VICOR MicroPAC User manual

vicorpower.com Applications Engineering: 800 927.9474 Page 1
Westcor
MicroPAC
USER GUIDE | UG:102
March 2013
Before Using the MicroPAC Power Supply
Be sure to read this design guide manual thoroughly before using this product.
Pay attention to all cautions and warnings.
Incorrect usage could lead to an electrical shock, damage to the unit or a fire hazard.
Warning
nDo not operate the without a secure protective earth (PE) lead
connected to the input power connector.
nDo not operate the MicroPAC with AC input without inserting
a correctly rated Vac fuse.
nDo not operate the MicroPAC with DC input without inserting a correctly
rated Vdc fuse.
nDo not obstruct the fan air intake or air exhaust.
(Care should be taken when connecting cabling).
nDo not connect or disconnect the output +Out or –Out cabling
while the MicroPAC is in operation.
nAlways make sure the output screws are properly torqued [15 inch-lb]
before applying power.
Contents Page
Mechanical
Considerations 2
Product
Description 2
Technical
Description 4
Output Power
De-rating Curve 5
MicroPAC to MicroPAC
Configuration 6
Power Shed Mode 7
Power Shed Mode
Functional Description 8
No Load
Power Dissipation
with and without
Power Shed Mode 9
Field Replacement Unit 10
Customer Interface 12
J2 Customer
Interface Signals 13
Mechanical 16
Front Panel 17
Model
Numbering Scheme 18
Specifications 19

vicorpower.com Applications Engineering: 800 927.9474 Page 2
Mechanical Considerations
The MicroPAC power supply can be mounted on four of the six surfaces using
standard 6-32 screws with a maximum torque of 7 inch-lb.
When using the mounting points the maximum insertion depth of the screw
into the chassis from the outside surface must not exceed 0.125”.
When considering a mounting location and/or orientation it is important not
to restrict the air flow entering and exiting the MicroPAC. Air is drawn into the
MicroPAC through the fan guard located next to the input power connector at the
rear of the power supply and exhausts through the load side of the power supply
next to the LED display panel. Westcor recommends a minimum clearance of 2”
be kept at the front and rear of the MicroPAC.
Care should be taken to minimize the output cabling as not impede the air
exhausting from the MicroPAC, the output screw securing the cabling to the
output terminals should be torque to 15 inc-lb not to exceed 20 inc-lb.
Product Description
The MicroPAC is a factory configurable power supply providing up to 1,300 W of
continuous power in a small slimline 1 u package. The power supply provides
up to 4 isolated outputs and combines power factor correction along with high eciency
and power density. The MicroPAC boasts a power density of 25 Win3and eciency up
to 92%, the power supply is available in a wide temperature range configuration and
for harsh environments and mil-cots applications conformal coated. All configurations
carry full safety agency approvals i.E. Ul60950 en60950 and are CE marked.
The MicroPAC power supply platform supports a wide range of customer power
requirements and is especially suited for distributed power architectures. The design
oers a small flexible cost-eective solution for applications requiring high eciency
and power density. The isolated outputs may be placed in parallel/series configurations
with automatic current sharing. For applications requiring higher power levels the
MicroPAC's can be configured in arrays with box to box current sharing.
Applications Include
nFactorized power architectures nPrinting
nDistributed bus architectures nMIL-COTS applications
nIndustrial nTelecommunications
nAutomation equipment nRenewable energy
Standard Features
nHigh eciency up to 92% nOutput series capability
nSmall Size nOutput current sharing
nHigh power density (25 W/In3) nMicroPAC to MicroPAC current sharing
nUp to 1300 W nPower shed capability
(Configuration dependent) nVibration MIL-STD 810-F
nLow power standby mode Figure 514.5C-17
(Green mode) nOvertemperature warning
nUniversal Input nOvertemperature shutdown
(85 to 264 Vac) (47 to 400 Hz)

vicorpower.com Applications Engineering: 800 927.9474 Page 3
Standard Features (Cont.)
nDC Input (120 to 300 Vdc) nIntelligent fan control
nUp to 4 isolated outputs nField replaceable fan
nVisual LED display panel nIndividual output enable / disable
nStandard 12 V output nAll output enables / disable capability
nStandard 14 V output nTTL control signal
nStandard 24 V output nVisual LED display panel
nStandard 28 V output nVisual LED display panel
nStandard 36 V output nShock MIL-STD 810F
nStandard 48 V output Method 516.5 procedure 1
n5 V @250 mA Isolated Aux Supply nWave, 40G 11 mS
nOutput parallel capability nTemperature Range
-20°C to +55°C (+65°C @ 50% load)
Optional Features
nExtended temperature range
-40ºC to +55ºC operation (+65°C @ 50% load)
nConformal coated
nPower shed Mode
AML Approved Manufacturing List
VAC Volts Alternating Current
VDC Volts Direct Current
BCM Bus Converter Module
PE Protective Earth
LED Light Emitting Diode
EMI Electro-Magnetic Interference
FPA Factorized Power Architecture
FRU Field Replaceable Unit
GSD General shutdown
MTBF Mean Time Between Failure
NTC Negative Temperature Coefficient
PFC Power Factor Correction
PCB Printed Circuit Board
PS Power Supply
MicroPAC MicroPAC
PSM Power Shed Mode
PC Performance Criteria
RoHS Restriction of Hazardous Substances
Acronym Term
Table 1.
Acroynm Defintitions

vicorpower.com Applications Engineering: 800 927.9474 Page 4
PFC Control
+12 V
+5 V
Smart Fan
controller
FAN
Temp detecon on
Boost heatsink
T
Microcontroller
PIC program
Port
+5 V+12 V
+12 V
Interface Connector
1) +5.0 Vdc
2) OV
3) ED 1
4) Over Temp Warning
5) ED 3
6) AC_OK
7) Standby Mode
8) General Shutdown
9) Fan Fault
10) ED 2
11) N/C
12) ED 4
LED Indicators
Reverse logic
BCM_1
ED/1
ED/2
ED/3
ED/4
GSD
Standby Mode
AC_OK
Fan Fault
Over Temp
20 MHz
EMI Filter
House Keeping
Bridge Recfier
85 – 264 Vrms 47 –400 Hz
120 –300 Vdc
External 15 A fuse required
DC
AC
MicroPAC Chassis
PE
PE
PE BCM_1
BCM_1
BCM_1
Boost ConvertersSo Start
Isolated Output
Isolated Output
Isolated Output
Isolated Output
Isolated +5 Vdc / 500 mA
+12 V
+5 V
BCM control
Technical Description
The MicroPAC power supply is designed to operate using a single phase voltage source
input between 85 Vrms and 264 Vrms or 120 to 300 V dc source. The basic building
blocks of the MicroPAC are an EMI filter, Power Factor Correction stage, cooling fan, and
housekeeping, associated microcontroller circuits along with customer interfaces and
galvanic isolated outputs and control signals.
Figure 1.
Simplified
MicroPAC
Block Diagram

vicorpower.com Applications Engineering: 800 927.9474 Page 5
Output Power De-rating Curve
The MicroPAC is designed to operate from a single electrical phase; as such it can be
operated directly from a normal wall outlet socket. These sockets are normally rated
for 12 A continuous current draw and 15 A peak current draw. With this in mind it is
necessary to institute a power de-rating curve to maintain the operational range of the
MicroPAC within these boundaries.
80 90 100 110 120 130 140150160170180 190200210 220230
850
895
940
985
1030
1075
1120
1165
1210
1255
1300
Output Power (Watts)
AC Input (Vrms)
Output Power (W)
Figure 2.
Output Power De-rating Curve
vs.
AC Input Voltage

vicorpower.com Applications Engineering: 800 927.9474 Page 6
MicroPAC to MicroPAC Configuration
The MicroPAC power supply’s with the same output voltages can be placed in parallel
arrays by connecting the output positive (+) and return (-) rails to the respective positive
and return rails of the next MicroPAC. If individual Micro-PAC’s are configured in an
array it is necessary to make sure all MicroPAC are powered up at the same time. Where
possible the same AC source should be used to power all MicroPAC's in the array.
Pin 2 0 V (+5 V return) of the customer interface connector should be daisy chained
together on each MicroPAC in the array. The GSD signal Pin 8 should also be daisy
chained together and be used to turn on all outputs at the same time. The current
sharing is achieved by using the droop sharing method and produces in the order of 5
–10% current sharing accuracy (contact factory for details). It is important to note that
following good cable routing and symmetry is critical for good current sharing and load
balancing.
Pin 8 should be connected to Pin 2 on power up of the array. This will ensure all outputs
are held in the disabled state. Upon successful power up of the array Pin 8 should be
released and le open circuit, allowing all the outputs to be enabled.
Figure 3.
MicroPAC to MicroPAC
Configuration

vicorpower.com Applications Engineering: 800 927.9474 Page 7
Power Shed Mode
Introduction to the MicroPAC Power Shed Mode
The aim of the power shed mode is to increase the overall light load eciency of the
MicroPAC. This is achieved by minimizing the power dissipation when light load or no
load conditions are present on the MicroPAC output.
The original concept of improving light load eciency for VI Chip Bus Converter arrays
was developed by Mr. Ankur Patel (Vicor Product Line Engineer).
The following is an alternative method of power shedding
incorporated within the MicroPAC.
Power Shed Mode Prerequisites
nSlots 1 to 4 must be populated
nAll outputs must be the same voltage
nAll slots must be configured in a parallel array
nCurrent rate slew rate not to exceed 20.8 A/s
nThe PSM is not suitable for constant dynamic loads
Configuring Power Shed Mode
The Power Shed Mode is factory configured.
Power Shedding Bands
There are four operational modes for the power shedding scheme.
1 0.0 – 250 W Output 1, active
2 250 – 500 W Output 1 and 2, active
3 500 – 750 W Output1, 2 and 3 active
4 750 – 1200 W / 1300 W Output 1, 2, 3 and 4 active
Table 2.
Connector Kit
(19-130066)
Material List
Category Customer Load Output

vicorpower.com Applications Engineering: 800 927.9474 Page 8
Power Shed Mode Functional Description
On power up with the power shed function enabled all four output channels are initially
enabled, channel one to four LED’s should be illuminated. Circuitry internal to
the MicroPAC monitors the amount of current drawn from the MicroPAC and is
proportional to the customer load.
If the load falls into category 1, the following will be observed.
Aer 5 seconds output 4 will turn o, aer 10 seconds output 3 will turn o,
aer 15 seconds output 2 will turn o.
If the customer load falls into category 2, the following will be observed.
Aer 5 seconds output 4 will turn o, aer 10 seconds output 3 will turn o,
output 1 and 2 will remain on.
If the customer load falls into category 3, the following will be observed.
Aer 5 seconds output 4 will turn o, output 1, 2 and 3 will remain on.
If the customer load falls into category 4, all output will remain on.
Output 1
Output 2
Output 3
Output 4
Off
Off
Off
Off
Off
Off
Off
On
On
On
On
5 sec
5 sec
5 sec
10 sec
15 sec
Category 1
Output 1
Output 2
Output 3
Output 4
Off
Off
Off
Off
Off
Off
On
On
On
On
5 sec
5 sec
10 sec
Category 2
Output 1
Output 2
Output 3
Output 4
Off
On
On
On
On
5 sec
Category 3
Output 1
Output 2
Output 3
Output 4
On
On
On
On
Category 4
Off
Off
Off
Off
Off
Off
Off
Off
Figure 4.
Power Shed

vicorpower.com Applications Engineering: 800 927.9474 Page 9
Shoot First, Ask Questions Later
When the MicroPAC is operating in categories 1 to 3 and detects an increase in load
current applied to the output which incurs into the next power band the internal
microcontroller will turn all outputs on, regardless of the actual amount of load added.
(Shoot first ask question later) with all the outputs enabled, the microcontroller will
turn o redundant outputs
In the Power Shed Mode this is a constant cycle of detecting output load and continually
adjusting the outputs to satisfy that need.
No Load Power Dissipation with and without Power Shed Mode
1234
5
7.5
10
12.5
15
17.5
20
22.5
25
27.5
30 7.06
7.055
7.05
7.045
7.04
Power Shed Mode Disabled
Power Shed Mode Enabled
Number of BCM’s
Power (Was)
Power (Was)
1234
5
8
11
14
17
20
23
26
29
32
35 8.26
8.255
8.25
8.245
8.24
Power Shed Mode Disabled
Power Shed Mode Enabled
Number of BCM’s
Power (Was)
Power (Was)
Figure 5.
No Load Power Dissipation @
25°C with 12 V Output
With the power shed enabled
the average power dissipation
is about 7.05 W
With the power shed disabled
the power dissipation
is around 28.20 W
Figure 6.
No Load Power Dissipation @
25°C with 48 V Output
With the power shed enabled
the average power dissipation
is about 8.25 W;
With the power shed disabled
the power dissipation
is around 33 W.

vicorpower.com Applications Engineering: 800 927.9474 Page 10
Field Replacement Unit
Figure 6.
Fan Assembly
1 1 ASSY FAN AVC DV-12M 40X28MM 14.4 CFM 10-130240-01
2 1 ASSY FAN SANYO DENKI -40C J-SPEED 40X28MM 18.4 CFM 10-130241-01
Table 3.
Field Replacement Unit
Westcor
Item QTY Description Part Number