BM80A
High
AMPSS™
Astec Modular Power Supply System
Series Highlights
•High Efficiency - up to 87%
•85°C baseplate/ case operating temperature
•Low output ripple and noise
•High Reliability - over 1 million hours MTBF
•Wide input voltage range
•Excellent Transient Response
• Fixed Switching Frequency
• Designed to meet Telecom specifications
DC-DC Converter Module
Technical Reference Manual
Series
Performance
BM80A High Power Performance Series
Rev. 10 Jan 03AMPSS® Reference Manual
2
Contents
Introduction............................................................................................................ 4
Special Features ...................................................................................................... 4
Ordering Information............................................................................................... 5
Safety..................................................................................................................... 5
Electrical Specifications............................................................... 6
Absolute Maximum Ratings – all models .................................................................. 6
Pin Connections - all models ................................................................................... 7
Insulation - all models .............................................................................................. 8
Electrical Specifications for 48V Input Models (BM80A-048L-xxxFyy)..................... 9
Electrical Specifications for 300V Input Models (BM80A-300L-xxxFyy).....................
........................................................................................................................ 10
Functional Description................................................................11
Remote Sense (+SENSE, -SENSE) ........................................................................11
Enable Control (ENABLE) .....................................................................................11
Output Voltage Adjustment (V ADJ) ...................................................................... 12
Current Limit Adjustment (C LIM ADJ) ................................................................. 12
Power Good/Identification (PG/ID) ....................................................................... 12
Clock Signals (CLK IN, CLK OUT)...................................................................... 13
Current Sharing (C SHARE).................................................................................. 14
Current Monitoring (C MON) ................................................................................ 14
Temperature Monitoring (TEMP MON) ................................................................. 14
Design Considerations ................................................................ 15
Input Bulk Capacitors ........................................................................................... 15
Input Fusing ......................................................................................................... 15
Remote Loads ...................................................................................................... 15
Thermal Data ........................................................................................................ 15
Overtemperature Protection................................................................................... 15
Parallel Connection Considerations ........................................................................ 16
Output Ripple and Noise....................................................................................... 16
Conducted EMI .................................................................................................... 16
Break Regulation................................................................................................... 16
Input Undervoltage Protection ............................................................................... 17
Rev. 10 Jan 03 AMPSS® Reference Manual
Specifications
3
Application Examples................................................................. 18
AC Input Design ................................................................................................... 18
Parallel Connection Design .................................................................................... 18
Mechanical Information............................................................. 19
Dimensions .......................................................................................................... 19
Recommended PCB Layout .................................................................................. 21
Heatsink Mounting Information ............................................................................ 23
BM80A High Power Performance Series
Rev. 10 Jan 03AMPSS® Reference Manual
4
BM80A High Power Performance Series DC-DC Converters
Introduction
The BM80A is an isolated, single output DC to DC
converter module, providing up to 300W output with a
maximum baseplate operating temperature of 85°C with
no derating. The BM80A features full safety isolated
low voltage secondary side control and Astec Linear
Programming (ALP™) for convenient adjustment of the
module's parameters.
Special Features
•High Efficiency - up to 87%
•1MHz fixed switching frequency
•85°C baseplate/Case operating temperature - no
derating
•Low output ripple and noise
•Excellent transient response
•Safety isolated low voltage interface with ALPTM
linear control
•High Reliability - over 1 million hours MTBF
•Wide input voltage range
•Parallelable with accurate current sharing
•Current and temperature monitoring outputs
*Note: PIN 20 and PIN 30 are only available on BM80A-300L-033F90
Rev. 10 Jan 03 AMPSS® Reference Manual
Specifications
5
Ordering Information
Please contact Astec for information on other output voltages, power ranges and configurations.
Safety UL: UL1950
CSA: CSA C22.2 No.950
VDE: VDE 0805
EN60950
CE: CE Mark
Please contact Astec for information on specific module approvals.
Note: Ensure all modules are used according to the Installation Instructions provided with each module.
Model Number Input
Voltage Output
Voltage Output
Current Output
Power
BM80A-300L-022F75 300V 2.2V 75A 165W
BM80A-300L-022F85 300V 2.2V 85A 187W
BM80A-300L-033F70 300V 3.3V 70A 231W
BM80A-300L-033F90 300V 3.3V 90A 297W
BM80A-300L-050F60 300V 5.0V 60A 300W
BM80A-300L-150F20 300V 15V 20A 300W
BM80A-048L-033F70 48V 3.3V 70A 231W
BM80A-048L-050F60 48V 5.0V 60A 300W
All modules are designed to meet the following specifications:
ETS300-132-2,
EN55022-A(1)
EN55022-B(1)
EN41003
IEC6100-44(1)
IEC6100-45(1)
IEC950
VDE0871-A(1)
VDE0878-A(1)
BTNR2511(5)(1)
(1) Require additional external circuitry for full compliance. Please refer to application section of this manual
or contact technical support office for further information.
BM80A High Power Performance Series
Rev. 10 Jan 03AMPSS® Reference Manual
6
General 300V Input 48VInput
Continuous Input Voltage 400V 72V
Input Surge Voltage (1 sec) 425V 75V (continuous)
Isolation, Input to Output* 2700VDC 2100VDC
Isolation Input to Baseplate* 2121VDC 2100VDC
Isolation, Output to Baseplate* 500VDC 500VDC
Operating Temperature (Baseplate) / Case -20 to 85°C
Storage Temperature -40 to 105°C
Operating Relative Humidity (non-condensing) 10% to 95%
Storage Relative Humidity (non-condensing) 95% Max
Altitude (Operating) < 3000m
Altitude (Storage) < 9000m
Lead Temperature (soldering 5 Seconds) 235°C
Electrical Specifications
Absolute Maximum Ratings – all models
Exceeding the specified absolute maximum ratings may severely damage the module. These ratings are intended as
guidelines for absolute worst case operating conditions and are not to be interpreted as recommended operating
condition
Notes:
* For 300V input :
All isolation barriers on 300V input modules have been designed
and tested to meet 4242VDC as required by IEC950 for reinforced
insulation. The complete module should NOT be subjected to a
3000VAC input-to-output test because this can result in input-
baseplate-output breakdown. AMPSS DC-DC modules are CLASS
I equipment. Power supply systems using AMPSS modules MUST
also be CLASS I equipment. Each AMPSS DC-DC module is fully
tested in factory according to the standards. Therefore power
supply systems need only be subjected to Hi-Pot test for BASIC
insulation which is 1500Vac (AC) input to GROUND.
Secondary Control Pins
+SENSE Vo - 0.5 to Vo + 0.5 VDC
-SENSE -0.5 to 0.5 VDC
TEMP MON -0.5 to 7 VDC
C MON -0.5 to 7 VDC
C SHARE -0.5 to 7 VDC
CLK OUT -10 to 10 VDC
CLK IN -10 to 10 VDC
C LIM ADJ -0.5 to 7 VDC
OVP ADJ -0.5 to 7 VDC
V ADJ -0.5 to 7 VDC
PG/ID 0.5 to Vo + 0.5VDC
ENABLE -0.5 to 20 VDC
Note : V o = module output voltage
All voltages referenced to negative output
Specifications
Electrical characteristics are guaranteed over the full baseplate/Case temperature range (-20 to 85°C) and for the full range
of input voltage (VI) and for the full load range (0 to IO rated). Except where indicated , +SENSE and -SENSE are connected
to the output terminals at the point of measurement, ENABLE is connected to -SENSE. All other pins are left floating.
Definitions
VI, VO and IO are actual operating conditions, VInom, VOnom and IOrated are nominal ratings.
Rev. 10 Jan 03 AMPSS® Reference Manual
Specifications
7
Pin Connections - all models
CONTROL PINS
Pin No Pin Name Type Description Recommended Connections
1+SENSE Input Used for remote sense function
to compensate for load bus
resistance
If remote sensing is not required connect
to +OUTPUT pins 21-24 of the module
2TEMP MON Output
Provides a voltage signal
proportional to the internal
absolute temperature of the
module
Analog signal output. Leave
unconnected if not used
3C MON Output Provides a current signal
proportional to the current
being supplied by the module
Analog signal output. Leave
unconnected if not used
4C SHARE Input/Output Allows modules connected in
parallel to accurately share
current
Connect to C SHARE pins of other
modules. Leave unconnected if not used
5CLK OUT Output Provides a 1MHz clock output
for synchronization with other
modules
Capacitor coupled output. Leave
unconnected if not used
6CLK IN Input Accepts a 1MHz clock input for
synchronization with other
modules
Capacitor coupled input. Leave
unconnected if not used
7PG/ID Output
High level output (VPG/ID = VO)
indicates module converter is
running. Can also be used to
identify the nominal output
voltage of the module by
measuring resistance between
PG/ID and +OUTPUT
ID Resistance = [Vo(nom)]KΩ
.
Leave unconnected if not used
8C LIM ADJ Input Used to adjust the current limit
set point Internal 1mA current source. Leave
unconnected if not used
9OVP ADJ Input Used to adjust module output
overvoltage threshold Internal 1mA current source. Leave
unconnected if not used
10 V ADJ Input Used to adjust module output
voltage Internal 1mA current source. Leave
unconnected if not used
11 ENABLE Input Enables or disables the output of
the module
Must be connected to -SENSE pin or
driven to <0.8V to enable the output of
the module
12 -SENSE
Input/
Reference
Used for remote sense function
to compensate for load bus
resistance
If remote sensing is not required connect
to -OUTPUT pins 26-29 of the module
INPUT PINS
Pin No Pin Name Type Description Recommended Connections
31 +INPUT Input Power input - positive A 220µF electrolytic capacitor connected
between the +INPUT and -INPUT pins is
recommended
32 -INPUT Input Power input - negative (return) See + INPUT for recommendations
OUTPUT PINS
Pin No Pin Name Type Description Recommended Connections
*20 +OUTPUT Output Power output - positive
Ensure good electrical connection and sufficient
copper on PCB layouts
21-24 +OUTPUT Output Power output - positive
Ensure good electrical connection and sufficient
copper on PCB layouts
26-29 -OUTPUT Output Power output - negative See +OUTPUT for recommendations
*30 -OUTPUT Output Power output - negative See +OUTPUT for recommendations
* Note: Only available on BM80A-300L-033F90
BM80A High Power Performance Series
Rev. 10 Jan 03AMPSS® Reference Manual
8
Insulation - all models
CONTROL SIGNALS
Control Function Conditions Parameter Min Typ Max Units
V
T MON
sensitivity
9.8
10
10.2
mV/°C
Source impedence
1
K
Ω
I
O
= I
Orated
I
C MON
0.9
1
1.1
mA
Measured Range
20
100
%I
O rated
C SHARE pins of modules in
C SHARE accuracy
±3%
±10
%I
O rated
parallel connected
Max no. of units
10
V
CLK OUT
3.3
5.5
Vp-p
CLK IN open Clock freq. 0.98 11.02 MHz
Max fan out 2
V
CLK IN
3.3
5.5
Vp-p
Clock freq 0.9 11.1 MHz
Converter running :
V
PG/ID
100
%V
O
I
O
³ 5%I
Orated
for I
Orated
³ 20A
Converter not running 300Vin
V
PG/ID
0.2
V
Converter not running 48Vin
V
PG/ID
0.8
V
2.2V output
Resistance, PG/ID
2.16
2.2
2.24
K
Ω
3.3 V output
to +OUTPUT
3.23
3.3
3.37
K
Ω
5V output 5.00 5.1 5.20 ΚΩ
15V output 14.70 15 15.30 ΚΩ
C LIM ADJ - current limit
V
C LIM ADJ
= 0.8V
C LIM set point
20
%I
Omax
adjustment
V
C LIM ADJ
= 4.0V
C LIM set point
100
%I
Omax
V
C LIM ADJ
= 1V
C LIM current source
0.95
1
1.05
mA
1
- output
V
OVP ADJ
= 0V
OVP set point
150
%V
Onom
overvoltage protection VOVP ADJ >= 1V OVP set point 110 %VOnom
adjustment VOVP ADJ = 1V OVP ADJ current
source
0.95 11.05 mA
V
Vadj
= 0V
V
O
78
80
82
%V
Onom
V
Vadj
= 2V
V
O
118
120
122
%V
Onom
V
VADJ
= 1V
V ADJ current source
0.95 11.05 mA
ENABLE - module enable
Module enabled
V
ENABLE
0
0.8
V
Module disabled
V
ENABLE
2
10
V
VENABLE = 0.8V ENABLE current source 100 150 µA
Notes :
INSULATION
Parameter Conditions Min Typ Max Units
Input-output insulation resistance
500VDC 10 MΩ
Input-baseplate insulation
resistance
500VDC 10 MΩ
Output-baseplate insulation
resistance 500VDC 10 MΩ
Rev. 10 Jan 03 AMPSS® Reference Manual
Specifications
9
Electrical Specifications for 48V Input Models (BM80A-048L-xxxFyy)
INPUT CHARACTERISTICS
Parameter Conditions Min Typ Max Units
Input voltage All models 40 48 72 V
Input surge voltage continuous 75 V
Input low line power on voltage Module power on 30 35 V
Input low line power off voltage Module shutdown 24 31.5 V
No load input power
V
I
= V
Inom
5
W
Input capacitance 5µF
Input current Low line, nom VO, max IO
BM80A-048L-033F70 8A
BM80A-048L-050F60 10 A
OUTPUT CHARACTERISTICS
Parameter Conditions Min Typ Max Units
Nominal (factory set) output voltage BM80A-048L-033F70 3.3 V
BM80A-048L-050F60 5.0 V
Output voltage set point accuracy
T
C
= +25°C, V
I
= V
Inom
, I
O
= I
Orated
-1
1
%V
Onom
Remote sense compensation
V
I
= V
Imin
0.5
V
Output voltage adjust
80
120
%V
Onom
Nominal (factory set) output
overvoltage protection trip point
110 115 120 %VO
Overvoltage protection trim range
110
150
%V
Onom
Line regulation
V
Imin
to V
Imax
All models 10 mV
Load regulation
I
Omin
to I
Omax
All models 10 mV
Noise and ripple 20MHz bandwidth
All models 50 100 mV
Output current BM80A-048L-033F70 0 70 A
BM80A-048L-050F60 060 A
Output current limit
V
O
dropped to 90% of V
Onom
105
110
115
%I
Omax
Short circuit current
160
%I
Omax
Temperature coefficient
Per °C Baseplate temperature
0.02
%V
O
/°C
Overtemperature shutdown All models 85 92 100 °C
Efficiency
V
O
= V
Onom
, V
I
= V
Inom
, I
O
= I
Orated
BM80A-048L-033F70 75 79 %
BM80A-048L-050F60 80 83 %
TRANSIENT CHARACTERISTICS
Parameter Conditions Min Typ Max Units
Turn-on time VI = 0 to VInom 110 msec
Transient response
Step-load excursion
(25% to 75% load change @ BM80A-048L-033F70 100 165 mV
0.1A/µS, recovery to 1% V O)BM80A-048L-050F60 150 250 mV
Step-load response
BM80A-048L-033F70 400 µS
BM80A-048L-050F60 400 µS
BM80A High Power Performance Series
Rev. 10 Jan 03AMPSS® Reference Manual
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Electrical Specifications for 300V Input Models (BM80A-300L-xxxFyy)
TRANSIENT CHARACTERISTICS
Parameter Conditions Min Typ Max Units
Turn-on time VI = 0 to V Inom 110 msec
Transient response - Step-load excursion
(25% to 75% load change @ BM80A-300L-022F75 70 110 mV
0.1A/µS, recovery to 1% VO) BM80A-300L-022F85 70 110 mV
BM80A-300L-033F70 100 165 mV
BM80A-300L-033F90 100 165 mV
BM80A-300L-050F60 150 250 mV
BM80A-300L-150F20 400 600 mV
Step load response
All models 250 µsec
except :
BM80A-300L-033F90 400 µsec
BM80A-300L-022F75 700 µsec
BM80A-300L-022F85 700 µsec
OUTPUT CHARACTERISTICS
Parameter Conditions Min Typ Max Units
Nominal (factory set) output voltage BM80A-300L-022F75 2.2 V
BM80A-300L-022F85 2.2 V
BM80A-300L-033F70 3.3 V
BM80A-300L-033F90 3.3 V
BM80A-300L-050F60 5.0 V
BM80A-300L-150F20 15 V
Output voltage set point accuracy
T
C
= +25°C, V
I
= V
Inom
, I
O
= I
Orated
-1
1
%V
Onom
Remote sense compensation
V
I
= V
Imin
0.5
V
Output voltage adjust
80
120
%V
Onom
Nominal (factory set) output overvoltage
protection trip point 110 115 120 %VO
Overvoltage protection trim range 110 150 %VOnom
Line regulation VImin to V Imax
All models 10 mV
Load regulation
I
Omin
to I
Omax
All models 10 mV
Noise and ripple 20MHz bandwidth
All models 50 100 mV
except
BM80A-300L-150F20 80 300 mV
Output current BM80A-300L-022F75 0 75 A
BM80A-300L-022F85 085 A
BM80A-300L-033F70 070 A
BM80A-300L-033F90 090 A
BM80A-300L-050F60 060 A
BM80A-300L-150F20 020 A
Output current limit
V
O
dropped to 90% of V
Onom
All models
105
110
115
%I
Omax
Short circuit current
All models
160
%I
Omax
Temperature coefficient
Per °C Baseplate temperature
0.02
%V
O
/°C
Overtemperature shutdown Baseplate temperature 85 92 100 °C
Efficiency VO = V Onom, V I = V Inom, IO = IOrated
BM80A-300L-022F75 71 73 %
BM80A-300L-022F85 69 72 %
BM80A-300L-033F70 76 79 %
BM80A-300L-033F90 76 79 %
BM80A-300L-050F60 80 82 %
BM80A-300L-150F20 84 85 %
INPUT CHARACTERISTICS
Parameter Conditions Min Typ Max Units
Input voltage All models - 180 300 400 V
except :
BM80A-300L-022F75 200 300 400 V
BM80A-300L-022F85
Input surge voltage (1 second) 425 V
Input low line power on voltage Module power on 150 175 V
Input low line power off voltage Module shutdown 120 157.5 V
V
I
= V
Inom
5
W
Input capacitance 0.5 µF
Low line, nom V
O
, max I
O
BM80A-300L-022F75 1.2 A
BM80A-300L-022F85 1.4 A
BM80A-300L-033F70 1.9 A
BM80A-300L-033F90 2.2 A
BM80A-300L-050F60 2.1 A
BM80A-300L-150F20
2.5
A
Rev. 10 Jan 03 AMPSS® Reference Manual
Specifications
11
Functional Description
This section explains how to implement the functions
found on the BM80A High Power Performance series.
Remote Sense (+SENSE, -SENSE)
Connect the +SENSE and -SENSE pins of the BM80A
directly to the load to allow the module to compensate for
the voltage drop across the conductors carrying the load
current. If remote sensing is not required (for example if
the load is close to the module) the sense pins should be
connected directly to the module’s output pins to ensure
accurate regulation.
Note: If the sense leads fail open circuit, the module will
revert to local sense at the output pins. Incorrect
connect of sense leads may damage the module
Enable Control (ENABLE)
The enable pin is a TTL compatible input used to turn the
output of the module on or off. The module output is
enabled when the ENABLE pin is connected to -SENSE or
driven to a logic low of <0.8V (but not negative).
The output is disabled when the enable pin is open or
driven to a logic high >2V. All monitoring and housekeep-
ing functions (including clock signals) continue to operate
normally.
BM80A High Power Performance Series
Rev. 10 Jan 03AMPSS® Reference Manual
12
Output Voltage Adjustment (V ADJ)
The output voltage of the module may be accurately
adjusted by up to ±20% of the nominal factory set output.
Adjustment is carried out using either an external voltage
source (0 to 2V, capable of sinking 1mA) or a resistor (0 to
2K) connected between V ADJ and -SENSE.
Current Limit Adjustment (C LIM
ADJ)
A constant current limiting circuit protects the module
under overload or short circuit conditions.
With the C LIM ADJ pin left unconnected the current limit
is factory set to 115% of the module's rated output, but
may be adjusted across the range from 20% to 100% using
an external voltage source (0.8 to 4V, capable of sinking
1mA) or a resistor (800R to 4K) connected between C LIM
ADJ and -SENSE.
Overvoltage Protection Adjustment
(OVP ADJ)
An independent overvoltage circuit monitors the module's
output pins and will shut the module down in the event of
an internal or external fault which causes the output
voltage to rise above the preset limit. The module is reset
by removing and re-applying the input power or toggle the
ENABLE OFF/ON.
Rev. 10 Jan 03 AMPSS® Reference Manual
Specifications
13
Clock Signals (CLK IN, CLK OUT)
The module's internal clock is accurate and stable over its
full operating range and synchronization is not normally
required, but it can reduce noise in paralleled systems.
Clock signals can be wired in series (the CLK OUT pin of
one module to the CLK IN pin of the next etc) in which
case all the modules will be synchronized with the first
module in the chain. Alternatively, an external clock signal
of 5Vpk-pk at 1MHz±10% can be connected to the CLK IN
pins of all the modules.
If the clock input to any module fails, the module will
automatically switch back to its internal clock and will
continue to operate normally. The CLK IN and CLK OUT
signals are AC coupled, so any module can clock another
module regardless of polarity.
Output Voltage
(V)
Resistance
(KW)
2.1/2.2 2.2
3.3 3.3
5.0 5.1
12.0 12.0
The resistance between the PG/ID pin and the +ve output
of the module can be used to determine the output voltage
of the module with no power applied according to the
table:
Power Good/Identification (PG/ID)
This pin provides an indication that the module's converters
are working, and can also be used to identify the factory set
output voltage of the module.
The PG/ID pin goes high to the level of the output voltage
(VO) to indicate that the module is operating and delivering
power. The output goes low if the converters stop operating
due to a fault such as an overtemperature or overvoltage
condition. The PG/ID pin will also go low if the module is
disabled via the ENABLE pin or under light load conditions (
see specification).
The overvoltage set point may be adjusted between 10%
and 50% above the output voltage (VO), and automatically
tracks adjustments made to the output voltage using V
ADJ.
OVP ADJ should be used to increase the OVP margin if the
voltage drop between power output pins and remote sense
is more than 0.2V
BM80A High Power Performance Series
Rev. 10 Jan 03AMPSS® Reference Manual
14
Current Sharing (C SHARE)
To ensure that all modules in a parallel system accurately
share current, the C SHARE pins on each module should
be connected together.
The voltage on the C SHARE pins represents the average
load current per module. Each module compares this
average with its own current and adjusts its output voltage
to correct the error. In this way the modules maintain
accurate current sharing.
Note: The -SENSE and +SENSE pins of each module must
also be connected together to ensure accurate current
sharing.
Current Monitoring (C MON)
The C MON pin provides an indication of the amount of
current supplied by the module. The output of the C MON
pin is a current source proportional to the
Temperature Monitoring (TEMP
MON)
The TEMP MON pin provides an indication of the
module's internal temperature.The voltage at the TEMP
MON pin is proportional to the temperature of the module
baseplate at 10mV per °C, where:
Module temperature (°C) = (VTEMP MON x 100) - 273
The temperature monitor signal can be used by thermal
management systems (e.g. to control a variable speed fan).
It can also be used for overtemperature warning circuits
and for thermal design verification of prototype power
supplies and heatsinks.
output current of the module, where 0.2 to 1mA = 20 to
100% IO rated.
The C MON output can be paralleled with C MON
outputs from other modules to indicate the total current
supplied in a paralleled system.
Rev. 10 Jan 03 AMPSS® Reference Manual
Specifications
15
Design Considerations
Input Bulk Capacitors
Electrolytic bulk reservoir capacitors placed close to the
module input pins are recommended to ensure the module
is fed with a low source impedance. For the BM80A High
Power Performance Series module typical values are 220µF/
100V for 48V modules and 220µF/450V for 300V modules.
Input Fusing
AMPSS modules do not have an in-line fuse fitted
internally. In order to comply with CSA, VDE and UL
safety regulations it is recommended that a fuse of the
following rating be fitted at the module's input.
Thermal Data
Natural convection thermal impedance of the BM80A
package without a heatsink is approximately 4°C/W.
The below characteristic is for a standard horizontal fin
heatsink available from Astec (part number APA501-80-
002) with 11mm fins and 8mm pitch. The heatsink will
reduce module thermal impedance to 1°C /W with a forced
air flow of 250 LFM when mounted with a thermal pad
(ASTEC P/N APA502-80-001) between heatsink and
module.
Input Fuse Rating
300V 10A / 250V
48V 10A / 250V
Remote Loads
If the sensed load is some distance from the module, the
module's output voltage may rise sufficiently to trigger the
OVP protection circuit during a step load change due to
bus inductance. For this reason the OVP margin should be
increased in extreme cases. Fitting a decoupling capacitor
at the load can reduce this effect.
It should be noted that a distributed power solution, using
AMPSSTM modules placed close to their loads, will
optimize transient response.
0
0.2
0.4
0.6
0.8
1
1.2
0200 400 600 800 1000
Vair (LFM)
Thermal Resistance Baseplate to
Ambient (°C/W)
Forced Convection for APA501-80-002
at 200W Output
Overtemperature Protection
If the module's baseplate temperature exceeds 92°C, the
module will latch OFF. To reset the module the input
supply or the enable pin of the module must be cycled off
and then on again, allowing a period of time for the module
to cool down.
Overtemperature shutdown can also be programmed to
occur at lower temperatures by using the TEMP MON
output to control the ENABLE pin.
BM80A High Power Performance Series
Rev. 10 Jan 03AMPSS® Reference Manual
16
Parallel Connection Considerations
A master-slave configuration is not required for AMPSSTM
modules. BM80A modules may be connected in parallel
using a simple, single wire connection.
Current Sharing
In multi-module paralleled systems, all modules will share
current to within ± 3% (typical) of the rated load current
per module when the C SHARE pins of each module are
connected together.
The +SENSE and -SENSE pins of each module should be
connected to common points as close as possible to the
load.
Synchronization
Modules are synchronized by connecting the CLK OUT
pin of one module to the CLK IN pin of the next. Consecu-
tively connected modules operate out of phase with each
other, resulting in ripple cancellation at the inputs and
outputs of paralleled modules. If the clock input to a
module fails, it will automatically revert to its internal clock
and continue to operate normally
Conducted EMI
Although AMPSS modules contain both common mode
and differential mode input EMI filtering, power supply
systems using these modules will require additional EMI
filtering to enable the system to meet relevant EMI
standards.
BM80A modules have an effective input to ground
(baseplate) capacitance of 700pF for 300V input models
and 580pF for 48V input models. This should be
accounted for when calculating the maximum EMI ‘Y’
capacitance to meet ground leakage current specifications.
Break Regulation
BM80A High Power Performance Series modules are
designed to deliver full rated output current at up to 0.5V
above VO nom at the minimum specified input voltage.
Output Ripple and Noise
BM80A High Power Performance Series modules are
designed to generate very low ripple and noise. When
mounted on logic boards, for example, sufficient
decoupling is normally provided by the components used
to decouple the logic ICs, and no additional decoupling is
required.
Rev. 10 Jan 03 AMPSS® Reference Manual
Specifications
17
Input Undervoltage Protection
An input undervoltage protection circuit protects the
module under low input voltage conditions. Hysteresis is
built into the BM80A High Power Performance Series
module to allow for high levels of ripple on the input
supply voltage without causing the module to cycle on
and off. Typically 300V modules will turn on when the
input exceeds 160V and turn off below 140V. 48V modules
will turn on above 33V and turn off below 28V (see
Electrical Specifications for exact figures).
BM80A High Power Performance Series
Rev. 10 Jan 03AMPSS® Reference Manual
18
Application Examples
AC Input Design
Parallel Connection Design
Rev. 10 Jan 03 AMPSS® Reference Manual
Specifications
19
Mechanical Information
Dimensions
The dimensions are given in mm (inches). Note that the
baseplate must be connected to protective earth before
power is supplied to the module.
BM80A High Power Performance Series
Rev. 10 Jan 03AMPSS® Reference Manual
20
Mechanical Information
Dimensions of BM80A-300L-021F100 and
BM80A-300L-033F90
The dimensions are given in mm (inches). Note that the baseplate must
be connected to protective earth before power is supplied to the module.
Rev. 10 Jan 03 AMPSS® Reference Manual
Specifications
21
Recommended PCB Layout
The BM80A High Power Performance Series module may
be mounted to a board either by soldering or by using
spring sockets.
Materials :
Control pins are tin plated phospher-bronze.
Input and output pins are tin plated copper.
BM80A High Power Performance Series
Rev. 10 Jan 03AMPSS® Reference Manual
22
The BM80A High Power Performance Series module may
be mounted to a board either by soldering or by using
spring sockets.
Materials :
Control pins are tin plated phospher-bronze.
Input and output pins are tin plated copper.
Recommended PCB Layout - BM80A-300L-021F100 and BM80A-300L-
033F90
Rev. 10 Jan 03 AMPSS® Reference Manual
Specifications
23
Heatsink Mounting Information
Heatsinks for AMPSSTM modules are available in a variety
of sizes and fin orientation. Mounting kits and thermal pads
are also available. The table below shows the options
available for BM80A High Power Performance Series.
A heatsink mounting kit provides the most convenient way
to mount the heatsink to the module and then mount the
assembly onto a circuit board
Description Model Number Dimensions Free air thermal
inches mm resistance
Heatsink, "80" size, vertical fin. APA501-80-001 4.53x2.32x0.6 115x59x15 2.7°C/W
Heatsink, "80" size, horizontal fin APA501-80-002 4.53x2.32x0.6 115x59x15 2.4°C/W
Heatsink, "80" size, vertical fin. APA501-80-003 4.53x2.32x0.9 115x59x22.5 2.2°C/W
Heatsink, "80" size, horizontal fin APA501-80-004 4.53x2.32x0.9 115x59x22.5 2.0°C/W
Heatsink, "80" size, vertical fin. APA501-80-005 4.53x2.32x1.5 115x59x37 2.0°C/W
Heatsink, "80" size, horizontal fin APA501-80-006 4.53x2.32x1.5 115x59x37 1.7°C/W
Heatsink, "80" size, low profile APA501-80-007 4.55x3.50x0.5 115.6x89x12 2.2°C/W
Thermal Pad, "80" size APA502-80-001
Mounting Kit, Tapped Studs APA503-00-001
Mounting Kit, Solder Studs APA503-00-002
Mounting Kit, Tapped Studs APA503-00-007
for low profile heatsink
Mounting Kit, Solder Studs APA503-00-008
for low profile heatsink
Spring Sockets (20 cont. 15pwr) APA504-00-001
12
To provide optimal thermal contact between heatsink and module, it is recommended that the mating surface of the
heatsink should have a surface flatness of no greater than 0.1mm. The use of a thermal pad or thermal grease is also
recommended.
AMPSSTM modules may be retained by their input and
output pins only, or may be fixed to the board using bolts
screwed into the tapped studs which are provided as part of
the mounting kit. In both cases the studs provide clearance
between the module and the circuit board to facilitate PCB
cleaning operations.
Note: 1) Baseplate and heatsink must be connected to protective earth
2) Mechanical support must not induce twist in the module baseplate and must incorporate strain relief,
e.g. spring washers.
The recommended torque of using AMPSS mounting kit for module/heatsink is:
Torque sequence:
It is assumed that all four mounting screws are being torqued to a common surface.
Other thermal management schemes are at customer discretion as long as the maximum thermal rating of the specific
module is not exceeded.
Screw size Torque
M3 4-6kg-cm (3.5-5.2 lb-in)
M3.5 6-8kg-cm (5.2-6.9 lb-in)
NORTH AMERICA
ASTEC AMERICA, INC,.
5810 Van Allen Way,
Carlsbad CA 92008,
USA.
Tel : 760-930-4600
Fax : 760-930-0698
EUROPE
ASTEC EUROPE LTD.
Astec House, Unit 9
Waterfront Business Park,
Merry Hill, Dudley
West Midlands,
DY5 1LX
U.K.
Tel : 01384-842211
Fax : 01384-843355
ASIA
ASTEC AGENCIES LIMITED
Units 2111 - 2116, Level 21
Tower 1, Metroplaza
223, Hing Fong Road
Kwai Fong,
N.T.
Hong Kong
Tel : 852 2437-9662
Fax : 852 2402-4426
APA701-BM80 Rev. 10 Jan 03
For further information contact :