Flex ROA128 6016 User manual

Evaluation Board User Guide BMR474
ROA 128 6016
USER GUIDE

Test Board User Guide BMR474
28701-ROA1286016 Rev A 2021/4/25 2 (20)
Copyright
© Flex 2021. All rights reserved
Disclaimer
No part of this document may be reproduced in any form without the written
permission of the copyright owner.
The contents of this document are subject to revision without notice due to
continued progress in methodology, design and manufacturing. Flex shall have no
liability for any error or damage of any kind resulting from the use of this
document.
Trademarks
All trademarks are properties of their owners.
Flex is the trademark of Flextronics International.
PMBus™ is a trademark of SMIF, Inc.
Windows® and Microsoft® are the trademarks of Microsoft Corporation in the
United States or other countries.

Test Board User Guide BMR474
28701-ROA1286016 Rev A 2021/4/25 3 (20)
Contents
1 Introduction ............................................................................................4
1.1 How to contact Flex..................................................................................4
1.2 Prerequisites ............................................................................................4
2 Reference Board ROA 128 6016 ...........................................................5
3 USB-PMBus adapter .............................................................................. 7
3.1 Connection of Flex KEP 910 17 USB-PMBus adapter.............................7
4 Power-up and Power-down Instructions .............................................7
4.1 Power-up instruction ................................................................................7
4.2 Power-down instruction............................................................................8
5 Address
and VSET Resistor..................................................................9
5.1 Adjustment of address resistor.................................................................9
5.2 Adjustment of VSET resistors ..................................................................9
6 Test
points..............................................................................................
9
7 Additional
Input/output Capacitance .................................................10
8 Electronic loads ................................................................................... 10
9 Schematic .............................................................................................
11
10 Bill
of Materials.....................................................................................11
11 Layout
description...............................................................................12
11.1 PCB stack-up summary .........................................................................12
11.2 Input capacitance ...................................................................................14
11.3 Output capacitance ................................................................................14
12 Layout
top view ....................................................................................
15

Test Board User Guide BMR474
28701-ROA1286016 Rev A 2021/4/25 4 (20)
1 Introduction
This User Guide provides a brief introduction and instruction on how to use the
Reference Board ROA128 6016 together with one BMR4742001 module
mounted.
1.1 How to contact Flex
For general questions or interest in our products, please contact your local sales
representative. Contact details are available from our website:
flexpowermodules.com
1.2 Prerequisites
In order to operate the ROA 128 6016 board, the following is needed:
Power supply 6 – 15 V.
USB-PMBus adapter Flex KEP 910 17. It is only needed when the PMBus
shall be used.
The “Flex Power Designer” software package and a compatible Windows
PC.

Test Board User Guide BMR474
28701-ROA1286016 Rev A 2021/4/25 5 (20)
62
1
13
89
89
13 7
111
10
14
4
10
12 32
5
2 Reference Board ROA 128 6016
In Figure 1a and 1b, the top and bottom sides of the ROA 128 6016 are shown.
Figure 1a. ROA 128 6016 (top side)

Test Board User Guide BMR474
28701-ROA1286016 Rev A 2021/4/25 6 (20)
Figure 1b. ROA 128 6016 (bottom side)
Position Description (Top Side)
1 Input
voltage connectors.
2 Output voltage connectors.
3 Power Good LED.
4 ENABLE
switch.
5 Connector for the USB-PMBus adaptor (KEP 910 17).
6 SMB Oscilloscope connectors for Vin ripple measurement
7 SMB Oscilloscope connectors for Vo ripple measurement
8 Input electrolytic and ceramic capacitors.
9 Output Polymer and ceramic capacitors.
10 Pin-strap resistors and jumper for Vout setting
11 Pin-strap resistors for PMBus address
12 PMBus, SYNC and EN signal probing points
13 Input voltage probing points
14 Output voltage probing points
Position Description (Bottom Side)
15 Output Polymer capacitors
17
16
18 19
15
17

Test Board User Guide BMR47401
28701-ROA1286016 Rev A 2021/4/25
7 (20)
16 Diode for input anti-reverse protection
17 Positions for populating Flex electronic load, ROA128 5552.
18 Positions for additional input ceramic capacitors
19 Positions for additional output ceramic capacitors
3 USB-PMBus adapter
The USB-PMBus adapter used with this board is the Flex KEP 910 17.
3.1 Connection of Flex KEP 910 17 USB-PMBus adapter
Connect the Flex KEP 910 17 USB-PMBus adapter to the PMBus
header, see position 5 in Figure 1a.
4 Power-up and Power-down Instructions
4.1 Power-up instruction
Before power up, read the following table to make sure the module works in the
best condition.
Note: The default switching frequency (f
sw
) is 500kHz, if the module work with
output voltage higher than 1.8V, frequency shall be changed, f
sw
change should
be done by using “Flex Power Designer” software tool.

Test Board User Guide BMR47401
28701-ROA1286016 Rev A 2021/4/25 8 (20)
Model Iout max Switching frequency
V
in/Vout range
BMR 474 2001
0.6V≤Vo ≤1.8V
Iomax=80A
1.8V < Vo ≤3.3V
Iomax=60A
0.6V≤Vo ≤1.8V
fsw =500kHz
1.8V < Vo ≤3.3V
fsw =800kHz
Vin =6-15 V
0.6V≤Vo ≤2.5V
Vin=7.5-15V
2.5V < Vo ≤3.3V
Make sure Enable switch is set to OFF position
By default, the module is configured to set Vout with pin-strap resistors.
Make sure jumper in the position 10 is populated with desired Vout.
Connect power supply to connectors on position 1.
Connect load to connectors on position 2.
Connect the PMBus adapter/cable to the board.
Apply Vin = 6-15V through connectors on position 1.
Set Enable switch to ON position. The power good LED will give green
light.
Note: PG LED is powered by USB-PMBus adapter, so only connect demo
board with computer through adapter, LED will be lit when module Vout is
ready.
Then increase the load, and through K2 (position 7) to measure the Vout
and ripple.
4.2 Power-down instruction
Set Enable switch to OFF position
Turn off Vin

Test Board User Guide BMR47401
28701-ROA1286016 Rev A 2021/4/25
9 (20)
R4 and R5
5 Address and VSET Resistor
5.1 Adjustment of address resistor
To change the address, change the resistor shown in Figure 2. Change R4
and R5 (position 11) to achieve the desired PMBus address for the
module.
Refer to chapter ‘PMBus addressing’ in the technical specification to select
the proper values.
Figure 2 Address resistor position, R4 and R5, is shown in the picture.
5.2 Adjustment of VSET resistors
Populate a jumper in each “Vset” position to get the desired output voltage. The
silk screen marking shows the voltage settings that can be achieved by populating
jumpers.
6 Test points
Input voltage should be measured at test points VIN/GND, which are
connected directly to the VIN / GND pin of the module.
Output voltage should be measured at test points VO/GND, which are
connected directly to the VO/GND pin of the module.

Test Board User Guide BMR47401
28701-ROA1286016 Rev A 2021/4/25
10 (20)
additional output
capacitors
additional input
capacitors
7 Additional Input/output Capacitance
At the bottom side, there are places for additional input/output capacitors.
Figure 3 Places for additional input/output capacitors.
8 Electronic loads
In order to perform load transient tests on the modules, up to 2 pcs of PuLS loads
can be connected to the output of the board.

Test Board User Guide BMR47401
28701-ROA1286016 Rev A 2021/4/25
11 (20)
The PuLS loads (ROA 128 5552) can be programmed for different transient loads
and waveforms, see the technical specification for further information. The PuLS
loads can be easily connected through the sockets. (see position 17 in Fig 1b)
9 Schematic
See schematic of Board ROA 128 6016 for more information.
10 Bill of Materials
Designator Qty Description
C1, C47 2 CAP ALUM 470uF 20% 25V SMD
C6,C7,C8,C9,
C43,C44,C45,C46,C48,C49
10 330uF 10% 6.3V polymer,CAPACITOR
C23,C25 2
CAP TANT POLY 10uF 35V 2917
C2,C3,C4,C5 4
22uF 10% 1210 25V X7R,CAPACITOR

Test Board User Guide BMR47401
28701-ROA1286016 Rev A 2021/4/25 12 (20)
C10,C11,C12,C13,C14,C15,
C16,C17,C18,C19,C20,C21
12 100uF 10% 1210 6.3V X7S,CAPACITOR
C22,C50 2
100nF 10% 0805 25V X7R,CAPACITOR
C24,C26 2
100nF 10% 0603 25V X7R,CAPACITOR
DC1 1
LED, green
J7,J8 2
PMBus connector
L1,L2,L3,L4,L5,L6 6
Ferrite Bead
R5, R16 2 0ohm 0603 ,RESISTOR, -55C~155C
R4 1 68.1kohm 1% 0603 0.1W,RESISTOR, -55C~155C
R6 1
6.65kohm 1% 0603 0.1W,RESISTOR, -55C~155C
R8 1
115kohm 1% 0603 0.1W,RESISTOR, -55C~155C
R20 1
6.34kohm 1% 0603 0.1W,RESISTOR, -55C~155C
R21 1
37.4kohm 1% 0603 0.1W,RESISTOR, -55C~155C
R30 1
46.4kohm 1% 0603 0.1W,RESISTOR, -55C~155C
R28,R25,R32 3
64.9kohm 1% 0603 0.1W,RESISTOR, -55C~155C
R23 1
162kohm 1% 0603 0.1W,RESISTOR, -55C~155C
R31 1
412kohm 1% 0603 0.1W,RESISTOR, -55C~155C
R10,R11,R12 3
10kohm 1% 0603 0.1W,RESISTOR, -55C~155C
R14,R15 2
180ohm 1% 0603 0.1W,RESISTOR, -55C~155C
R17,R18 2
100kohm 1% 0603 0.1W,RESISTOR, -55C~155C
T1,T2 2
nfet_d3-g1-s2, BSS123, sot23
D1 1
VS-43CTQ100SPBF,100V,2x20A,
D2PAK(TO-263AB)
11 Layout description
The following sections describe how the layout guidelines provided in the ROA
128 6016. Technical Specification have been applied to the reference board
layout. The purpose is to give the reader a better understanding of the guidelines
by examples. Please note that every system is different and that there may well
be considerations to make which are not provided here, depending on the system
requirements and limitations set in the end application
11.1 PCB stack-up summary
Layer Description Thickness
Top layer VIN, VOUT, PGND planes
Component footprints, signal traces
2 oz

Test Board User Guide BMR47401
28701-ROA1286016 Rev A 2021/4/25
13 (20)
Layer 2 VOUT, PGND plane, signal traces 2 oz
Layer 3 VIN, VOUT, PGND planes 2 oz
Bottom layer VIN, VOUT, PGND planes
Component footprints, signal traces
2 oz
Figure 4 Connection of power pins on top layer

Test Board User Guide BMR47401
28701-ROA1286016 Rev A 2021/4/25 14 (20)
11.2 Input capacitance
The ceramic input capacitors should be placed as close as possible to the
VIN/PGND pins to minimize the connection impedance. For the same reason,
multiple vias are placed close to the capacitors’ terminals, utilizing inner layers to
connect to input pins of the module.
Note there are places for additional input capacitors on the bottom side of the
board, see section 7.
Placement and connections of the larger bulk input capacitor (used mainly to hold
up the input voltage during large load transients or changes in input voltage)
follows the rules of the ceramic capacitors described above.
11.3 Output capacitance
Ceramic output capacitors are placed close to VOUT pins of the module to handle
the module’s output ripple. Polymer capacitor are added to take care of load
transient, see Technical Specification for load transient performance. It is
important to secure low impedance connections
Note there are places for additional output capacitors on the bottom side of the
board, see section 7.
Furthermore, it is important to use planes to distribute the output current to the
load in order to minimize losses and the effective output impedance, providing
good conditions for the module’s control loop to compensating for load transient.
See layout top view of ROA 128 6016 for more information.

Test Board User Guide BMR47401
28701-ROA1286016 Rev A 2021/4/25
15 (20)
12 Layout top view
Top side component layout

Test Board User Guide BMR47401
28701-ROA1286016 Rev A 2021/4/25
16 (20)
Top layer

Test Board User Guide BMR47401
28701-ROA1286016 Rev A 2021/4/25
17 (20)
Layer 2

Test Board User Guide BMR47401
28701-ROA1286016 Rev A 2021/4/25
18 (20)
Layer 3

Test Board User Guide BMR47401
28701-ROA1286016 Rev A 2021/4/25
19 (20)
Bottom Layer

Test Board User Guide BMR47401
28701-ROA1286016 Rev A 2021/4/25
20 (20)
Bottom side component layout