Product # PQ24280FTx22 Phone 1-888-567-9596 www.synqor.com Doc.# 005-0005178 Rev. E 03/24/11 Page 1
Technical
Specification
PQ24280FTx22
Contents
Operational Features
• High efciency, 91% at full rated load current
• Delivers 602W full power with minimal derating - no heatsink required
• Operating input voltage range: 18-36 V
• Input voltage transient capability: 50V, 100ms
• Fixed frequency switching provides predictable EMI
• On-board input and output ltering
• Output voltage trim permits custom voltages and voltage margining
• Synchronization feature available (full feature only)
• Paralleling capability
• Output voltage trim range of -50%, +15%
Protection Features
• Input under-voltage lockout
• Output current limit and short circuit protection
• Active back bias limit
• Output over-voltage protection
• Thermal shutdown
PQ24280FTx22 Model
Mechanical Features
• Industry standard full-brick pin-out conguration
• Size: 4.60” x 2.40” x .395", 116.8 x 60.96 x 10.03mm
• Total weight: 4.3oz (121g)
The PQ24280FT PowerQor Tera converter is an
isolated, xed switching frequency DC/DC converter
that uses synchronous rectication and a patented
topology to achieve extremely high efciency and
power density. This module is ideally suited to support
wireless base station ampliers and for applications to
drive cooling fans used in networking systems, servers
and data storage units. The Tera series converters
offer industry leading useable output power for any
standard “full-brick” module. These 28Vout modules
are available in open frame and baseplated versions.
RoHS compliant (see last page for details).
Safety Features
• UL 60950-1:2007
• EN60950-1/A11:2009/A1:2010
• CAN/CSA-C22.2 No. 60950-1:2007
• IEC 61000-4-2
Page No.
Mechanical Information ................................... 2
Electrical Characteristics................................... 4
Standards & Qualifications ................................. 6
Technical Figures........................................ 7
Applications Section..................................... 11
Ordering Information.................................... 15
Control Features
• On/Off control referenced to input side
• Positive and negative logic options are available
18-36 V 50V 28V 600W 2250V dc Full-brick
Input Transient Input Output Max Power Isolation DC-DC Converter
Product # PQ24280FTx22 Phone 1-888-567-9596 www.synqor.com Doc.# 005-0005178 Rev. E 03/24/11 Page 2
Technical Specification
Input:
18-36 V
Output:
28V
Current:
22A
Package:
Full-brick
Open Frame Mechanical Diagram
Mechanical Information
MECHANICAL DIAGRAM (open frame)
NOTES
1) Pins 1-4, 7-12 are 0.040” (1.02mm) diameter, with 0.080” (2.03mm)
diameter standoff shoulders.
2) Pins 5-6, 13-18 are 0.080” (2.03 mm) diameter with 0.125” (3.18mm)
diameter standoff shoulders.
3) Other pin extension lengths available. Recommended pin length is
0.03” (0.76mm) greater than the PCB thickness.
4) All Pins: Material - Copper Alloy Finish - Matte Tin over Nickel plate
5) Undimensioned components are shown for visual reference only.
6) Weight: 4.3 oz (121 g) typical
7) All dimensions in inches (mm) Tolerances: x.xx +/-0.02 in. (x.x +/-
0.5mm) x.xxx +/-0.010 in. (x.xx +/-0.25mm)
8) Workmanship: Meets or exceeds IPC-A-610C Class II
9) UL/TUV standards require a clearance greater than 0.04” (1.02mm)
between input and output for Basic insulation. This issue should
be considered if any copper traces are on the top side of the user’s
board. Note that the ferrite cores are considered part of the input/
primary circuit.
Pin Designations Notes:
1) Leave TRIM pin open for nominal output voltage.
2) SENSE(+) should be connected to Vout(+) either remotely or at the
converter.
3) SENSE(–) should be connected to Vout(–) either remotely or at the
converter.
PIN DESIGNATIONS
Pin Name Function
1SyncIn Synchronization Input (full feature versions only)
2SyncOut Synchronization Output (full feature versions only)
3+ON/OFF Turn converter on and off, referenced to
– ON/OFF
4– ON/OFF Fully isolated ground
5Vin(+) Positive input voltage
6Vin(–) Negative input voltage
7Vaux Remote ON/OFF power, referenced to Vout(–)
8IOG Power Good or Inverted Operation Good
9PARALLEL Current share (full feature versions only)
10 TRIM Output voltage trim. see note 1
11 SENSE(+) Positive remote sense. see note 2
12 SENSE(–) Negative remote sense. see note 3
13 Vout(–) Negative output voltage
14 Vout(–) Negative output voltage
15 Vout(–) Negative output voltage
16 Vout(+) Positive output voltage
17 Vout(+) Positive output voltage
18 Vout(+) Positive output voltage
Top View Side View
(60.96)
Bottom side
Clearance
1.750
2.40
(44.45)
1.400 (35.56)
1.150 (29.21)
0.900 (22.86)
0.500 (12.7)
0.250 (6.35)
0.050 (1.27)
3.150
(80.01)
4.20
(106.7)
4.60
(116.8)
0.20
(5.1)
0.45
(11.4)
0.150 (3.81)
0.300 (7.62)
0.450 (11.43)
0.600 (15.24)
0.750 (19.05)
1.250 (31.75)
0.850 (21.59)
0.450 (11.43)
0.300 (7.62)
0.150 (3.81)
0.033 ±0.027
(0.84 ±0.68)
0.180
(4.57)
See Note 3
Overall Height
0.395 ±0.025
(10.03 ±0.63)
1 2 56
3 4
13
7
8
9
10
11
12
14151618 17
Input:
18-36 V
Output:
28V
Current:
22A
Package:
Full-brick
Product # PQ24280FTx22 Phone 1-888-567-9596 www.synqor.com Doc.# 005-0005178 Rev. E 03/24/11 Page 3
Technical Specification
Input:
18-36 V
Output:
28V
Current:
22A
Package:
Full-brick
Baseplated Mechanical Diagram
Mechanical Information
Top View Side View
(60.96)
Bottom side Clearance
1.750
2.40
(50.8)
2.000
(44.45)
1.400 (35.56)
1.150 (29.21)
0.900 (22.86)
0.500 (12.7)
.20
(5.1)
(5.1)
.20
0.050 (1.27)
3.150
(80.01)
4.20
(106.7)
4.20
(106.7)
4.60
(116.8)
0.20
(5.1)
0.45
(11.4)
0.150 (3.81)
0.300 (7.62)
0.450
(11.43)
0.600
(15.24)
0.750
(19.05)
1.250 (31.75)
0.850 (21.59)
0.450 (11.43)
0.300 (7.62)
0.150 (3.81)
0.061 +0.019
- 0.022
1.55 +0.48
- 0.55
Overall Height
1 2 5 63 4
13
7
8
9
10
11
12
61 51 4118 17
4 places
M3 standoff
Available Threaded & Non-threaded
See note 10
M3
THREADED
STANDOFF
(
(
0.492 +0.002
- 0.005
12.5 +0.05
- 0.12
(
(
MECHANICAL DIAGRAM (base-plated)
NOTES
1) Pins 1-4, 7-12 are 0.040” (1.02mm) diameter, with 0.080” (2.03mm)
diameter standoff shoulders.
2) Pins 5-6, 13-18 are 0.080” (2.03 mm) diameter with 0.125” (3.18mm)
diameter standoff shoulders.
3) Other pin extension lengths available. Recommended pin length is
0.03” (0.76mm) greater than the PCB thickness.
4) All Pins: Material - Copper Alloy Finish - Matte Tin over Nickel plate
5) Undimensioned components are shown for visual reference only.
6) All dimensions in inches (mm) Tolerances: x.xx +/-0.02 in. (x.x +/-
0.5mm) x.xxx +/-0.010 in. (x.xx +/-0.25mm)
7) Weight: 5.6 oz. (160 g) typical
8) Workmanship: Meets or exceeds IPC-A-610C Class II
9) UL/TUV standards require a clearance greater than 0.04” (1.02mm)
between input and output for Basic insulation. This issue should be
considered if any copper traces are on the top side of the user’s board.
Note that the ferrite cores are considered part of the input/primary
circuit.
10) Applied torque per screw should not exceed 6 in-lb (.7Nm)
Pin Designations Notes:
1) Leave TRIM pin open for nominal output voltage.
2) SENSE(+) should be connected to Vout(+) either remotely or at the
converter.
3) SENSE(–) should be connected to Vout(–) either remotely or at the
converter.
PIN DESIGNATIONS
Pin Name Function
1 SyncIn Synchronization Input (full feature versions only)
2 SyncOut Synchronization Output (full feature versions only)
3 +ON/OFF Turn converter on and off, referenced to – ON/OFF
4 – ON/OFF Fully isolated ground
5 Vin(+) Positive input voltage
6 Vin(–) Negative input voltage
7 Vaux Remote ON/OFF power, referenced to Vout(–)
8 IOG Power Good or Inverted Operation Good
9 PARALLEL Current share (full feature versions only)
10 TRIM Output voltage trim. see note 1
11 SENSE(+) Positive remote sense. see note 2
12 SENSE(–) Negative remote sense. see note 3
13 Vout(–) Negative output voltage
14 Vout(–) Negative output voltage
15 Vout(–) Negative output voltage
16 Vout(+) Positive output voltage
17 Vout(+) Positive output voltage
18 Vout(+) Positive output voltage
Product # PQ24280FTx22 Phone 1-888-567-9596 www.synqor.com Doc.# 005-0005178 Rev. E 03/24/11 Page 4
Technical Specification
Input:
18-36 V
Output:
28V
Current:
22A
Package:
Full-brick
Electrical Characteristics
PQ24280FTx22 Electrical Characteristics
Ta = 25 °C, airow rate = 300 LFM, Vin = 24V dc unless otherwise noted; full operating temperature range is -40 °C to +100 °C baseplate temperature
with appropriate power derating. Specications subject to change without notice.
Parameter Min. Typ. Max. Units Notes & Conditions
ABSOLUTE MAXIMUM RATINGS
Input Voltage
Non-Operating 50 V Continuous
Operating 36 V Continuous
Operating Transient Protection 50 V 100ms transient
Isolation Voltage
Input to Output 2250 V dc Input to output
Operating Temperature -40 100 °C Baseplate temperature
Storage Temperature -55 125 °C
Voltage at ON/OFF input pin -2 18 V
INPUT CHARACTERISTICS
Operating Input Voltage Range 18 24 36 V
Input Under-Voltage Lockout
Turn-On Voltage Threshold 16.13 16.80 17.47 V
Turn-Off Voltage Threshold 14.69 15.30 15.91 V
Lockout Voltage Hysteresis 1.5 V
Maximum Input Current 37.5 A 100% Load, Vin min, nominal Vout
No-Load Input Current 300 400 mA
Disabled Input Current 60 75 mA
Inrush Current Transient Rating 0.2 A
Recommended External Input Capacitor ESR1 0.04 0.2 1 Ohms
Input Reected Ripple Current 275 mA RMS thru 2.2μH inductor
Input Terminal Ripple Current 350 mA RMS @ 36Vin
Recommended Input Fuse 50 A Fast Acting Fuse
Recommended External Input Capacitance 470 µF Typical ESR 0.1-0.2 Ω
Input Filter Component Values (L\C) 0.05/80.0 µH/µF
OUTPUT CHARACTERISTICS
Output Voltage Set Point 27.75 28 28.25 V
Output Voltage Regulation
Over Line ±0.05/14 +0.1/28 %mV
Over Load ±0.1/28 +0.2/56 %mV
Over Temperature 45 90 mV
Total Output Voltage Range 27.5 28.5 V Over sample, line, load, temperature & life
Output Voltage Ripple and Noise 20 MHz bandwidth
Peak-to-Peak 250 350 mV Full load
RMS 60 90 mV Full load
Operating Output Current Range 0 21.5 A Subject to thermal derating
Output DC Current-Limit Inception 23.5 25.6 28.5 A Output voltage 10% Low
Back-Drive Current Limit while Enabled 0.6 1.8 3 A Negative current drawn from output
Back-Drive Current Limit while Disabled 0.14 0.3 0.45 A Negative current drawn from output
Current Share Accuracy (2 units paralleled) 2.5 A
Maximum Output Capacitance Ceramic 4000 uF Vout nominal at full load (resistive load)
EFFICIENCY
100% Load 91 %
50% Load 93 %
Input:
18-36 V
Output:
28V
Current:
22A
Package:
Full-brick
Product # PQ24280FTx22 Phone 1-888-567-9596 www.synqor.com Doc.# 005-0005178 Rev. E 03/24/11 Page 5
Technical Specification
Input:
18-36 V
Output:
28V
Current:
22A
Package:
Full-brick
PQ24280FTx22 Electrical Characteristics (continued)
Ta = 25 °C, airow rate = 300 LFM, Vin = 24V dc unless otherwise noted; full operating temperature range is -40 °C to +100 °C baseplate temperature
with appropriate power derating. Specications subject to change without notice.
Parameter Min. Typ. Max. Units Notes & Conditions
DYNAMIC CHARACTERISTICS
Input Voltage Ripple Rejection 30 dB 120 Hz
Output Voltage during Load Current Transient
Step Change in Output Current (0.1 A/µs) 1750 mV 50% to 75% to 50% Iout max, 47uF
Step Change in Output Current (0.5 A/µs) 800 mV 50% to 75% to 50% Iout max, 470uF
Lockout Voltage Hysteresis 100 µs To within 1% Vout nom
Turn-On Transient
Turn-On Time 25 30 35 ms Full load, Vout=90% nom.
Start-Up Inhibit Time 180 200 230 ms
First Startup Delay: 200 ms
Restart Inhibit Delay: 320 ms
Output Voltage Overshoot 0 0 % 4,000 µF load capacitance, Iout = 26A resistive load
ISOLATION CHARACTERISTICS
Isolation Voltage (dielectric strength) 2250 See Absolute Maximum Ratings
Isolation Resistance 30 MΩ
Isolation Capacitance (input to output) 3300 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 100 °C Applies to baseplated units only
FEATURE CHARACTERISTICS
Switching Frequency 275 300 325 kHz Regulation and isolation stages
ON/OFF Control (Option P)
On Current (threshold) 0.1 0.5 1 mA
Off Current (threshold) 50 µA
ON/OFF Control (Option N)
On Current (threshold) 50 µA
Off Current (threshold) 0.1 0.5 1 mA
Maximum allowable current 4 mA through ON/OFF Pin
Auxiliary Power Supply Voltage 6 9 V
Auxiliary Power Supply Current 0 10 mA
Output Voltage Trim Range -50 15 % Measured across Pins 9 & 5; Figure C
Output Voltage Remote Sense Range 15 % Measured across Pins 9 & 5
Output Over-Voltage Protection 33 35 37 V Over full temp range; % of nominal Vout
Over-Temperature Shutdown OTP Trip Point 120 °C Average PCB Temperature
Over-Temperature Shutdown Restart Hysteresis 10 °C
Load Current Scale Factor 750 See App Note: Output Load Current Calc.
RELIABILITY CHARACTERISTICS
Calculated MTBF (Telcordia) TR-NWT-000332 2.1 106 Hrs. 80% load, 200LFM, 40 °C Ta
Calculated MTBF (MIL-217) MIL-HDBK-217F 1.9 106 Hrs. 80% load, 200LFM, 40 °C Ta
Field Demonstrated MTBF See our website for details
Note 1: Higher values of isolation capacitance can be added external to the module.
Electrical Characteristics
Product # PQ24280FTx22 Phone 1-888-567-9596 www.synqor.com Doc.# 005-0005178 Rev. E 03/24/11 Page 6
Technical Specification
Input:
18-36 V
Output:
28V
Current:
22A
Package:
Full-brick
Standards & Qualifications
Standards Compliance & Qualification Testing
Parameter Notes & Conditions
STANDARDS COMPLIANCE
UL 60950-1:2007 Basic insulation
EN60950-1/A11:2009/A1:2010
CAN/CSA-C22.2 No. 60950-1:2007
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 ofcial safety certicates on new
releases or download from the SynQor website.
Parameter # Units Test Conditions
QUALIFICATION TESTING
Life Test 32 95% rated Vin and load, units at derating point, 1000 hours
Vibration 5 10-55 Hz sweep, 0.060" total excursion, 1 min./sweep, 120 sweeps for 3 axis
Mechanical Shock 5 100g minimum, 2 drops in x, y and z axis
Temperature Cycling 10 -40 °C to 100 °C, unit temp. ramp 15 °C/min., 500 cycles
Power/Thermal Cycling 5 Toperating = min to max, Vin = min to max, full load, 100 cycles
Design Marginality 5 Tmin-10 °C to Tmax+10 °C, 5 °C steps, Vin = min to max, 0-105% load
Humidity 5 85 °C, 85% RH, 1000 hours, continuous Vin applied except 5 min/day
Solderability 15 pins MIL-STD-883, method 2003
Product # PQ24280FTx22 Phone 1-888-567-9596 www.synqor.com Doc.# 005-0005178 Rev. E 03/24/11 Page 7
Technical Specification
Input:
18-36 V
Output:
28V
Current:
22A
Package:
Full-brick
0
5
10
15
20
25
30
35
40
45
50
55
60
65
0 2 4 6 9 11 13 15 17 19 22
Load Current (A)
Power Dissipation (W)
18 Vin
24 Vin
36 Vin
80
82
84
86
88
90
92
94
96
0 2 4 6 9 11 13 15 17 19 22
Load Current (A)
Efficiency (%)
18 Vin
24 Vin
36 Vin
80
82
84
86
88
90
92
94
96
98
100
100 200 300 400
Air Flow (LFM)
Efficiency (%)
25 ºC
40 ºC
55 ºC
Semiconductor junction temperature is
within 1
°
C of surface temperature
14
16
18
20
22
24
26
28
30
32
100 200 300 400
Air Flow (LFM)
Power Dissipation (W)
25 ºC
40 ºC
55 ºC
0
2
4
6
8
10
12
14
16
25 40 55 70 85
Ambient Air Temperature (ºC)
Iout (A)
400 LFM (2.0 m/s)
300 LFM (1.5 m/s)
200 LFM (1.0 m/s)
100 LFM (0.5 m/s)
Figure 1: Efciency at nominal output voltage vs. load current for minimum,
nominal, and maximum input voltage at 25°C.
Figure 2: Efciency at nominal output voltage and 60% rated power vs. airow
rate for ambient air temperatures of 25°C, 40°C, and 55°C (nominal input
voltage).
Figure 3: Power dissipation at nominal output voltage vs. load current for
minimum, nominal, and maximum input voltage at 25°C.
Figure 4: Power dissipation at nominal output voltage and 60% rated power
vs. airow rate for ambient air temperatures of 25°C, 40°C, and 55°C (nominal
input voltage).
Figure 5: Maximum output power derating curves vs. ambient air temperature
for airow rates of 100 LFM through 400 LFM with air owing from pin 1 to pin
2 (nominal input voltage). See Figure 21 for baseplate derating curve.
Figure 6: Thermal plot of converter at 9.6 amp load current (268.8W) with 55°C
air owing at the rate of 200 LFM. Air is owing from pin 1 to pin 2 (nominal
input voltage).
Technical Figures
Technical Figures
Input:
18-36 V
Output:
28V
Current:
22A
Package:
Full-brick
Product # PQ24280FTx22 Phone 1-888-567-9596 www.synqor.com Doc.# 005-0005178 Rev. E 03/24/11 Page 8
Technical Specification
Input:
18-36 V
Output:
28V
Current:
22A
Package:
Full-brick
source
impedance
DC-DC
Converter
Input
Terminal
Ripple
Current
Input
Reflected
Ripple
Current Output
Voltage
Ripple
ceramic
capacitor
tantalum
capacitor
electrolytic
capacitor
VSOURCE
VOUT
i
S
i
C
Figure 7: Turn-on transient at full load (resistive load) (10 ms/div). Input voltage
pre-applied. Top Trace: Vout (10V/div). Bottom Trace: ON/OFF input (1.0V/div)
Figure 8: Turn-on transient at zero load (10 ms/div). Top Trace: Vout (10V/div).
Bottom Trace: ON/OFF input (1.0V/div)
Figure 9: Output voltage response to step-change in load current (50%-
75%-50% of Iout(max); dI/dt = 0.1A/µs). Load cap: 47µF, ceramic output
capacitance. Top trace: Vout (2V/div). Bottom trace: Iout (10A/div).
Figure 10: Output voltage response to step-change in load current (50%-
75%-50% of Iout(max): dI/dt = 0.5A/µs). Load cap: 470µF, ceramic output
capacitance. Top trace: Vout (500mV/div). Bottom trace: Iout 5A/div).
Figure 11: Test set-up diagram showing measurement points for Input Terminal
Ripple Current (Figure 12), Input Reected Ripple Current (Figure 13) and
Output Voltage Ripple (Figure 14).
Figure 12: Input Terminal Ripple Current, ic, at full rated output current
and 36V input voltage with 2.2µH source impedance and 470µF electrolytic
capacitor (Ch2 500mA/div). (See Figure 11).
Technical Figures
Input:
18-36 V
Output:
28V
Current:
22A
Package:
Full-brick
Input:
18-36 V
Output:
28V
Current:
22A
Package:
Full-brick
Product # PQ24280FTx22 Phone 1-888-567-9596 www.synqor.com Doc.# 005-0005178 Rev. E 03/24/11 Page 9
Technical Specification
Input:
18-36 V
Output:
28V
Current:
22A
Package:
Full-brick
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
10 100 1,000 10,000 100,000
Hz
Forward Transmission (dB)
18 Vin
24 Vin
36 Vin
0.0001
0.001
0.01
0.1
1
10
10 100 1,000 10,000 100,000
Hz
Output Impedance (ohms)
18 Vin
24 Vin
36 Vin
Figure 13: Input reected ripple current, is, through a 2.2 µH source inductor at
36V input voltage and rated load current (200 mA/div). (See Figure 11).
Figure 14: Output voltage ripple at nominal input voltage and rated load current
(200 mV/div). Load capacitance: two 6.8µF ceramic capacitors and 15µF
tantalum capacitor. Bandwidth: 20 MHz. (See Figure 11).
Figure 15: Output voltage response to step-change in input voltage. Load cap:
no output capacitance. Ch 1: Vout (5V/div), Ch 2: Vin (10V/div) 200uS/div.
Figure 16: Load current (20A/div) as a function of time when the converter
attempts to turn on into a 1 mΩ short circuit.
Figure 17: Magnitude of incremental output impedance (Zout = vout/iout) for
minimum, nominal, and maximum input voltage at full rated power.
Figure 18: Magnitude of incremental forward transmission (FT = vout/vin) for
minimum, nominal, and maximum input voltage at full rated power.
Technical Figures
10µH
47µF <1Ω 1µF15µF 100mΩ ESR
Input:
18-36 V
Output:
28V
Current:
22A
Package:
Full-brick
Input:
18-36 V
Output:
28V
Current:
22A
Package:
Full-brick
Input:
18-36 V
Output:
28V
Current:
22A
Package:
Full-brick
Product # PQ24280FTx22 Phone 1-888-567-9596 www.synqor.com Doc.# 005-0005178 Rev. E 03/24/11 Page 10
Technical Specification
Input:
18-36 V
Output:
28V
Current:
22A
Package:
Full-brick
0
5
10
15
20
25
0 25 40 55 70 85
Ambient Air Temperature (°C)
Iout (A)
400 LFM (2.0 m/s)
300 LFM (1.5 m/s)
200 LFM (1.0 m/s)
100 LFM (0.5 m/s)
0
5
10
15
20
25
30
35
-5 0 5 10 15 20 25 30 35
Load Current (A)
Output Voltage (V)
-55
-45
-35
-25
-15
-5
5
15
25
10 100 1,000 10,000 100,000
Hz
Reverse Transmission (dB)
18 Vin
24 Vin
36 Vin
0.01
0.1
1
10
10 100 1,000 10,000 100,000
Hz
Input Impedance (ohms)
18 Vin
24 Vin
36 Vin
Figure 19: Magnitude of incremental reverse transmission (RT = iin/iout) for
minimum, nominal, and maximum input voltage at full rated power.
Figure 20: Magnitude of incremental input impedance (Zin = vin/iin) for
minimum, nominal, and maximum input voltage at full rated power.
Figure 21: Baseplated unit maximum output power derating curves vs. ambient
air temperature for airow rates of 100 LFM through 400 LFM with air owing
from input to output (nominal input voltage). No derating if baseplate is <100ºC.
Figure 22: Output voltage vs. load current showing typical current limit curves
and converter shutdown points.
Technical Figures
Product # PQ24280FTx22 Phone 1-888-567-9596 www.synqor.com Doc.# 005-0005178 Rev. E 03/24/11 Page 11
Technical Specification
Input:
18-36 V
Output:
28V
Current:
22A
Package:
Full-brick
Applications Section
Applications Section
VIN
IN
(+)
+ON/OFF
-ON/OFF
V (-)
V
OUT (+)
SENSE (+)
SENSE (-)
VOUT (-)
VIN
IN
(+)
+ON/OFF
-ON/OFF
V (-)
V
OUT (+)
SENSE (+)
SENSE (-)
VOUT (-)
ION/OFF
ION/OFF
Application Section
BASIC OPERATION AND FEATURES
The PowerQor series converter uses a two-stage power conversion
topology. The rst stage 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-down to achieve the low output voltage required.
Both the rst stage and the second stage switch at a xed frequency
for predictable EMI performance. Rectication of the transformer’s
output is accomplished with synchronous rectiers. 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 PowerQor converter has such high efciency, even at very
low output voltages and very high output currents.
Dissipation throughout the converter is so low that it does not
require a heatsink for operation. Since a heatsink is not required,
the PowerQor series of converters do not need a metal baseplate
or potting material to help conduct the dissipated energy to the
heatsink. The PowerQor series of converters can thus be built
more simply and reliably using high yield surface mount techniques
on a PCB substrate.
The PowerQor series converters use the industry standard
footprint and pin-out conguration.
CONTROL FEATURES
REMOTE ON/OFF (Pin 3): The (+)ON/OFF input, Pin 3, permits
the user to control when the converter is on or off. This input is
referenced (-)ON/OFF. There are two versions of the converter
that differ by the sense of the logic used for the ON/OFF input.
In the positive logic version, the ON/OFF input is active high
(meaning that a high ION/OFF turns the converter on). In the
negative logic version, the ON/OFF signal is active low (meaning
that a low ION/OFF turns the converter on). Figures A & B detail
two possible circuits for driving the ON/OFF pin.
REMOTE SENSE(+) (Pins 11 and 12): The SENSE(+) inputs
correct for voltage drops along the conductors that connect the
converter’s output pins to the load.
Pin 11 should be connected to Vout(+) and Pin 12 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 specied in this datasheet, that is
Pins 11 and 12 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 specied
value.
Note: the output over-voltage protection circuit senses the voltage
across the output (pins 16 and 13) to determine when it should
trigger, not the voltage across the converter’s sense leads (pins
11 and 12). Therefore, the resistive drop on the board should be
small enough so that output OVP does not trigger, even during
load transients.
OUTPUT VOLTAGE TRIM (Pin 10): The TRIM input permits the
user to adjust the output voltage across the sense leads up or
down according to the trim range specications.
To decrease the output voltage, the user should connect a resistor
between Pin 10 and Pin 11 (SENSE(-) input). For a desired
decrease of the nominal output voltage, the value of the resistor
should be
Figure A: Typical circuit for driving the ON/OFF pin.
Figure B: Another circuit for driving the ON/OFF pin.
Rtrim-down =
(732)- 8.94 (kΩ)
Δ
where
Δ%= Vnominal – Vdesired x 100%
Vnominal
To increase the output voltage, the user should connect a
resistor between Pin 7 and Pin 8 (SENSE(+) input). For a
desired increase of the nominal output voltage, the value of
the resistor should be
Rtrim-up = 732x(Voutnomx(1+∆%)-1.225) -
1.225x∆%
Input:
18-36 V
Output:
28V
Current:
22A
Package:
Full-brick
Product # PQ24280FTx22 Phone 1-888-567-9596 www.synqor.com Doc.# 005-0005178 Rev. E 03/24/11 Page 12
Technical Specification
Input:
18-36 V
Output:
28V
Current:
22A
Package:
Full-brick
Applications Section
Figure C graphs 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 Vout: For the converter to meet its full
specications, the maximum variation of the DC value of Vout, due
to both trimming and remote load voltage drops, should not be
greater than that specied for the output voltage trim range.
Current Share (pin 9): The active current share feature allows
for N+1 and parallel applications. To achieve load sharing, directly
connect the PARALLEL pins of multiple units. The voltage at the
PARALLEL pin will range from 1.0 to 2.4 volts (at full rated current),
referenced to the secondary side ground, SENSE(-).
1
10
100
1,000
10,000
100,000
1,000,000
0 5 10 15 20 25 30 35 40 45 50
Trim Resistance (kOhms)
% increase Vout % decrease Vout
Figure C: Trim Graph 28V Module.
SYNCHRONIZATION: The converter’s switching frequency can
be synchronized to an external frequency source that is in the
270 kHz to 330 kHz range. A pulse train at the desired frequency
should be applied to the SYNC IN pin (pin 1) with respect to the
INPUT RETURN (pin 6). Its frequency can be anywhere in that
range, regardless of the natural frequency of the power converter.
This pulse train should have a duty cycle in the 20% to 80%
range. Its low value should be below 0.8V to be guaranteed to be
interpreted as a logic low, and its high value should be above 2.0V
to be guaranteed to be interpreted as a logic high. The transition
time between the two states should be less than 300ns.
If the converter is not to be synchronized, the SYNC IN pin should
be left open circuit. The converter will then operate in its free-
running mode at a frequency of approximately 300 kHz.
The converter also has a SYNC OUT pin (pin 2). The pulse train
coming out of SYNC OUT has a frequency that matches the
switching frequency of the converter with which it is associated.
This frequency is either the free-running frequency if there is no
synchronization signal at the SYNC IN pin, or the synchronization
frequency if there is.
Product # PQ24280FTx22 Phone 1-888-567-9596 www.synqor.com Doc.# 005-0005178 Rev. E 03/24/11 Page 13
Technical Specification
Input:
18-36 V
Output:
28V
Current:
22A
Package:
Full-brick
Applications Section
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”. 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*
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: If the output current exceeds the “Output
DC Current Limit Inception” point*, then a fast linear current limit
controller will reduce the output voltage to maintain a constant
output current. There is no minimum operating output voltage. The
converter will run with low on-board power dissipation down to zero
output voltage. A redundant circuit will shutdown the converter if
the primary current limit fails.
Back-Drive Current Limit: If there is negative output current
of a magnitude larger than the “Back-Drive Current Limit while
Enabled” specication*, then a fast back-drive limit controller will
increase the output voltage to maintain a constant output current.
If this results in the output voltage exceeding the “Output Over-
Voltage Protection” threshold*, then the unit will shut down. The
full I-V output characteristic can be seen in Figure 19.
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.
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.
Start-up Inhibit Period: If any protection feature causes the
converter to shut down, the converter will attempt to restart after
320ms (typical), the “Restart Inhibit Period”.* On initial application
of input voltage, the rst startup delay is about 200ms from input
voltage valid to unit output rising. With the on/off pin set to enable
the converter, the “Turn-On Time”* will increase by only 2ms.
*See specications page for details.
Input:
18-36 V
Output:
28V
Current:
22A
Package:
Full-brick
Product # PQ24280FTx22 Phone 1-888-567-9596 www.synqor.com Doc.# 005-0005178 Rev. E 03/24/11 Page 14
Technical Specification
Input:
18-36 V
Output:
28V
Current:
22A
Package:
Full-brick
Applications Section
Vin
External
Input
Filter
Trim
Vin(+)
Iload
Cload
Vout(
Local
ceramic
+)
Rtrim-up
or
Rtrim-down
Vsense(+)
ON/OFF
Vin(_)Vout(_)
Vsense(_)
Electrolytic
Capacitor
C2
C1
Lin Lout/2
Lout/2
Cout
V
in(+)
Vin(_)
Vout(+)
Vout(-)
Regulation
Stage Current
Sense
Isolation
Stage
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 below provides a typical circuit
diagram which details the input ltering and voltage trimming.
Input Filtering and External Input Capacitance: This lter
dramatically reduces input terminal ripple current, which otherwise
could exceed the rating of an external electrolytic input capacitor.
The recommended external input capacitance is specied in
the “Input Characteristics” section. More detailed information is
available in the application note titled “EMI Characteristics” on the
SynQor website.
Output Filtering and External Output Capacitance: Figure
E below shows the internal output lter components. This lter
dramatically reduces output voltage ripple. However, some
minimum external output capacitance is required, as specied in
the Output Characteristics section on the Electrical Specications
page. No damage will occur without this capacitor connected, but
peak output voltage ripple will be much higher.
Figure D: Typical application circuit (negative logic unit, permanently enabled).
Figure E: Internal Input and Output Filter Diagram (component values listed on specications page).
2 x 4.7μF
100µF ESR
@0.2Ω
Product # PQ24280FTx22 Phone 1-888-567-9596 www.synqor.com Doc.# 005-0005178 Rev. E 03/24/11 Page 15
Technical
Specification
PQ24280FTx22
Ordering Information
Part Numbering System
The part numbering system for SynQor’s dc-dc converters follows the format
shown in the example below.
The first 12 characters comprise the base part number and the last 3
characters indicate available options. The “-G” suffix indicates 6/6 RoHS
compliance.
Application Notes
A variety of application notes and technical white papers can be downloaded
in pdf format from our website.
RoHS Compliance: The EU led RoHS (Restriction of Hazardous
Substances) Directive bans the use of Lead, Cadmium, Hexavalent
Chromium, Mercury, Polybrominated Biphenyls (PBB), and Polybrominated
Diphenyl Ether (PBDE) in Electrical and Electronic Equipment. This SynQor
product is 6/6 RoHS compliant. For more information please refer to
SynQor’s RoHS addendum available at our RoHS Compliance / Lead Free
Initiative web page or e-mail us at rohs@synqor.com.
Ordering Information
The tables below show the valid model numbers and ordering options for
converters in this product family. When ordering SynQor converters, please
ensure that you use the complete 15 character part number consisting of
the 12 character base part number and the additional characters for options.
Add “-G” to the model number for 6/6 RoHS compliance.
The following options must be included in place of the
w x y z
spaces in the
model numbers listed above.
Not all combinations make valid part numbers, please contact SynQor for
availability. See the Product Summary web page for more options.
Warranty
SynQor offers a three (3) 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.
Product Family
Package Size
Performance Level
Thermal Design
Output Current
6/6 RoHS
Options (see
Ordering Information)
Input Voltage
Output Voltage
Contact SynQor for further information:
Phone: 978-849-0600
Toll Free: 888-567-9596
Fax: 978-849-0602
E-mail: power@synqor.com
Web:
www.synqor.com
Address: 155 Swanson Road
Boxborough, MA 01719
USA
PQ 24 280 F T B 2 2 N R S - G
Ordering Information
Model Number Input Voltage Output
Voltage
Max Output
Current
PQ24280FTw22xyz-G 18-36 V 28V 21.5A
Options Description: w x y z
Thermal Design Enable Logic Pin Style Feature Set
A - Open Frame
B - Threaded Baseplate
F - Non-threaded Baseplate
N - Negative
P - Positive
K - 0.110"
N - 0.145"
R - 0.180"
Y - 0.250"
S - Standard
F - Full Feature
PATENTS
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 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 7,765,687 7,787,261
