25A/45W

Technical
Specification
PQ24018QGx25
18 - 36V
1.8V
25A
45W
2000V dc
Quarter-brick
Continuous Input
Outputs
Current
Max Power
Isolation
DC-DC Converter
The PQ24018QGx25 PowerQor Giga quarter-brick
converter is a next-generation, board-mountable, isolated,
fixed switching frequency DC-DC converter that uses
synchronous rectification to achieve extremely high
conversion efficiency. The power dissipated by the converter
is so low that a heatsink is not required, which saves cost,
weight, height, and application effort. All of the power and
control components are mounted to the multi-layer PCB
substrate with high-yield surface mount technology. Since
the PowerQor converter has no explicit thermal connections,
it is extremely reliable. RoHS Compliant, see last page.
PQ24018QGx25 Module
Operational Features
• High efficiency, >84% at full rated load current
• Delivers up to 25 amps of output current with minimal derating
- no heatsink required
• Wide input voltage range: 18V - 36V meets or exceeds all 24V
bus standards
• Fixed frequency switching provides predictable EMI performance
• No minimum load requirement means no preload resistors required.
Protection Features
• Input under-voltage lockout disables converter at low input
voltage conditions
• Output current limit and short circuit protection protects converter
from excessive load current or short circuits
• Output over-voltage protection protects load from damaging voltages
• Thermal shutdown protects converer from abnormal
Mechanical Features
•
•
•
•
•
Safety Features
Industry standard pin-out configuration
Standard Size Open Frame:1.45" x 2.30" (36.8 x 58.4mm)
Open Frame height: .40” (10.2mm),
Open Frame Weight: 1.2 oz. (34g)
Flanged pins designed to permit surface mount soldering
(avoid wave solder) using FPiP technique on Open Frame Units
• UL 60950-1:R2011-12
• EN60950-1/A12:2011
• CAN/CSA-C22.2 No. 60950-1/A1:2011
Control Features
Contents
• On/Off control referenced to input side
(positive and negative logic options are available)
• Remote sense for the output voltage compensates for output
distribution drops
• Output voltage trim permits custom voltages and voltage margining
Product # PQ24018QGx25
Phone 1-888-567-9596
Page No.
Mechanical Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Application Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
www.synqor.com
Doc.# 005-2QG218D Rev. B
04/09/13
Page 1
Input:
Output:
Current:
Package:
Open Frame Mechanical Diagram
18 - 36V
1.8V
25A
Quarter-brick
1.45 [36.8]
.40
[10.2]
0.600 [15.24]
0.450 [11.43]
0.300 [7.62]
0.150 [3.81]
0.145
[3.68]
See Note 3
8
2.30 [58.4]
7
6 5 4
Top View
2.00 [50.8]
Side View
0.14 [3.6]
1
2
3
Pin Farside Typical
See Notes 1, 2, and 3
0.43 [10.9]
0.300 [7.62]
0.063+/- .026
[1.60+/- .66]
Bottomside Clearance
0.600 [15.24]
NOTES
1)
2)
3)
4)
5)
6)
7)
8)
PIN DESIGNATIONS
Pins 1-3, 5-7 are 0.040” (1.02mm) diameter
with 0.080” (2.03mm) diameter standoff shoulders
Pins 4 and 8 are 0.0620” (1.57mm) diameter
with 0.100” (2.54mm) diameter standoff shoulders
All Pins: Material - Copper Alloy
Finish: Tin-Lead over Nickel Plate
Other pin extension lengths available.
Undimensioned components are shown for visual reference only.
Open Frame Weight: 1.2 oz. (34g)
All dimensions in inches (mm)
Unless otherwise specified:
Tolerances X.XXin. +/-0.02 (X.Xmm +/-0.5mm)
X.XXin. +/-0.010 (X.XXmm +/-0.25mm)
Workmanship: Meets or exceeds IPC-A-610 Class II
Product # PQ24018QGx25
Phone 1-888-567-9596
Pin
Name
Function
1
Vin(+)
Positive input voltage
2
ON/OFF
3
4
5
6
7
8
Vin(–)
Vout(–)
SENSE(–)
TRIM
SENSE(+)
Vout(+)
TTL input to turn converter on and off, referenced
to Vin(–), with internal pull up.
Negative input voltage
Positive output voltage
Negative remote sense (See note 1)
Output voltage trim (See note 2)
Positive remote sense (See note 3)
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.
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Doc.# 005-2QG218D Rev. B
04/09/13
Page 2
Input:
Output:
Current:
Package:
Baseplated Mechanical Diagram
1.47 [37.3]
1.030 [26.16]
0.22 [5.6]
0.600 [15.24]
0.450 [11.43]
0.300 [7.62]
0.150 [3.81]
18 - 36V
1.8V
25A
Quarter-brick
0.50 [12.7]
M3 Threaded Insert
4 Places
See Notes 1 and 2
0.23 [5.8]
8
7
6 5 4
0.145 [3.68]
See Note4
Top View
2.32 [58.9]
1.86 [47.2]
Side View
2.00 [50.8]
1
2
3
0.15 [3.8]
0.300 [7.62]
0.063+/- .026
[1.60+/- .66]
Bottomside Clearance
Pin Farside Typical
See Notes 5, 6, and 7
0.44 [11.2]
0.600 [15.24]
NOTES
1)
2)
3)
4)
5)
6)
7)
PIN DESIGNATIONS
M3 Screws used to bolt unit's Baseplate to other surfaces
(such as heatsink) Must not exceed 0.138" (3.50mm) depth
below the surface of the Baseplate
Applied Torque should not exceed 6in-lb (0.7Nm)
Baseplate flatness tolerance is 0.004" (.10mm) TIR for surface
Other pin extension lengths available.
Pins 1-3, 5-7 are 0.040" (1.02mm) Dia. with 0.080" (2.03mm)
Dia. Standoff shoulders
Pins 4, 8 are 0.062" (1.57mm) Dia. with 0.100" (2.54mm)
Dia. Standoff shoulders
All Pins: Material - Copper Alloy
Finish: Tin-Lead over Nickel Plate
Undimensioned components are shown for visual reference only.
All dimensions in inches (mm)
9)
Baseplate Weight: 2.1 oz. (61g) typical
10) All dimensions in inches (mm)
Unless otherwise specified:
Tolerances X.XXin. +/-0.02 (X.Xmm +/-0.5mm)
X.XXin. +/-0.010 (X.XXmm +/-0.25mm)
11) Workmanship: Meets or exceeds IPC-A-610 Class II
Pin
Name
1
Vin(+)
2
ON/OFF
3
4
5
6
7
8
Vin(–)
Vout(–)
SENSE(–)
TRIM
SENSE(+)
Vout(+)
8)
Product # PQ24018QGx25
Phone 1-888-567-9596
Function
Positive input voltage
TTL input to turn converter on and off, referenced
to Vin(–), with internal pull up.
Negative input voltage
Positive output voltage
Negative remote sense (See note 1)
Output voltage trim (See note 2)
Positive remote sense (See note 3)
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.
www.synqor.com
Doc.# 005-2QG218D Rev. B
04/09/13
Page 3
Input:
Output:
Current:
Package:
Technical Specifications
18 - 36V
1.8V
25A
Quarter-brick
PQ24018QGx25 Electrical Characteristics
Ta = 25 °C, airflow rate = 300 LFM, Vin = 24Vdc, nominal Vout unless otherwise noted; full operating temperature range is -40 °C to +115 °C ambient
temperature with appropriate power derating. Specifications subject to change without notice.
Parameter
Min.
INPUT CHARACTERISTICS
Operating Input Voltage Range
18
Input Under-Voltage Lockout
Turn-On Voltage Threshold
15.5
Turn-Off Voltage Threshold
14
Lockout Hysteresis Voltage
1.0
Maximum Input Current
No-Load Input Current
Off Converter Input Current
Input Reflected-Ripple Current
OUTPUT CHARACTERISTICS
Output Voltage Set Point
1.782
Output Voltage Regulation
Over Line
Over Load
Over Temperature
Total Output Voltage Range
1.75
Output Voltage Ripple and Noise
Peak-to-Peak
RMS
Operating Output Current Range
0
Output DC Current-Limit Inception
26
Short-Circuit Protection (redundant shutdown)
52
DYNAMIC CHARACTERISTICS
Input Voltage Ripple rejection
Output Voltage Current Transient
Positive Step Change in Outpu Current
Negative Step Change in Output Current
Settling Time to within 1% Vout nominal
Turn-On Transient
Turn-On Time
1
Start-Up Inhibit Period
180
Maximum Output Capacitance
EFFICIENCY
100% Load
50% Load
TEMPERATURE LIMITS FOR POWER DERATING CURVES
Semiconductor Junction Temperature
Board Temperature
Transformer Temperature
ISOLATION CHARACTERISTICS
Isolation Voltage
2000
Isolation Resistance
10
Isolation Capacitance
Product # PQ24018QGx25
Phone 1-888-567-9596
Typ.
Max.
24
36
V
16
14.5
1.5
16.5
15
2.0
3.0
100
3
V
V
V
A
mA
mA
mA
60
1.6
6
1.800
1.816
+0.1 (2)
+0.1 (2)
±9
+0.3 (5)
+0.3 (5)
±27
1.85
25
6
50
12
25
34
60
30
56
Units Notes & Conditions
% (mV)
% (mV)
mV
V
over sample line, load and temperature
20MHz bandwidth; Figures 13 & 16
mV
Full Load, 1μF ceramic, 10μF tantalum
mV
Full Load, 1μF ceramic, 10μF tantalum
A
A
Output Voltage 10% Low; Fig 17 & 18
A
dB
190
190
700
mV
mV
μs
8
215
35,000
84
87
125
125
125
470
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P-P thru 3.3μH inductor; Figures 13 & 15
V
TBD
4
200
100% Load, 18Vin
120 Hz; Figure 20
470μF load cap, 5A/μs; Figure 12
50% lo to 75% lo
75% lo to 50% lo
ms
ms
μF
Full load, Vout=90% nom.; Figs 9 & 10
-40°C to +125°C; Figure F
Full load; 5% overshoot of Vout at startup
%
%
Figure 1
°C
°C
°C
Plastic Package rated to 150°C
Board rated to 165°C
Figures 5 - 8
V
MΩ
pF
Doc.# 005-2QG218D Rev. B
04/09/13
Page 4
Input:
Output:
Current:
Package:
Technical Specifications
18 - 36V
1.8V
25A
Quarter-brick
PQ24018QGx25 Electrical Characteristics (continued)
Ta = 25 °C, airflow rate = 300 LFM, Vin = 24V dc unless otherwise noted; full operating temperature range is -40 °C to +115 °C baseplate temperature
with appropriate power derating. Specifications subject to change without notice.
Parameter
FEATURE CHARACTERISTICS
Switching Frequency
ON/OFF Control (Option P)
Off-Stage Voltage
On-Stage Voltage
ON/OFF Control (Option N)
Off-Stage Voltage
On-Stage Voltage
ON/OFF Control (Either Option)
Pull-up Voltage
Pull-up Resistance
Output Voltage Trim Range
Output Over-Voltage Protection
Over-Tempperature Shutdown
Product # PQ24018QGx25
Min.
Typ.
Max.
220
240
260
kHz
-2
2.4
0.8
18
V
V
2.4
-2
18
0.8
V
V
9.6
V
kΩ
%
%
°C
Vin/3
33
-20
117
Phone 1-888-567-9596
122
125
+10
127
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Units Notes & Conditions
See circuit diagram; Figure B
Pull up to Vin/3
Across Pins 8 & 4; % of nominal Vout
Over full temp range; % of nominal Vout
Average PCB Temperature
Doc.# 005-2QG218D Rev. B
04/09/13
Page 5
Input:
Output:
Current:
Package:
Technical Figures
95
88
90
87
86
Efficiency (%)
Efficiency (%)
85
80
75
70
65
60
0
3
5
8
10
13
15
18
20
85
84
83
82
18Vin
24Vin
81
36Vin
80
23
25 C
40 C
55 C
0
25
100
Figure 1: Efficiency at nominal output voltage vs. load current for minimum,
nominal, and maximum input voltage at 25°C.
10
5.5
Power Dissipation (W)
6.0
8
6
4
18Vin
36Vin
0
3
5
8
10
13
15
18
20
23
400
500
5.0
4.5
4.0
25 C
3.5
24Vin
0
300
Figure 2: Efficiency at nominal output voltage and 60% rated power vs. airflow
rate for ambient air temperatures of 25°C, 40°C, and 55°C (nominal input
voltage).
12
2
200
Air Flow (LFM)
Load Current (A)
Power Dissipation (W)
18 - 36V
1.8V
25A
Quarter-brick
40 C
55 C
3.0
0
25
100
200
300
400
500
Air Flow (LFM)
Load Current (A)
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. airflow rate for ambient air temperatures of 25°C, 40°C, and 55°C (nominal
input voltage).
25
Iout (A)
20
15
10
400 LFM (2.0 m/s)
300 LFM (1.5 m/s)
200 LFM (1.0 m/s)
5
100 LFM (0.5 m/s)
0 LFM (0 m/s)
0
0
25
40
55
70
85
Ambient Air Temperature (oC)
Figure 5: Maximum output power derating curves vs. ambient air temperature
for airflow rates of 0 LFM through 400 LFM with air flowing across the
converter from pin 1 to pin 3 (nominal input voltage)
Product # PQ24018QGx25
Phone 1-888-567-9596
Figure 6: Thermal plot of converter at 25 amp load current with 55°C air flowing
at the rate of 200 LFM. Air is flowing across the converter sideways from pin 1
to pin 3 (nominal input voltage)
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Doc.# 005-2QG218D Rev. B
04/09/13
Page 6
Input:
Output:
Current:
Package:
Technical Figures
18 - 36V
1.8V
25A
Quarter-brick
25
Iout (A)
20
15
10
400 LFM (2.0 m/s)
300 LFM (1.5 m/s)
200 LFM (1.0 m/s)
5
100 LFM (0.5 m/s)
0 LFM (0 m/s)
0
0
25
40
55
70
85
Ambient Air Temperature (oC)
Figure 7: Maximum output power derating curves vs. ambient air temperature
for airflow rates of 0 LFM through 400 LFM with air flowing lengthwise from
output to input (nominal input voltage).
Figure 8: Thermal plot of converter at 25 amp load current with 55°C air
flowing at the rate of 200 LFM. Air is flowing across the converter from output
to input (nominal input voltage).
Figure 9: Turn-on transient at full load (resistive load) (2 ms/div).
Ch 1: Vout (500mV/div) Ch 2: ON/OFF input (5V/div)
Figure 10: Turn-on transient at zero load (2 ms/div). Ch 1: Vout (500mV/div).
Ch 2: ON/OFF input (5V/div).
Figure 11: Output voltage response to step-change in load current (50%-75%50% of Iout(max); dI/dt = 0.1A/µs). Load cap: 10µF, 100 mΩ ESR tantalum cap
and 1µF ceramic cap. Ch 1: Vout (100mV/div), Ch 2: Iout (10A/div).
Figure 12: Output voltage response to step-change in load current (50%-75%50% of Iout(max): dI/dt = 5A/µs). Load cap: 470µF, 30 mΩ ESR tantalum cap
and 1µF ceramic cap. Ch 1: Vout (100mV/div), Ch 2: Iout (10A/div).
Product # PQ24018QGx25
Phone 1-888-567-9596
www.synqor.com
Doc.# 005-2QG218D Rev. B
04/09/13
Page 7
Input:
Output:
Current:
Package:
Technical Figures
18 - 36V
1.8V
25A
Quarter-brick
Fig. 15
3.3 μH
source
impedance
Fig. 14
Fig. 16
iS
iC
VSOURCE
100 μF,
~
= 0.33Ω ESR
electrolytic
capacitor
DC-DC
Converter
VOUT
1 μF,
10 μF,
ceramic 100mΩ ESR
capacitor tantalum
capacitor
Figure 13: Test set-up diagram showing measurement points for Input Terminal
Ripple Current (Figure 14), Input Reflected Ripple Current (Figure 15) and
Output Voltage Ripple (Figure 16).
Figure 14: Input Terminal Ripple Current, ic, at full rated output current and
nominal input voltage with 3.3µH source impedance and 100µF electrolytic
capacitor (500 mA/div). See Figure 13
Figure 15: Input reflected ripple current, is, through a 3.3 µH source inductor at
nominal input voltage and rated load current (10 mA/div). See Figure 13
Figure 16: Output voltage ripple at nominal input voltage and rated load current
(20 mV/div). Load capacitance: 1µF ceramic capacitor and 10µF tantalum
capacitor. Bandwidth: 20 MHz. (See Figure 13)
2.0
1.9
Output Voltage (V)
1.8
1.7
1.6
1.5
1.4
1.3
1.2
18V
1.1
24 V
1.0
36 V
0.9
Series1
0.8
0
5
10
15
20
25
30
35
Load Current (A)
Figure 17: Output voltage vs. load current showing typical current limit curves.
Below 0.9V (tpical), the converter will shut off, and restart after a start-up inhibit
period has elapsed. (see Figure F)
Product # PQ24018QGx25
Phone 1-888-567-9596
Figure 18: Load current (20A/div) as a function of time when the converter
attempts to turn on into a 10 mΩ short circuit. Top trace (2.5ms/div) is an
expansion of the on-time portion of the bottom trace.
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Doc.# 005-2QG218D Rev. B
04/09/13
Page 8
Input:
Output:
Current:
Package:
Technical Figures
1
18 - 36V
1.8V
25A
Quarter-brick
0
0.1
18 Vin
24 Vin
36 Vin
0.01
Forward Transmission (dB)
Output Impedance (Ω)
-10
-20
-30
18 Vin
24 Vin
-40
36 Vin
-50
-60
0.001
-70
10
100
1,000
10,000
100,000
10
100
Hz
1,000
10,000
100,000
Hz
Figure 19: Magnitude of incremental output impedance (Zout = vout/iout) for
minimum, nominal, and maximum input voltage at full rated power.
Figure 20: Magnitude of incremental forward transmission (FT = vout/vin) for
minimum, nominal, and maximum input voltage at full rated power.
100
0
-20
18 Vin
-30
24 Vin
36 Vin
-40
Input Impedance (Ω)
Reverse Transmission (dB)
-10
10
18 Vin
24 Vin
36 Vin
1
-50
-60
0.1
10
100
1,000
10,000
100,000
10
Hz
Phone 1-888-567-9596
1,000
10,000
100,000
Hz
Figure 21: Magnitude of incremental reverse transmission (RT = iin/iout) for
minimum, nominal, and maximum input voltage at full rated power.
Product # PQ24018QGx25
100
Figure 22: Magnitude of incremental input impedance (Zin = vin/iin) for
minimum, nominal, and maximum input voltage at full rated power.
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Doc.# 005-2QG218D Rev. B
04/09/13
Page 9
Input:
Output:
Current:
Package:
Application Section
BASIC OPERATION AND
FEATURES
The PowerQor series converter uses a two-stage power circuit 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 stepdown to achieve the low 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 used in conventional dc/dc converters. This
is the primary reason that the PowerQor converter has such
high efficiency—even at very low output voltages and very
high output currents.
Dissipation throughout the converter is so low that the
PowerQor converter requires no heatsink to deliver
a greater level of power than can be delivered by a conventional, Schottky-diode-based dc/dc converter with a
0.5” high heatsink. At equivalent ambient air temperature,
airflow rate, and output power level, the hottest semiconductor junction temperature and the hottest PCB temperature
within the PowerQor converter are cooler than those found
in conventional dc/dc converters with a 0.5” high heatsink
attached.
Since a heatsink is not required, the PowerQor converter
does not need a metal baseplate or potting material to help
conduct the dissipated energy to the heatsink. The
PowerQor converter can thus be built more simply using
high yield surface mount techniques on a PCB substrate.
Unlike conventional dc/dc converters, which have critical
thermal connections between the power components and the
baseplate, and between the baseplate and the heatsink, the
PowerQor converter has no explicit, failure-prone thermal
connections.
Compared to a conventional Schottky-diode-based dc/dc
converter with a 0.5” high heatsink, the PowerQor converter is more efficient and therefore it dissipates less than half
the energy. Additionally, because the PowerQor converter is
thinner (0.4” vs. 1.0”), the board-to-board pitch in a rack
can be much smaller, and cooling airflow is less impeded by
Product # PQ24018QGx25
Phone 1-888-567-9596
18 - 36V
1.8V
25A
Quarter-brick
the converter. Because the PowerQor converter is much
lighter, vibration and shock-induced problems are greatly
reduced. Moreover, due to the lack of failure-prone explicit
thermal connections and the lack of potting material the
PowerQor converter is more reliable than conventional
dc/dc converters.
The PowerQor series converter uses the industry standard
pin-out configuration used by other vendors of comparably
sized and rated dc/dc converters. The unit is pin for pin
compatible with the Lucent QW series.
The PowerQor converter has many standard control and
protection features. All shutdown features are non-latching,
meaning that the converter shuts off for 200ms before
restarting. (see Figure F)
• An ON/OFF input permits the user to control when the
converter is on and off in order to properly sequence different power supplies and to reduce power consumption
during a standby condition.
• Remote sense inputs permit the user to maintain an
accurate voltage at the load despite distribution voltage
drops between the converter’s output and the load.
• An output voltage trim input permits the user to trim
the output voltage up or down to achieve a custom voltage level or to do voltage margining.
• An input under-voltage lockout avoids input system
instability problems while the input voltage is rising.
• The output current limit protects both the converter
and the board on which it is mounted against a short circuit condition. (see Figure 18)
• An output over-voltage limit circuit shuts the unit
down if the output voltage at the output pins gets too
high.
• A sensor located in a central spot of the PCB provides a
PCB temperature limit. If, due to an abnormal condition, this spot gets too hot, the converter will turn off.
Once the converter has cooled, it will automatically turn
on again without the need to recycle the input power.
CONTROL PIN DESCRIPTIONS
Pin 2 (ON/OFF): The ON/OFF input, Pin 2, permits the
user to control when the converter is on or off. This input is
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Doc.# 005-2QG218D Rev. B
04/09/13
Page 10
Input:
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Current:
Package:
Application Section
voltage across the output (pins 8 and 4) to determine when
it should trigger, not the voltage across the converter’s sense
pins (pins 7 and 5). Therefore, the resistive drop on the
board should be small enough so that output OVP does not
referenced to the return terminal of the 24V input bus. There
are two versions of the PowerQor series converter that differ
by the sense of the logic used for the ON/OFF input. In the
PQxxyyyQGAzzPxx version, the ON/OFF input is active
high (meaning that a high turns the converter on). In the
PQxxyyyQGAzzNxx version, the ON/OFF signal is active
low (meaning that a low turns the converter on). Figure A
details five possible circuits for driving the ON/OFF pin.
Figure B shows detail of the internal ON/OFF circuitry.
trigger, even during load transients.
Pin 6 (TRIM): The TRIM input permits the user to adjust the
output voltage across the sense leads up or down. To lower
the output voltage, the user should connect a resistor
between Pin 6 and Pin 5, which is the SENSE(-) input. To
raise the output voltage, the user should connect a resistor
between Pin 6 and Pin 7, which is the SENSE(+) input.
Pins 7 and 5 (SENSE(+)): The SENSE(+) inputs correct
for voltage drops along the conductors that connect the converter’s output pins to the load.
A resistor connected between Pin 6 and Pin 5 will decrease
the output voltage. For a desired decrease of ∆ percent of
the nominal output voltage, the value of this resistor should
be
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. That is,
[Vout(+) - Vout(-)] – [SENSE(+) - SENSE (-)]
< 10%Vout
Remote Enable Circuit
and
Positive Logic
5V
VNOM
5V
Vin(+)
100k
50k
TTL
ON/OFF
50k
Vin(_)
Direct Logic Drive
        
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x 100%
VNOM = Nominal Voltage
VDES = Desired Voltage
ON/OFF
Vin(_)
Product # PQ24018QGx25
VNOM – VDES
(Permanently Enabled)
TTL/
CMOS
Open Collector Enable Circuit
)
Vin(_)
Vin(_)
Negative Logic
ON/OFF
(
(kΩ)
ON/OFF
ON/OFF
(Permanently Enabled)
(511
∆% ) - 10.22
∆=
Note: the output over-voltage protection circuit senses the
Vin(_)
Rtrim-down =
where
Pins 7 and 5 must be connected for proper regulation of the
output voltage. However, if these connections are not made,
nothing catastrophic will happen to the converter under normal operating conditions—the converter will simply deliver
an output voltage that is slightly higher than its specified
value.
ON/OFF
18 - 36V
1.8V
25A
Quarter-brick
www.synqor.com
100pF
Vin(_)
      
Doc.# 005-2QG218D Rev. B
04/09/13
Page 11
Input:
Output:
Current:
Package:
Application Section
Figure C graphs this relationship between Rtrim-down and ∆.
The output voltage can be trimmed down as much as 20%.
  

18 - 36V
1.8V
25A
Quarter-brick
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 trip, particularly during transients.
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 +10%/-20%


PROTECTION FEATURES












    
      
A resistor connected between Pin 6 and Pin 7 will increase
the output voltage. For a desired increase of ∆ percent of the
nominal output voltage, the value of this resistor should be
Rtrim-up =
(
5.11VOUT(100+∆%) _ 511 _
10.22
1.225∆%
∆%
)
(kΩ)
where
VOUT = Nominal Output Voltage
Figure D graphs this relationship between Rtrim-up and ∆.
The output voltage can be trimmed up as much as 10%.
Output Current Limit: The current limit does not change
appreciably as the output voltage drops. However, once the
impedance of the short across the output is small enough to
make the output voltage drop below approximately 60% of
its nominal value, the converter turns off.
The converter then enters a 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 O.V. threshold, the converter will
immediately stop switching. This prevents damage to the
load circuit due to 1) a sudden unloading of the converter,
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.

  
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 below. The lockout circuitry is a comparator with
dc hysteresis. When the input voltage is rising, it must
exceed a typical value of 16V before the converter will turn
on. Once the converter is on, the input voltage must fall
below a typical value of 14.5V before the converter will turn
off.













    
      
Product # PQ24018QGx25
Phone 1-888-567-9596

Thermal Shutdown: The PowerQor series has a temperature sensor located such that it senses the average temperature of the converter. The thermal shutdown circuit is
designed to turn the converter off when the temperature at
the sensed location reaches 125°C. It will allow the con-
www.synqor.com
Doc.# 005-2QG218D Rev. B
04/09/13
Page 12
Input:
Output:
Current:
Package:
Application Section
18 - 36V
1.8V
25A
Quarter-brick
verter to turn on again when the temperature of the sensed
location falls below 115°C.
APPLICATION CONSIDERATIONS
Input System Instability: This condition can occur
because a dc/dc converter appears incrementally as a
negative resistance load. A detailed application note titled
“Input System Instability” is available on the SynQor web
site (www.synqor.com) which provides an understanding
of why this instability arises, and shows the preferred solution for correcting it.
Application Circuits: Figure E below provides a typical
circuit diagram which is useful when using input filtering
and voltage trimming.
Input Filtering
3.3µH
Electrolytic
Capacitor
100µF
ESR ≅0.33Ω
Vin(+ )
Vout(+ )
Vsense(+ )
ON/OFF
18V < Vin < 36V
Vin(_)
Trim
Vsense(_)
Vout(_)
Rtrim-up
or
Rtrim-down
Cload
Iload
         
Product # PQ24018QGx25
Phone 1-888-567-9596
www.synqor.com
Doc.# 005-2QG218D Rev. B
04/09/13
Page 13
Input:
Output:
Current:
Package:
STARTUP INHIBIT PERIOD
The Startup Inhibit Period ensures that the converter will
remain off for at least 200ms when it is shut down for any
reason. When an output short is present, this generates a
5Hz "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 (not present in Quarterbrick)
18 - 36V
1.8V
25A
Quarter-brick
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 16V (typ.),
the unit is disabled by the Input Under-Voltage Lockout feature. When the input voltage rises above 16V, 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 t1, the unit is disabled by the ON/OFF pin, and it
cannot be enabled again until the Startup Inhibit Period has
elapsed.
• Output Over-Voltage Protection
• Over Temperature Shutdown
When the ON/OFF pin goes high after t2, the Startup Inhibit
Period has elapsed, and the output turns on within the 4ms
(typ.) "Turn On Time."
• Current Limit
• Short Circuit Protection
• Turned off by the ON/OFF input
Vin
Under-Voltage
Lockout Turn-On
Threshold
ON/OFF
(pos logic)
ON
OFF ON
OFF
ON
Vout
4ms (typical
turn on time)
200ms
(typical start-up
inhibit period)

200ms

200ms


         
Product # PQ24018QGx25
Phone 1-888-567-9596
www.synqor.com
Doc.# 005-2QG218D Rev. B
04/09/13
Page 14
Input:
Output:
Current:
Package:
Standards and Qualifications
Parameter
18 - 36V
1.8V
25A
Quarter-brick
Notes & Conditions
STANDARDS COMPLIANCE
UL 60950-1:R2011-12
Basic insulation
EN60950-1/A12:2011
CAN/CSA-C22.2 No. 60950-1/A1:2011
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.
Parameter
QUALIFICATION TESTING
Life Test
Vibration
Mechanical Shock
Temperature Cycling
Power/Thermal Cycling
Design Marginality
Humidity
Solderability
Product # PQ24018QGx25
# Units
32
5
5
10
5
5
5
15 pins
Phone 1-888-567-9596
Test Conditions
95% rated Vin and load, units at derating point, 1000 hours
10-55 Hz sweep, 0.060" total excursion, 1 min./sweep, 120 sweeps for 3 axis
100g minimum, 2 drops in x, y and z axis
-40 °C to 100 °C, unit temp. ramp 15 °C/min., 500 cycles
Toperating = min to max, Vin = min to max, full load, 100 cycles
Tmin-10 °C to Tmax+10 °C, 5 °C steps, Vin = min to max, 0-105% load
85 °C, 95% RH, 1000 hours, continuous Vin applied except 5 min/day
MIL-STD-883, method 2003
www.synqor.com
Doc.# 005-2QG218D Rev. B
04/09/13
Page 15
Input:
Output:
Current:
Package:
Ordering Information
PART NUMBERING SYSTEM
18 - 36V
1.8V
25A
Quarter-brick
ORDERING INFORMATION
The part numbering system for SynQor’s dc-dc converters
follows the format shown in the example below.
PQ 2 4 0 1 8Q G A2 5 N K S
Options
(see
Ordering Information)
Output Current
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.
Thermal Design
Performance Level
Thermal Design
Package Size
Output Voltage
Options Description: w x y z
Enable Logic
Pin Style
A - Open Frame
B - Baseplated
Input Voltage
K - 0.110"
N - 0.145"
R - 0.180"
Y - 0.250"
N - Negative
P - Positive
Product Family
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.
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 [email protected]
S - Standard
Not all combinations make valid part numbers, please contact
SynQor for availability.
Model Number
Application Notes
Feature Set
PQ24018QGw25xyz
PQ24033QGw25xyz
PQ24050QGw20xyz
PQ24120QGw08xyz
PQ24150QGw07xyz
Input Voltage
Range
18
18
18
18
18
-
Output
Voltage
Max Output
Current
1.8V
3.3 V
5.0 V
12 V
15 V
25A
25A
20A
8.3A
6.7A
36V
36V
36V
36V
36V
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 filed in the future.
Contact SynQor for further information and to order:
Phone:
Toll Free:
Fax:
E-mail:
Web:
Address:
Product # PQ24018QGx25
978-849-0600
888-567-9596
978-849-0602
[email protected]
www.synqor.com
155 Swanson Road
Boxborough, MA 01719
USA
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
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.
www.synqor.com
Doc.# 005-2QG218D Rev. B
04/09/13
Page 16
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