75 Watt, High Density, Eighth Brick DC/DC Converter ASD75EB series
WWW.ASTRODYNE.COM ASTRODYNE USA: 1-800-823-8082
ASTRODYNE PACIFIC: 886-2-26983458
Small 2.32” x 0.9” x 0.37” Size
Constant Frequency
High Typical Efciency of 92% (12Vout)
Low Output Noise
24 or 48VDC Nominal Input Voltage Options
Output Over Voltage Protection
Current Limit/Short Circuit Protection
Adjustable Output Voltage 80-110% of Vo
No Sink Current from Output During Shutdown
Logic ON/OFF Control
MTBF of 1.3Mhrs
RoHS Compliant
CSA Certied to IEC 60950-1 for Basic Insulation
Model Number Output Voltage Output Amps Input Range Max. Iin FL Efciency Max Output Power
ASD75-24S3.3EB 3.3 VDC 20 18-36 VDC 4.9A 89%, typ. 66 Watts
ASD75-24S5EB 5 VDC 15 18-36 VDC 5.5A 90.5%, typ. 75 Watts
ASD75-24S12EB 12 VDC 6.25 18-36 VDC 5.5A 91.5%, typ. 75 Watts
ASD75-48S3.3EB 3.3 VDC 20 36-75 VDC 2.5A 89%, typ. 66 Watts
ASD75-48S5EB 5 VDC 15 36-75 VDC 2.9A 91%, typ. 75 Watts
ASD75-48S12EB 12 VDC 6.25 36-75 VDC 2.9A 92%, typ. 75 Watts
DESCRIPTION:
The ASD75EB Series of products are open frame, high density, dc/dc convert-
ers designed for use in distributed power architectures and may, in many cases,
be used as t and function replacements for industry standard quarter brick
modules with a 34% space savings. Synchronous Rectication enables these
power supplies to produce up to 75W of high efciency power in an 1/8th brick
(2.32in. x 0.90in. x 0.37in. ) package.
75 Watt, High Density, Eighth Brick DC/DC Converter ASD75EB series
WWW.ASTRODYNE.COM ASTRODYNE USA: 1-800-823-8082
ASTRODYNE PACIFIC: 886-2-26983458
ABSOLUTE MAXIMUM RATINGS (MIN TO MAX.)
Input Voltage (+In to -In) 24Vin: 18-36VDC Continuous
48Vin: 36-75VDC Continuous
Transient Input Voltage 24Vin: 50VDC (100mS max.)
48Vin: 100VDC (100mS max.)
Operating Temperature -40 to 85°C (See Derate Curve)
Storage Temperature (Ambient) 125°C
Wave Solder Temperature 260°C for 10 Seconds
INPUT SPECIFICATIONS (400LFM AIRFLOW)
Input Operation Voltage: See Model Chart on Page 1
Input Current FL (0 Vin - Vin max.) See Model Chart on Page 1
Input Transient 1A²t
Input Reected Ripple Current 20mAp-p, typ. (Note 1)
Startup Input Voltage (Note 4) 24Vin: 16-18VDC
48Vin: 33-36VDC
Shutoff Input Voltage 24Vin: 14-16VDC
48Vin: 30-33VDC
Hysteresis 1V
OUTPUT SPECIFICATIONS
Output Voltage See Model Chart on Page 1
Output Current (Io, max.) See Model Chart on Page 1
Output Set Point (Vo,set) +/-1.5%, Nominal Vin, FL
Total Output Voltage Range +/- 3%
Line/Load Regulation +/-1%
Temperature Regulation +/-1%, -40 to 70°C
Ripple/Noise 150mV p-p max., 30mVrms (Note 2)
Dynamic Response: (Note 3)
Peak Deviation 4% Vnom
Settling Time 200uS Vout within 1% Vnom
Over Voltage Protection 110-140% of Output, Hiccup Mode
Over Temperature Protection 105-125°C, auto recover
(converter hot spot temperature)
External Capacitance (Electrolytic) 3.3 & 5Vout: 10 to 5000uF max.
12Vout: 220 to 1200uF max.
Short Circuit Protection (rms) 15Arms, Hiccup, Rout ≤10M Ω
Current Limit (rms.) 105-140%, Hiccup Mode
Efciency FL See Model Chart on Page 1
ISOLATION SPECIFICATIONS
Input-Output 1500VDC
Input-Output Capacitance 1500pF
Isolation Resistance 10MΩ
GENERAL SPECIFICATIONS
MTBF 1.3Mhrs
Weight 0.72 oz (20.5g)
Dimensions 2.3” x 1.45” x 0.47”
(58.4 x 36.8 x 12mm)
CONTROL SPECIFICATIONS
Input Logic Low Voltage at 1mA current relative to
-Vin is 1V max.
Current at 0 volts is 1mA
Input Logic High Enable pin voltage relative to -Vin
is 5.5V
Leakage current is 100uA
Turn-On Time 500mS, FL, o=90% Vo, set
Trim Adjustment Range 80-110% See TRIM FUNCTION
Fig 4
NOTES
1.Measured before Input Filter, 12uH inductor
2.Scope measurement should be made using a BNC connector with 1uF
and 10uF aluminum electrolytic capacitor across output. Scope set to
read at 20MHz bandwidth.
3. 25%-50%-75% load, 0.1A/
u
S
4. The Cold Start condition is a uniform converter temperature of -40°C
after thermal stabilization. An additional 2x220uF is needed for cold
startup conditions. The Hot Start condition for start up is a uniform con-
verter temperature of 65°C after thermal stabilization.
All specications are typical at nominal input, full load, and 25DegC unless
otherwise noted
75 Watt, High Density, Eighth Brick DC/DC Converter ASD75EB series
WWW.ASTRODYNE.COM ASTRODYNE USA: 1-800-823-8082
ASTRODYNE PACIFIC: 886-2-26983458
PIN OUTS
Figure 1: ASD75EB Series Pin Outs
OUTLINE DRA
WING
Figure 2: Mechanical Outline
75 Watt, High Density, Eighth Brick DC/DC Converter ASD75EB series
WWW.ASTRODYNE.COM ASTRODYNE USA: 1-800-823-8082
ASTRODYNE PACIFIC: 886-2-26983458
OPERATING INFORMATION
Enable Pin
The Enable Pin (pin 2) enables the user to control when the converter will turn on or off. This pin is
referenced to –Vin (pin 3). There are two versions available for each converter, positive logic and
negative logic. For positive logic, leaving the Enable pin open or applying TTL/CMOS high voltage level
turns the converter on, while pulling this pin to –Vin or drawing more than 1mA turns it off. The negative
logic is just the inverse. An external semiconductor switch or mechanical switch can be used to
implement this function.
Remote Sense
The remote sense pins +Sense (pin 7) and –Sense (pin 5) allows the converter to correct for voltage drops
across the connections from the converter output pins +/-Vout (pins 8 and 4 respectively) to the intended
load. The +/- Sense pins should be connected at the point in the board where regulation is needed. Figure
3 shows the recommended connection.
Figure 3: Remote Sense connection
The resistive drop across the connections should be small enough since Over Voltage Protection might be
triggered during high load applications. The OVP circuit senses the +/-Vout pins.
75 Watt, High Density, Eighth Brick DC/DC Converter ASD75EB series
WWW.ASTRODYNE.COM ASTRODYNE USA: 1-800-823-8082
ASTRODYNE PACIFIC: 886-2-26983458
R
trim-down
= (511 /Δ%) – 10.22 kOhms
R
trim-up
= (5.11Vout|100 +Δ% | / 1.225Δ%) – (511/Δ%) – 10.22 kohms
Where:
Δ% = [(V
nominal
-V
desired
)/V
nominal
] x 100%
Figure 4: TRIM Function
There is an upper limit to the trim up since the OVP level is fixed. Trimming the output voltage too high
may trigger the OVP circuit during higher load applications or during transients.
Current Limit Protection
The ASD75EB series modules include over current protection that allows them to withstand prolonged
overloads or short circuit conditions on the output without over heating. The ASD75EB series employs
hiccup mode protection such that the output shuts down during these conditions, waits for a predetermined
time (~500mS), and tries to restart. If the overload condition is still present, the converter will stop trying to
increase the output voltage and repeat the cycle.
Over Voltage Protection
The ASD75EB series modules have output over voltage protection. In the event of an over voltage
condition in the output pins, the converter will shut down immediately. Similar to hiccup mode, it
will make continuous attempts to start up until the over voltage is gone and resume normal operation
automatically
Input Under-Voltage Lockout
The ASD75EB series is designed to turn off when the input voltage is too low. This is done to avoid
stressing the input side circuitry of the primary circuit. The lockout is a comparator with hysteresis,
thus avoiding the converter jumping from on-off condition when crossing the UVLO threshold.
Trim
The Trim pin (pin 6) allows the user to adjust the output voltage across the sense pins from the initial
value. Trimming the output voltage requires the user to connect a resistor between Trim and + Vout for
output voltage trim up, or connect a resistor between Trim and – Vout for output voltage trim down. The
functions for trim up, trim down and the circuit implementation is shown in the figure 4.
75 Watt, High Density, Eighth Brick DC/DC Converter ASD75EB series
WWW.ASTRODYNE.COM ASTRODYNE USA: 1-800-823-8082
ASTRODYNE PACIFIC: 886-2-26983458
Over Temperature Protection
The ASD75EB series modules are protected from thermal overload by an internal over temperature protection
IC. When the PCB temperature sense point reaches 125°C, the converter will shut down immediately. The
converter will attempt to restart when the temperature has dropped at least 10°C below the Over
Temperature threshold.
Thermal Considerations
The ASD75EB series are designed to operate in a wide range of thermal environments. However, enough
cooling should be provided to ensure reliable performance. Heat is removed from the converter in 3 ways:
conduction, convection and radiation.
Improved cooling by convection can be done by increasing the airflow through the module. The available
load current for a given ambient air temperature is in the de-rating curves section. The test is done using
the test fixture shown in figure 5.
Figure 5: Thermal Test Fixture
Pin3
Pin1
Pin4
Pin8
Proper cooling can be verified by monitoring the temperature of the critical components of the power
stage. Each of the selected critical components was monitored by using thermocouple. The generation of
the thermal de-rating curves involves extensive thermal testing at different combinations of input voltage,
ambient air temperature, load current and airflow with the given test fixture.
However, the final temperature of the module in the final system will depend again on several factors,
including host PCB size, number of layers, and copper weight, airflow direction and turbulence, operating
ambient temperatures, etc… It is highly recommended to verify the thermal performance of the converter
when included in the end system.
ASD75
75 Watt, High Density, Eighth Brick DC/DC Converter ASD75EB series
WWW.ASTRODYNE.COM ASTRODYNE USA: 1-800-823-8082
ASTRODYNE PACIFIC: 886-2-26983458
Thermal Characteristic
Test done using Thermal Set-up of Figure 5; Vin = Vin
nom
ASD75-48S3.3EB Power Derating Curve
0%
20%
40%
60%
80%
100%
120%
25 03 53 04 54 05 55 06 56 07 57 08 58
Temperature (ºC)
Temperature (ºC)Temperature (ºC)
Temperature (ºC)
Power
Power
Power
Power
0 LFM
0 LFM0 LFM
0 LFM
100 LFM
100 LFM100 LFM
100 LFM
200 LFM
200 LFM200 LFM
200 LFM
300 LFM
300 LFM300 LFM
300 LFM
400 LFM
400 LFM400 LFM
400 LFM
ASD75-48S5EB Power Derating Curve
Temperature (ºC)
Temperature (ºC)Temperature (ºC)
Temperature (ºC)
Power
Power
Power
Power
0 LFM
0 LFM0 LFM
0 LFM
100 LFM
100 LFM100 LFM
100 LFM
200 LFM
200 LFM200 LFM
200 LFM
300 LFM
300 LFM300 LFM
300 LFM
400 LFM
400 LFM400 LFM
400 LFM
ASD75-48S12EB Power Derating Curve
Temperature (ºC)
Temperature (ºC)Temperature (ºC)
Temperature (ºC)
Power
Power
Power
Power
0 LFM
0 LFM0 LFM
0 LFM
100 LFM
100 LFM100 LFM
100 LFM
200 LFM
200 LFM200 LFM
200 LFM
300 LFM
300 LFM300 LFM
300 LFM
400 LFM
400 LFM400 LFM
400 LFM
ASD75-24S3.3EB Power Derating Curve
Temperature (ºC)
Temperature (ºC)Temperature (ºC)
Temperature (ºC)
Power
Power
Power
Power
0 LFM
0 LFM0 LFM
0 LFM
100 LFM
100 LFM100 LFM
100 LFM
200 LFM
200 LFM200 LFM
200 LFM
300 LFM
300 LFM300 LFM
300 LFM
400 LFM
400 LFM400 LFM
400 LFM
ASD75-24S5EB Power Derating Curve
Temperature (ºC)
Temperature (ºC)Temperature (ºC)
Temperature (ºC)
Power
Power
Power
Power
0 LFM
0 LFM0 LFM
0 LFM
100 LFM
100 LFM100 LFM
100 LFM
200 LFM
200 LFM200 LFM
200 LFM
300 LFM
300 LFM300 LFM
300 LFM
400 LFM
400 LFM400 LFM
400 LFM
ASD75-24S12EB Power Derating Curve
Temperature (ºC)
Temperature (ºC)Temperature (ºC)
Temperature (ºC)
Power
Power
Power
Power
0 LFM
0 LFM0 LFM
0 LFM
100 LFM
100 LFM100 LFM
100 LFM
200 LFM
200 LFM200 LFM
200 LFM
300 LFM
300 LFM300 LFM
300 LFM
400 LFM
400 LFM400 LFM
400 LFM
0%
20%
40%
60%
80%
100%
120%
25 03 53 04 54 05 55 06 56 07 57 08 58
0%
20%
40%
60%
80%
100%
120%
25 03 53 04 54 05 55 06 56 07 57 08 58
0%
20%
40%
60%
80%
100%
120%
25 03 53 04 54 05 55 06 56 07 57 08 58
0%
20%
40%
60%
80%
100%
120%
25 03 53 04 54 05 55 06 56 07 57 08 58 0%
20%
40%
60%
80%
100%
120%
25 03 53 04 54 05 55 06 56 07 57 08 58
75 Watt, High Density, Eighth Brick DC/DC Converter ASD75EB series
WWW.ASTRODYNE.COM ASTRODYNE USA: 1-800-823-8082
ASTRODYNE PACIFIC: 886-2-26983458
Efficiency Curves
Ta=25
o
C, airflow rate = 400LFM
ASD75-48S3.3EB Efficiency Curve
55%
60%
65%
70%
75%
80%
85%
90%
95%
59
0% %01 %02 %03 %04 %05 %06 %07 %08 %09 100%
Output Load Current; Imax = 20A
Output Load Current; Imax = 20AOutput Load Current; Imax = 20A
Output Load Current; Imax = 20A
Eciency
Eciency
Eciency
Eciency
36Vdc Input
36Vdc Input36Vdc Input
36Vdc Input
48Vdc Input
48Vdc Input48Vdc Input
48Vdc Input
75Vdc Input
75Vdc Input75Vdc Input
75Vdc Input
ASD75-48S5EB Efficiency Curve
60%
65%
70%
75%
80%
85%
90%
95%
0% %01 %02 %03 %04 %05 %06 %07 %08 %09 100%
Output Load Current; Imax = 15A
Output Load Current; Imax = 15AOutput Load Current; Imax = 15A
Output Load Current; Imax = 15A
Eciency
Eciency
Eciency
Eciency
36Vdc Input
36Vdc Input36Vdc Input
36Vdc Input
48Vdc Input
48Vdc Input48Vdc Input
48Vdc Input
75Vdc Input
75Vdc Input75Vdc Input
75Vdc Input
ASD75-48S12EB Efficiency Curve
60%
65%
70%
75%
80%
85%
90%
95%
0% %01 %02 %03 %04 %05 %06 %07 %08 %09 100%
Output Load Current; Imax = 6.25A
Output Load Current; Imax = 6.25AOutput Load Current; Imax = 6.25A
Output Load Current; Imax = 6.25A
Eciency
Eciency
Eciency
Eciency
36Vdc Inpit
36Vdc Inpit36Vdc Inpit
36Vdc Inpit
48Vdc Input
48Vdc Input48Vdc Input
48Vdc Input
75Vdc Input
75Vdc Input75Vdc Input
75Vdc Input
ASD75-24S3.3EB Efficiency Curve
70%
75%
80%
85%
90%
95%
Output Load Current; Imax = 20A
Output Load Current; Imax = 20AOutput Load Current; Imax = 20A
Output Load Current; Imax = 20A
Eciency
Eciency
Eciency
Eciency
18Vdc Input
18Vdc Input18Vdc Input
18Vdc Input
24Vdc Input
24Vdc Input24Vdc Input
24Vdc Input
36Vdc Input
36Vdc Input36Vdc Input
36Vdc Input
ASD75-24S5EB Efficiency Curve
65%
70%
75%
80%
85%
90%
95%
Output Load Current; Imax = 15A
Output Load Current; Imax = 15AOutput Load Current; Imax = 15A
Output Load Current; Imax = 15A
Eciency
Eciency
Eciency
Eciency
18Vdc Input
18Vdc Input18Vdc Input
18Vdc Input
24Vdc Input
24Vdc Input24Vdc Input
24Vdc Input
36Vdc Input
36Vdc Input36Vdc Input
36Vdc Input
ASD75-24S12EB Efficiency Curve
Output Load Current; Imax = 6.25A
Output Load Current; Imax = 6.25AOutput Load Current; Imax = 6.25A
Output Load Current; Imax = 6.25A
Eciency
Eciency
Eciency
Eciency
18Vdc Input
18Vdc Input18Vdc Input
18Vdc Input
24Vdc Input
24Vdc Input24Vdc Input
24Vdc Input
36Vdc Input
36Vdc Input36Vdc Input
36Vdc Input
0% %01 %02 %03 %04 %05 %06 %07 %08 %09 100%
0% %01 %02 %03 %04 %05 %06 %07 %08 %09 100%
60%
65%
70%
75%
80%
85%
90%
95%
0% %01 %02 %03 %04 %05 %06 %07 %08 %09 100%