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Automotive Electronics

Data Acquisition System for High-Voltage Battery Modules with 12-Bit SAR ADC

The MAX17823H from Maxim Integrated is a data acquisition system for managing high-voltage battery modules. With a 12-bit SAR ADC, MAX17823H can measure 12 cell voltages and two temperatures in 161µs. It features 12 internal switches for cell-balancing and has extensive built-in diagnostics. Up to 32 devices can be daisy-chained to manage 384 cells and monitor 64 temperatures.

Applications for MAX17823H include battery-backup systems, battery-powered tools, electric bikes, EVs, high voltage battery stacks, supercapacitor systems, and related resources.

MAX17823H operates from 9V to 65V. It features an AECQ-100 Grade 2 temperature range of -40°C to 105°C.

Cell voltages of 0V to 5V are measured differentially over a 65V common-mode range. Cell measurements have a typical accuracy of 2mV (3.6V cell, 25°C). If oversampling is enabled, up to 128 measurements per channel can be averaged internally with 14-bit resolution.

It can sense thermal overload by measuring its die temperature, and then shut itself down. With ultra-low power operation, it uses 2mA in standby mode and 2µA in shutdown mode.

MAX17823H features built-in diagnostics to support ASIL-D and FMEA requirements.

The system uses the company’s battery-management UART protocol for robust communications, and when used in conjunction with the MAX17880 12-channel battery monitor, it is suitable for automotive battery-management systems that require a high safety-integrity level.

Key Features
  • AECQ-100 Grade 2 Temperature Range
    • -40°C to 105°C
  • Operating Voltage from 9V to 65V
  • Ultra-Low Power Operation
    • Standby Mode: 2mA
    • Shutdown Mode: 2µA
  • 12 Cell-Voltage Measurement Channels
    • 2mV Accuracy (3.6V, +25°C)
    • 5mV Accuracy (0°C to +45°C)
    • 10mV Accuracy (-40°C to +105°C)
  • 12 Cell-Balancing Switches
    • Up to 650mA per switch
    • Emergency Discharge Mode
  • 2 Temperature Measurement Channels
  • Die Temperature Measurement
  • Automatic Thermal Protection
  • 29 Voltage Threshold Alerts
    • 12 Over-voltage Faults
    • 12 Under-voltage Faults
    • 2 Over-temperature Faults
    • 2 Under-temperature Faults
    • 1 Cell Mismatch Alert
  • 4 GPIOs
  • Built-in Diagnostics to Support ASIL-D and FMEA Requirements
  • Battery-Management UART Protocol
    • Daisy-Chain up to 32 Devices
    • Communication Port Isolation
    • Up to 2 Mbps Baud Rate (auto-detect)
    • 1.5µs Propagation Delay per Device
    • Packet-Error Checking (PEC)
  • Factory-Trimmed Oscillators
    • No External Crystals Required
  • 10mm x 10mm Package (64-pin LQFP)