Vicor DC MegaPAC DC-DC Switcher User Manual

Rev. 3/04 Vicor 800-735-6200 Mission Power Solutions [phone] (phone) or [phone] (fax) [e-mail]

DC MegaPAC™
DC-DC Switcher

Operator’s Manual

and

“Quick Install” Instructions

www.mpwrs.com

Pg. 2 Vicor 800-735-6200 Mission Power Solutions [phone] (phone) or [phone] (fax) Rev. 3/04

DC MegaPAC Operator’s Manual

DC MegaPAC™

DC-DC Switcher

DC MegaPAC “Quick Install” Instructions

Mounting the DC MegaPAC

* The DC MegaPAC can be mounted on any of four sides.
* Use #8-32 or M4 mounting screws. Maximum penetration should not exceed 0.15" (3,8mm).
* Maintain 2" (5,1cm) clearance at either end for airflow.

Output Connections

Power Connections

Installing ring lugs and/or bus bars on output studs:

* The upper stud is Positive and the lower stud is the Return.
* Remove outer nut. Do not remove or loosen inner nut.
* Place ring lug over output stud.
* Replace and tighten outer nut to a maximum torque of 45 lb-in.

Do Not Over-Tighten Nuts.

Installing power connectors on DualPACs (J1A and J1B):

* Use Molex mating receptacle #39-01-2060 with #39-00-0039 terminals

provided.
* Pins 1 and 4 are Positive, while pins 2 and 5 are the Return.
* Attach terminals to 18-24 AWG stranded wire using Molex tool #11-01-0197.

Sense Connections

Sense connections must always be made. Failure to connect Sense lines can
cause failure to the unit.

Sense Connector J2:

* Sense connections do not have to be made if the Local Sense option has been

ordered. (An “L” in the ConverterPAC part number means the Local Sense

option has been installed; e.g. M5V/40AL.)
* Use Molex mating receptacle #50-57-9403 with #16-02-0103 terminals pro-

vided.
* J2-2 is the +Sense and J2-3 is the -Sense.
* Attach terminals to 22-24 AWG twisted pair wire using Molex tool #11-01-

0208.

* Attach opposite ends of Sense lines to point where regulation is desired.

* Verify that Sense lines are not cross-connected before applying input

power.

Sense Connections on DualPACs:

* Sense connections do not have to be made if the Local Sense option has been

ordered. (An “L” in the ConverterPAC part number means the Local Sense

option has been installed; e.g. D5V/20AL-12V/4.2AL.)
* Sense connections are available on the J2 connector or the J1A and J1B con-

nectors. Either can be used.
* If using J2 connector, see instructions above for “Sense Connector J2.”
* Pin 3 is the +Sense and Pin 6 is the -Sense.
* Attach terminals to 18-24 AWG twisted pair wire using Molex tool #11-01-

0197.

* Verify that Sense lines are not cross-connected before applying input

power.

DualPAC Output Connector

Pin
1
2
3

1&4 +Vout
2&5 -Vout
3 +Sense
6 -Sense

4
5
6

J1A & J1B

Sense Connector

Pin

1

1 Trim Pin Access

2

2 +Sense

3

3 -Sense

J2

DualPAC Output Connector

Pin
1
2
3

1&4 +Vout
2&5 -Vout
3 +Sense
6 -Sense

4
5
6

J1A & J1B

DC MegaPAC Operator’s Manual

Rev. 3/04 Vicor 800-735-6200 Mission Power Solutions [phone] (phone) or [phone] (fax) Pg. 3

Trim Pin Connection J2

* The Trim J2 connection should only be made if the Trim option has not

been installed. (A “T” or an “F” in the ConverterPAC part number
means the Trim option is installed; e.g. M5V/40AT.)

* Use Molex mating receptacle #50-57-9403 with #16-02-0103 terminals

provided.

* J2-1 provides Trim access.

DC OK (Power Good) Connection J3
* DC OK is only available as an option and is not always present.

* J3-4 is Vcc In , J3-3 is Power Good, J3-2 is Power Good inverted, and

J3-1 is Signal Ground.

* Use Molex mating receptacle #39-01-0043 with #39-00-0031 terminals

provided.

* Attach terminals to 22-28 AWG stranded wire using Molex tool

#57005-5000.

Input Connections

Input Power J9
* Input DC power is applied to solderless lugs on J9 using 2 AWG wire.
* Maximum torque is 25 lb-in.
* A fuse or circuit breaker is recommended in the input line.

Interface Connections J10

* Use 25 pin D-sub connector provided.
* J10-8 to 11 and J10-21 to 24 are Enable/Disable for slots 1-8.
* J10-16, 17 are Vcc, J10-12 and 15 are Signal Ground, J10-18 is AC

Power OK, and J10-5 is General Shutdown.

J10

Sense Connector

Pin

1

1 Trim Pin Access

2

2 +Sense

3

3 -Sense

J2

DC OK (Power Good)

J3

Pin

J3-4 Vcc

4
3

J3-3 Power Good

2

J3-2 Power Good Inverted

1

J3-1 Signal Ground

J10 INTERFACE CONNECTOR IDENTIFICATION
1 Signal Ground 14 No Connection
2 Signal Ground 15 Signal Ground
3 Overtemp. Warning 16 Vcc +5 volt, 300 mA
4 Analog Temperature 17 Vcc +5 volt, 300 mA
5 General Shutdown 18 Input Power OK
6 No Connection 19 Input Power Fail
7 No Connection 20 No Connection
8 Enable/Disable #8 21 Enable/Disable #7
9 Enable/Disable #6 22 Enable/Disable #5
10 Enable/Disable #4 23 Enable/Disable #3
11 Enable/Disable #2 24 Enable/Disable #1
12 Signal Ground 25 Gate Out Slot #8
13 Gate In Slot #1

1

14 15

2

3

16 17 18 19

5

7

6

20 21 22 23

8

9

10 111213

24 25

4

Amp 25 pin connector #746862-2
plug for flat ribbon cable. Mates with
housing Amp #747548-2 plus slide
latch or similar.

Pg. 4 Vicor 800-735-6200 Mission Power Solutions [phone] (phone) or [phone] (fax) Rev. 3/04

DC MegaPAC Operator’s Manual

DC MegaPAC™
DC-DC Switcher

Overview

The DC MegaPAC DC-DC switcher allows users to instantly configure high efficiency power supplies. Although
small in size (3.4"H x 6.0"W x 11.7"L), (85,8mm x 153,4mm x 296,7mm), the DC MegaPAC provides up to
1600W of output power with up to 16 isolated outputs.

A complete power supply is configured by selecting and inserting up to eight slide-in output assemblies called
“ConverterPACs.” ConverterPACs incorporate one or two Vicor DC to DC converters and are available in a wide
array of outputs and power levels. The net result is a power supply that offers the advantages of a custom supply,
but is assembled from standard and modular building blocks.

The entire family of MegaPAC power supplies is completely user-configurable. If output requirements change, i.e.,
more power or a different output voltage is needed, upgrading is easy: simply unlock a single screw and replace
the slide-in ModuPAC assembly with one that has the desired rating. For additional flexibility, ModuPACs can be
connected in parallel to increase output power (booster ModuPACs), or in series for higher voltages. The driver is
to the left of the boosters when looking at the output end of the supply. A user-friendly interface provides control
and output sequencing capability, in addition to useful status indicators. Please consult our Applications
Engineering Department if you have other special requirements.

Standard Features

• DC Input: 12 Vdc (10-20 Vdc), 24 Vdc (18-36 Vdc), 36 Vdc (21-56 Vdc), 48 Vdc (36-76 Vdc), 72 Vdc (55-100
Vdc)

• Output Power: 1600W; 1-16 outputs

• Full power output to 45°C; half power to 65°C

• Soft start for limiting inrush current

• Conducted EMI meets BTR 2511

• Output Sequencing and General Shutdown (Consult Applications Engineering for automatic sequencing

circuitry.)

• Remote Sense capability and output overcurrent protection on all outputs

• Output overvoltage protection on most outputs

• Output overtemperature protection on all outputs

• Vin OK status signal

• Input over, under and reverse voltage protection

• Box-to-box paralleling capability

• Input temperature monitor, warning, and shutdown

• CE Mark, UL, CSA

Optional Features

• DC OK status signal

• Output voltage adjustment range with built-in potentiometer

• Reversed fan airflow direction

• Industrial-grade screening of output converters

• Hardwired Local Sense

Rev. 3/04 Vicor 800-735-6200 Mission Power Solutions [phone] (phone) or [phone] (fax) Pg. 5

DC MegaPAC Operator’s Manual

Technical Description

The DC MegaPAC chassis consists of an EMI filter, cooling fan, customer interface and associated housekeeping circuits.
Input DC voltage (+VIN, -VIN, and GND) is applied to the input connectors. The input current is passed through an EMI
filter designed to meet conducted British Telecom specifications. At start-up, inrush current is limited by a thermistor. The
thermistor is shunted out shortly after initial power-up by a relay driven by a DC bus voltage sense circuit. The DC voltage
is then fed to the backplane. The backplane supplies power to a variety of ConverterPAC assemblies that provide the
desired low voltage, regulated outputs.

Voltage conversion in the output assemblies is achieved by Vicor's family of Zero-Current-Switching (ZCS) DC-DC con­verters. These are forward converters in which the main switching element switches at zero current. This patented topology
has a number of unique attributes: low switching losses; high frequency operation resulting in reduced size for magnetics
and capacitors; excellent line and load regulation; wide adjustment range for output; low EMI/RFI emission and high effi­ciencies.

At initial power-up, the DC MegaPAC outputs are disabled to limit the inrush current and to allow the DC bus potential to
charge to the operating level. A low-power flyback converter operating with PWM current-mode control converts the DC
bus into regulated low voltage to power the internal housekeeping circuits and DC cooling fan. When operating on 48 Vdc,
the internal housekeeping Vcc comes up within 3s after the application of input power. Once the input range is within speci­fication, the VIN OK signal asserts to a TTL "1" indicating the input power is OK, and allows the power outputs to be
enabled. The power outputs will be in regulation 500 ms after the Vin OK signal asserts to a TTL "1." An auxiliary Vcc out­put of 5 Vdc sourcing up to 0.3A is provided for peripheral use.

An output Enable/Disable function is provided by using an optocoupler to control the Gate In pins of the ConverterPAC
assemblies. If the Enable/Disable control pin is pulled low, the optocoupler turns on, pulling the Gate In pin low and dis­abling the ConverterPAC output. The nominal delay associated for an output to come up when measured from release of the
Enable/Disable pin is 5-10 ms. The General Shutdown function controls all outputs simultaneously and works in a similar
manner. If driven from an electromechanical switch or relay, a capacitor should be connected to eliminate the effects of
switch bounce.

There is no ride-through (holdup) time available with the DC MegaPAC.

Figure 1. DC MegaPAC Architecture

Pg. 6 Vicor 800-735-6200 Mission Power Solutions [phone] (phone) or [phone] (fax) Rev. 3/04

DC MegaPAC Operator’s Manual

ConverterPAC Functional Description

ConverterPACs are the family of slide-in output assemblies used in MegaPAC power supplies.
ConverterPACs are interchangeable within a MegaPAC so they can be added, moved, or changed
as necessary. They are also interchangeable between different AC input MegaPAC chassis. A
ConverterPAC removed from a Mini MegaPAC could be used in a 3 Phase MegaPAC, for exam­ple. ConverterPACs can be selected with a variety of options and in voltages from 2 to 95 Vdc.

ModuPAC

The ModuPAC output assembly consists of a VI-200 DC to DC converter that converts the high
voltage bus to the desired regulated output voltage. Each ModuPAC can provide up to 200 watts
of power. Multiple ModuPACs can be paralleled in a driver-booster configuration to provide more
power. ModuPACs are fused with a PC-Tron, DC-rated, fast-acting fuse. Apassive LC filter is used
to reduce output ripple/noise down to 1% typical, and 2% maximum peak-to-peak from 10% to
100% of rated load. An optional DC Power Good signal, or output voltage Trim potentiometer can
be specified. The ModuPAC contains overvoltage protection (OVP), overcurrent protection (OCP),
and overtemperature protection (OTP). The OCP has automatic recovery when the overcurrent
condition is removed. The OVP and OTP are latching functions and require recycling of the AC
input power to restart.

DualPAC

This output assembly consists of two VI-J00 DC to DC converters that convert the high voltage
bus to the desired regulated output voltages. Each output on a DualPAC can provide up to 100
watts of power and is fused with a single PC-Tron, DC-rated, fast-acting fuse. A passive LC filter
is used to reduce output ripple/noise down to 1% typical, and 2% maximum peak-to-peak from
10% to 100% of rated load. An optional output voltage Trim potentiometer can be specified. DC
Power Good signal is not available. The DualPAC contains overcurrent protection, which recovers
automatically when the overcurrent condition is removed. Overvoltage and overtemperature

protection are not available.

JuniorPAC

The JuniorPAC consists of one VI-J00 DC to DC converter that converts the high voltage bus to
the desired regulated output voltage. JuniorPACs can provide up to 100 watts of output power and
are fused with a single PC-Tron, DC-rated, fast-acting fuse. A passive LC filter is used to reduce
output ripple/noise down to 1% typical, and 2% maximum peak-to-peak from 10% to 100% of
rated load. An optional DC Power Good signal or output voltage Trim potentiometer can be spec­ified. The JuniorPAC contains output overcurrent protection, which recovers automatically when
the overcurrent condition is removed. Overvoltage and overtemperature protection are not avail­able.

RAMPAC

This output assembly consists of a VI-J00 DC to DC converter with a Ripple Attenuator Module
(RAM) and is designed for applications requiring low output ripple/noise. The RAMPAC can
attenuate the ripple/noise down to 10 mV peak-to-peak over a 20 MHz bandwidth from 10% to
100% of rated load of the converter. Each RAMPAC can provide up to 100 watts of output power,
and outputs from 5V to 50V are available. An optional DC Power Good signal or output voltage
Trim potentiometer can be specified. The RAMPAC contains output overcurrent protection, which
recovers automatically when the overcurrent condition is removed. Overvoltage and overtempera­ture protection are not available.

Configuring and Reconfiguring MegaPACs

ConverterPACs can be easily added, replaced, or moved by sliding the assemblies in or out of a MegaPAC chassis.
Most ConverterPACs are driver ModuPACs and can be inserted into any available slot. For outputs greater than
200 watts, a driver ModuPAC and one or more booster ModuPACs will be used. Arrays of drivers and boosters

Figure 2. ModuPAC

Figure 3. DualPAC

Figure 4. JuniorPAC

Figure 5. RAMPAC