5V and 3.3V, 2" x 2"
33 Watt, DC/DC Converters
Dual Output
Mixed Voltage, BWR Models
Features
Figure 1. Simplifi ed Schematic
INNOVATION and EX C ELL E N C E
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Regulated 3.3V and 5V outputs
5V @ 6Amps/3.3V @ 7 Amps capability
33 Watts total output power
No-load operation
Available input voltage ranges:
10-18V, 18-36V or 36-75V
Small 2" x 2" x 0.45" package
UL1950 and EN60950 safety approvals
mark available (75V-input models)
Continuous short-circuit protection
Fully isolated, 1500Vdc guaranteed
40 to +100C operating temperature
Input under and overvoltage shutdown
Output overvoltage protection
Thermal shutdown
DATEL, Inc., Mansfi eld, MA 02048 (USA) Tel: (508)339-3000, (800)233-2765 Fax: (508)339-6356 Email: sales@datel.com Internet: www.datel.com
+INPUT
(1)
INPUT
(2)
SWITCH
CONTROL
+5V OUTPUT
(5)
+3.3V OUTPUT
(7)
OUTPUT
RETURN
(6)
TRIM
(8)
PWM
CONTROLLER
REFERENCE &
ERROR AMP
OPTO
ISOLATION
ON/OFF
CONTROL
(4)
UV & OV
COMPARATORS
ACTIVE
BLEEDER
THERMAL
SHUTDOWN
For applications requiring 33 Watts of power from 5V and 3.3V, DATEL offers a
new power sharing DC/DC converter capable of meeting your output current require-
ments. The BWR-5/6-3.3/7-D48 (36-75V input), BWR-5/6-3.3/7-D24 (18-36V input)
and BWR-5/6-3.3/7-D12 (10-18V input) are fully isolated DC/DC converters capable
of delivering any combination of 5V and 3.3V loading up to a combined total of 33
Watts of output power.
Housed in a standard 2" x 2" x 0.45" metal package coated with electrically non-
conductive fi nish, these converters utilize a shared control-loop system to assure load
regulation of 1% for 3.3V output and 1.5% for 5V output. All models include input
Pi fi ltering, input overvoltage and undervoltage shutdown circuitry, output overvoltage
protection, output short-circuit and current limiting protection, and thermal shutdown.
Each design also provides trim capability and on/off control function. Fully synchro-
nous output rectifi cation renders high effi ciency and no-load operation.
BWR power sharing modules offer low ripple and noise performance, high
effi ciency (88%), 1500Vdc of isolation voltage, and are fully specifi ed for 40
to +100C operation. These devices meet IEC950, UL1950 and EN6950 safety
standards, including BASIC insulation requirements for "D48" models. CB reports
are available on request. "D48" models are CE marked (meet LVD requirements).
3 3 W , D U A L O U T P U T , M I X E D - V O L T A G E D C / D C C O N V E R T E R S
XWR Series
Performance Specifi cations and Ordering Guide
BWR-5/6-3.3/7-D12
5 6 40 100 1% 1.5%
2.5%
12 10-18 70/3308 83% 86% C4, P33
3.3 7 95 140 0.5% 1%
1.5%
BWR-5/6-3.3/7-D24
5 6 40 100 1% 1.5%
2.5%
24 18-36 50/1615 85% 88% C4, P33
3.3 7 95 140 0.5% 1%
1.5%
BWR-5/6-3.3/7-D48
5 6 40 100 1% 1.5%
2.5%
48 36-75 25/780 85% 88% C4, P33
3.3 7 95 140 0.5% 1%
1.5%
Typical at T
A
= +25C under nominal line voltage and balanced "full-load" conditions (5V @ 3.3A/3.3V @ 5A).
Any combination of 5V/3.3V rated I
OUT
current, not to exceed 33 Watts of output power. (See derating graphs.)
Ripple/Noise (R/N) measured over a 20MHz bandwidth. All models are specifi ed with 1F ceramic
output capacitors.
Output
Input
Tested from 10% load to 100% load (other output at 10% load).
Nominal line voltage, no load/balanced full-power condition.
Tested from no-load to 100% load (other output at no-load).
Output trim may impact 5V load regulation.
R/N (mVp-p)
Regulation
(Max.)
Effi ciency
Package
V
OUT
I
OUT
V
IN
Nom.
Range
I
IN
(Case,
Model
(Volts)
(Amps) Typ. Max. Line
Load
No
Load
(Volts) (Volts) (mA) Min. Typ. Pinout)
2
BOTTOM VIEW
1.800
(45.72)
0.10
(2.54)
2.00
(50.80)
8
5
6
7
0.40
(10.16)
0.200
(5.08)
0.400
(10.16)
0.100
(2.54)
1
2
4
METAL CASE
INSULATED BASE
0.040 0.002 DIA.
(1.016 0.051)
2.00
(50.80)
0.20 MIN
(5.08)
0.45
(11.43)
1.200
(30.48)
3 EQ. SP. @
0.400 (10.16)
I/O
Connections
Pin Function
P33
1 +Input
2
Input
3
No
Pin
4 On/Off
Control
5
+5V
Output
6 Output
Return
7 +3.3V
Output
8
Trim
Notes:
For "D12" and "D24" models
the case is connected to
pin 2 (Input).
For "D48" models, the case
is connected to pin 1 (+Input).
Case C4
P A R T N U M B E R S T R U C T U R E
V
1
Nominal Output Voltage:
5 Volts
5
BWR
6
-
/
D48
-
Input Voltage Range:
D12 = 10-18 Volts (12V nominal)
D24 = 18-36 Volts (24V nominal)
D48 = 36-75 Volts (48V nominal)
I
1
Maximum Output Current:
6 Amps
Dual Output/
Mixed-Voltage Series
3.3
7
/
-
V
2
Nominal Output Voltage:
3.3 Volts
I
2
Maximum Output Current:
7 Amps
Optional Functions
Optional Functions
BWR 33 Watt DC/DC's are designed with an On/Off Control
function with positive polarity in the pin 4 position.
L1 Pin length: 0.110 in. (2.79mm) 0.010
L2 Pin length: 0.145 in. (3.68mm) 0.010
Refer to the last page for additional options.
LX
M E C H A N I C A L S P E C I F I C A T I O N S
BWR Models
3 3 W , D U A L O U T P U T , M I X E D - V O L T A G E D C / D C C O N V E R T E R S
Output (continued)
Short Circuit Current:
5V Output 5 Amps average, continuous
3.3V Output 6 Amps average, continuous
Overvoltage Protection:
Magnetic feedback
5V Output 6.8 volts
3.3V Output 4.5Volts
Maximum Capacitive Loading
D12 Models
3.3V 1000F
5V 470F
D24, D48 Models 3.3V 2000F
5V 1000F
Dynamic Characteristics
Dynamic Load Response:
5V (50-100% load step to 4% V
OUT
) 300sec maximum
3.3V (50-100% load step to 2.5% V
OUT
) 300sec maximum
Start-Up Time:
V
IN
to V
OUT
20msec maximum
On/Off to V
OUT
15msec maximum
Switching Frequency 285kHz (15kHz)
Environmental
MTBF
Bellcore, ground fi xed, full power,
+25C operating ambient temperature
D12 Models 1.3 million hours
D24/D48 Models 1.67 million hours
Operating Temperature (Ambient):
Without Derating:
D12 Models 40 to +50C
D24 Models 40 to +60C
D48 Models 40 to +68C
With Derating To +100C (See Derating Curves)
Case Temperature:
Maximum Operational +100C
For Thermal Shutdown
+110C minimum, +117C maximum
Storage Temperature 40 to +120C
Physical
Dimensions 2" x 2" x 0.45" (50.8 x 50.8 x 11.43mm)
Internal Case Connection:
D12/D24 Models Input (Pin 2)
D48 Models +Input (Pin 1)
Case Material Corrosion resistant steel with
non-conductive, epoxy-based, black
enamel fi nish and plastic baseplate
Pin Material Brass, solder coated
Weight: 2.7 ounces (76.5 grams)
Balanced "full-load" is 5V @ 3.3A/3.3V @ 5A. All models are specifi ed with external
1F ceramic output capacitors.
See Technical Notes/Graphs for details.
Applying a voltage to On/Off Control (pin 4) when no input power is applied to the
converter may cause permanent damage.
Output noise may be further reduced with the installation of additional external output
capacitors. See Technical Notes.
On/Off control is designed to be driven with open collector or by appropriate voltage
levels. Voltages must be referenced to the input return pin (Input).
Demonstrated MTBF available on request.
3
Input
Input Voltage Range:
D12 Models 10-18 Volts (12V nominal)
D24 Models 18-36 Volts (24V nominal)
D48 Models 36-75 Volts (48V nominal)
Overvoltage Shutdown:
D12 Models 19-23 Volts (21V nominal)
D24 Models 37-42 Volts (40V nominal)
D48 Models 77-81 Volts (79V nominal)
Start-Up Threshold:
D12 Models 9-10 Volts (9.3V nominal)
D24 Models 16.5-18 Volts (17V nominal)
D48 Models 34-36 Volts (35V nominal)
Undervoltage Shutdown:
D12 Models 8.5-9.6 Volts (9.3V nominal)
D24 Models 16-17 Volts (16.5V nominal)
D48 Models 32.5-35 Volts (34V nominal)
Input Current:
Normal Operating Conditions See Ordering Guide
Standby Mode:
Off, OV, UV, Thermal Shutdown 10mA typical
Input Refl ected Ripple Current:
Source Impedance <0.1
, no external input fi ltering
D12 Models 200mAp-p (150mAp-p typical)
D24/D48 Models 250mAp-p (225mAp-p typical)
Internal Input Filter Type Pi (0.022F - 4.7H - 2.46F)
Reverse-Polarity Protection:
D12 Models 1 minute duration, 6A maximum
D24 Models 1 minute duration, 4A maximum
D48 Models 1 minute duration, 2A maximum
On/Off Control (Pin 4):
D12, D24 & D48 Models On = open or 13V to +V
IN
, I
IN
= 50A max.
Off = 0-0.8V, I
IN
= 1mA max.
Output
V
OUT
Accuracy:
5V Output 3% maximum
3.3V Output 1.5% maximum
Minimum Loading Per Specifi cation No load, see Performance Specifi cations
Ripple/Noise (20MHz BW)
See Ordering Guide
Line/Load Regulation
See Ordering Guide
Effi ciency See Ordering Guide / Effi ciency Curves
Cross Regulation:
5V Output (5V@0.6A, 3.3V@0.7-7A) 6% maximum
3.3V Output (3.3V@0.7A, 5V@0.6-6A) 0.5% maximum
Trim Range
5%
Isolation Voltage:
Input-to-Output 1500Vdc minimum
Isolation Capacitance 470pF
Isolation Resistance 100M
Primary to Secondary Insulation Level
D12/D24 Models Operational
D48 Models Basic
Temperature Coeffi cient 0.02%/perC
Current Limit Inception:
5V @ 95% V
OUT
(3.3V @ 0A) 7.6-9.0 Amps
3.3V @ 98.5% V
OUT
(5V @ 0A) 11.3-12.7 Amps
Performance/Functional Specifi cations
Typical @ T
A
= +25C under nominal line voltage, balanced "full-load" conditions, unless noted.
3 3 W , D U A L O U T P U T , M I X E D - V O L T A G E D C / D C C O N V E R T E R S
XWR Series
4
Absolute Maximum Ratings
Input Voltage:
Continuous:
"D12" Models 23 Volts
"D24" Models 42 Volts
"D48" Models 81 Volts
Transient (100msec): "D12" Models 25 Volts
"D24" Models 50 Volts
"D48" Models 100 Volts
Input Reverse-Polarity Protection
Input Current must be limited. 1 minute
duration. Fusing recommended.
"D12" Models
6 Amps
"D24" Models
4 Amps
"D48" Models
2 Amps
Output Current
Current limited. Devices can withstand
an indefi nite output short circuit.
On/Off Control (Pin 4) Max. Voltages
Referenced to Input (pin 2) +V
IN
Storage Temperature
40 to +120C
Lead Temperature (Soldering, 10 sec.) +300C
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 Specifi cations Table is not implied, nor recommended.
T E C H N I C A L N O T E S
5V & 3.3V Regulation
The BWR 33 Watt Series converters are designed such that both the 5V and
3.3V outputs share a common regulation feedback control loop. Though the
feedback loop is infl uenced by both outputs, the 3.3 Volt output is dominant.
As a result, the 3.3 Volt regulation (1%) is superior to the 5 Volt regulation (1.5%).
The converters are specifi ed for load regulation of 10% to 100% loading and
for no-load to 100% loading. Operation below 10% of full load mandates
an increase in the regulation tolerance of 0.5% for 3.3 Volt output and an
increase of 1% for the 5 Volt output. A slight increase in switching noise
may also be observed for operation below 10% loading.
Operation with a full load on 3.3 Volt output and light to no load on 5 Volt
output is the most demanding for +5V regulation. Under such conditions the
internal "bleeder" circuit is activated to provide an internal load thereby keep-
ing regulation within the published specifi cations. The bleeder is activated
gradually so as not to cause any erratic behavior on the converters outputs. A
slight degradation in effi ciency will occur while this internal load is activated.
Filtering and Noise Reduction
The BWR 33 Watt Series Converters achieve their rated ripple and noise
specifi cations with the use of 1F output capacitors. In critical applications,
input/output noise may be further reduced by installing additional external
I/O capacitors. Input capacitors should be selected for bulk capacitance,
low ESR and high rms-ripple-current ratings. Output capacitors should be
selected for low ESR and appropriate frequency response. All caps should
have appropriate voltage ratings and be located as close to the converter
as possible.
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 specifi ed accuracy band. Actual measured times will
vary with input source impedance, external input/output capacitance, and the
slew rate of the input voltages. The BWR-5/6-3.3/7 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 specifi cation defi nes the interval between the time at which the converter
is turned on and the fully loaded output voltage enters and remains within
its specifi ed 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
voltage drops below the Undervoltage Shutdown limit (34V 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 specifi cation listed
in the Performance/Functional Specifi cations 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 suffi ciently reduced.
On/Off Control
The On/Off Control (pin 4) may be used for remote on/off operation. As
shown in Figure 1, the control pin is referenced to the Input (pin 2) and will
be internally pulled to a high state. The standard BWR model (no suffi x) is
designed so that it is enabled when the control pin is left open and disabled
when the control pin is pulled low (less than +0.8V relative to Input).
Dynamic control of the on/off function is best accomplished with a mechanical
relay or an open-collector/open-drain circuit (optically isolated if appropriate).
The drive circuit should be able to sink approximately 1 mA for logic low.
The on/off control function is designed such that the converter can be
disabled while the input power is ramping up, and then "released" once the
input has stabilized.
Figure 1. Internal Circuitry for On/Off Control
4
2
1
R
A
R
B
+INPUT
INPUT
ON/OFF
CONTROL
D12 R
A
= 34.8k
, R
B
= 6.83k
D24 R
A
= 100k
, R
B
= 9.74k
D48 R
A
= 100k
, R
B
= 4.53k
BWR Models
3 3 W , D U A L O U T P U T , M I X E D - V O L T A G E D C / D C C O N V E R T E R S
5
Current Limiting
When power demands from either output fall within 126% to 181% of the rated
output current, the DC/DC converter will go into a current limiting mode. In
this condition both output voltages will decrease proportionately with increases
in output current, thereby maintaining a somewhat constant power dissipa-
tion. This is commonly referred to as power limiting (see Figures 2a and
2b). Current limit inception is defi ned as the point where the full-power output
voltage falls below the specifi ed tolerance. If the load current being drawn
from the converter is signifi cant 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 (see fi gures 2a and 2b). If the output volt-
age 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 of 5 to 15 milliseconds, 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 is capable of enduring an indefi nite
short circuit output condition.
Thermal Shutdown
These BWR converters are equipped with Thermal Shutdown Circuitry. If
the internal temperature of the DC/DC converter rises above the designed
operating temperature, a precision temperature sensor will power down the
unit. When the internal temperature decreases below the threshold of the
temperature sensor the unit will self start.
Output Overvoltage Protection
Both output voltages are monitored for an overvoltage condition via magnetic
coupling to the primary side. If either output voltage should rise to a level
which could be damaging to the load circuitry, the sensing circuitry will power
down the PWM controller causing the output voltages to decrease. Following
a time-out of 5 to 15 milliseconds the PWM will restart, causing the output
voltages to ramp to their appropriate values. If the fault condition persists,
and the output voltages again climb to excessive levels, the overvoltage
circuitry will initiate another shutdown cycle. This on/off cycling is referred
to as "hiccup" mode.
Figure 2a. Current Limiting Characteristics for 3.3V Output
Figure 2b. Current Limiting Characteristics for 5V Output
4
3
2
1
0
0
2
4
6
8
10
12
14
3.3 V
OUT
Average Ouput Current (Amps)
Typical Current Limiting Characteristics for 3.3V Output
Ouput V
olta
g
es
(V
olts)
V
IN
NOM, V
IN
LO All Models
V
IN
HI D12, D24 Models
V
IN
HI
D48 Models
5
4.5
4
3.5
3
2.5
2
1.5
1
0.5
0
0
1
2
3
4
5
6
7
8
9
5 V
OUT
Average Ouput Current (Amps)
Ouput V
olta
g
es
(V
olts)
V
IN
NOM, V
IN
LO
All Models
V
IN
HI D12, D24
Models
V
IN
HI
D48 Models
Typical Current Limiting Characteristics for 5V Output
(3.3V Output @ 700mA)
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