Vicor PRM-AL User Manual

USER GUIDE | UG:003

PRM-AL Customer Evaluation Boards

Contents Page

Introduction 1

Board Overview 2

Recommended 4
Hardware

Initial Set Up 4

Baseline Test 4
Procedure

VTM Evaluation Board 8

The DC-DC 9
Converter Chip Set

Ordering 9
Information

Introduction

A Factorized Power Architecture oers a fundamentally new and improve d approach
to distributed power. Factorizing DC-DC power conversion into its basic functions
– isolation and transformation on the one hand and output voltage control and
regulation on the other – and arranging those functions in a sequence maximizes
power system performance and cost eectiveness. VTM® modules put isolated
current multiplication and voltage division directly at the Point of Load (POL), and an
upstream PRM®.

non-isolated regulator controls the Factorized Bus voltage supplied to the VTM to
provide line and load regulation. With this architecture, the Factorized Bus voltage
can be relatively high; distribution losses can be minimized with narrower copper
traces; and the PRM may be located at any convenient location, either adjacent to or
remote from the VTM. PRMs operate from a wide variety of input sources to drive
VTMs. VTMs are extremely fast and quiet and provide voltage division ratios as high
as 32. VTMs enable the user to eciently supply up to 100 A from each full VI Chip®
package at regulated output voltages as low as 0.8 Vdc or higher, as needed.

With FPA, only a VTM is needed at the POL. VTMs, unimpeded by serial inductance,
feature very high bandwidth and extremely fast transient response, allowing
energy to be stored eciently at the relatively high Factorized Bus voltage. Without
bulkcapacitors at the POL, precious board real estate may be reclaimed for essential
functions. The density, eciency, performance, cost-eectiveness, and architectural
superiority of FPA make it the least intrusive form of distributed power and facilitate
the development of more advanced, competitive products.

The PRM may be used as a stan dalone non-isolated regulation stage, whereas the VTM
is intended to be used with a PRM.

IMPORTANT NOTICE:

Be sure to read this design guide manual thoroughly before using this product.
Pay attention to all cautions and warnings.

The Customer Evaluation Boards described in this document are intended to acquaint
you with the benefits and features of a Factorized Power Architecture (FPATM). They
are not designed to be installed in end-use equipment.

During operation, the power devices and surrounding structures can be operated safely
at high tem peratures.

n Remove power and use caution when connecting and disconnecting test probes

and interface lines to avoid inadvertent short circuits and contact with hot surfaces.

n When testing electronic products always use approved safety glasses. Follow good

laboratory practice and procedures.

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Figure 1.

PRM-AL mounted

to PRM-CB board

Please take a closer look at the PRM-CB board.

Figure 1 is a picture of a PRM-AL mounted to the PRM-CB board.

The board has several features that enable the user to fully explore the capabilities of the
PRM-AL:

Board Overview

1. Source voltage input points are designed to accommodate #10 hardware and

Panduit ring lugs.
BE CERTAIN THAT THE POLARITY IS CORRECT BEFORE APPLYING POWER.

2. Auxiliary control (H01) - access points for PR, IL, TM, PC, and VH,
(header shown installed).

3. Reference test point Signal Ground (SG).

4. Adjustment potentiometers for indicated function are used in conjunction with

actuation of corresponding switch in Item 5.

5. PRM® port connections (switch bank and silk screen reference).

a. Toggling the switch indicated PC to the ON position inhibits the PRM output.

b. Toggling the switch indicated IL to the ON position enables an adjustable current
limit eected by varying the corresponding IL trim pot (Item 4).

c. Toggling the switch indicated SC to the ON position enables adjustment of the
output voltage down from the set point determined by the OS resistor by varying
the corresponding SC trim pot (Item 4). CAUTION: depending upon the initial
output voltage set point determined by the OS resistor it is possible to trim the SC
so low that the output shuts o. The minimum output voltage per the data sheet
is 26 Vdc.

d. Toggling the switch indicated CD to the ON position places the PRM in Adaptive
Loop regulation mode (for use with the VTM-CB) from the Local Loop regulation
mode. (In Local Loop mode the set voltage is regulated at the output terminals
of the PRM.) Adjusting the corresponding CD trim pot (Item 4) changes the gain
of the loop to compensate for dierent OS settings and/or interconnect
resistive losses.

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e. Toggling the switch indicated OSV (OS Variable) to the ON position requires the
switch indicated OSF (OS Fixed) be placed in the OFF position and allows the
PRM® output set point to be varied within the range specified on the data sheet.

f. Toggling the switch indicated OSF to the ON position sets the output of the PRM
to the nominal value indicated on the data sheet. If this switch is in the OFF
position and the OSV switch is also OFF, the unit will not function.

g. IT IS BEST TO SET THE SWITCH POSITION AND CORRESPONDING TRIM POT

SETTINGS BEFORE APPLYING POWER TO THE BOARD.

6. Test point for Secondary Control (SC).

7. Output voltage points are designed to accommodate #10 hardware and

Panduit ring lugs.

8. Output connector (J01) for mating with VTM-CB providing Vout and VC. As shown
on the schematic (Figure 2) there are four pins dedicated to the + Out, four for the

-Out, and two for the VC. Each contact is rated for 3 A. The excess capacity aorded
by these pins can facilitate testing multiple VTM-CBs from a single PRM-CB using an
appropriate wiring harness and mating connector. This may also be achieved using
the large pads of Item 7.

9. Output scope jack (J02). Headers H01 and J01 are 0.100" spacing, 10 position female,
manufactured by Sullins Electronics and available from Digi-Key as part # S5519-ND.

Figure 2.

PRM-CB schematic diagram

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