A-SERIES
A-Series, BWR Models
Dual Output
For full details go to
www.cd4power.com/rohs
High-Reliability, 1" x 2"
15-17 Watt, DC/DC Converters
For your mid-range power requirements, it’s hard to beat the combination of
small packaging, low cost, proven reliability and outstanding electrical performance
offered by the 15-17W, dual-output models of C&D’s A-Series DC/DC converters.
These highly efficient, rugged converters combine straightforward circuit topolo-
gies, the newest components, proven SMT-on-pcb construction methods, and highly
repeatable automatic-assembly techniques. Their superior durability is substantiated
by a rigorous in-house qualification program that includes HALT (Highly Accelerated
Life Testing).
The input voltage ranges of the BWR 15-17 Bipolar Series (10-18V for "D12A"
models, 18-36V for "D24A" models and 36-75V for "D48A" models) make them
excellent candidates for telecommunication system line drivers, or distributed power
architectures. Their ±5, ±12 or ±15 Volt outputs cover virtually all standard applica-
tions.
These popular power converters are fully isolated (1500Vdc guaranteed) and
display excellent line and load regulation (±0.5% max. for line and load). They are
completely I/O protected (input overvoltage shutdown and reverse-polarity protec-
tion, output current limiting and overvoltage protection) and contain input (pi type)
and output filtering to reduce noise.
These extremely reliable, cost-effective power converters are housed in standard
1" x 2" x 0.48" UL94V-0 rated plastic packages. They offer industry-standard pinouts
and are ideally suited for high-volume computer, telecom/datacom, instrumentation
and ATE applications.
Features
Output voltages: ±5, ±12 or ±15 Volts
Input voltage ranges:
10-18V, 18-36V or 36-75V
Small packages, 1" x 2" x 0.48"
Industry-standard pinouts
Low cost; Highly reliable
Proven SMT-on-pcb construction
Qual tested; HALT tested; EMC tested
IEC/EN/UL60950 certified
mark available (75V-input models)
Fully isolated, 1500Vdc guaranteed
Efficiencies to 86%
–40 to +100°C operating temperature
Thermal protection
On/Off control
+INPUT
(1)
+OUTPUT
(4)
COMMON
(5)
–INPUT
(2)
ON/OFF
CONTROL
(OPTION)
(3)
–OUTPUT
(6)
PWM
CONTROLLER
OPTO
ISOLATION
REFERENCE &
ERROR AMP
Figure 1. Simplified Schematic
Typical topology is shown
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A Series
1 5 - 1 7 W, D UA L O U T P U T D C / D C C O N V E RT E R S
Performance Specifications and Ordering Guide
Output
Root Model
➄
➀
Input
Regulation (Max.)
Line
Load
➂
±0.5%
±0.5%
±0.5%
±0.5%
±0.5%
±0.5%
±0.5%
±0.5%
±0.5%
±0.5%
±0.5%
±0.5%
±0.5%
±0.5%
±0.5%
±0.5%
±0.5%
±0.5%
V
OUT
(Volts)
±5
±5
±5
±12
±12
±12
±15
±15
±15
I
OUT
(mA)
±1500
±1500
±1500
±725
±725
±725
±575
±575
±575
R/N (mVp-p)
➁
Typ.
Max.
75
75
75
75
75
75
75
75
75
100
100
100
100
100
100
100
100
100
V
IN
Nom.
(Volts)
12
24
48
12
24
48
12
24
48
Range
(Volts)
10-18
18-36
36-75
10-18
18-36
36-75
10-18
18-36
36-75
I
IN
➃
(mA/A)
240/1.5
112/0.75
59/0.38
265/1.7
127/0.85
62/0.4
266/1.7
125/0.84
65/0.41
Efficiency
Min.
Typ.
79%
81%
81%
82%
83%
84%
82%
84%
85%
81%
83%
83%
83.5%
85%
86%
84%
86%
87%
Package
(Case,
Pinout)
C14A, P43
C14A, P43
C14A, P43
C14A, P43
C14A, P43
C14A, P43
C14A, P43
C14A, P43
C14A, P43
BWR-5/1500-D12A
BWR-5/1500-D24A
BWR-5/1500-D48A
BWR-12/725-D12A
BWR-12/725-D24A
BWR-12/725-D48A
BWR-15/575-D12A
BWR-15/575-D24A
BWR-15/575-D48A
➀ Typical at T
A
= +25°C under nominal line voltage and full-load conditions unless otherwise noted.
➁ Ripple/Noise (R/N) measured over a 20MHz bandwidth.
➂
Balanced loads, 10% to 100% load step.
➃
Nominal line voltage, 10% load/100% load conditions.
➄
These are incomplete part numbers, use the part number structure when ordering.
P A R T
N U M B E R
S T R U C T U R E
M E C H A N I C A L
S P E C I F I C A T I O N S
B WR
-
12
/
725
-
D48 A C
-
C
Output Configuration:
B = Bipolar
RoHS-6 Compliant*
Add C or N suffix as
desired. See below.
A-Series
High Reliability
Input Voltage Range:
D12 = 10-18 Volts (12V nominal)
D24 = 18-36 Volts (24V nominal)
D48 = 36-75 Volts (48V nominal)
2.00
(50.80)
PLASTIC CASE
0.465
(11.81)
Wide Range Input
Nominal Output Voltages:
±5, ±12 or ±15 Volts
Maximum Output Current
in mA from each output
Case C14A
STANDOFF
0.015 (0.38)
0.20 MIN
(5.08)
0.040 ±0.002 DIA.
(1.016 ±0.051)
0.800
(20.32)
0.60
(15.24)
4
1
1.00
(25.40)
0.100
(2.54)
0.800
(20.32)
2
3
0.200
(5.08)
BOTTOM VIEW
5
0.400
(10.16)
Part Number Suffixes
BWR 15-17 Watt DC/DC's are designed so an On/Off Control function
with either positive polarity ("C" suffix) or negative polarity ("N" suffix)
can be added to the pin 3 position. Models ordered without On/Off
control (without C or N suffix) will not have pin 3 installed.
No Suffix
Pin 3 not installed
C
N
Positive On/Off control function (pin 3)
Negative On/Off control function (pin 3)
6
DIMENSION ARE IN INCHES (MM)
0.10
(2.54)
I/O Connections
Pin Function P43
1
+Input
2
–Input
3 On/Off Control*
4
+Output
5 Output Return
6
–Output
* Pin is optional
* Contact C&D Technologies for availability.
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2
A Series
Performance/Functional Specifications
Typical @ T
A
= +25°C under nominal line voltage and full-load conditions, unless noted.
➀
1 5 - 1 7 W, D UA L O U T P U T D C / D C C O N V E RT E R S
Dynamic Characteristics
Transient Response:
(50-100% load step to 2% V
OUT
)
Start-Up Time:
V
IN
to V
OUT
On/Off to V
OUT
Switching Frequency
MTBF
➅
Operating Temperature (ambient):
±5V Models
±12V Models
±15V Models
Thermal Shutdown
Storage Temperature
Flammability
Dimensions
Case Material
Pin Material
Weight
250µsec maximum
35msec
30msec
300kHz (±30kHz)
Input
Input Voltage Range:
D12A Models
D24A Models
D48A Models
Overvoltage Shutdown:
D12A Models
D24A Models
D48A Models
Start-Up Threshold:
➂
D12A Models
D24A Models
D48A Models
Undervoltage Shutdown:
➂
D12A Models
D24A Models
D48A Models
Input Current
Normal Operating Conditions
Standby Mode (Off, OV, UV)
Input Reflected Ripple Current
➆
Input Filter Type
Reverse-Polarity Protection
On/Off Control: ➃
➄
C Models
N Models
V
OUT
Accuracy
(balanced half load)
Minimum Load Requirement
➁
Ripple/Noise
(20MHz BW) ➀
➅
Line/Load Regulation
Efficiency
Isolation Voltage
Isolation Capacitance
Isolation Resistance
Current Limit Inception
(@ 98% V
OUT
)
±5V Models
±12V Models
±15V Models
Short-Circuit Current
±5V Models
±12V Models
±15V Models
Overvoltage protection
±5V Models
±12V Models
±15V Models
Maximum Capacitive Loading
Temperature Coefficient
10-18 Volts (12V nominal)
18-36 Volts (24V nominal)
36-75 Volts (48V nominal)
19-21 Volts
37-40 Volts
77-81 Volts
9.4-10 Volts
16.5-18 Volts
34-36 Volts
7-8.5 Volts
15.5-17.5 Volts
32.5-34.5 Volts
See Ordering Guide
5mA
10 mAp-p
Pi
Brief duration, 5A maximum.
On = open or 13V- +V
IN
, I
IN
= 1mA max.
Off = 0-0.8V, I
IN
= 1mA max.
On = 0-0.5V, I
IN
= 3mA max.
Off = open or 3.5- +V
IN
, I
IN
= 1mA max.
Environmental
Bellcore, ground fixed, fullpower
25°C ambient, 1 million hours
48-58°C
50-60°C
55-65°C
115°C
–40 to +120°C
UL 94V-0
Physical
1" x 2" x 0.48" (25.4 x 50.8 x 12.19mm)
Diallyl Phthalate
Gold-plate over copper alloy
1.19 ounces (34 grams)
Primary to Secondary Insulation Level
Operational
➀ All models are specified with no external I/O capacitors.
➁
See Technical Notes/Graphs for details.
➂ Applying a voltage to the On/Off Control (pin 3) when no input power is applied
to the
converter can cause permanent damage to the converter.
➃ Output noise may be further reduced with the addition of additional external output capacitors.
See Technical Notes.
➄
The On/Off Control is designed to be driven with open-coolector logic or the application of
appropriate voltage levels. Voltages may be referenced to the –Input (pin 2).
➅
Demonstrated MTBF available on request.
➆
Input Ripple Current is tested/specified over a 5-20MHz bandwidth with an external 33µF
input capacitor and a simulated source impedance of 220µF and 12µH. See I/O Filtering, Input
Ripple Current and Output Noise for details.
Output
±2.0%, maximum
10%
See Ordering Guide
See Ordering Guide
See Ordering Guide
1500Vdc, minimum
550pF
10MΩ
1.9-2.5A
1-1.5A
0.85-1.2A
800mA maximum
700mA maximum
700mA maximum
Output voltage comparator
5.45-7.15 Volts
13-15.8 Volts
16.2-19.8 Volts
1000µF (per output)
±0.02% per °C
Absolute Maximum Ratings
Input Voltage:
Continuous:
D12A Models
D24A Models
D48A Models
Transient (100msec):
D12A Models
D24A Models
D48A Models
On/Off Control (pin 3) Max. Voltages
Referenced to –Input (pin 2)
"C" Suffix
"N" Suffix
Input Reverse-Polarity Protection
Output Current
Case Temperature
Storage Temperature
Lead Temperature (soldering, 10 sec.)
23 Volts
42 Volts
81 Volts
50 Volts
50 Volts
100 Volts
+V
IN
+7 Volts
Current must be <5 Amps. Brief
duration only. Fusing recommended.
Current limited. Devices can withstand
sustained output short circuits without
damage.
120°C
–40 to +120°C
+300°C
These are stress ratings. Exposure of devices to any of these conditions may adversely
affect long-term reliability. Proper operation under conditions other than those listed in the
Performance/Functional Specifications Table is not implied.
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3
A Series
T E C H N I C A L
N O T E S
1 5 - 1 7 W, D UA L O U T P U T D C / D C C O N V E RT E R S
Input Fusing
Certain applications and/or safety agencies may require the installation of
fuses at the inputs of power conversion components. Fuses should also be
used if the possibility of sustained, non-current-limited, input-voltage polartiy
reversal exists. For C&D BWR 15-17 Watt DC/DC Converters, you should
use slow-blow type fuses with values no greater than the following:
Model
All D12A Models
BWR-5/1500-D24A
BWR-12/725-D24A, BWR-15/575-D24A
All D48A Models
Fuse Value
4 Amp
2 Amp
2.5 Amp
1 Amp
External input capacitors (C
IN
in Figure 2) serve primarily as energy-storage
elements, minimizing line voltage variations caused by transient IR drops in
conductors from backplane to the DC/DC. Input caps should be selected
for bulk capacitance (at appropriate frequencies), low ESR, and high rms-
ripple-current ratings. The switching nature of DC/DC converters requires
that dc voltage sources have low ac impedance as highly inductive source
impedance can affect system stability. In Figure 2, C
BUS
and L
BUS
simulate
a typical dc voltage bus. Your specific system configuration may necessitate
additional considerations.
TO
OSCILLOSCOPE
CURRENT
PROBE
L
BUS
C
BUS
–
–INPUT
C
IN
= 33µF, ESR < 700m @ 100kHz
C
BUS
= 220µF, ESR < 100m @ 100kHz
L
BUS
= 12µH
C
IN
+INPUT
+
V
IN
Start-Up Time
The V
IN
to V
OUT
start-up time is the interval of time where the input voltage
crosses the turn-on threshold point, and the fully loaded output voltage
enters and remains within its specified accuracy band. Actual measured
times will vary with external output capacitance and load. The BWR
15-17W Series implements a soft start circuit that limits the duty cycle
of the PWM controller at power up, thereby limiting the Input Inrush current.
The On/Off Control to V
OUT
start-up time assumes the converter has its
nominal input voltage applied but is turned off via the On/Off Control pin.
The specification defines the interval between the time at which the converter
is turned on and the fully loaded output voltage enters and remains within
its specified accuracy band. Similar to the V
IN
to V
OUT
start-up, the On/Off
Control to V
OUT
start-up time is also governed by the internal soft start
circuitry and external load capacitance.
Input Overvoltage/Undervoltage Shutdown and Start-Up Threshold
Under normal start-up conditions, devices will not begin to regulate until
the ramping-up input voltage exceeds the Start-Up Threshold Voltage (35V
for D48 models). Once operating, devices will not turn off until the input volt-
age drops below the Undervoltage Shutdown limit (33.5V for D48 models).
Subsequent re-start will not occur until the input is brought back up to the
Start-Up Threshold. This built in hysteresis prevents any unstable on/off
situations from occurring at a single input voltage.
Input voltages exceeding the input overvoltage shutdown specification listed
in the Performance/Functional Specifications will cause the device to shut-
down. A built-in hysteresis of 0.6 to 1.6 Volts for all models will not allow the
converter to restart until the input voltage is sufficiently reduced.
Input Source Impedance
The converters must be driven from a low ac-impedance input source. The
DC/DC's performance and stability can be compromised by the use of highly
inductive source impedances. The input circuit shown in Figure 2 is a practical
solution that can be used to minimize the effects of inductance in the input
traces. For optimum performance, components should be mounted close to
the DC/DC converter. If the application has a high source impedance, low V
IN
models can benefit of increased external input capacitance.
I/O Filtering, Input Ripple Current, and Noise Reduction
All BWR 15-17W DC/DC Converters achieve their rated ripple and noise
specifications without the use of external input/output capacitors. In critical
applications, input/output ripple and noise may be further reduced by install-
ing additional external I/O caps.
Figure 2. Measuring Input Ripple Current
In critical applications, output ripple/noise (also referred to as periodic and
random deviations or PARD) may be reduced below specified limits using
filtering techniques, the simplest of which is the installation of additional
external output capacitors. These output caps function as true filter elements
and should be selected for bulk capacitance, low ESR and appropriate
frequency response. All external capacitors should have appropriate voltage
ratings and be located as close to the converter as possible. Temperature
variations for all relevant parameters should also be taken carefully into
consideration.
The most effective combination of external I/O capacitors will be a function
of line voltage and source impedance, as well as particular load and layout
conditions. Our Applications Engineers can recommend potential solutions
and discuss the possibility of our modifying a given device's internal filtering
to meet your specific requirements. Contact our Applications Engineering
Group for additional details.
Floating Outputs
Since these are isolated DC/DC converters, their outputs are "floating," with
respect to the input. As such, it is possible to use +Output, –Output or Output
Return as the system ground thereby allowing the flexibility to generate a
variety of output voltage combinations.
Regulation for BWR 15-17W bipolar converters is monitored between
–Output and +Output (as opposed to Output to Return).
Minimum Loading Requirements
BWR 15-17W converters employ a classical diode-rectification design topol-
ogy and require a minimum 10% loading to achieve their listed regulation
specifications and a stable operating condition.
Load Regulation
Regulation for the BWR 15-17W bipolar converters is monitored between
–Output and +Output (as opposed to Output to Return). As such regulation
will assure that voltage between –Output and +Output pins remains within the
V
OUT
accuracy listed in the Performance/Functional Specifications table.
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4
A Series
If loading from +/– Outputs to Output Return is symmetrical, the voltage
at Output pins with respect to Output Return will also be symmetrical. An
unbalance in loading will consequently result in a degraded V
OUT
regulation
accuracy from +/– Outputs to Output Return ( –Output to +Output regulation
will still be within specification) with a load step from minimum to maximum
load and with the other output at full load, the maximum deviation is 2.5%
V
OUT
nominal.
BWR-15/575-D48A Unbalanced Output Load Regulation
15.5
15.4
15.3
15.2
+/–15V
OUT
15.1
15
14.9
14.8
14.7
–15V@ 0A to 0.575A
+15V@ 0.575A
+15V@ 0A to 0.575A
–15V@ 0.575A
1 5 - 1 7 W, D UA L O U T P U T D C / D C C O N V E RT E R S
Start-Up Time
The V
IN
to V
OUT
start-up time is the interval of time where the input voltage
crosses the turn-on threshold point, and the fully loaded output voltage
enters and remains within its specified accuracy band. Actual measured
times will vary with external output capacitance and load. The BWR 15-17W
Series implements a soft start circuit that limits the duty cycle
of the PWM controller at power up, thereby limiting the Input Inrush current.
The On/Off Control to V
OUT
start-up time assumes the converter has its
nominal input voltage applied but is turned off via the On/Off Control pin. The
specification defines the interval between the time at which the converter is
turned on and the fully loaded output voltage enters and remains within its
specified accuracy band. Similar to the V
IN
to V
OUT
start-up, the On/Off Con-
trol to V
OUT
start-up time is also governed by the internal soft start circuitry
On/Off Control
The input-side, remote On/Off Control function (pin 3) can be ordered to
operate with either polarity. Positive-polarity devices ("C" suffix) are enabled
when pin 3 is left open (or is pulled high, +13V to V
IN
applied with respect to
–Input, pin 2, see Figure 2). Positive-polarity devices are disabled when pin
3 is pulled low (0-0.8V with respect to –Input). Negative-polarity devices are
off when pin 3 is left open (or pulled high, 3.5V to V
IN
), and on when pin 3 is
pulled low (0-0.5V). See Figure 5.
0
10
20
30
40
50
60
70
80
90
100
1
+INPUT
Output Load Regulation (%)
Figure 4. Output Voltage Accuracy vs. Imbalanced Loading
3
13V CIRCUIT
ON/OFF
CONTROL
Current Limiting
When output current increases to approximately 15% to 50% above the rated
output current, the DC/DC converter will go into a current limiting mode. In
this condition the output voltage will decrease proportionately with increases
in output current, thereby maintaining a somewhat constant power dissipa-
tion. This is commonly referred to as power limiting. Current limit inception
is defined as the point where the full-power output voltage falls below the
specified tolerance. See Performance/Functional Specifications. If the load
current being drawn from the converter is significant enough, the unit will go
into a short circuit condition. See "Short Circuit Condition."
Short Circuit Condition
When a converter is in current limit mode the output voltages will drop as
the output current demand increases. If the output voltage drops too low, the
magnetically coupled voltage used to develop primary side voltages will also
drop, thereby shutting down the PWM controller.
Following a time-out period, the PWM will restart, causing the output voltages
to begin ramping to their appropriate values. If the short-circuit condition
persists, another shutdown cycle will be initiated. This on/off cycling is
referred to as "hiccup" mode. The hiccup cycling reduces the average output
current, thereby preventing internal temperatures from rising to excessive
levels. The BWR 15-17W Series is capable of enduring an indefinite short
circuit output condition.
Thermal Shutdown
These BWR converters are equipped with Thermal Shutdown Circuitry. If
environmental conditions cause the internal temperature of the DC/DC con-
verter rises above the designed operating temperature, a precision tempera-
ture sensor will power down the unit. When the internal temperature
3
5V CIRCUIT
2
–INPUT
Figure 4. Driving the Positive Polarity On/Off Control Pin
1
+INPUT
ON/OFF
CONTROL
2
–INPUT
Figure 5. Driving the Negative Polarity On/Off Control Pin
Dynamic control of the remote on/off function is best accomplished with
a mechanical relay or an open-collector/open-drain drive circuit (optically
isolated if appropriate). The drive circuit should be able to sink appropriate
current (see Performance Specs) when activated and withstand appropriate
voltage when deactivated.
Applying an external voltage to pin 3 when no input power is applied to the
converter can cause permanent damage to the converter.
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5