Components

Advanced Battery Management System Enables Safer, Smarter EVs

Automotive OEMs can enhance the safety of their lithium-ion battery packs with robust communications, comprehensive diagnostics, and lower system costs with the MAX17843 12-channel, high-voltage smart sensor data-acquisition device announced by Maxim Integrated Products, Inc. at CES 2018.

Electric vehicles (EVs), hybrid EVs, and plug-in hybrids rely on large lithium-ion battery packs filled with hundreds or even thousands of individual battery cells. With industry experts predicting that 25% of cars sold by 2025 will have electric engines, automotive OEMs and Tier 1s need an intelligent battery management system to enable safe, low cost solutions with robust communications.

Maxim is enabling a safer, smarter car of the future with the MAX17843 battery management system (BMS). MAX17843 meets the highest safety standards, adhering to ISO 26262 and ASIL D requirements (also applicable for ASIL C). Its differential universal asynchronous receiver/transmitter (UART) using capacitive isolation reduces bill of materials costs and failure in time (FIT) rates.

With this, designers can save up to 90% of their isolation BOM cost. The UART, with ultimate flexibility, enables robust communications in noisy environments. Using Maxim’s unique proprietary daisy-chain architecture and successive-approximation-register (SAR) analog-to-digital converter (ADC), the MAX17843 captures fast, accurate voltage measurements and delivers high EMC performance. It is applicable for a variety of automotive and EV powertrain applications.

Key advantages

  • Safety: ISO 26262 and ASIL D certification, as well as TUV certification in design and management process; meets various BCI requirements; comprehensive diagnostics
  • Low System Cost: Internal cell balancing and UART reduces BOM costs compared to competitive solutions; only IC to allow capacitive or transformer isolation
  • Robust Communications: Reliable distributive and centralized CMC architecture with UART; Supports 100m daisy-chain segments and high noise immunity; Supports emission, ESD, and hot plug

“The BMS market is expected to grow at a CAGR of 43% from 2016 to 2021,” said Siddharth Jaiswal, automotive industry analyst at Technavio. “This ASIL D-certified battery management system by Maxim proactively detects faults and is extremely important to the safety of vehicles.”

“It goes without saying that there’s no room for compromise when it comes to automotive safety,” said Tamer Kira, Director, Automotive Business Unit at Maxim Integrated. “The MAX17843 gives our customers the functionality necessary for safe and intelligent battery management operation.”

The MAX17843 is available at Maxim’s website for $7.61 (1000-up, FOB USA). The MAX17843EVKIT# evaluation kit is available for $1,000. The MAX17843 operates over the -40-degree Celsius to +125-degree Celsius temperature range and is available in a 64-pin LQFP package (10mm x 10mm).

Summary of features:

  • 12-Cell Battery-Voltage Measurement for Lithium-Ion, NiMH, or Super-Cap Cells
  • Two Auxiliary Analog Inputs for NTC Thermistor or Absolute Voltage Measurement
  • Die Temperature Measurement and alert
  • High-Accuracy Differential Measurement I/Os
    • ±2mV Accuracy at +25°C and 3.6V
  • Integrated 12-Channel Data-Acquisition System
    • Differential High-Voltage Mux to ADC
    • 14-Bit ADC Resolution with Oversampling
    • 12 Cell Voltages Measured within 142μs
    • Module Voltage Measurement
    • Redundant ADC
  • Battery Fault Detection
    • Overvoltage and Undervoltage Digital Threshold Detection
    • Enhanced Diagnostic Features for Fault Detection to Support ASIL and FMEA
  • 12 Internal Cell-Balancing Switches
    • Support Up to 150mA per Switch
    • Emergency Cell-Discharge Mode
  • Integrated 9V to 65V Input Linear Regulator
  • Integrated Temperature-Compensated, Voltage Reference
  • Robust Differential Daisy-Chain UART Interface
    • Up to 32 Connected ICs in a Single Daisy-Chain
    • Compatible with Direct MCU Connection
    • Standard UART bytes at 2Mb/s (max) Rate
  • Four General-Purpose Digital I/O Lines
  • Built-In Diagnostics to Support ASIL D and FMEA Requirements
  • Ultra-Low-Power Dissipation
    • 2.0mA (typ) Standby-Mode Supply Current
    • 3µA Shutdown Mode Leakage Current
  • -40°C to +125°C Operating Temperature Range (AEC-Q100 Grade 1)
  • 64-Pin, Lead-Free/RoHS-Compliant, 10mm x 10mm LQFP Package
Maxim Integrated Products Inc.
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