QW24T25033 DC-DC Converter
18-60 VDC Input; 3.3 VDC @ 25 A Output
Data Sheet
Features
RoHS lead-free solder and lead-solder-exempted
products are available
Wide input range: 18 to 60 VDC
Delivers up to 25 A
Industry-standard quarter-brick pinout
On-board input differential LC-filter
Startup into pre-biased load
No minimum load required
Dimensions: 1.45” x 2.30” x 0.482”
(36.83 mm x 58.42 mm x 12.24 mm)
Weight: 1.3 oz (37 g)
Meets Basic Insulation requirements
Withstands 80 V input transient for 100 ms
Fixed frequency operation
Remote output sense
Negative ON/OFF logic
Output voltage trim range:
−20%/+10%
with
industry-standard trim equations
High reliability: MTBF approx. 10.7 million hours,
calculated per Telcordia TR-332, Method
I
Case 1
Agency approved to UL60950-1/CSA60950-1 2
nd
Edition, and EN/IEC60950-1 2
nd
Edition
Designed to meet Class B conducted emissions per
FCC and EN55022 when used with external filter
All materials meet UL94, V-0 flammability rating
Applications
Telecommunications
Data communications
Wireless communications
Servers, workstations
Industrial applications
Benefits
High efficiency – no heat sink required
Description
The QW Series provides outstanding thermal performance in high temperature environments. This performance is
accomplished through the use of patented/patent-pending circuits, packaging, and processing techniques to
achieve ultra-high efficiency, excellent thermal management, and a low-body profile.
The low-body profile and the preclusion of heat sinks minimize impedance to system airflow, thus enhancing
cooling for both upstream and downstream devices. The use of 100% automation for assembly, coupled with
advanced electronic circuits and thermal design, results in a product with extremely high reliability.
The QW-Series is an excellent choice in applications where multiple input voltage options are required. The
designer can use a single QW converter to cover 24Vin through 48Vin input ranges, eliminating the need to
specify multiple circuit packs to handle each input range. This is particularly useful in wireless base station
applications where the power plants tend to vary and could provide nominal 24 or 48 V input. Besides operating
from a 18-60 V input, the QW-Series converters provide outputs that can be trimmed from –20% to +10% of the
nominal output voltage, thus providing outstanding design flexibility.
ZD-00374 Rev. 1.0, 07-Sep-09
Page 1 of 13
www.power-one.com
QW24T25033 DC-DC Converter
18-60 VDC Input; 3.3 VDC @ 25 A Output
Data Sheet
Environmental and Mechanical Specifications
All specifications apply over specified input voltage, output load and temperature range, unless otherwise noted.
Parameter
Ambient Temperature Range
Storage Temperature (Ts)
Weight
Operating Vibration
(sinusoidal)
Non-Operating Shock
(half sine)
MTBF
Lead Plating
Moisture Sensitivity Level
per JEDEC J-STD-020C
Conditions/Description
Min
-40
-55
Nom
Max
85
125
Units
C
C
oz [g]
Hz
G
oct/min
sweeps
G
ms
1.3 [37]
Frequency Range
Magnitude
Sweep Rate
Repetitions in each axis (Min-Max-Min Sweep)
Acceleration
Duration
Number of shocks in each axis
Calculated Per Telcordia Technologies SR-
332
QW24T25033-xyz0
QW24T25033-xyz0G
5
0.5
1
2
50
11
10
10.7
100% Matte Tin
2
3
500
MHrs
Electrical Specifications
All specifications apply over specified input voltage, output load and temperature range, unless otherwise noted.
Parameter
Absolute Maximum Ratings
Input Voltage
Operating Ambient Temperature
Storage Temperature
Isolation Characteristics
I/O Isolation
Isolation Capacitance
Isolation Resistance
Feature Characteristics
Switching Frequency
Output Voltage Trim Range
1
Remote Sense Compensation
1
Output Overvoltage Protection
Overtemperature Shutdown (PCB)
Auto-Restart Period
Turn-On Time (Rise Time)
Turn-On Time (Rise Time)
Turn-On Delay Time
ON/OFF Control (Negative Logic)
Converter Off (logic high)
Converter On (logic low)
Continuous
Notes
Min
0
-40
-55
2000
Typ
Max
60
85
125
Units
VDC
°C
°C
VDC
2.7
10
200
Industry-std. equations
Percent of V
OUT
(
NOM
)
Non-latching
Non-latching, at Thermal Ref. Points
Applies to all protection features
Full Load (resistive)
20,000µF plus Full Load (resistive)
Turn-On by Enable
2.4
-20
117
122
130
200
2.5
5
1
20
0.8
-20
+10
+10
127
nF
MΩ
kHz
%
%
%
°C
ms
ms
ms
ms
VDC
VDC
ZD-00374 Rev. 1.0, 07-Sep-09
Page 2 of 13
www.power-one.com
QW24T25033 DC-DC Converter
18-60 VDC Input; 3.3 VDC @ 25 A Output
Data Sheet
Electrical Specifications (Continued)
All specifications apply over specified input voltage, output load and temperature range, unless otherwise noted.
Parameter
Input Characteristics
Operating Input Voltage Range
Input Undervoltage Lockout
Turn-on Threshold
Turn-off Threshold
Input Voltage Transient
Maximum Input Current
Input Standby Current
Input No Load Current (0 load on the
output)
Minimum Input Capacitance (external)
Inrush Transient
Input Reflected-Ripple Current
Input Voltage Ripple Rejection
Output Characteristics
Output Voltage Set Point (no load)
Output Regulation
Over Line
Over Load
Output Voltage Range
Output Ripple and Noise – 20 MHz bandwidth
External Load Capacitance
Output Current Range
Current Limit Inception
Peak Short-Circuit Current
RMS Short-Circuit Current
Dynamic Response
Non-latching
100 ms
Non-latching
Notes
Min
18
16
13
Typ
36
17
15
Max
60
18
16.5
80
5.2
Units
VDC
VDC
VDC
VDC
ADC
mADC
mADC
µF
18 VDC in, 3.3 VDC Out @ 25A
converter disabled, 25 °C ambient
converter enabled, 25 °C ambient
ESR < 0.7
Ω
3
25 MHz bandwidth, 25 °C ambient
120 Hz, 25 °C ambient
3.267
100
3
60
0.1
10
65
3.300
±10
±10
Over line, load and temperature
2
Plus Full Load (resistive)
0
110
5
50
165
50
Vin = 36VDC, 25
°
C ambient
Vin = 36VDC, 25
°
C ambient
92.5
92
100
300
Non-latching, Short = 10 mΩ
Non-latching, 25
°
C ambient
3.250
30
3.333
±20
±20
3.350
60
20,000
25
140
50
A2s
mA
PK-PK
dB
VDC
mV
mV
VDC
mV
PK-PK
µF
ADC
%Iomax
A
Arms
mV
mV
µs
%
%
Load Change 75%-100%-75%, di/dt = 0.1A/µs Co = 1 µF ceramic + 10µF tantalum
di/dt = 1 A/µs Co = 1 µF ceramic + 10µF tantalum
Settling Time to 1%
Efficiency
100% Load
50% Load
Additional Notes:
1
Vout can be increased up to 10% via the sense leads or up to 10% via the trim function. However, the total output voltage trim from all
sources should not exceed 10% of V
OUT
(
NOM
), in order to ensure specified operation of overvoltage protection circuitry.
Operating ambient temperature range of -40 ºC to 85 ºC for converter.
Not required when used with low impedance inputs.
2
3
ZD-00374 Rev. 1.0, 07-Sep-09
Page 3 of 13
www.power-one.com
QW24T25033 DC-DC Converter
18-60 VDC Input; 3.3 VDC @ 25 A Output
Data Sheet
Operations
Input and Output Impedance
These power converters have been designed to be
stable with no external capacitors when used in low
inductance input and output circuits.
In many applications, the inductance associated with
the distribution from the power source to the input of
the converter can affect the stability of the converter.
The addition of a 100 µF electrolytic capacitor with
an ESR < 0.7
Ω
across the input helps to ensure
stability of the converter. In many applications, the
user has to use decoupling capacitance at the load.
The power converter will exhibit stable operation with
external load capacitance up to 20,000 µF on 3.3 V
output.
Additionally, see the EMC section of this data sheet
for discussion of other external components which
may be required for control of conducted emissions.
ON/OFF (Pin 2)
The ON/OFF pin is used to turn the power converter
on or off remotely via a system signal. Negative
logic, is referenced to Vin(-). A typical connection is
shown in Fig. A.
QW Series
Converter
(Top View)
Vin
ON/OFF
Remote Sense (Pins 5 and 7)
The remote sense feature of the converter
compensates for voltage drops occurring between
the output pins of the converter and the load. The
SENSE(-) (Pin 5) and SENSE(+) (Pin 7) pins should
be connected at the load or at the point where
regulation is required (see Fig. B).
Vin (+)
QW Series
Converter
(Top View)
Rw
Vout (+)
100
SENSE (+)
TRIM
SENSE (-)
10
Rload
Vin
ON/OFF
Vin (-)
Vout (+)
Rw
Fig. B: Remote sense circuit configuration.
CAUTION
If remote sensing is not utilized, the SENSE(-) pin must be
connected to the Vout(-) pin (Pin 4), and the SENSE(+) pin
must be connected to the Vout(+) pin (Pin 8) to ensure the
converter will regulate at the specified output voltage. If these
connections are not made, the converter will deliver an
output voltage that is slightly higher than the specified data
sheet value.
Vin (+)
Vout (+)
SENSE (+)
TRIM
SENSE (-)
Rload
Because the sense leads carry minimal current,
large traces on the end-user board are not required.
However, sense traces should be run side-by-side
and located close to a ground plane to minimize
system noise and ensure optimum performance.
The converter’s output overvoltage protection (OVP)
senses the voltage across Vout(+) and Vout(-), and
not across the sense lines, so the resistance (and
resulting voltage drop) between the output pins of
the converter and the load should be minimized to
prevent unwanted triggering of the OVP.
When utilizing the remote sense feature, care must
be taken not to exceed the maximum allowable
output power capability of the converter, which is
equal to the product of the nominal output voltage
and the allowable output current for the given
conditions.
When using remote sense, the output voltage at the
converter can be increased by as much as 10%
above the nominal rating in order to maintain the
required voltage across the load. Therefore, the
designer must, if necessary, decrease the maximum
current (originally obtained from the derating curves)
by the same percentage to ensure the converter’s
actual output power remains at or below the
maximum allowable output power.
Vin (-)
CONTROL
INPUT
Vout (-)
Fig. A: Circuit configuration for ON/OFF function.
The negative logic version turns on when the pin is
at a logic low and turns off when the pin is at a logic
high. The ON/OFF pin can be hardwired directly to
Vin(-) to enable automatic power-up of the converter
without the need of an external control signal.
The ON/OFF pin is internally pulled up to 5 V
through a resistor. A properly debounced mechanical
switch, open-collector transistor, or FET can be used
to drive the input of the ON/OFF pin. The device
must be capable of sinking up to 0.2 mA at a low
level voltage of
0.8 V. An external voltage source
(±20 V maximum) may be connected directly to the
ON/OFF input, in which case it must be capable of
sourcing or sinking up to 1 mA depending on the
signal polarity. See the Startup Information section
for system timing waveforms associated with use of
the ON/OFF pin.
ZD-00374 Rev. 1.0, 07-Sep-09
Page 4 of 13
www.power-one.com
QW24T25033 DC-DC Converter
18-60 VDC Input; 3.3 VDC @ 25 A Output
Data Sheet
Output Voltage Adjust /TRIM (Pin 6)
The output voltage can be adjusted up 10% or down
20% relative to the rated output voltage by the
addition of an externally connected resistor.
The TRIM pin should be left open if trimming is not
being used. To minimize noise pickup, a 0.1 µF
capacitor is connected internally between the TRIM
and SENSE(-) pins.
To increase the output voltage, refer to Fig. C. A trim
resistor, R
T-INCR
, should be connected between the
TRIM (Pin 6) and SENSE(+) (Pin 7), with a value of:
R
T
INCR
½
5.11(100
Δ)V
O
NOM
626
10.22
1.225Δ
Vin
Note:
The above equations for calculation of trim resistor values match
those typically used in conventional industry-standard quarter-
bricks.
Vin (+)
QW Series
Converter
(Top View)
Vout (+)
SENSE (+)
TRIM
SENSE (-)
R
T-DECR
Rload
ON/OFF
Vin (-)
Vout (-)
[kΩ]
Fig. D: Configuration for decreasing output voltage
.
where,
R
T
INCR
½
Required value of trim-up resistor [kΩ]
V
O
NOM
½
Nominal value of output voltage [V]
Δ
½
(V
O-REQ
V
O-NOM
)
X 100
V
O -NOM
[%]
Trimming/sensing beyond 110% of the rated output
voltage is not an acceptable design practice, as this
condition could cause unwanted triggering of the
output overvoltage protection (OVP) circuit. The
designer should ensure that the difference between
the voltages across the converter’s output pins and
its sense pins does not exceed 10% of V
OUT
(
NOM
),
or:
[V
OUT
(
)
V
OUT
(
)]
[V
SENSE
)
V
SENSE
)]
V
O - NOM X
10%
[V]
(
(
V
O
REQ
½
Desired (trimmed) output voltage [V].
When trimming up, care must be taken not to exceed
the converter‘s maximum allowable output power.
See the previous section for a complete discussion
of this requirement.
QW Series
Converter
(Top View)
Vin
ON/OFF
This equation is applicable for any condition of
output sensing and/or output trim.
Vin (+)
Vout (+)
SENSE (+)
TRIM
SENSE (-)
R
T-INCR
Rload
Vin (-)
Vout (-)
Fig. C: Configuration for increasing output voltage.
To decrease the output voltage (Fig. D), a trim
resistor, R
T-DECR
, should be connected between the
TRIM (Pin 6) and SENSE(-) (Pin 5), with a value of:
R
T
DECR
½
511
10.22
|
Δ
|
[kΩ]
where,
R
T
DECR
½
Required value of trim-down resistor [kΩ]
and
Δ
is defined above.
ZD-00374 Rev. 1.0, 07-Sep-09
Page 5 of 13
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