Chip for industrial battery management applications up to 5 cells

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Product overview


The L9961 is part of a complete battery pack monitoring, balancing, and protection system for Li-Ion and Li-Polymer cells in 3, 4 or 5 series configurations. The L9961 uses a high precision ADC to provide cell voltage, stack voltage and temperature conversion via external NTC. Voltage monitoring functions are cyclically performed with a programmable loop time. Stack current is also monitored via a high accuracy CSA, continuously running and performing also Coulomb Counting. Cell balancing is available and can be simultaneously activated on all cells. IC configuration and information exchange for SOC/SOH estimation are performed via I2C peripheral. The IC also integrates a dual pre-driver programmable in both HS/LS configurations for driving pack relays. L9961 also implements battery pack fuse protection to prevent fire and explosion hazards. A 3.3 V regulator with a high current capability is available for supplying pack controller and other external circuitry in both standby and normal operation modes. The IC protects the battery pack against over/under voltage conditions and monitors for over/under temperature. It also features protection against over current (both directions) and short-circuit in discharge events. Safety-relevant configurations can be stored in the internal NVM to avoid re-programming the device at each wakeup.

  • All features

    • 2 μA SHIPMENT - DEEP SLEEP mode current and 5 μA Standby consumption (with VREG LDO active)
    • Integrated 3.3 V VREG LDO for supplying MCU and LEDs
    • Measures Cell Voltage (3 to 5 cells), with Over/Under voltage detection and Balance Under voltage protection
    • 12-bit voltage measurement with maximum error of ± 15 mV in the [1.5 – 4.5] V range, for -40 °C < TJ < 105 °C
    • Measures Stack Voltage, with Over/Under voltage detection and Plausibility Check vs. Sum Of Cells
    • Measures Pack Temperature via NTC, with Over/Under Temperature detection
    • Ratiometric temperature measurement with ± 0.8% max. gain error in the [0.2 – VREG] V range, for -40 °C < TJ < 105 °C
    • Measures Battery Current, with Coulomb Counting, Over current (both directions) and Short-circuit in discharge protection.
    • 16-bit signed current measurement with maximum error of 0.25%, for -40 °C < TJ < 120 °C after customer end of line calibration with a single point
    • I2C peripheral for device programming and data transfers over I2C bus
    • Cell balancing supporting up to 70 mA per cell
    • Dual configurable HS/LS pre-driver for pack relay management
    • Pack fuse management
    • Embedded NVM for configuration parameters storage
    • High hot plug robustness

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STMicroelectronics - L9961

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Quality and Reliability

Part Number Marketing Status Package Grade RoHS Compliance Grade Material Declaration**
VFQFPN 5X5X1 32L P0.5 Industrial Ecopack2



VFQFPN 5X5X1 32L P0.5

Material Declaration**:


Marketing Status



VFQFPN 5X5X1 32L P0.5



RoHS Compliance Grade


(**) The Material Declaration forms available on may be generic documents based on the most commonly used package within a package family. For this reason, they may not be 100% accurate for a specific device. Please contact our sales support for information on specific devices.

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