This article analyzes the processing method of the power lithium-ion battery management system (bMS) developed by Pinjia Group, which uses Infineon's high-performance 16-bit MCU XC164 as the platform and is supplemented by AMS's high-precision, zero-temperature-drift power lithium-ion battery current test chip AS8510.
I. Battery Management System (bMS) for Power Lithium-ion Batteries
II. The battery management system has three main functions:
1. Real-time monitoring of battery status. By testing the battery's external characteristic parameters (such as voltage, current, temperature, etc.) and employing appropriate algorithms, the internal state of the battery (such as capacity and SOC) can be estimated and monitored. This is the foundation and key to the effective operation of the battery management system.
2. After correctly obtaining the battery status, perform thermal management, battery balancing management, charge/discharge management, and fault alarms;
3. Establish a communication bus to exchange data with the display system, vehicle controller, and charger.
III. Actual Product Images – Infineon MCUXC164 Main Control Module
IV. XC164 Function Introduction
1. High-performance 16-bit CPU piping and 5-Stage
-25ns in a 40MHz CPU instruction clock (single-cycle execution) cycle time
-1-Cycle multiplication (16×16 bits), background part (32/16 bits) 21 cycles
-1- Explanation of CycleMultiply-and-Accumulate (MAC)
-16 megabytes of total linear address space for code and data
-1024 bytes of on-chip special function register area (C166 series compatible)
2.16-priority-Level interrupt system with up to 63 sources, sampling rate reduced to 50ns
3.8-Channel interrupt-driven single-cycle data transmission facility via
4. Peripheral Event Controller (PEC), a 24-bit pointer that overwrites the total address space.
5. The clock generator is connected via a chip PLL or via a prescaler.
6. On-chip memory module
-2Kb dual-port RAM (dual-port RAM)
-2 kilobytes of on-chip data SRAM (DSRAM, XC164GM-8F only)
-2Kb on-chip program/data SRAM (pSRAM)
- 64-byte (XC164GM-8F) or 32-byte (XC164GM-4F) chip plan
7. Memory (Flash Memory)
8. On-chip peripheral module
– 14-channel A/D converter with programmable analysis (10-bit or 8-bit) and conversion time (down to 2.55µs or 2.15µs)
–16-Channel Universal Capture/Compare Unit (CApCOM2)
– Multi-functional universal timer unit with 5 timers
– Two synchronous/asynchronous (USART interface) serial channels
– Two High-Speed-Synchronous serial channels
– TwinCAN interface (Revision 2.0b Active) message objects with 32 (full CAN/basic) pairs for two CAN nodes and gateway functions.
– A real-time clock driven by a master oscillator.
9. Idle, sleep, and power-down modes and flexible power management.
10. Programmable watchdog timer and watchdog for oscillators
V. Features of AS8510
1. Internal dual independent 16-bit ADC conversion and programmable sampling rate up to 100K/s.
2. Zero offset
3.130dB dynamic range, 4-level gain adjustment, with gain settings changed at 5x, 2x, 4x, and 100x respectively, improving accuracy.
4. Fully compliant with the AECQ100 automotive integrated circuit stress detection certification standard, each IC has a unique ID.
5. Separate current and voltage synchronous test channels;
6. Internal high-precision reference voltage source, 20mV, high-precision reference voltage source +/-20ppm;
7. Integrates an RC oscillator with 2% accuracy;
8. The voltage test channel can be reused as a temperature test channel;
9.30µAStandbyModeCurrent. Standby current;
10.SSOp20packager.
11. AMS Battery High-Side (Positive) Step-Down ICAS8525 Function
-High-precision voltage attenuation;
- Precise differential gain amplification effectively reduces common-mode interference;
- Power restart function, adjustable over-temperature restart;
-Integrates watchdog timer for normal operation and watchdog timer for standby mode;
-Loaddumpprotection(42V)forallbatterysuppliedpins,LINbuspin,andEnablepin
- Built-in reverse polarity protection for all battery strings, tested by LINpin, up to -27V;
-Over-temperature alarm (Shutdown functions).
12. Features of the Active Balancing Management ICAS8505:
-AS8505Cellbalancer/Monitor provides active battery balancing with an accuracy of 20mV across the entire temperature range;
- Synchronous, precise battery voltage comparison;
- Active balancing, up to 14 battery cells;
Most of these products on the market perform passive measurement, requiring the battery cells to participate, and cannot quickly and accurately track the charge of each battery cell.
