Product # PQ24018QGx25 Phone 1-888-567-9596 www.synqor.com Doc.# 005-2QG218D Rev. B 04/09/13 Page 1
Technical
Specification
PQ24018QGx25
PQ24018QGx25 Module
Operational Features
Protection Features
Control Features
Safety Features
Contents
Mechanical Features
The PQ24018QGx25 PowerQor Giga quarter-brick
converter is a next-generation, board-mountable, isolated,
xed switching frequency DC-DC converter that uses
synchronous rectication to achieve extremely high
conversion efciency. 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.
• High efciency, >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.
• 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
• 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
18 - 36V 1.8V 25A 45W 2000V dc Quarter-brick
Continuous Input Outputs Current Max Power Isolation DC-DC Converter
• Industry standard pin-out conguration
• 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
Page No.
Mechanical Diagrams..................................... 2
Electrical Characteristics................................... 4
Figures............................................... 6
Application Section ......................................10
Ordering Information.....................................16
Product # PQ24018QGx25 Phone 1-888-567-9596 www.synqor.com Doc.# 005-2QG218D Rev. B 04/09/13 Page 2
Input:
Output:
Current:
Package:
18 - 36V
1.8V
25A
Quarter-brick
Mechanical Diagrams
Open Frame Mechanical Diagram
mech01
1.45 [36.8]
0.600 [15.24]
0.600 [15.24]
0.063+/- .026
[1.60+/- .66]
Bottomside Clearance
0.145
[3.68]
See Note 3
.40
[10.2]
Pin Farside Typical
See Notes 1, 2, and 3
Top View Side View
0.450 [11.43]
0.300 [7.62]
0.150 [3.81]
2.00 [50.8]
321
8 7 6 5 4
2.30 [58.4]
0.14 [3.6]
0.43 [10.9]
0.300 [7.62]
NOTES
1) Pins 1-3, 5-7 are 0.040” (1.02mm) diameter
with 0.080” (2.03mm) diameter standoff shoulders
2) Pins 4 and 8 are 0.0620” (1.57mm) diameter
with 0.100” (2.54mm) diameter standoff shoulders
3) All Pins: Material - Copper Alloy
Finish: Tin-Lead over Nickel Plate
4) Other pin extension lengths available.
5) Undimensioned components are shown for visual reference only.
6) Open Frame Weight: 1.2 oz. (34g)
7) All dimensions in inches (mm)
Unless otherwise specied:
Tolerances X.XXin. +/-0.02 (X.Xmm +/-0.5mm)
X.XXin. +/-0.010 (X.XXmm +/-0.25mm)
8) Workmanship: Meets or exceeds IPC-A-610 Class II
PIN DESIGNATIONS
Pin Name Function
1 Vin(+) Positive input voltage
2 ON/OFF TTL input to turn converter on and off, referenced
to Vin(–), with internal pull up.
3 Vin(–) Negative input voltage
4 Vout(–) Positive output voltage
5 SENSE(–) Negative remote sense (See note 1)
6 TRIM Output voltage trim (See note 2)
7 SENSE(+) Positive remote sense (See note 3)
8 Vout(+) Positive output voltage
Notes:
1) SENSE(–) should be connected to Vout(–) either remotely or at the converter.
2) Leave TRIM pin open for nominal output voltage.
3) SENSE(+) should be connected to Vout(+) either remotely or at the converter.
Product # PQ24018QGx25 Phone 1-888-567-9596 www.synqor.com Doc.# 005-2QG218D Rev. B 04/09/13 Page 3
Input:
Output:
Current:
Package:
18 - 36V
1.8V
25A
Quarter-brick
Baseplated Mechanical Diagram
mech02
NOTES
1) 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
2) Applied Torque should not exceed 6in-lb (0.7Nm)
3) Baseplate atness tolerance is 0.004" (.10mm) TIR for surface
4) Other pin extension lengths available.
5) Pins 1-3, 5-7 are 0.040" (1.02mm) Dia. with 0.080" (2.03mm)
Dia. Standoff shoulders
6) Pins 4, 8 are 0.062" (1.57mm) Dia. with 0.100" (2.54mm)
Dia. Standoff shoulders
7) All Pins: Material - Copper Alloy
Finish: Tin-Lead over Nickel Plate
8) 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 specied:
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 DESIGNATIONS
Pin Name Function
1 Vin(+) Positive input voltage
2 ON/OFF TTL input to turn converter on and off, referenced
to Vin(–), with internal pull up.
3 Vin(–) Negative input voltage
4 Vout(–) Positive output voltage
5 SENSE(–) Negative remote sense (See note 1)
6 TRIM Output voltage trim (See note 2)
7 SENSE(+) Positive remote sense (See note 3)
8 Vout(+) Positive output voltage
Notes:
1) SENSE(–) should be connected to Vout(–) either remotely or at the converter.
2) Leave TRIM pin open for nominal output voltage.
3) SENSE(+) should be connected to Vout(+) either remotely or at the converter.
1.47 [37.3]
2.00 [50.8]
1.030 [26.16]
0.22 [5.6]
0.23 [5.8]
0.600 [15.24]
0.600 [15.24]
0.063+/- .026
[1.60+/- .66]
Bottomside Clearance
0.145 [3.68]
See Note4
0.50 [12.7]
Pin Farside Typical
See Notes 5, 6, and 7
M3 Threaded Insert
4 Places
See Notes 1 and 2
Top View Side View
0.450 [11.43]
0.300 [7.62]
0.150 [3.81]
1.86 [47.2]
3
2
1
8 7 6 5 4
2.32 [58.9]
0.44 [11.2]
0.300 [7.62]
0.15 [3.8]
Product # PQ24018QGx25 Phone 1-888-567-9596 www.synqor.com Doc.# 005-2QG218D Rev. B 04/09/13 Page 4
Input:
Output:
Current:
Package:
18 - 36V
1.8V
25A
Quarter-brick
PQ24018QGx25 Electrical Characteristics
Ta = 25 °C, airow 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. Specications subject to change without notice.
Parameter Min. Typ. Max. Units Notes & Conditions
INPUT CHARACTERISTICS
Operating Input Voltage Range 18 24 36 V
Input Under-Voltage Lockout
Turn-On Voltage Threshold 15.5 16 16.5 V
Turn-Off Voltage Threshold 14 14.5 15 V
Lockout Hysteresis Voltage 1.0 1.5 2.0 V
Maximum Input Current 3.0 A 100% Load, 18Vin
No-Load Input Current 60 100 mA
Off Converter Input Current 1.6 3 mA
Input Reected-Ripple Current 6 mA P-P thru 3.3μH inductor; Figures 13 & 15
OUTPUT CHARACTERISTICS
Output Voltage Set Point 1.782 1.800 1.816 V
Output Voltage Regulation
Over Line +0.1 (2) +0.3 (5) % (mV)
Over Load +0.1 (2) +0.3 (5) % (mV)
Over Temperature ±9±27 mV
Total Output Voltage Range 1.75 1.85 V over sample line, load and temperature
Output Voltage Ripple and Noise 20MHz bandwidth; Figures 13 & 16
Peak-to-Peak 25 50 mV Full Load, 1μF ceramic, 10μF tantalum
RMS 6 12 mV Full Load, 1μF ceramic, 10μF tantalum
Operating Output Current Range 0 25 A
Output DC Current-Limit Inception 26 30 34 A Output Voltage 10% Low; Fig 17 & 18
Short-Circuit Protection (redundant shutdown) 52 56 60 A
DYNAMIC CHARACTERISTICS
Input Voltage Ripple rejection TBD dB 120 Hz; Figure 20
Output Voltage Current Transient 470μF load cap, 5A/μs; Figure 12
Positive Step Change in Outpu Current 190 mV 50% lo to 75% lo
Negative Step Change in Output Current 190 mV 75% lo to 50% lo
Settling Time to within 1% Vout nominal 700 μs
Turn-On Transient
Turn-On Time 1 4 8 ms Full load, Vout=90% nom.; Figs 9 & 10
Start-Up Inhibit Period 180 200 215 ms -40°C to +125°C; Figure F
Maximum Output Capacitance 35,000 μF Full load; 5% overshoot of Vout at startup
EFFICIENCY
100% Load 84 % Figure 1
50% Load 87 %
TEMPERATURE LIMITS FOR POWER DERATING CURVES
Semiconductor Junction Temperature 125 °C Plastic Package rated to 150°C
Board Temperature 125 °C Board rated to 165°C
Transformer Temperature 125 °C Figures 5 - 8
ISOLATION CHARACTERISTICS
Isolation Voltage 2000 V
Isolation Resistance 10 MΩ
Isolation Capacitance 470 pF
Technical Specifications
Electrical Characteristics
Product # PQ24018QGx25 Phone 1-888-567-9596 www.synqor.com Doc.# 005-2QG218D Rev. B 04/09/13 Page 5
Input:
Output:
Current:
Package:
18 - 36V
1.8V
25A
Quarter-brick
PQ24018QGx25 Electrical Characteristics (continued)
Ta = 25 °C, airow 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. Specications subject to change without notice.
Parameter Min. Typ. Max. Units Notes & Conditions
FEATURE CHARACTERISTICS
Switching Frequency 220 240 260 kHz
ON/OFF Control (Option P)
Off-Stage Voltage -2 0.8 V
On-Stage Voltage 2.4 18 V
ON/OFF Control (Option N)
Off-Stage Voltage 2.4 18 V
On-Stage Voltage -2 0.8 V
ON/OFF Control (Either Option)
Pull-up Voltage Vin/3 9.6 V See circuit diagram; Figure B
Pull-up Resistance 33 kΩ Pull up to Vin/3
Output Voltage Trim Range -20 +10 % Across Pins 8 & 4; % of nominal Vout
Output Over-Voltage Protection 117 122 127 % Over full temp range; % of nominal Vout
Over-Tempperature Shutdown 125 °C Average PCB Temperature
Technical Specifications
Product # PQ24018QGx25 Phone 1-888-567-9596 www.synqor.com Doc.# 005-2QG218D Rev. B 04/09/13 Page 6
Input:
Output:
Current:
Package:
18 - 36V
1.8V
25A
Quarter-brick
60
65
70
75
80
85
90
95
0
3
5
8
10
13
15
18
20
23
25
Efficiency (%)
Load Current (A)
18Vin
24Vin
36Vin
80
81
82
83
84
85
86
87
88
0
100
200
300
400
500
Efficiency (%)
Air Flow (LFM)
25 C
40 C
55 C
0
2
4
6
8
10
12
0
3
5
8
10
13
15
18
20
23
25
Power Dissipation (W)
Load Current (A)
18Vin
24Vin
36Vin
3.0
3.5
4.0
4.5
5.0
5.5
6.0
0
100
200
300
400
500
Power Dissipation (W)
Air Flow (LFM)
25 C
40 C
55 C
0
5
10
15
20
25
0
25
40
55
70
85
Iout (A)
Ambient Air Temperature (oC)
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 LFM (0 m/s)
Figures
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 0 LFM through 400 LFM with air owing across the
converter from pin 1 to pin 3 (nominal input voltage)
Figure 6: Thermal plot of converter at 25 amp load current with 55°C air owing
at the rate of 200 LFM. Air is owing across the converter sideways from pin 1
to pin 3 (nominal input voltage)
Technical Figures
Product # PQ24018QGx25 Phone 1-888-567-9596 www.synqor.com Doc.# 005-2QG218D Rev. B 04/09/13 Page 7
Input:
Output:
Current:
Package:
18 - 36V
1.8V
25A
Quarter-brick
0
5
10
15
20
25
0
25
40
55
70
85
I
out
(A)
Ambient Air Temperature (
o
C)
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 LFM (0 m/s)
Figure 7: Maximum output power derating curves vs. ambient air temperature
for airow rates of 0 LFM through 400 LFM with air owing lengthwise from
output to input (nominal input voltage).
Figure 8: Thermal plot of converter at 25 amp load current with 55°C air
owing at the rate of 200 LFM. Air is owing 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).
Technical Figures
Product # PQ24018QGx25 Phone 1-888-567-9596 www.synqor.com Doc.# 005-2QG218D Rev. B 04/09/13 Page 8
Input:
Output:
Current:
Package:
18 - 36V
1.8V
25A
Quarter-brick
DC-DC
Converter
3.3 μH
source
impedance
Fig. 15
Fig. 14
Fig. 16
VSOURCE
i
S
i
C
VOUT
100 μF,
~
=0.33Ω ESR
electrolytic
capacitor
1 μF,
ceramic
capacitor
10 μF,
100mΩ ESR
tantalum
capacitor
0.8
0.9
1.0
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2.0
0
5
10
15
20
25
30
35
Output Voltage
(V)
Load Current
(A)
18V
24 V
36 V
Series1
Figure 13: Test set-up diagram showing measurement points for Input Terminal
Ripple Current (Figure 14), Input Reected 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 reected 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)
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)
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.
Technical Figures
Product # PQ24018QGx25 Phone 1-888-567-9596 www.synqor.com Doc.# 005-2QG218D Rev. B 04/09/13 Page 9
Input:
Output:
Current:
Package:
18 - 36V
1.8V
25A
Quarter-brick
0.001
0.01
0.1
1
10 100 1,000 10,000 100,000
Output Impedance
(Ω)
Hz
18 Vin
24 Vin
36 Vin
-70
-60
-50
-40
-30
-20
-10
0
10 100 1,000 10,000 100,000
Forward Transmission (dB)
Hz
18 Vin
24 Vin
36 Vin
-60
-50
-40
-30
-20
-10
0
10 100 1,000 10,000 100,000
Reverse Transmission (dB)
Hz
18 Vin
24 Vin
36 Vin
0.1
1
10
100
10 100 1,000 10,000 100,000
Input Impedance
(Ω)
Hz
18 Vin
24 Vin
36 Vin
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.
Figure 21: Magnitude of incremental reverse transmission (RT = iin/iout) for
minimum, nominal, and maximum input voltage at full rated power.
Figure 22: Magnitude of incremental input impedance (Zin = vin/iin) for
minimum, nominal, and maximum input voltage at full rated power.
Technical Figures
Product # PQ24018QGx25 Phone 1-888-567-9596 www.synqor.com Doc.# 005-2QG218D Rev. B 04/09/13 Page 10
Input:
Output:
Current:
Package:
18 - 36V
1.8V
25A
Quarter-brick
Application Section
Application Section
BASIC OPERATION AND
FEATURES
The
Power
Qor series converter uses a two-stage power cir-
cuit 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-
down 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
Power
Qor 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
Power
Qor converter requires no heatsink to deliver
a greater level of power than can be delivered by a con-
ventional, 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 semicon-
ductor junction temperature and the hottest PCB temperature
within the
Power
Qor 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
Power
Qor converter
does not need a metal baseplate or potting material to help
conduct the dissipated energy to the heatsink. The
Power
Qor 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
Power
Qor 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
Power
Qor convert-
er is more efficient and therefore it dissipates less than half
the energy. Additionally, because the
Power
Qor 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
the converter. Because the
Power
Qor 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
Power
Qor converter is more reliable than conventional
dc/dc converters.
The
Power
Qor 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
Power
Qor 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 dif-
ferent 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 volt-
age 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 cir-
cuit 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 con-
dition, 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
Product # PQ24018QGx25 Phone 1-888-567-9596 www.synqor.com Doc.# 005-2QG218D Rev. B 04/09/13 Page 11
Input:
Output:
Current:
Package:
18 - 36V
1.8V
25A
Quarter-brick
Application Section
referenced to the return terminal of the 24V input bus. There
are two versions of the
Power
Qor 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.
Pins 7 and 5 (SENSE(+)): The SENSE(+) inputs correct
for voltage drops along the conductors that connect the con-
verter’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 regu-
lation is desired. That is,
[Vout(+) - Vout(-)]– [SENSE(+) - SENSE (-)] < 10%Vout
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 nor-
mal operating conditions—the converter will simply 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
pins (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.
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.
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
Open Collector Enable Circuit
Remote Enable Circuit
Direct Logic Drive
Negative Logic
(Permanently Enabled) Positive Logic
(Permanently Enabled)
ON/OFF
Vin(_)
ON/OFF
ON/OFF
Vin(_)
ON/OFF
5V
TTL/
CMOS
Vin(_)
ON/OFF
Vin(_)
Vin(_)
Rtrim-down =
(
511
)
- 10.22
∆%
(k
Ω)
∆=
(
VNOM – VDES
)
x100%
VNOM
where
VNOM = Nominal Voltage
VDES = Desired Voltage
and
TTL
5V
50k
100k
Vin(+)
ON/OFF
Vin(_)
50k 100pF
Product # PQ24018QGx25 Phone 1-888-567-9596 www.synqor.com Doc.# 005-2QG218D Rev. B 04/09/13 Page 12
Input:
Output:
Current:
Package:
18 - 36V
1.8V
25A
Quarter-brick
Application Section
Figure C
graphs this relationship between Rtrim-down and ∆.
The output voltage can be trimmed down as much as 20%.
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
Figure D
graphs this relationship between Rtrim-up and ∆.
The output voltage can be trimmed up as much as 10%.
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 trip, particularly during tran-
sients.
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
Input Under-Voltage Lockout: The converter is
designed to turn off when the input voltage is too low, help-
ing 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.
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 pre-
vents 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.
Thermal Shutdown: The
Power
Qor series has a temper-
ature sensor located such that it senses the average temper-
ature 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-
Rtrim-up
(k
Ω)
)
where
VOUT = Nominal Output Voltage
= (
_511 _10.22
5.11VOUT(100+
∆%)
1.225∆%∆%
Product # PQ24018QGx25 Phone 1-888-567-9596 www.synqor.com Doc.# 005-2QG218D Rev. B 04/09/13 Page 13
Input:
Output:
Current:
Package:
18 - 36V
1.8V
25A
Quarter-brick
Application Section
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 solu-
tion for correcting it.
Application Circuits:
Figure E
below provides a typical
circuit diagram which is useful when using input filtering
and voltage trimming.
18V < Vin < 36V
Input Filtering
Trim
3.3µH
Vin(+)
Iload
Cload
Vout(+)
Rtrim-up
or
Rtrim-down
Vsense(+)
ON/OFF
Vin(_)Vout(_)
Vsense(_)
Electrolytic
Capacitor
100µF
ESR
≅
0.33
Ω
Product # PQ24018QGx25 Phone 1-888-567-9596 www.synqor.com Doc.# 005-2QG218D Rev. B 04/09/13 Page 14
Input:
Output:
Current:
Package:
18 - 36V
1.8V
25A
Quarter-brick
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 over-
heating. 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 Quarter-
brick)
• 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 16V (typ.),
the unit is disabled by the Input Under-Voltage Lockout fea-
ture. 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.
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."
Under-Voltage
Lockout Turn-On
Threshold
ON/OFF
(pos logic)
Vout
Vin
200ms 200ms
200ms
(typical start-up
inhibit period)
4ms (typical
turn on time)
ON ON ONOFF OFF
Product # PQ24018QGx25 Phone 1-888-567-9596 www.synqor.com Doc.# 005-2QG218D Rev. B 04/09/13 Page 15
Input:
Output:
Current:
Package:
18 - 36V
1.8V
25A
Quarter-brick
Standards and Qualifications
Parameter 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 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, 95% RH, 1000 hours, continuous Vin applied except 5 min/day
Solderability 15 pins MIL-STD-883, method 2003
Product # PQ24018QGx25 Phone 1-888-567-9596 www.synqor.com Doc.# 005-2QG218D Rev. B 04/09/13 Page 16
Input:
Output:
Current:
Package:
18 - 36V
1.8V
25A
Quarter-brick
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.
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.
Contact SynQor for further information and to order:
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
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 8,023,290 8,149,597
PQ 24 018 Q G A 25 N K S
Product Family
Package Size
Performance Level
Thermal Design
Output Current
Options (see
Ordering Information)
Input Voltage
Output Voltage
Ordering Information
Model Number Input Voltage
Range
Output
Voltage
Max Output
Current
PQ24018QGw25xyz 18 - 36V 1.8V 25A
PQ24033QGw25xyz 18 - 36V 3.3 V 25A
PQ24050QGw20xyz 18 - 36V 5.0 V 20A
PQ24120QGw08xyz 18 - 36V 12 V 8.3A
PQ24150QGw07xyz 18 - 36V 15 V 6.7A
Options Description: w x y z
Thermal Design Enable Logic Pin Style Feature Set
A - Open Frame
B - Baseplated
N - Negative
P - Positive
K - 0.110"
N - 0.145"
R - 0.180"
Y - 0.250"
S - Standard
Ordering Information
