{
  "node": {
    "id": "term:mcu",
    "type": "Term",
    "label": "Microcontroller",
    "properties": {
      "id": "mcu",
      "name": "Microcontroller",
      "abbr": "MCU",
      "section": "topic-data",
      "definition": "The processor that runs BMS firmware: state estimation, protection, balancing decisions and communication. Automotive BMS controllers use safety microcontrollers with lockstep cores and hardware self-tests so they can meet ASIL C or D.",
      "related": [
        "bmu",
        "firmware",
        "functional-safety",
        "fpga",
        "afe"
      ],
      "url": "https://lemonergy.com/learn/glossary/mcu/",
      "mentions": [
        "bms",
        "lockstep-core"
      ]
    }
  },
  "edges": [
    {
      "id": "edge:4068",
      "source": "term:mcu",
      "target": "topic:topic-data",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:4069",
      "source": "term:mcu",
      "target": "term:bmu",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:4070",
      "source": "term:mcu",
      "target": "term:firmware",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:4071",
      "source": "term:mcu",
      "target": "term:functional-safety",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:4072",
      "source": "term:mcu",
      "target": "term:fpga",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:4073",
      "source": "term:mcu",
      "target": "term:afe",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/mcu/bms",
      "source": "term:mcu",
      "target": "term:bms",
      "type": "mentions",
      "properties": {
        "sourceFile": "terms.json",
        "method": "build_glossary.mention_index + mentions",
        "field": "definition",
        "meaning": "Text mention; not a causal claim"
      }
    },
    {
      "id": "edge:mentions/mcu/lockstep-core",
      "source": "term:mcu",
      "target": "term:lockstep-core",
      "type": "mentions",
      "properties": {
        "sourceFile": "terms.json",
        "method": "build_glossary.mention_index + mentions",
        "field": "definition",
        "meaning": "Text mention; not a causal claim"
      }
    },
    {
      "id": "edge:4076",
      "source": "term:mcu",
      "target": "reference:ti-bms",
      "type": "cites",
      "properties": {
        "sourceFile": "wiki-references.json",
        "scope": "direct technical reference"
      }
    }
  ],
  "neighbors": [
    {
      "id": "topic:topic-data",
      "type": "Topic",
      "label": "Data, communication and electronics",
      "properties": {
        "id": "topic-data",
        "name": "Data, communication and electronics",
        "lede": "The control units, chips, protocols and file formats through which a battery is measured, controlled and logged.",
        "context": "Separate quantities from encoding and transport.",
        "example": "2500 in a log might mean 25.00 °C, 2.5 V or raw counts. Units and scale must accompany the value.",
        "lesson_url": "https://lemonergy.com/learn/fundamentals/battery-basics/",
        "lesson_label": "Open battery basics"
      }
    },
    {
      "id": "term:bmu",
      "type": "Term",
      "label": "Battery management unit",
      "properties": {
        "id": "bmu",
        "name": "Battery management unit",
        "abbr": "BMU",
        "aka": [
          "BMS master",
          "master BMS"
        ],
        "section": "topic-data",
        "definition": "The master controller of a battery management system: it collects cell voltages and temperatures from the monitoring boards, runs the state estimation and protection logic, drives the contactors and talks to the vehicle. In some architectures the same name is used for a per-module slave, so a datasheet’s block diagram is the safe reference.",
        "related": [
          "bms",
          "cell-supervision-circuit",
          "bcu",
          "contactor",
          "can-bus",
          "bms-power-modes"
        ],
        "url": "https://lemonergy.com/learn/glossary/bmu/",
        "mentions": [
          "datasheet"
        ]
      }
    },
    {
      "id": "term:firmware",
      "type": "Term",
      "label": "Firmware",
      "properties": {
        "id": "firmware",
        "name": "Firmware",
        "aka": [
          "embedded software",
          "BMS software"
        ],
        "section": "topic-data",
        "definition": "The software that runs on a BMS or charger controller. Its version decides how SOC, limits and faults behave, so it is tracked like a part number, updated by flashing over CAN or over the air, and recorded in the battery passport.",
        "related": [
          "mcu",
          "flashing",
          "bmu",
          "battery-passport",
          "functional-safety"
        ],
        "url": "https://lemonergy.com/learn/glossary/firmware/",
        "mentions": [
          "charger",
          "state-of-charge",
          "bms",
          "over-the-air-update"
        ]
      }
    },
    {
      "id": "term:functional-safety",
      "type": "Term",
      "label": "Functional safety",
      "properties": {
        "id": "functional-safety",
        "name": "Functional safety",
        "abbr": "ISO 26262",
        "aka": [
          "ASIL"
        ],
        "section": "topic-hvsafety",
        "definition": "The discipline, standardised for vehicles in ISO 26262, of making sure electronic failures do not cause harm. Battery functions such as overvoltage protection are classified by risk into ASIL levels A to D, which set how redundant and verified their hardware and software must be.",
        "related": [
          "bms",
          "high-voltage-interlock",
          "insulation-resistance",
          "fmea",
          "mcu",
          "iso-13849"
        ],
        "url": "https://lemonergy.com/learn/glossary/functional-safety/",
        "mentions": []
      }
    },
    {
      "id": "term:fpga",
      "type": "Term",
      "label": "Field-programmable gate array",
      "properties": {
        "id": "fpga",
        "name": "Field-programmable gate array",
        "abbr": "FPGA",
        "aka": [
          "Xilinx",
          "AMD FPGA"
        ],
        "section": "topic-data",
        "definition": "A chip whose logic is configured after manufacture, best known from Xilinx, now AMD, and Intel. In battery work it appears where timing must be exact and fast: test-bench and HIL simulators that emulate cells in microseconds, high-speed data acquisition, and some fast protection and power-electronics control.",
        "related": [
          "hil",
          "mcu",
          "adc",
          "battery-emulator"
        ],
        "url": "https://lemonergy.com/learn/glossary/fpga/",
        "mentions": []
      }
    },
    {
      "id": "term:afe",
      "type": "Term",
      "label": "Analog front end",
      "properties": {
        "id": "afe",
        "name": "Analog front end",
        "abbr": "AFE",
        "aka": [
          "cell monitoring IC",
          "battery monitor IC",
          "BMIC"
        ],
        "section": "topic-data",
        "definition": "The integrated circuit that measures a stack of series cells — typically 6 to 18 per chip — with millivolt accuracy, reads thermistors, switches balancing and talks to the controller over an isolated daisy chain. It is the part of a BMS that touches the cells, and its accuracy limits how well SOC can be known.",
        "related": [
          "cell-supervision-circuit",
          "isospi",
          "voltage-sense",
          "cell-balancing",
          "adc",
          "bmu"
        ],
        "url": "https://lemonergy.com/learn/glossary/afe/",
        "mentions": [
          "state-of-charge",
          "bms"
        ]
      }
    },
    {
      "id": "term:bms",
      "type": "Term",
      "label": "Battery management system",
      "properties": {
        "id": "bms",
        "name": "Battery management system",
        "abbr": "BMS",
        "section": "topic-pack",
        "definition": "The electronics and software that keep a battery inside its safe window: measuring every cell voltage and many temperatures, estimating SOC and SOH, balancing cells, computing current limits, controlling the contactors and reporting over the vehicle network.",
        "related": [
          "state-of-charge",
          "cell-balancing",
          "state-of-power",
          "cell-supervision-circuit",
          "contactor",
          "can-bus"
        ],
        "lesson": "fundamentals/battery-basics/#cell-module-pack",
        "url": "https://lemonergy.com/learn/glossary/bms/",
        "mentions": [
          "state-of-health",
          "cell-voltage"
        ]
      }
    },
    {
      "id": "term:lockstep-core",
      "type": "Term",
      "label": "Lockstep core",
      "properties": {
        "id": "lockstep-core",
        "name": "Lockstep core",
        "aka": [
          "dual-core lockstep",
          "DCLS",
          "lockstep processor",
          "lockstep"
        ],
        "section": "topic-data",
        "definition": "Two identical processor cores running the same program slightly offset in time, with hardware comparing their outputs continuously. Any mismatch, from a radiation-flipped bit or a silicon fault, triggers a reset or safe state, giving the high diagnostic coverage a BMS controller needs for ASIL C or D.",
        "related": [
          "mcu",
          "functional-safety",
          "diagnostic-coverage",
          "redundant-bms",
          "hardware-safety-metrics"
        ],
        "url": "https://lemonergy.com/learn/glossary/lockstep-core/",
        "mentions": [
          "bms"
        ]
      }
    },
    {
      "id": "reference:ti-bms",
      "type": "Reference",
      "label": "Getting Started with the BQ76925",
      "properties": {
        "title": "Getting Started with the BQ76925",
        "publisher": "Texas Instruments",
        "url": "https://www.ti.com/lit/an/slua619b/slua619b.pdf",
        "type": "Application report",
        "scope": "A concrete BMS analog front-end example: cell voltage, current, temperature measurement and MCU integration.",
        "year": 2019,
        "accessed": "2026-10-27"
      }
    }
  ]
}