MR-BMS771 Reference Design

“

Product Information

Specifications:

Product Name: MR-BMS771 Reference Design
Manufacturer: NXP Semiconductors

Model Number: UM12287
Components: MC33771C, S32K1 MCU, NTAG 5 NFC interface

Features: 14-channel Li-ion battery cell controller, CAN, NFC,
display

Product Usage Instructions:

1. Introduction

This document serves as the user manual for the MR-BMS771
reference design. It is designed for engineers involved in the
evaluation, design, implementation, and validation of the
components included in the reference design.

2. Finding Kit Resources

NXP Semiconductors provides online resources for the reference
design on their website. You can find more information at http://www.nxp.com/MR_BMS771.

3. Getting Ready

Before using the MR-BMS771 reference design, ensure you have the
kit contents, additional hardware, and required software.

3.1 Kit Contents

The kit contents include the MR-BMS771 board and necessary
accessories for operation.

3.2 Additional Hardware

In addition to the kit contents, you may need additional
hardware to fully utilize the features of the reference design.

3.3 Software

Software installation is essential for working with the
MR-BMS771 reference design. The required software can be downloaded
from http://www.nxp.com/MR-BMS771.

FAQ (Frequently Asked Questions):

Q: What is the purpose of the MR-BMS771 reference
design?

A: The MR-BMS771 reference design is intended
for engineers to evaluate, design, and validate battery management
systems using specific NXP components.

Q: Can the reference design be used in a finished
product?

A: No, the reference design is meant for
engineering development and evaluation purposes only and is not a
finished product.

Q: Where can I find more information and resources
related to the MR-BMS771 reference design?

A: Additional information can be found on the
NXP website at http://www.nxp.com/MR_BMS771.
You can also join the NXP community for further discussions and
support at http://community.nxp.com.

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UM12287
MR-BMS771 reference design
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User manual

Document information

Information

Content

Keywords

BMS771, battery management, MR, S32K146, MC33771, UJA1169, NTAG 5, SE051, Mobile Robotics, CAN, NFC, display

Abstract

This user manual describes package contents, programing environments, instructions, board block diagram, and configurations.

NXP Semiconductors

UM12287
MR-BMS771 reference design

1 Introduction
This document is the user manual for the MR-BMS771 reference design. This document is intended for the engineers involved in the evaluation, design, implementation, and validation of MC33771C, 14-channel Li-ion battery cell controller, S32K1 MCU and NTAG 5 near-field communication (NFC) interface.
The scope of this document is to provide the user with information that covers interfacing with the hardware, install the GUI software, using other tools, and configure the board for the application environment.

Figure 1.MR-BMS771 board

IMPORTANT NOTICE
For engineering development or evaluation purposes only
NXP provides this evaluation product under the following conditions:
Evaluation kits or reference designs are intended solely for technically qualified professionals, specifically for use in research and development environments to facilitate evaluation purposes. This evaluation kit or reference design is not a finished product, nor is it intended to be a part of a finished product. Any software or software tools provided with an evaluation product are subject to the applicable terms that accompany such software or software tool.
The evaluation kit or reference design is provided as a sample IC pre-soldered to a printed circuit board to make it easier to access inputs, outputs, and supply terminals. This evaluation kit or reference design may be used with any development system or other source of I/O signals by connecting it to the host MCU or computer board via off-the-shelf cables. Final device in an application will be heavily dependent on proper printed circuit board layout and heat sinking design as well as attention to supply filtering, transient suppression, and I/O signal quality. This evaluation kit or reference design provided may not be complete in terms of required design, marketing, and or manufacturing related protective considerations, including product safety measures typically found in the end device incorporating the evaluation product. Due to the open construction of the evaluation product, it is the responsibility of the user to take all appropriate precautions for electric discharge. To minimize risks associated with the customers’ applications, adequate design and operating safeguards must be provided by the customer to minimize inherent or procedural hazards. For any safety concerns, contact NXP sales and technical support services.

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MR-BMS771 reference design

2 Finding kit resources and information on the NXP website
NXP Semiconductors provides online resources for this reference design and its supported devices on http:// www.nxp.com.
The information page for the MR-BMS771 reference design is at http://www.nxp.com/MR_BMS771. The information page provides overview information, documentation, software and tools, parametric, ordering information and a Getting Started tab. The Getting Started tab provides quick reference information applicable to using the MR-BMS771 reference design, including the downloadable assets referenced in this document.
2.1 Collaborate in the NXP community
The NXP community is for sharing ideas and tips, ask and answer technical questions, and receive input on just about any embedded design topic.
The NXP community is at http://community.nxp.com.
3 Getting ready
Working with the MR-BMS771 requires the kit contents, additional hardware, and a PC workstation with installed software.
3.1 Kit contents
· Assembled and tested MR-BMS771 in an antistatic bag · Controller area network (CAN) bus termination resistor (DRONE-CAN-TERM) · Unmounted cell connectors for 8S to 14S with precrimped wires · 4-pin JST-GH to 4-pin JST-GH 300 mm cable (CAN) · Power input and power output connectors · External thermistor with cable · Small SSD1306 OLED display · Quick start guide · Small cell count selector interposer boards (7 cells to 14 cells) · An NFC antenna
3.2 Additional hardware
In addition to the kit contents, the following hardware is necessary or beneficial when working with this kit.
· Battery pack (7S to 14S with cell balancing connector), with a range of 15 V to 59 V and a current limit of 30 A DC (up to 30 A DC has been tested)
· Suitable charger for the battery · Soldering iron to configure the board · PEmicro multilink universal or SEGGER J-Link mini debugger or other suitable debugger · Optional: The DCD-LZ adapter Note: The MR-BMS771 board is able to open the charge circuit when the battery is overcharging. Therefore, the charger does not need to have a battery management system (BMS) connector.

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MR-BMS771 reference design

3.3 Software
Installing software is necessary to work with this reference design. All listed software is available on the reference design information page at http://www.nxp.com/MR-BMS771.
· S32 Design Studio for Arm-based MCUs (recommended) · Model-based design toolbox (MBDT) example (recommended)
4 Getting to know the hardware
4.1 MR-BMS771 overview
The MR-BMS771 is a standalone BMS reference design suitable for mobile robotics, such as drones and rovers, supporting 7 cells to 14 cells batteries.
The device performs analog-to-digital conversion on the differential cell voltages and currents. It is capable of accurate battery charge coulomb counting and battery temperature measurements. Also, it could communicate with a flight management unit (FMU) through DroneCAN/CyphalCAN and/or a system management bus (SMBus).
4.2 MR-BMS771 features
The MR-BMS771 integrates the following functions and features:
· Supports battery from 7S to 14S, with stack voltage ranging from 15 V to 59 V · Measures battery stack and cell voltages, battery charge or discharge current up to 30 A DC tested · Passive cell balancing option over ~66 balance resistors per cell · Offers a deep sleep mode (for transportation and storage) with low leakage current, and an automatic sleep
mode with low current consumption on the battery · Allows CAN, I2C and NFC communication · Implements serial wire debug (SWD) and joint test action group (JTAG) debugging interfaces, works with
standard J-Link and other debuggers · Implements DCD-LZ combined debug console interface for use with PX4 Dronecode and HoverGames
platforms

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MR-BMS771 reference design

4.3 Block diagram

Battery 15 V-59 V POWER IN +

MOS T°

NFC ant 1

NFC ant 2

Power switch

LDO1 3V3_LDO

12V_DCDC

VCC

Inp
GATE DRIVER (LTC7001)

GATE_IN

Flip-flop (74AUP1G79)

Vcc

Security (SE051)

NFC

(NTAG5)

RST_EN EN
SCL SDA SCL SDA HPD
ED

MAX5035DASA+ DC/DC
12 V 1 A
Enable
Ant.

12V_DCDC

Vout

TCKE712
BNL,RF
Switch +
OCP

15 V – 59 V POWER OUT +

12 V 1 A

12 V

External 12 V

3 V/5 V SCL SDA

Display/ I2C initiator

GPIO

ADC inputs /GPIOs
Temp (opt)
Battery cell terminals cell 1-14
Balance and sense wires

IO6 IO5 NTC GND CT14 CT13
CT2 CT1 CTref

GPIO GPIO GPIO

Cell select board

BCC14 (MC33771C)

GPIO GPIO

AFE T° Vout

GPIO

FAULT RESET CSB MISO MOSI SCLK

GPIO GPIO SPI_CS0 SPI_SIN SPI_SOUT SPI_SCLK

3V3_SBC
HW overcurrent

OR gates

MCU (S32K146)

12x GPIO

DEBUG

GND ISENSE_X
GPIO VSS

Battery POWER IN –

BGND

Shunt T° 0.5 m

External GPIOs SWD DEBUG

GPIO GPIO GPIO GPIO GPIO

RGB LED

SCL SDA GPIO GPIO

3V3_SBC

VDD CAN0_RX CAN0_TX SPI_CS SPI_SIN SPI_SOUT SPI_SCLK

V1 RXD TXD SCSN MISO MOSI SCLK

VCC 5V_SBC V2

push button

SBC

CANH

(UJA1169A)

CANL

R LED

CAN1_RX CAN1_TX

RXD TXD

SIC transceiver
(TJA1463

3V3_SBC

VIO

5V_SBC

VCC

CANH

CANL

SCLS SDAS

SMBUS/ I2CS peripheral

E-stop button

Emergency + button + OGND

CAN0_H

CAN0_L CAN0_H

Default CAN bus

CAN0_L

CAN1_H

CAN1_L CAN1_H

Signal improved (2nd) CAN bus

CAN1_L

LED

DCD_LZ DEBUG OGND

UART + programming
POWER OUT –

Battery GND (BGND)

(OGND) output GND

BMS BOARD

aaa-061040

Figure 2.Block diagram

4.4 MR-BMS771 board characteristics

The MR-BMS771 board has been designed and optimized for the operating conditions described in Table 1. Usage of the MR-BMS771 boards out of the range can lead to malfunction and damage.

Table 1.Maximum ratings Parameter
Battery input voltage Battery charge/discharge current (DC)[1]

Min

Max

Unit

–

[1] Up to 30 A DC has been tested with this board.

4.5 Featured components
Figure 3 and Figure 4 identify important components on the board.

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Ref D block diagram top
Power OUT system/charger
(J5)

Shunt resistor (R1)

DC/DC (U15)

C61

U10

U12 U11

LDO (U7)

BCC (U1)

M3 mounting holes

Power IN battery (J4)

Cell terminal (JP1)

Figure 3.Featured component placement block diagram (top)

12V_EXT (J29)

RGB LED (D1)

12 V SW (U26)
XTAL (Y1)

MCU (U2)

CAN1 (U17)

Q11 SBC (U3)

Button (SW1)
LED CAN0
LED CAN1

CAN1 (J27)

CAN0 (J3)

JTAG (J2)

DCD-LZ UART + prog (J19)

Unused pins (J21)
SE (U4)

NFC antenna

NFC 1 Batt.
Temp (J1)

NFC ant SE
(J7)

SMBusI2C S. (J18)

I2C M display (J23)
aaa-061041

Ref D block diagram bottom

PB_ESW E-stop (J29)

Power OUT system/charger
(J5)

CAN0 (J20)

CAN1 (J28)

NTAG5 (U5)

U30
U31
U32 Rbal Rbal Rbal

Gate driver (U6)
Rbal
Rbal Rbal
Rbal Rbal Rbal

Rbal

Rbal F8
Rbal

Rbal

NFC antenna
board

Cell count selector board MR-BMS771-SW (J32- J38)

NFC ant NTAG (J24)

F1 F3 F5 F7 F9 F11 F13 F15 IO5 opt. IO6 opt. temp 2 temp 3
(J39) (J40)

F10

F12

F14

Figure 4.Featured component placement block diagram (bottom)

Optional heat sink

Power IN battery (J4)

aaa-061042

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Power switch Q1 to Q6

Power out (J5)

Battery cell controller (BCC) (U1)
MCU

12 V

JTAG

(J26)

(J2)

RGB

(Start)

LED

button

Power in Shunt (J4) resistor (R1)

Cell terminal (JP1)

Figure 5.Featured component placement (top)

Batt NFC ant. NTC SE051 (J1) (J7)

LED_CAN0
LED_CAN1 CAN0A (J3) CAN1A (J27) DCD-LZ (J19)
SMBus-I2CS (J18) Display-I2C (J23)
NTAG NFC board antenna
aaa-061043

Pushbutton + SW E-stop (J29)

Power out (J5)

CAN0B (J20)
CAN1B (J28)

NTAG NFC board antenna

NFC ant. IO5 IO6 NTAG NTC NTC (J24) (J39) (J40)

1A cell fuses

Figure 6.Featured component placement (bottom)

Cell count Power in (J4) selection board
placement

The main featured devices are listed in Table 2:

Optional heat sink
aaa-061044

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Table 2.Featured devices

Label

Description

battery cell controller (BCC)

microcontroller unit (MCU)

system basis chip (SBC)

U4 U5[1]

security near-field communication (NFC)

U17

CAN signal improvement capability (SIC) transceiver

[1] The NTAG 5 chip is not installed for the first batch.

Reference MC33771CTP1AE FS32K146UAT0VLHT UJA1169ATK/F/3 SE051 NTA53321G10FHK TJA1463ATK

4.5.1 MC33771C: 14-channel Li-ion battery cell controller

4.5.1.1 General description
The MC33771C is a Li-ion battery cell controller IC designed for automotive applications, such as hybrid electric vehicle (HEV) and electric vehicle (EV) along with industrial applications, such as energy storage system (ESS) and uninterruptible power supply (UPS) systems.
The device performs analog-to-digital conversions of the differential cell voltages and current, as well as battery coulomb counting and battery temperature measurements. The information is digitally transmitted through the serial peripheral interface (SPI) or transport protocol link (TPL) to a microcontroller for processing.

4.5.1.2 Features
· 9.6 V VPWR 63 V operation, 75 V transient · 7 cells to 14 cells management · Isolated 2.0 Mbit/s differential communication or 4.0 Mbit/s SPI · Addressable on initialization · Bidirectional transceiver to support up to 63 nodes in daisy chain · 0.8 mV maximum total voltage measurement error · Synchronized cell voltage/current measurement with coulomb count · Averaging of cell voltage measurements · Total stack voltage measurement · Seven general-purpose input/output (GPIO)/temperature sensor inputs · 5.0 V at 5.0 mA reference supply output · Automatic overvoltage and undervoltage and temperature detection routable to fault pin · Integrated sleep mode overvoltage and undervoltage and temperature monitoring · Onboard 300 mA passive cell balancing with diagnostics · Hot plug capable · Detection of internal and external faults, such as open lines, shorts, and leakages · Designed to support ISO 26262, up to ASIL D safety system · Qualified in compliance with AEC-Q100

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4.5.2 Connectors

Power out (J5)

Power in (J4)
Figure 7.Connectors placements (top)

UM12287
MR-BMS771 reference design

MCU expansion header (J21)

12 V (J26)

Button jumper (J22)

Cell terminal (JP1)

Batt NFC ant. NTC SE051 (J1) (J7)

Reset jumper (J6)
CAN0A (J3) CAN1A (J27)
DCD-LZ (J19)
SMBus-I2CS (J18) Display-I2C (J23)
JTAG (J2)
aaa-061045

Pushbutton + SW E-stop (J29)

Power out (J5)

CAN0B (J20)
CAN1B (J28)

NFC ant. IO5 IO6 NTAG NTC NTC (J24) (J39) (J40)
Figure 8.Connectors placements (bottom)

Cell count Power in (J4) selection board
placement

aaa-061046

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Table 3.Reference design connector description

Label Description

Manufacturer

Reference

JP1

cell terminal connector

J.S.T. Mfg. Co., Ltd.

SxB-XH-A(LF)(SN)

external temperature sensor J.S.T. Mfg. Co., Ltd.

SM02B-GHS-TB(LF)(SN)

JTAG debugger

SMD header 10 position 0.050″/1.27 mm (several manufacturers, for example, FTS-105-01-F-D by Samtec)

CAN0 bus

J.S.T. Mfg. Co., Ltd.

SM04B-GHS-TB(LF)(SN)

battery power input

battery power output

XT90 connectors (several manufacturers, for example, FIT0588 by DFRobot)

reset jumper

FCI

68000-202HLF

SE051 antenna connector J.S.T. Mfg. Co., Ltd.

J18

SMBus (I2C peripheral bus) J.S.T. Mfg. Co., Ltd.

SM02B-GHS-TB(LF)(SN) SM04B-GHS-TB(LF)(SN)

J19

DCD-LZ debugger

J.S.T. Mfg. Co., Ltd.

SM07B-GHS-TB(LF)(SN)

J20

additional CAN0 bus

J.S.T. Mfg. Co., Ltd.

SM04B-GHS-TB(LF)(SN)

J21

MCU expansion header

Sullins Connector Solutions GRPB072VWVN-RC

J22

wake jumper

J23

I2C controller bus

FCI Würth Elektronik

68000-202HLF 61300411821

J24

NTAG 5 antenna connector J.S.T. Mfg. Co., Ltd.

SM02B-GHS-TB(LF)(SN)

J26

external 12 V output

J.S.T. Mfg. Co., Ltd.

SM05B-GHS-TB(LF)(SN)

J27

CAN1 bus

J.S.T. Mfg. Co., Ltd.

SM04B-GHS-TB(LF)(SN)

J28

additional CAN1 bus

J.S.T. Mfg. Co., Ltd.

SM04B-GHS-TB(LF)(SN)

J29

pushbutton and SW E-stop J.S.T. Mfg. Co., Ltd.

SM04B-GHS-TB(LF)(SN)

J30

cell select board 7S /

–

MRBMS771SW

J31

cell select board place /

–

MRBMS771INTERPOSER

J32

cell select board 10S /

–

MRBMS771SW

J33

cell select board 12S /

–

MRBMS771SW

J34

cell select board 13S /

–

MRBMS771SW

J35

cell select board 14S /

–

MRBMS771SW

J36

cell select board 11S /

–

MRBMS771SW

J37

cell select board 8S /

–

MRBMS771SW

Populated or DNP[1] DNP populated populated
populated DNP DNP DNP populated populated populated populated DNP DNP DNP populated populated populated populated populated –
DNP
–
–
–
–
–
–

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Table 3.Reference design connector description…continued

Label Description

Manufacturer

J38

cell select board 9S /

–

MRBMS771SW

J39

IO5 / ext. temp. sensor 2 J.S.T. Mfg. Co., Ltd.

J40

IO6 / ext. temp. sensor 3 J.S.T. Mfg. Co., Ltd.

Reference –

Populated or DNP[1] –

SM02B-GHS-TB(LF)(SN) populated SM02B-GHS-TB(LF)(SN) populated

[1] DNP: do not populate.
Note: Hardware configuration of the board is done via cell selector boards to solder (J32 to J38 on J31).

4.5.3 Programming and debug
There are two ways to program and debug the MR-BMS771 board:
· Through the DCD-LZ connector (J19) · Through the JTAG connector (J2) Note: The DCD-LZ combines a debug interface with a debug serial console. It is used on RDDRONE-FMUK66 (HoverGames). For more information, see HoverGames gitbook.

4.5.4 LED
The MR-BMS771 has an RGB LED that can be used for status indications. Various color combinations and blink patterns are used to indicate the state of the battery and system. There are two red CAN LEDs that could indicate the CAN bus status.

4.5.5 External display
An external display could be used to display important battery information. This display can be connected to J23. This header could be supplied with 3.3 V (D34) or 5.0 V (D35). By switching the diode, 3.3 V or 5 V could be used.
An SSD1306 OLED display is provided with the MR-BMS771 board kit.

4.5.6 External and additional components

4.5.6.1 External components
An optional external temperature sensor can be added onto the MR-BMS771 board using connector J1, J39, or J40. An example of application for this external sensor is used to monitor the cells temperature inside the battery pack.

4.5.6.2 Additional components
Some components are included in the design but are not mounted on the MR-BMS771 original board. They are marked DNP on the schematics and the BOM. Table 4 provides the list of additional components that can be implemented in the design and their use:

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Table 4.Additional features

Feature

Description

Heat sinks

To dissipate more power, a heat sink can be mounted on the bottom side of the board. The recommended part is HSB30-373710.

Optional termination resistor One 60.4 resistor on each CAN line connected to a

network on CAN bus

4700 pF capacitor wired to the ground (split termination).

Capacitors on cell

A filter can be added to the cell voltage measurements

measurements connections connections, according to the number of cells in use.

Capacitors on external temperature sensor

If the external temperature sensor is implemented, two capacitors can be added on the external temperature sensor low-pass filter for more electromagnetic compatibility (EMC) demanding applications.

Capacitor on cell balancing connections

Capacitors can be added on the cell balancing circuit for EMC, according to the number of cells in use.

External NFC antenna

coil as an alternative option for the printed-circuit board (PCB) NFC antenna for extended range operations

Resistor on gate driver RS pin resistor to link RS pin on gate driver to MCU

MCU expansion header

Additional MCU pins are wired to a 2 × 7 header slot. Possible uses: additional battery level LEDs, emergency button, and more

Wake jumper

jumper for SBC wake-up (in parallel to the button)

Label none
R49, R50, C66 C6, C12, C18, C22, C26, C29, C34 C49, C54
C99, C100, C101, C102, C103, C104, C105, C106, C107 L2 R99 J21
J22

4.5.7 Test points definition Figure 9 and Figure 10 show the location of the test points on the board.
TP19 TP18 TP8

TP12 TP1
TP14
TP13 TP11

TP4 TP21 TP23 TP26 TP27 TP28
TP24 TP10 TP9 TP25

Figure 9.Test points (top)

TP16 TP17 TP5 TP3

TP2

aaa-061047

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TP20 TP22

UM12287
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Figure 10.Test points (bottom)

aaa-061048

Table 5.Test points Test point name TP1 TP2 TP3 TP4 TP5 TP8 TP9 TP10 TP11 TP12 TP13 TP14 TP16 TP17 TP18 TP19 TP20 TP21 TP22 TP23 TP24 TP25

Signal name OVERCURRENT SE_NFC_SCL SE_NFC_SDA VCC_3V3_SBC RST_N VCC_3V3_LDO1 SMBUS_SCL SMBUS_SDA VBAT_IN VBAT_OUT BGND Gate BCC_CIPO BCC_CS BCC_SCLK BCC_COPI SBC_CS SBC_CIPO SBC_COPI SBC_SCK VCC_HARVEST N/A

Description overcurrent signal secure element and NTAG NFC I2C bus clock signal secure element and NTAG NFC I2C bus data signal SBC 3.3 V regulator output reset signal (active LOW) low dropout (LDO) 3.3 V regulator output SMBus I2C bus clock signal SMBus I2C bus data signal voltage input voltage output battery ground reference power switches gate command BCC SPI bus CIPO out signal BCC SPI bus chip select signal BCC SPI bus clock signal BCC SPI bus COPI input signal SBC SPI bus chip select signal SBC SPI bus CIPO signal SBC SPI bus COPI signal SBC SPI bus clock signal antenna energy harvesting output SMBus connector pin 1

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Table 5.Test points…continued

Test point name

Signal name

TP26

CAN1_TX

TP27

CAN1_RX

TP28

CAN1_INH

Description CAN bus 1 TX signal CAN bus 1 RX signal INH pin of U17 (TJA1463ATK)

4.6 CAN bus termination resistor
The MR-BMS771 board does have a CAN termination resistor on the board but this resistor is not placed by default. The board needs a termination resistor network (DRONE-CAN-TERM) to provide termination on any CAN bus. It is used on the last CAN device on the daisy chain, providing a termination at both ends of a CAN bus.

Figure 11.DRONE-CAN-TERM
4.7 Schematic, board layout, and bill of materials
The schematic, board layout, and bill of materials for the MR-BMS771 board are available at http:// www.nxp.com/MR-BMS771.
5 Configuring the hardware
5.1 Power connectors
As the MR-BMS771 board aims to be adaptable for every battery setup, power and battery cell termination connectors are not mounted on the PCB. The user can configure the board with the connector. The power connectors footprints on the design correspond to the DFRobot FIT0588 connector. They are also used for soldering typical silicone insulation heavy gage power wires. TE Connectivity provides a line unmanned power (UMP) connector specifically for professional highpower mobile systems.

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5.2 Cell terminal connection
The MR-BMS771 board is configurable to fit 7S to 14S battery packs. Depending on the desired configuration, some adjustments must be done on the board: · The correct cell terminal connector must be soldered as JP1 on the top side (7S to 14S connectors are
provided in the kit). · By soldering the correct small cell count selector interposer board, the connection to the cell terminal circuit is
done.
5.3 Shunt resistor
The shunt resistor (R1) can be disconnected from the overcurrent protection circuit and the BCC by opening the SJ13 and SJ14 jumpers. Both jumpers are closed by default.
5.4 External NFC antenna
The external antenna is selected by default. The onboard NTAG 5 chip is designed to provide active antenna matching and amplification and gives enhanced performance when the battery is present and providing power. However, for extended range operation, an external NFC antenna can replace the PCB antenna. To use the PCB antenna, the user must reconfigure the board using the following steps: · Place both 0.75 resistors R93 and R94 · Replace C72 (56 pF capacitor) by an 82 pF capacitor and place C116 (680 pF capacitor). The NTAG 5 chip is not installed for the first batch.
5.5 Optional components
5.5.1 Heat sink
Depending on the application, the user can add an optional heat sink onto the MR-BMS771 board. The recommended part to use as a heat sink is the HSB30-373710. It is advised to use an electrically isolated layer, but good thermal conductive layer (for example, special adhesive tape) between the BMS771 and the heat sink. The thermal conductive layer improves the thermal conductivity.

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UM12287
MR-BMS771 reference design

6 Startup checklist

6.1 First startup
Figure 12 and Figure 13 present a typical hardware configuration.

System to be
powered

Vbatt_out+

Vbatt_out-

12 V system to be
powered

JTAG debugger

12 V 1 A

Computer

(UAV) CAN bus 0
(UAV) CAN bus 1
DCD-LZ debugger SMBus/I2CS bus I2C bus/display

Vbatt_in+

Vbatt_in-

–

7S to 14S battery

Cell terminals

Figure 12.Board components (top)

External temp. sensor (opt.)

External NFC antenna SE (opt.)

aaa-061049

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(UAV) CAN bus 0 (UAV) CAN bus 1

SW E-stop Pushbutton

UM12287
MR-BMS771 reference design

System to be
powered

Vbatt_out-

Vbatt_out+

Cell select

Optional heat sink

External NFC antenna NTAG (opt.)
Figure 13.Board components (bottom)

Extra external temp. sensor/IO6 (opt.)
Extra external temp. sensor/IO5 (opt.)

Vbatt_in-

Vbatt_in+

–

7S to 14S battery

aaa-061050

Before the first startup, make sure that the board is configured properly:
1. Solder the correct cell terminal connector at the JP1 location. Ensure it is correctly positioned and aligned. 2. Configure the board for your application by soldering the corresponding small cell count selector interposer
board for the cell count. 3. Solder your power in and power out connectors or wires on the J4 and J5 footprints. 4. Configure the board with additional and/or optional components as described in Section 5 “Configuring the
hardware” to fit the application requirements.

6.2 Powering the MR-BMS771 board
Once the board is configured properly (see Section 5 “Configuring the hardware” for more details about configuration), connect the board.
To power on the MR-BMS771 board, connect the battery (or power source) to the power input connector (J4) first and then the cell terminal connector (JP1). The correct order protects the boards from internal damage due to hot plugging. Press the small pushbutton (SW1) on the side for the BMS to power the MCU and other electronics. The pushbutton is located next to the 12 V connector.
Similarly, to disconnect the battery from the board, disconnect the cell terminal connector (JP1) first. The power input (J4) can then be disconnected.

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UM12287
MR-BMS771 reference design

7 References

[1] MR-BMS771 — detailed information on this board, including documentation, downloads, and software and tools http://www.nxp.com/MR-BMS771 [2] MC33771C — product information on MC33771C, 14-channel Li-ion battery cell controller IC http://www.nxp.com/ MC33771C [3] UJA1169

— product information on UJA1169ATK, Mini high-speed CAN system basis chip http://www.nxp.com/ products/UJA1169ATK

[4] S32K [5] NTAG

— product information on S32K1 microcontrollers for general purpose http://www.nxp.com/S32K
— product information on NTAG 5 boost, NFC forum-compliant I2C bridge for tiny devices http:// www.nxp.com/NTAG5-BOOST

[6] TJA1463

— product information on TJA1463 CAN signal improvement capability transceiver with sleep mode http://www.nxp.com/products/TJA1463

[7] SE051

— product information on the EdgeLock SE051 device http://www.nxp.com/products/SE051

8 Revision history

Table 6.Revision history Document ID
UM12287 v.1.0

Release date 30 June 2025

Description initial version

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MR-BMS771 reference design

Legal information
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Security — Customer understands that all NXP products may be subject to unidentified vulnerabilities or may support established security standards or specifications with known limitations. Customer is responsible for the design and operation of its applications and products throughout their lifecycles to reduce the effect of these vulnerabilities on customer’s applications and products. Customer’s responsibility also extends to other open and/or proprietary technologies supported by NXP products for use in customer’s applications. NXP accepts no liability for any vulnerability. Customer should regularly check security updates from NXP and follow up appropriately.
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Notice: All referenced brands, product names, service names, and trademarks are the property of their respective owners.
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AMBA, Arm, Arm7, Arm7TDMI, Arm9, Arm11, Artisan, big.LITTLE, Cordio, CoreLink, CoreSight, Cortex, DesignStart, DynamIQ, Jazelle, Keil, Mali, Mbed, Mbed Enabled, NEON, POP, RealView, SecurCore, Socrates, Thumb, TrustZone, ULINK, ULINK2, ULINK-ME, ULINKPLUS, ULINKpro, Vision, Versatile — are trademarks and/or registered trademarks of Arm Limited (or its subsidiaries or affiliates) in the US and/or elsewhere. The related technology may be protected by any or all of patents, copyrights, designs and trade secrets. All rights reserved.
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MR-BMS771 reference design

Tables

Tab. 1. Tab. 2. Tab. 3.

Maximum ratings ………………………………………..5 Featured devices ………………………………………..8 Reference design connector description ……… 10

Tab. 4. Tab. 5. Tab. 6.

Additional features …………………………………….12 Test points ………………………………………………. 13 Revision history ………………………………………..18

Figures

Fig. 1. Fig. 2. Fig. 3.
Fig. 4.
Fig. 5. Fig. 6.

MR-BMS771 board ……………………………………. 2 Block diagram …………………………………………… 5 Featured component placement block diagram (top) ……………………………………………..6 Featured component placement block diagram (bottom) ………………………………………..6 Featured component placement (top) …………… 7 Featured component placement (bottom) ……… 7

Fig. 7. Fig. 8. Fig. 9. Fig. 10. Fig. 11. Fig. 12. Fig. 13.

Connectors placements (top) ………………………. 9 Connectors placements (bottom) …………………. 9 Test points (top) ………………………………………. 12 Test points (bottom) …………………………………. 13 DRONE-CAN-TERM ………………………………… 14 Board components (top) …………………………….16 Board components (bottom) ……………………….17

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Contents

1 2
2.1 3 3.1 3.2 3.3 4 4.1 4.2 4.3 4.4 4.5 4.5.1
4.5.1.1 4.5.1.2 4.5.2 4.5.3 4.5.4 4.5.5 4.5.6 4.5.6.1 4.5.6.2 4.5.7 4.6 4.7
5 5.1 5.2 5.3 5.4 5.5 5.5.1 6 6.1 6.2 7 8

Introduction ……………………………………………… 2 Finding kit resources and information on the NXP website …………………………………..3 Collaborate in the NXP community ………………..3 Getting ready …………………………………………… 3 Kit contents ………………………………………………..3 Additional hardware ……………………………………. 3 Software …………………………………………………….4 Getting to know the hardware …………………… 4 MR-BMS771 overview ………………………………… 4 MR-BMS771 features …………………………………. 4 Block diagram …………………………………………….5 MR-BMS771 board characteristics ……………….. 5 Featured components ………………………………….5 MC33771C: 14-channel Li-ion battery cell controller …………………………………………………… 8 General description ……………………………………..8 Features …………………………………………………….8 Connectors …………………………………………………9 Programming and debug …………………………… 11 LED ………………………………………………………… 11 External display ……………………………………….. 11 External and additional components …………….11 External components ………………………………… 11 Additional components ……………………………… 11 Test points definition …………………………………. 12 CAN bus termination resistor ………………………14 Schematic, board layout, and bill of materials …………………………………………………. 14 Configuring the hardware ……………………….. 14 Power connectors …………………………………….. 14 Cell terminal connection ……………………………. 15 Shunt resistor ………………………………………….. 15 External NFC antenna ………………………………. 15 Optional components …………………………………15 Heat sink ………………………………………………….15 Startup checklist ……………………………………..16 First startup ………………………………………………16 Powering the MR-BMS771 board ……………….. 17 References ………………………………………………18 Revision history ………………………………………18 Legal information …………………………………….19

UM12287
MR-BMS771 reference design

Please be aware that important notices concerning this document and the product(s) described herein, have been included in section ‘Legal information’.

Documents / Resources

NXP Semiconductors MR-BMS771 Reference Design [pdf] User Guide
MC33771, S32K146, UJA1169, NTAG 5, SE051, MR-BMS771 Reference Design, MR-BMS771, Reference Design, Design

References

User Manual

NXP Semiconductors MR-BMS771 Reference Design User Guide

MR-BMS771 Reference Design

Product Information

Specifications:

Product Usage Instructions:

1. Introduction

2. Finding Kit Resources

3. Getting Ready

3.1 Kit Contents

3.2 Additional Hardware

3.3 Software

FAQ (Frequently Asked Questions):

Documents / Resources

References

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