Proprietary – For Big-bit New Energy Seminar Use Only

Battery Management Solution

Big-bit New Energy Seminar

For Big-bit Seminar Use Only

Who needs a BMS

l Cell lifetime is highAny Lithium battery technology

l Cell voltage outside its operation range (i.e. 2.5-4.2V) kills the cell and

can creates a fire hazard.

l Cell Lifetime is highly dependent on cell SOC control at all times

For Big-bit Seminar Use Only

What are the transportation market for BMS

Application Bus Voltage Power Battery Series

Electric Bicycle 36V to 48V 250W-500W 8-12S

Scooter 48V 1-10kW 12S

Motorcycle 60V 1-10kW 12-20S

48Vnet ICE mild HEV 48V 16kW 12-14S

HEV 120V-450V 10-150kW 20-100S

EV 270V-800V 20-300kW 65-200S

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Why MPS chooses 16 cells / BMS IC

On most Lithium technologiesto center the SOC around 48Vfor long life time the optimum is between 13 and 14 cells.

The “industry standard” 12 cellis just 1 or 2 cells short of the optimum.

To have 2 or 3 cell inputs reserve for alternative cell technologies is a very small overhead, since the additional circuitry (larger mux, pins, balance switch) is a small fraction.

For Big-bit Seminar Use Only

Battery Lifetime

For the user the battery reaches its EOL if the capacity of the weakest cell is to low to be usable.

Or if imbalance yield the same effect with one cell at the high side of SOC and another on the low side.

For this reason Lithium cells need to be balanced.

Imbalance result from cell temperature differences, different self discharge rates and different cell loading i.e. through monitoring electronics like the BMS.

For Big-bit Seminar Use Only

Battery Lifetime

For the user the battery reaches its EOL if the capacity of the weakest cell is to low to be usable.

Or if imbalance yield the same effect with one cell at the high side of SOC and another on the low side.

For this reason Lithium cells need to be balanced.

Imbalance result from cell temperature differences, different self discharge rates and different cell loading i.e. through monitoring electronics like the BMS.

For Big-bit Seminar Use Only

MPQ2645 Family Key Features

l Up to 80V Sustainable voltagel Up to 16-celll 16Bit SAR ADCl Integrated Balance Switchesl Up to 5GPIOs for Ext. Temp Monitorsl Stackable Differential BMS-LinkTM

l Compatible with both Daisy-chain and Multi-drop Connection

l Independent UV/OV Comparator for Each Cell

l Self-Diagnosisl Support Open-wire Detectionl AEC-Q100 Qualified

• Device Temperature Grade 2: -40ºC to 125ºC ambient Operating Temperature Range

• Device HBM ESD Classification Level 2• Device CDM ESD Classification Level

C3l Engineered for ISO26262 ASIL C

For Big-bit Seminar Use Only

MPQ2645 Family Derivatives

Derivatives MPQ2645A-AEC1

MPQ2645B-AEC1

MPQ2645C-AEC1

Daisy-chain

Multi-drop

I2C/SPI BMS-LinkTM I2C SPI

Cell Count 16 16 16

Package QFN64 10x10 QFN64 10x10 QFN64 10x10

For Big-bit Seminar Use Only

Typical Application CircuitDaisy-chain Differential signals

For Big-bit Seminar Use Only

Typical Application CircuitMulti-drop (I2C)

For Big-bit Seminar Use Only

Typical Application CircuitMulti-drop (SPI)

For Big-bit Seminar Use Only

Safety Analysis Methods Introduction

l HARA (Hazard Analysis and Risk Assessment)l FTA (Fault Tree Analysis)l FMEA (Failure Mode and Effect Analysis)l FMEDA (Failure Mode Effects and Diagnostic Analysis)l DFA (Dependant Failure Analysis)l DRBFM (Design Review Based on Failure Modes)

For Big-bit Seminar Use Only

Steps for FMEDA

Safety Goal

Identify the relevant modules

Determine failure rate and mode

Analysis of failure effects

Collection and assignment of

safety mechanism

Sorting the failure classes

Review the diagnostic coverage of each

safety mechanism

Output your FEMDA report and review it

For Big-bit Seminar Use Only

Functional Safety Focused

Built-In Self Tests

Separate Hardware Protection

Flexible Communication Architectures