Features and Benefits
- Measures Battery Stack Voltage, Current and Power
- Indicates Accumulated Battery Charge and Energy
- 20-Bit Current Measurement with <1μV Offset
- Built-In Isolated isoSPI™ or SPI Interface
- LTC68xx/ADBMS68xx Compatible, Supports Synchronous Measurements with Cell Monitors
- Up to 12 Buffered Voltage Measurement Inputs
- Up to 5 GPIOs, Configurable to Drive Ground, Supply or Toggling at 400kHz
- High or Low Side Current Sense
- 0.3% Current and Voltage Accuracy
- 1% Energy and Charge Accuracy
- True Average ADCs
- I2C EEPROM Interface to Store Board Calibration Factors
- Threshold Registers for all Measured Quantities
- Engineered for ISO26262 Compliant Systems
- Open Wire Detection on Input Pins
- Available in 48-Lead LQFP Package
- AEC-Q100 Qualified for Automotive Applications
The LTC2949 is a high precision current, voltage, temperature, charge and energy meter for electrical and hybrid vehicles and other isolated current sense applications. It infers charge and energy flowing in and out of the battery pack by monitoring simultaneously the voltage drop over up to two sense resistors and the battery pack voltage.
Low offset ΔΣ ADCs ensure accurate measurement of voltage and current with insignificant power loss. Continuous integration of current and power ensures lossless tracking of charge and energy delivered or received by the battery pack.
The built-in serial interface can be configured to support isolated isoSPI communication to the host or as SPI interface.
The LTC2949 features 12 internally buffered high impedance inputs (V1 to V12) for measuring voltages from external sensors or resistor dividers allowing to measure temperatures, HV-Link voltages, chassis isolation and supervise contactor states. LTC2949 has up to five programmable digital outputs which can be set to ground, supply or toggling at 400kHz.
Programmable threshold and tracking registers reduce digital traffic to the host.
- Electric and Hybrid Vehicles
- Isolated Current Sensing
- Backup Battery Systems
- High Power Portable Equipment
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (2)
The demonstration circuit DC2792B is an SPI serial to dual-port isoSPI adapter that uses a pair of multiplexed LTC6820 isoSPI transceivers and miniaturized isoSPI connectors (2 contact DuraClik). The board can functionally replace a DC1941 in cases where isoSPI battery-management (BMS) devices are being evaluated, but provides a second isoSPI master to exercise the reversible isoSPI feature where available. The SPI interface can be provided via the legacy 14-contact ribbon cable from either a DC590 or DC2026 USB adapter, or directly installed on the DC2026 as a Linduino shield. The two isoSPI ports are MAIN and AUXiliary, with activity of each indicated by blue LEDs. For use in place of DC1941 or non-reversible isoSPI networks, the MAIN port must be used. Power for the DC2792B comes indirectly from the USB port of the host computer, via the USB to serial adapter being used.
The DC2732A demonstrates a high voltage battery pack monitor based on the LTC2949. The LTC2949 is a high precision current, voltage, temperature, charge and energy meter for electrical and hybrid vehicles and other isolated current sense applications. It infers charge and energy flowing in and out of the battery pack by simultaneously monitoring the voltage across two sense resistors and the battery pack voltage.
Due to its compatible protocol, the LTC2949 can share the same communication bus with ADI battery stack monitors that contain the isoSPI™ interface.
The LTC2949 is typically powered from an isolated supply and directly connected to the battery stack on the low or high side depending on the shunt position. Resistive high voltage dividers provide connections to high voltage terminals that need to be supervised.
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Sample & Buy
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