ALLEGRO A4919 Evaluation Board User Guide

: June 13, 2024
: ALLEGRO

Table of Contents

DESCRIPTION
FEATURES
EVALUATION BOARD CONTENTS
USING THE EVALUATION BOARD
Controlling the Motor
SCHEMATIC
LAYOUT
BILL OF MATERIALS
RELATED LINKS
APPLICATION SUPPORT
Revision History
Documents / Resources

A4919 Evaluation Board
User Guide

DESCRIPTION

This board provides the basic components required to use the A4919 to drive a motor. The motor can be controlled via an externally supplied PWM signal input on the logic input terminals. The circuit diagram is shown on page 6 of this guide.
The maximum current limit for the board is 10 A, and it is important to keep the maximum current below this value.
All information on how to use this board is described in this guide as well as the full circuit schematic. The component placement and layout are shown on pages 7 through 9.

FEATURES

28-pin QFN package A4919GETTR-T gate driver
5 V on-board voltage regulator
High-current three-way connector for motor connection
High-current two-way connector for supply connection
Fault display LED
Eight-position DIP switch for manual control of logic inputs

EVALUATION BOARD CONTENTS

A4919 evaluation board with A4919 device soldered on.

Table 1: General Specifications

Specification	Min.	Nom.	Max.	Units
Board Current Limit	–	10	20 (peak)	A

USING THE EVALUATION BOARD

Board Setup and Operation
In order to run a motor using the A4919 evaluation board, the following items are required:

A4919 evaluation board
External motor supply (5.5 to 50 V)
External method of switching the outputs (e.g., PWM signal generator)
A typical connection diagram is shown in Figure 2. The A4919 evaluation board can be used in conjunction with an external microcontroller using the logic input terminals.
Board Connections
The A4919 evaluation board has four connectors.
X1: A single three-way screw connector for the motor connections
X2: One two-way screw connector for the main supply
X3: One two-way connector that provides the supply from the 5 V on-board voltage regulator
X5: A 26-pin IDC cable connector to interface to an external microcontroller (X5)
Note : X4 connector is not used for this product variant.

Power Connections

A positive supply between 5.5 and 50 V should be connected to X2 (labelled VBAT). The supply return is labelled PGND at X2.
The power source for the motor phase current must be capable of providing the necessary continuous input current at the required input voltage to drive the motor up to the board current limit plus an inrush current. The motor supply voltage must not exceed 50 V in any conditions, otherwise permanent damage may occur to the A4919, other components on the board and possibly the motor. In normal operation, the current limit of the supply should be set to twice the maximum operating current for the motor being driven.
The two-way connector X3 provides an output for the 5 V LDO voltage for biasing external circuitry. The voltage of this connector can be measured via the VBIAS test point. If this voltage is not required, then J1 can be removed from the evaluation board.
The VDDM pin is a logic voltage monitor input, and this pin must be connected to the on-board 5 V regulator U2. The voltage of the regulator can be sensed on the VU2 test point.
Load Connections
A three-phase BLDC motor is connected through the three-way screw terminal, X1, labelled A, B, and C. Each letter represents the phase connection and has the same potential as the respective Sx terminal.
The current to drive the motor is provided via the three-phase MOSFET bridge from the main supply connected to X2.
Control Connections
The control of the evaluation board can be achieved by an externally generated PWM signal applied to connector X5.
The positive signal level needs to be connected to any of the X5 terminals:
X5.9, X5.10, X5.11, X5.12, X5.13, X5.14, according to which channel needs to be driven.
The return path must be connected to any GND terminals of the evaluation board namely GND2 or GND3.
Alternatively, there is an on-board DIP switch, S1, which might be used to set the control logic inputs AHI, ALO, BHI, BLO, CHI, and CLO.
More information on how to use the board can be found in the next sections.

Setting up for First-Time Use
Before operating the evaluation board for the first time, it should be set into a safe condition to avoid overcurrent stress to any components or attached load. The jumpers should be in their default position as shown in Table 1 and all switches on S1 should be in the off position.
Set the Supply Current to the Minimum
Before connecting the supply for the first time, ensure the supply current limit is set to a low value to avoid unexpected current caused by any component or load problems—300 mA is recommended when the motor is connected.
After connecting the power supply to VBAT (connector X2), the power supply current should be less than 5 mA at 12 V without any load/motor connected.
Once the supply voltage and current have been checked, the board is ready for use.
Initial Functionality Check
Before connecting the motor to the board, an initial check of the board supplies will confirm your connections are correct. This can be accomplished following the sequence below:

Power-up the board via VBAT (start with 12 V).
Check VBAT supplies the correct voltage to VBB. This can be done by measuring either the positive side of the C5, or the side connected to the VBB pin from the J5 jumper.
Check VBAT supplies the correct voltage to VBRG, by measuring the voltage on terminal VBRG. This will also confirm that J10 is correctly placed.
Set S1 DIP 7 (VDDM) and S1 DIP 1 (AHI) to the on position and confirm VREG is within the datasheet specification by measuring the voltage on the VREG test point.
Confirm LED1 FAULT is not illuminated. Faults are explained under the Diagnostics section of the product datasheet.
Check the state of each control logic input corresponds to its respective S1 DIP switch setting.
For example, when AHI is commanded on (S1 DIP 1 is in the on position or PWM signal being high), then the AHI terminal should go to high (5 V) and when it is commanded off (S1 DIP 1is in the off position, or PWM signal being low, then the AHI terminal should be low (0 V).

If all of the above is as expected and specified within the product datasheet, the next step is to connect the motor to the board.

Important Additional Notes

For the A4919 to come out of sleep mode and operate, two conditions should be satisfied.

A voltage greater than the gate drive disable threshold VGDD (typically 1.5 V as defined in the Electrical Characteristics table of the A4919 datasheet) should be present on pin 20 (VDDM). Otherwise, the charge pump is turned off and all gate drive outputs will remain disabled.
One or more logic inputs should be switched on, either via the S1 DIP switch or an external PWM signal.

Table 2: Default jumper connections

Jumper	Terminal Detail	Default Setting
J1	Enable output to connector X3	Short
J2	Configures VBIAB as 5 V	VU2 position
J3	VBB supply to on-board 5 V regulator	Short
J4	Enable output to connector X4	Open
J5	Supply voltage to VBB input	Short
J6	Connect VU1 to VDDM	Short
J7	Fault pin pullup; if a fault is present, the internal pull-down is off,
and the FAULT output is pulled up to approximately VB[AB	Short
J8	Enable input to VDSTH programming pin	Short
J9	VDSTH Programming selection: Internal hardwired value / Disabled / Voltage
select using pot R15	INT position
J10	VBB supply to VBRG pin	Short

Controlling the Motor

The A4919 can control the motor by switching the outputs on and off. There are two ways to achieve this: either by controlling the inputs of the A4919 via a PWM signal or via the S1 DIP switch which will keep the outputs 100% on or off.
Before driving the A4919, ensure that the PWM signal is set up according to the user timing requirements, i.e., frequency, duty, etc.
The expected outputs for a PWM control are shown in Figure 3.

EVALUATION BOARD PERFORMANCE DATA
The board is rated for up to 10 A of DC current. This value should not be exceeded.

SCHEMATIC

LAYOUT

BILL OF MATERIALS

Table 3: Axxxxx Version Evaluation Board Bill of Materials

ELECTRICAL COMPONENTS

Designator| Quantity| Description| Manufacturer| Manufacturer Part Number| PCB Label
CI. C8| 2| Capacitor: Mu Electrolytic Radial| Mu!beam| MCMR2S/I06M4X7| Cl. C8
C2| 1| Capacitor: Mu Electrolytic SMT| Panasonic| EEEFP1E100AR| C2
C3. C4| 2| Capacitor: Ceramic Chip| Multicomp| MC12068105K250CT| C3. C4
C5| 1| Capacitor: Ceramic Chip| KEMET| C0805X224K5RACTU| C5
C6| 4| Capacitor: Ceramic Chip| Murata| GRM21BR71H224KAO1L| C6
C7. C17| 1| Capacitor: Ceramic Chip| Murata| GCJ21BR71H474KAl2L| C7. C17
C9. C10| 2| Capacitor: Ceramic Chip| KEMET| C0805C104K5RACTU| C9. C10
011. 012,
C13. C18| 2| Capacitor: Ceramic Chip| Panasonic| ECA1HHG102| Cll. C12.
C13. C18
C14. C15. C16| 3| Capacitor: Ceramic Chip| KEMET| C0805X224K5RACTU| C14. C15.
C16
D2| 4| Diode: 100 V. 0.15A| Diodes| 1N4148W-7-F| D2
GND1| 1| Test Point: 1.4 mm Round Loop. Black| Keystone
Electronics| 5001| GNDI
GND2. GND3| I| Ground Bar: Tinned Copper Wire| Multicomp| TCVV20 500G| GND2. GND3
J1. J3, -14, -15,
.16. J7. J8. J10| 2| Jumper: Header Male 2-pin| Hanvin| M20-9990246| JI, J3, J4. J5.
-16. -17. -18.-110
J2, J9| 8| Jumper: Header Male 3-pin| Amphenol| G800W305018EU| .12…19
LED1| 2| LED: SMT. 2-pin, Red| ams OSRAM| LS M676-P2S1-1| LED1
Ml, M2. M3.
M4. M5. M6| 1| MOSFET: N-Channel. 56k 55 V| Inlineon| IFtFR2405TRPBF| Ml. M2. M3.
Md, M5, M6
PCB| 6| PCB: A4919GET Demo Board EDC158R0| | | PCB
1| 5| Transistor: NPN. 50 V. 0.5 A| Nexperia| 8C817-25.215| 1
R3. R4, R5.
R6. R7, R8.
R9, RIl| 1| Resistor: Ceramic Chip| Multicomp| MCMR08X1001FTL| R3. R4. R5.
R6. R7. R8.
R9. R11
R10| 1| Resistor: Ceramic Chip| Multicomp| MCMR08X1002FTL| R10
R12| 8| Resistor: Ceramic Chip| TT Welwyn| WCR0805-270KFI| R12
R13. R14| 1| Resistor: Ceramic Chip| Multicomp| MCMR08X4701FTI| R13. R14
R15| 1| Resistor: Trim Pot. 3296Y. 25 kfl| Boums| 3296Y-1-253LF| R15
R16. R18.
R20. R22.
R24. R26| 2| Resistor: Ceramic Chip| Multicomp| MCMR08X22ROFTL| R16, R18,
R20. R22.
R24. R26
R17. R19.
R21. R23.
R25. R27| 1| Resistor: Ceramic Chip| Multicomp| MCMR08X4703FTL| R17. R19.
R21. R23.
R25. R27
R30| 1| Resistor: Ceramic Chip| Multicomp| MCSRO8X3301FTL| R30
R31. R38| 2| Resistor: Ceramic Chip| Multicomp| MCSRO8X1003FTL| R31. R38
SI| 1| Resistor: Ceramic Chip| Grayhill| 78808ST| S1
U1| 1| Allegro Motor Driver| MiaosystemsAllegro| A4919ET| U1
U2| 1| Voltage Regulator 5 V| TI| LM2936HVBMA-5.0/NOPB| L/2
Designator| Quantity| Description| Manufacturer| Manufacturer Part Number| PCB Label
---|---|---|---|---|---
X1| 1| Connector: Screw Terminal, 3-way, 30 A| Phoenix
Contact| 1731734| X1
X2| 1| Connector: Screw Terminal, 2-way, 30 A| Phoenix
Contact| 1731721| X2
X3, X4| 2| Connector: Screw Terminal, 2-way, 20 A| Weidmuller| PM5.08/2/90BLK| X3, X4
X5| 1| Connector: IDC 26-way Ribbon Header| 3M| N2526-6002-RB| X5
AIII, ALO, BHI,
BLO, CA, CB,
CC, CHI, CLO,
FAULT, GHA,
GHB, GHC,
GLA, GLB,
GLC, LSS,
SA, SB, SC,
VBIAS, VBRG,
VDSTH,
VREG, VU1,
VU2| | Test point
VBRG, VDSTH,| Keystone
Electronics
CB, CC, CHI, CLO, FAULT, GHA, GHB, SC, VBIAS,| 5000
GHC, GLA,| AIII, ALO,
BHI, BLO, CA,
C
G
GLB, GLC,
LSS, SA, SB,
VREG, VU1,
VU2
JMP_
SHORT_R| 10| Jumper Short Link: Red| Harwin| M7566-05|
ESDBAG_6x8| 1| ESD bag 6″ x 8″| Desco SCS| 10068|

Product page and information: https://www.allegromicro.com/en/products/motor- drivers/bldc-drivers/a4919

APPLICATION SUPPORT

For technical support, contact Allegro using the email addresses on this page: https://www.allegromicro.com/en/about-allegro/contact-us/technical- assistance
For sales support, contact Allegro by filling in the form on this page: https://go.allegromicro.com/contact-sales
For any other enquiries, use the information of this page: https://www.allegromicro.com/en/about-allegro/contact-us

Revision History

Number	Date	Description
–	26-Jun-23	Initial release

Copyright 2023, Allegro MicroSystems.
Allegro MicroSystems reserves the right to make, from time to time, such departures from the detail specifications as may be required to permit improvements in the performance, reliability, or manufacturability of its products. Before placing an order, the user is cautioned to verify that the information being relied upon is current.
Allegro’s products are not to be used in any devices or systems, including but not limited to life support devices or systems, in which a failure of Allegro’s product can reasonably be expected to cause bodily harm.
The information included herein is believed to be accurate and reliable. However, Allegro MicroSystems assumes no responsibility for its use; nor for any infringement of patents or other rights of third parties which may result from its use.
Copies of this document are considered uncontrolled documents.

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