Figure 5: Maximum output current vs. base plate temperature.
Product # MCOTS-C-270-12-HT
Phone 1-888-567-9596
5
10
15
20
Load Current (A)
25
30
35
Figure 6: Output voltage vs. load current showing typical current limit
curves. See Current Limit section in the Application Notes.
www.synqor.com
Doc.# 005-0005517
Rev. C
02/27/15
Page 5
MCOTS-C-270-12-HT
Output: 12V
Current: 25A
Technical Charts
Figure 7: Typical startup waveform. Input voltage pre-applied, ON/OFF Pin on
Ch 1.
Figure 8: Turn-on transient at full resistive load and zero output capacitance
initiated by Vin. ON/OFF Pin previously low. Ch 1: Vin (200V/div). Ch 3: Vout
(5V/div).
Figure 9: Input terminal current ripple, iC, at full rated output current and
nominal input voltage with 100µH source impedance and 47µF electrolytic
capacitor (100 mA/div). Bandwidth: 20MHz. See Figure 17.
Figure 10: Output voltage ripple, Vout, at nominal input voltage and rated load
current (200 mV/div). Load capacitance: 1µF ceramic capacitor and 15µF
tantalum capacitor. Bandwidth: 10 MHz. See Figure 17.
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 (10A/div).
Figure 12: Output voltage response to step-change in input voltage (250V/ms).
Load cap: 1µF ceramic and 15µF tantalum capacitors. Ch 1: Vout (500mV/div),
Ch 2: Vin (100V/div).
Product # MCOTS-C-270-12-HT
Phone 1-888-567-9596
www.synqor.com
Doc.# 005-0005517
Rev. C
02/27/15
Page 6
MCOTS-C-270-12-HT
Output: 12V
Current: 25A
Technical Charts
0
10
1
0.1
0.01
155Vin
0.001
-20
Forward Transmission (dB)
Output Impedance (ohms)
-10
270Vin
-30
-40
-50
-60
-70
425Vin
0.0001
10
100
1,000
10,000
-80
155Vin
-90
425Vin
-100
100,000
10
Hz
100
1,000
10,000
100,000
Hz
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.
1000
Input Impedance (Ohms)
-10
Reverse Transmission (dB)
270Vin
-20
-30
-40
155Vin
100
10
155Vin
270Vin
270Vin
425Vin
425Vin
1
-50
10
100
1,000
10,000
10
100,000
100
1,000
Figure 15: Magnitude of incremental reverse transmission (RT = iin/
iout) for minimum, nominal, and maximum input voltage at full rated
power.
100,000
Figure 16: Magnitude of incremental input impedance (Zin = vin/iin)
for minimum, nominal, and maximum input voltage at full rated power.
1 µF
ceramic capacitor
100 µH
source impedance
iC
VSOURCE
10,000
Hz
Hz
47 µF,
0.2Ω ESR
electrolytic capacitor
DC-DC
Converter
VOUT
15 µF,
100mΩ ESR
tantalum capacitor
Figure 17: Test set-up diagram showing measurement points for Input Terminal
Ripple Current (Figure 9) and Output Voltage Ripple (Figure 10).
Product # MCOTS-C-270-12-HT
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Figure 18: Load current (10A/div) as a function of time (10ms/div and 100ms/
div) when the converter attempts to turn on into a 10 mΩ short circuit.
www.synqor.com
Doc.# 005-0005517
Rev. C
02/27/15
Page 7
MCOTS-C-270-12-HT
Output: 12V
Current: 25A
Application Section
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 uses the industry standard footprint
and pin-out configuration.
ON/OFF
ON/OFF
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.
5V
68.1k
Vin(_)
Vin( )
_
Remote Enable Circuit
ON/OFF
Negative Logic
(Permanently
Enabled)
5V
ON/OFF
TTL/
CMOS
124k
TTL
249k
2200pF
ON/OFF
Vin(-)
Figure B: Internal ON/OFF pin circuitry
Vin(_)
Vin(_)
Open Collector Enable Circuit
Direct Logic Drive
Figure A: Various circuits for driving the ON/OFF pin.
Product # MCOTS-C-270-12-HT
Phone 1-888-567-9596
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 (TRIM) and Pin 5 (SENSE(-) input).
For a desired decrease of the nominal output voltage, the
value of the resistor should be
www.synqor.com
Doc.# 005-0005517
Rev. C
02/27/15
Page 8
MCOTS-C-270-12-HT
Output: 12V
Current: 25A
Application Section
Rtrim-down =
(
90.9
Δ%
) - 0.909 (kΩ)
Protection Features
where
Δ% =
|
Vnominal – Vdesired
Vnominal
| x 100%
To increase the output voltage, the user should connect a
resistor between Pin 6 (TRIM) and Pin 7 (SENSE(+) input).
For a desired increase of the nominal output voltage, the
value of the resistor should be:
(
Rtrim-up =
1.0VOUT x (100+Δ%)
1.225Δ%
-
90.9
Δ%
- 0.909
) (kΩ)
where
Vout = Nominal Output Voltage
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 overvoltage 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 VOUT: For the converter to meet
its full specifications, the maximum variation of the dc value
of VOUT, due to both trimming and remote load voltage
drops, should not be greater than that specified for the
output voltage trim range.
Trim Resistance (kΩ)
10,000
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”
available on www.SynQor.com . 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 specification 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 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 400 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.
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 2.23 Hz (nominal) frequency
with 11% duty cycle until the short circuit condition is
removed. This prevents excessive heating of the converter
or the load board.
1,000
100
10
1
0
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20
% Increase in Vout
% Decrease in Vout
Figure C: Trim graph for trim-up, trim down.
Product # MCOTS-C-270-12-HT
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Doc.# 005-0005517
Rev. C
02/27/15
Page 9
MCOTS-C-270-12-HT
Output: 12V
Current: 25A
Application Section
APPLICATION CONSIDERATIONS
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.
Vin(+)
Vin
External
Input
Filter
Electrolytic
Capacitor
Vout(+)
Vsense(+)
ON/OFF
Trim
Vsense(_)
Vin(_)
Rtrim-up
or
Rtrim-down
Cload
Iload
Vout(_)
Figure D: Typical application circuit (negative logic unit, permanently enabled).
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(+)
C
Vin(_)
Figure E: Internal Input Filter Diagram (Component values listed on page 3)
Product # MCOTS-C-270-12-HT
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Doc.# 005-0005517
Rev. C
02/27/15
Page 10
MCOTS-C-270-12-HT
Output: 12V
Current: 25A
Application Section
Startup Inhibit Period: The Startup Inhibit Period
ensures that the converter will remain off for approximately
400 ms when it is shut down for any reason. When an
output short is present, this generates a 2.23 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:
When the ON/OFF pin goes high after t2, 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, TB, is 100 ºC. Refer to the
thermal derating curve, Figure 5, to see the available
output current at baseplate temperatures below 100 ºC.
•
•
•
•
•
•
•
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, RTHBA, 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 then be used to determine the maximum power the
converter can dissipate for a given thermal condition:
Input Under-Voltage Lockout
Input Over-Voltage Lockout
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 t0, t1, and t2:
Before time t0, 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.
Pdiss
max
=
TB - T
A
RTHBA
This value of power dissipation can then be used in
conjunction with the data shown in Figure 3 to determine
the maximum load current (and power) that the converter
can deliver in the given thermal condition.
At time t1, the unit is disabled by the ON/OFF pin, and it
cannot be enabled again until the Startup Inhibit Period has
elapsed.
Vin
Under-Voltage
Lockout Turn-On
Threshold
ON/OFF
(Negative
logic)
ON
OFF
OFF ON
ON
42ms
(typical turn on time)
Vout
215ms
400ms
(initial start-up
inhibit period)
t0
400ms
(typical start-up
inhibit period)
t1
t
t2
Figure F: Startup Inhibit Period (turn-on time not to scale)
Product # MCOTS-C-270-12-HT
Phone 1-888-567-9596
www.synqor.com
Doc.# 005-0005517
Rev. C
02/27/15
Page 11
MCOTS-C-270-12-HT
Output: 12V
Current: 25A
Application Section
Full-Featured Application Notes
This section provides some basic application information for
the full-feature version of the MCOTS series converter.
All units in this product family include back-drive protection
to simplify the use of multiple converters in a parallel or
sequencing application. However, any voltage applied to
the output of the converter should be kept below 120% of
the rated output voltage of the converter.
In addition to back-drive protection, these units include the
following features (pins):
Current Share (pin C): The active current share feature
allows for N+1 and parallel applications. To achieve load
sharing, directly connect the I share pins of multiple units.
The load current will share equally among the multiple
units (±5% at full rated current). It is important that the
Vin(-) pins of the sharing units be directly connected and
NOT placed outside of an EMI filter or other impedance
path. The voltage at the I Share pin will range from 0 to 5
volts (at full rated current), referenced to the primary-side
ground, Vin(-).
Start Sync (pin B): The Start Synchronization pin will
allow a more consistent start-up sequence. To operate this
feature, connect together the Start-Sync pins of multiple
current-sharing units. This will permit immediate start-up
with loads greater than the current limit of a single unit.
Without this connection, any set of converters attempting to
asynchronously start (or re-start) with a load greater than
the current limit of a single unit will “hiccup”. This “hiccup”
mode will continue until one converter attempts a start at
the same time as the minimum number of additional units
necessary to sustain the load condition. For example, three
50 amp units starting into a 90 amp load would require
two units to simultaneously attempt a start. The Start
Sync connection synchronizes these starting attempts and
provides a more consistent and reliable start-up sequence.
For details about the “hiccup” mode or repeated startup
attempts, please see the “Startup Inhibit Period” note in the
Technical Specification.
Product # MCOTS-C-270-12-HT
Phone 1-888-567-9596
Clock Sync (pin A): The External Clock Synchronization pin
provides the ability for the user to control the EMI signature
and synchronize sensitive circuitry to quiet periods in the
converter operation. With this option, the converter can be
synchronized to an external clock signal whose frequency is
greater than that of the free-running internal clock. However,
substantially raising the converter’s frequency will reduce its
efficiency. Therefore, the recommended frequency range
for the external clock synchronization signal applied to this
pin is listed in the Technical Specification.
The following requirements should also be met:
• The external clock signal should be referenced to the
negative input voltage, Vin(-)
• The high level of the signal should be between
3.5V and 5.0V.
• The low level should be between -0.5V and +1.2V.
• Do not apply a clock sync or change frequency while
unit is running.
• Do not apply a clock signal lower than the
specified frequency.
• For using more than 5 units in parallel Contact SynQor.
www.synqor.com
Doc.# 005-0005517
Rev. C
02/27/15
Page 12
MCOTS-C-270-12-HT
Output: 12V
Current: 25A
Standard Mechanical Drawing
2.486 [63.14]
2.000 [50.80]
SEATING PLANE HEIGHT
0.495±0.025
[ 12.57±0.63 ]
PIN EXTENSION
0.180
[4.57]
0.700 [17.78]
7
6
5
4
8
0.004 [0.10]
TOP VIEW
1.900 2.386
[48.26] [60.60]
1.900
[48.26]
0.01
[0.3]
3
1
0.30
[7.6]
B
A
2
1
0.400 [10.16]
THREADED INSERT
SEE NOTE 1
(4 PLCS)
0.600
0.800
1.000
1.400
[15.24]
[20.32]
[25.40]
[35.56]
PIN DESIGNATIONS
NOTES
1) APPLIED TORQUE PER M3 SCREW 4in-lb RECOMMENDED (5in-lb LIMIT)
SCREW SHOULD NOT EXCEED 0.100” (2.54mm) DEPTH BELOW THE
SURFACE OF THE BASEPLATE.
2) BASEPLATE FLATNESS TOLERANCE IS 0.004” (.10mm)
TIR FOR SURFACE.
3) PINS 1-3, 5-7, A, B, AND C ARE 0.040” (1.02mm) DIA. WITH 0.080”
(2.03mm) DIA. STANDOFFS.
4) PINS 4 AND 8 ARE 0.080” (2.03mm) DIA. WITH 0.125” (3.18mm)
DIA STANDOFFS
5) ALL PINS: MATERIAL: COPPER ALLOY
FINISH: MATTE TIN OVER NICKEL PLATE
6) WEIGHT: 4.7 oz. (134 g) TYPICAL
7) ALL DIMENSIONS IN INCHES(mm)
8) TOLERANCES: X.XXIN +/-0.02 (X.Xmm +/-0.5mm)
X.XXXIN +/-0.010 (X.XXmm +/-0.25mm)
Product # MCOTS-C-270-12-HT
C
Phone 1-888-567-9596
Pin
1
2
Name
Vin(+)
ON/OFF
A
B
C
3
4
5
6
7
8
CLOCK SYNC
START SYNC
I SHARE
IN RTN
OUT RTN
SENSE(–)
TRIM
SENSE(+)
Vout(+)
Function
Positive input voltage
TTL input to turn converter on and off,
referenced to Vin(–), with internal pull up.
Clock synchronization
Startup synchronization
Single wire parallel signal
Input Return
Output Return
Negative remote sense1
Output voltage trim2
Positive remote sense3
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.
4)
Pins A, B, and C are populated on Full Feature version only.
www.synqor.com
Doc.# 005-0005517
Rev. C
02/27/15
Page 13
MCOTS-C-270-12-HT
Output: 12V
Current: 25A
Flanged Mechanical Drawing
3.150 [80.01]
SEATING
PLANE
HEIGHT
0.495±0.025
[ 12.57±0.63 ]
2.950 [74.93]
2.486 [63.14]
PIN
EXTENSION
0.180
[4.57]
0.700 [17.78]
4
5
7
6
8
TOP VIEW
1.300
[33.02]
0.010 [0.25]
1.866
[47.40]
0.31
[7.9]
1.900
[48.26]
2.386
[60.60]
3
1
0.775±0.020
[ 19.69±0.50 ]
.130 [3.30]
SEE NOTE 1
(6 PLCS)
C
B
A
2
FLANGE
THICKNESS
0.125
[3.18]
1
0.400 [10.16]
0.600 [15.24]
0.800 [20.32]
1.000 [25.40]
1.400 [35.56]
PIN DESIGNATIONS
NOTES
1) APPLIED TORQUE PER M3 OR 4-40 SCREW 4in-lb RECOMMENDED
(5in-lb LIMIT)
2) BASEPLATE FLATNESS TOLERANCE IS 0.010” (.25mm)
TIR FOR SURFACE.
3) PINS 1-3, 5-7, A, B, AND C ARE 0.040” (1.02mm) DIA. WITH 0.080”
(2.03mm) DIA. STANDOFFS.
4) PINS 4 AND 8 ARE 0.080” (2.03mm) DIA. WITH 0.125” (3.18mm)
DIA STANDOFFS
5) ALL PINS: MATERIAL: COPPER ALLOY
FINISH: MATTE TIN OVER NICKEL PLATE
6) WEIGHT: 4.9 oz. (140 g) TYPICAL
7) ALL DIMENSIONS IN INCHES(mm)
8) TOLERANCES: X.XXIN +/-0.02 (X.Xmm +/-0.5mm)
X.XXXIN +/-0.010 (X.XXmm +/-0.25mm)
Product # MCOTS-C-270-12-HT
Phone 1-888-567-9596
Pin
1
2
Name
Vin(+)
ON/OFF
A
B
C
3
4
5
6
7
8
CLOCK SYNC
START SYNC
I SHARE
IN RTN
OUT RTN
SENSE(–)
TRIM
SENSE(+)
Vout(+)
Function
Positive input voltage
TTL input to turn converter on and off,
referenced to Vin(–), with internal pull up.
Clock synchronization
Startup synchronization
Single wire parallel signal
Input Return
Output Return
Negative remote sense1
Output voltage trim2
Positive remote sense3
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.
4)
Pins A, B, and C are populated on Full Feature version only.
www.synqor.com
Doc.# 005-0005517
Rev. C
02/27/15
Page 14
MCOTS-C-270-12-HT
Output: 12V
Current: 25A
Qualifications & Screening
Mil-COTS Qualification
Test Name
# Tested Consistent with MIL(# Failed)
STD-883F Method
Details
Life Testing
Shock-Vibration
Visual, mechanical and electrical testing before, during
and after 1000 hour burn-in @ full load
Visual, mechanical and electrical testing before, during
and after shock and vibration tests
Humidity
+85˚C, 95% RH, 1000 hours, 2 minutes on / 6 hours off
Temperature
Cycling
500 cycles of -55˚C to +100˚C
(30 minute dwell at each temperature)
Solderability
15 pins
DMT
-65˚C to +110˚C across full line and load specifications
in 5˚C steps
Altitude
70,000 feet (21 km), see Note
15
(0)
5
(0)
8
(0)
10
(0)
15
(0)
7
(0)
2
(0)
Consistent with MIL-STD883F Method 5005
Method 1005.8
MIL-STD-202,
Methods 201A & 213B
Method 1004.7
Method 1010.8
Condition A
Method 2003
Note: A conductive cooling design is generally needed for high altitude applications because of naturally poor convective cooling at rare atmospheres.
Mil-COTS DC-DC Converter and Filter 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 Cycling
Method 1010, Condition B, 10 Cycles
Burn-In
Final Electrical Test
Final Visual Inspection
●
100˚C Baseplate
12 Hours
96 Hours
100%
25˚C
-55˚C, +25˚C, +100˚C
MIL-STD-2008
●
●
Mil-COTS MIL-STD-810G Qualification Testing
MIL-STD-810G Test
Fungus
Altitude
Method
508.6
Description
Table 508.6-I
500.5 - Procedure I
Storage: 70,000ft. / 2 Hr. duration
500.5 - Procedure II
Operating; 70,000ft. / 2 Hr. duration; Ambient Temperature
Rapid Decompression
500.5 - Procedure III
Storage: 8,000ft. to 40,000ft.
Acceleration
513.6 - Procedure II
Operating - 15g's
Salt Fog
509.5
Storage
501.5 - Procedure I
Storage: 135°C / 3 hrs
501.5 - Procedure II
Operating: 100°C / 3 hrs
502.5 - Procedure I
Storage: -65C / 4 hrs
502.5 - Procedure II
Operating: -55C / 3 hrs
Temperature Shock
503.5 - Procedure I - C
Storage: -65C to 135C; 12 cycles
Rain
506.5 - Procedure I
Wind Blown Rain
Immersion
512.5 - Procedure I
Non-Operating
Humidity
507.5 - Procedure II
Aggravated cycle @ 95% RH (Figure 507.5-7 aggravated temp - humidity cycle, 15 cycles)
Random Vibration
514.6 - Procedure I
10-2000 Hz, PSD level of 1.5 g2/Hz(54.6grms), duration = 1 hr/axis
516.6 - Procedure I
20g's peak, 11ms, Functional Shock (Operating no load) (saw tooth)
516.6 - Procedure VI
514.6 - Category 14
510.5 - Procedure I
Bench Handling Shock
Rotary wing aircraft - helicopter, 4hrs/axis, 20g's (sine sweep from 10 - 500HZ)
Blowing Dust
510.5 - Procedure II
Blowing Sand
High Temperature
Low Temperature
Shock
Sinusoidal vibration
Sand and Dust
Product # MCOTS-C-270-12-HT
Phone 1-888-567-9596
www.synqor.com
Doc.# 005-0005517
Rev. C
02/27/15
Page 15
MCOTS-C-270-12-HT
Output: 12V
Current: 25A
Ordering Information
Ordering Information/ Part Numbering
Example MCOTS-C-270-12-HT-N-S
Not all combinations make valid part numbers, please contact SynQor for availability.
Family
MCOTS
Product
Input Voltage
C: Converter
270: 155-425V
Output
Voltage
3R3:
05:
06:
12:
15:
24:
28:
48:
3.3V
5.0V
6.0V
12V
15V
24V
28V
48V
Package
Half Brick
HT:
Tera
Thermal Design
Screening
Level
N: Normal Threaded
S: S-Grade
F: Flanged
M: M-Grade
Options
[ ]: Standard
Feature
F: Full
Feature
APPLICATION NOTES
PATENTS
A variety of application notes and technical white papers can be downloaded
in PDF format from our website.
SynQor holds the following U.S. patents, one or more of which apply to
each product listed in this document. Additional patent applications may
be pending or filed in the future.
Contact SynQor for further information and to order:
Phone:
Toll Free:
Fax:
E-mail:
Web:
Address:
978-849-0600
888-567-9596
978-849-0602
[email protected]
www.synqor.com
155 Swanson Road
Boxborough, MA 01719
USA
Product # MCOTS-C-270-12-HT
Phone 1-888-567-9596
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
7,765,687
7,787,261
8,023,290
8,149,597
8,493,751
8,644,027
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.
www.synqor.com
Doc.# 005-0005517
Rev. C
02/27/15
Page 16
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