Vicor Half-chip PRM-RS Customer Board User Manual

UG:008 vicorpower.com Applications Engineering: 800 927.9474 Page 1

The half-chip PRM-RS Customer Board described in this document is designed for use with the
Remote Sense (RS) family of half-chip PRMs, and demonstrates the benefits of Factorized Power
Architecture™. This demonstration board is not designed for installation in end-user equipment.
The system demonstrates the use of a PRM Regulator and a VTM

®

Current Multiplier for general

laboratory evaluation only.

Please read this document before setting up a customer demonstration board.

The User Guide is not comprehensive and is not a substitute for common sense and good
practice. For example:

1. When testing electronic products always use approved safety glasses.

2. Provide a strain relief for wires and place the system on the bench in such a way as to prevent
accidental dislodgment from the bench top.

3. Remove power and use caution when connecting and disconnecting test probes and interface
lines to avoid inadvertent short circuits and contact with hot surfaces.

4. Never use a jumper in place of the fuse. Replace the fuse only with its equivalent type
and rating.

5. Never attempt to disconnect the demonstration board from a VTM Customer Board while
power is applied. This system is not designed to demonstrate hot plug capability.

1.0 Introduction

The half-chip PRM-RS Customer Board can be used to demonstrate a stand-alone regulator or in
conjunction with a VTM Customer Board to enable demonstration of a Factorized Power
Architecture (FPA) system. There are many combinations possible using PRM

®

and VTM Customer
Boards, but the focus in this user guide is using one PRM Customer Board and one VTM
Customer Board. The half-chip PRM Customer Board can be configured for local sensing (at the
PRM output), or non-isolated remote sensing (at the VTM output). The half-chip PRM Customer
Board is nominally configured for local sensing where the voltage feedback circuit regulates the
output voltage of the PRM. Implementing remote sensing requires component changes and
rework to the board which is detailed in section 8.3.

1.1 Part Numbers and Ratings

Refer to the specific PRM data sheet for ratings of the device. It is important to remain
within the device limits when testing.

1.2 Contents

The half-chip PRM-RS Customer Board arrives with the following contents:

1. 1 x half-chip PRM-RS Customer Board fully populated

2. 1 x 11mm VI Chip

®

push pin heat sink

3. 2 x VI Chip push pins for heat sink installation

4. 2 x VI Chip push pin heat sink grounding clip

5. 2 x 10 pin male to male headers

Half-chip PRM®-RS Customer Board User Guide

Contents Page

Introduction 1

Features 2

General 2 – 4

Schematic 5

Bill of Material 7

VTM Boards 8

Testing 10

Modifications 16

Conclusions 19

USER GUIDE | UG:008

For use with PCB part number: 35307

UG:008 vicorpower.com Applications Engineering: 800 927.9474 Page 2

2.0 Features

The half-chip PRM-RS Customer Board has the following features:

1. Input and output lugs for source and load connections

2. Input fuse (appropriately rated)

3. Input capacitor for source decoupling

4. Test points for access to various device pins and circuit voltages

5. Trim pot for adjusting the output voltage set point

6. Voltage regulation, and current sensing circuitry appropriately set for proper operation

7. Recommended output filter inductor

8. Dual output headers (female) for transferring power and signal connections to downstream
VTM

®

Customer Board.

9. Switch for enabling / disabling the device through the PC pin

10. Oscilloscope probe jack for making accurate output voltage measurements

11. Provisions for installing custom VI Chip

®

push pin heat sink with grounding clips (optional,

included with board)

3.0 Board Description

The following section provides a detailed description of the half-chip PRM-RS Customer Board
components and test points.

Figure 1

Board Description

UG:008 vicorpower.com Applications Engineering: 800 927.9474 Page 3

3.1 General Components

Refer to Figure 1 and Figure 2:

1. Input Lugs: Sized for #10 hardware. Use these for making connections to the input source.

This board does not contain reverse polarity protection. Check for proper polarity before
applying power.

2. Half-chip PRM-RS module (PS01)

3. Input Fuse (F01): 10 A rated

4. Input Capacitor (C01): 100 µF, 63 V capacitor allows for stable operation with

most input sources.

5. Enable / Disable Switch (S01): Dual switch with the following functionality:

a. S01_1 (Top): Spare switch. Wired to H07 and H06 on the PRM signal test point header (#6)
to allow for extra functionality if needed. Both positions are open and not connected

anywhere else on the board.

b. S01_2 (Bottom): PC enable switch. When in the right position (ON), the PC pin will be

connected to –IN and the device will be disabled. When in the left position, PC will be
open, and the device will be enabled.

6. Signal Test Point Header: Dual row of plated through hole test points for making measurements

or connections to the signals labeled.

7. VTM

®

Signal Test Point Header: Plated through holes for measuring VTM signals returned

through connector X03. For use only with VTM Customer Boards containing dual headers.

8. Output Lugs: Sized for #10 hardware. Use these lugs to connect the output directly to the load

9. Signal Connector (X03): Used to transfer the VTM PC, IM, TM, and output sense signals

between the PRM and VTM Customer Boards. For use only with VTM Customer Boards
containing dual headers. Refer to Figure 2 for pinout.

10. Power / Signal Connector (X01): Used to transfer power (+/-Out) and VC to downstream VTM

Customer Board when used. For use with all VTM Customer Boards. Refer to Figure 2 for pinout.

11. Output Oscilloscope Probe Jack (J01): Used for making accurate scope measurements of the

output voltage (i.e. ripple). Remove scope grounding lead and insert probe directly into jack
ensuring a good connection between the jack and the probe ground barrel. Do not attempt to
install while power is applied. May not be compatible with all scope probes.

Figure 2

Power / Signal Connectors Pinout,

Front View

-OUT

-OUT

+OUT

-OUT

VC

+OUT

2

+OUT

+OUT

1

VC

-OUT

VS-

VS+

VTM -IN

NC

TM-VTM

NC

PC-VTM

IM-VTM

2

1

Power / Signal Connector (10)

X01

X03

Signal Connector (9)

UG:008 vicorpower.com Applications Engineering: 800 927.9474 Page 4

12. Output Voltage Trim Pot (R22): 11 turn trim pot adjusts the output voltage by increasing or

decreasing the error amplifier reference voltage (V

REF). Turn clockwise to increase the output

voltage, and counterclockwise to decrease the output voltage. Adjustment slot is

1.5 mm (L) x 0.6 mm (W).

13. High Side Current Sense Circuit (R

08, Q02): Current sense shunt and IC monitor the output

current and provide feedback to the IF pin for current limit protection. Gain is typically 400
mV/A, and is set for appropriate current limit set point. IF signal can be monitored at the
Signal Test Point Header (#6) to provide approximate output current measurement, but should
not be used if accurate output current measurements are required (<10% error). Efficiency
measurements should always be performed using an external calibrated shunt.

14. Output Inductor (L01): 0.4 uH inductor provides high AC impedance between PRM

®

and VTM

®

(when used) to prevent high- frequency switching currents from circulating between devices.

15. Voltage Sense and Error Amplifier (U09A, U09B): Dual op amp provides voltage sensing and

error amplifier function. The customer board is nominally configured for local voltage sensing
at the PRM output. U09B can be re-configured as a differential amplifier to allow for
non-isolated remote sensing at the VTM output or load. This requires rework as described in
Section 8.3.

16. Push Pin Heat Sink and Grounding Clip Mounting Holes: Use these holes for installing the

optional push pin heat sink and grounding clips included with the board.
Use of a heat sink is highly recommended for appropriate cooling of the PRM.

3.2 Test Points

In addition to the Signal Test Point Headers (#6, #7), there are a number of surface mount test
points on the board with the following functions.

1. V

IN+, VIN- (TP01, TP03): Input voltage test points provide Kelvin connections to the input

leads. Use these test points for measuring the input voltage to avoid error due to interconnect
losses.

2. V

OUT+, VOUT- (TP04, TP05): Output voltage test points provide Kelvin connections to the

output leads. Use these test points for measuring the output voltage to avoid error due to
interconnect losses.

3. Signal Ground (TP01): Signal Ground (SG) test point is the ground reference for all control

circuitry.

4. VS+, VS- (TP10, TP11): +/- sense inputs to the differential amplifier when remote sense is

implemented. When used with a VTM Customer Board, the sense leads may be wired to the
VTM output voltage through X03 depending on which VTM board is used. If not, a twisted
pair of wires can be used to connect sense leads to the VTM board output from these test
points.

UG:008 vicorpower.com Applications Engineering: 800 927.9474 Page 5

4.0 Schematic, Assembly and Bill of Material (BOM)

4.1 Schematic

Figure 3: Half-chip PRM-RS Customer Board Schematic

P01

TM-VTM

X03

IM-VTM

PC-VTM

H12

H11

H13

12345678910

32770

Vout+

Vout-

J0

VS- VS+

Vvtm_out-

R03

TP01

2

3

S01 SW DIP-2

1

4

H07 H06

H10

H08

VS

H09

TP18

TP13

C01

IF

NC4

15

16

VS

PO

TP16

GND

RE

11

14

12SG13

IM

RE

VC

PRM-RS

PC

TP19

H05

PC

PR

TP17

H04

1

RE

TM3NC4NC5NC

2

6

Vref

NC2

NC1

TP12

TM

H03

H01

PR

H02

TP15

C02

TP14

NC3

GND

R02

P02

8mR08

TP08

TP04

10

7

TP02

TP06

F01

VIN+

0
8

2

X01

PRMOUT

2512

+OUT

+IN

C05

29207-010

P03

91
7
56
3 4
1

32770

IF

9

–OUT

–IN

8

100u

VIN-

R09

TP09

TP05

TP03

TP07

P04

RE

Q02

OUT

1

0

PS01

FD2

FD1

0.1uH

L02

4

5

V+

HS01

FID UCIA L

FID UCIA L

2

GND

GND

GND

Vout-

4

VIN-

VIN+

3

1206

10

R10

SOT 23_5

VIN-

C07

R16

Vs-

Vs+

VS-

VS+

PRMOUT

TP10

TP11

54.9k

R29

R24

OPEN

OPEN

R40

1.24k

1.24k

R23

R30

GND

6

5

U09B

7

C10

R28

C13

Vref

R25

R31

R42

Vref

2

GND

3

48

U09A

1

R27

0 OHM

VS

GND

C11

R22

10k

C08

R32

1206

OPEN

U03

RE

3

C12

GND

T

IN

OUT2O

SOT 23_3

1

C14

GND

REF3312 Regulator (1.25V)

PR

UG:008 vicorpower.com Applications Engineering: 800 927.9474 Page 6

Figure 4

Half-chip PRM-RS

Customer Board

Assembly Drawing

4.2 Assembly Drawing