The ISL78714 monitors and balances up to 14 series-connected cells with an accuracy of ±2 mV across automotive temperature ranges, enabling system designers to make informed decisions based on absolute voltage levels. The ISL78714 includes a precision 14-bit analog-to-digital converter and associated data acquisition circuitry. The device also offers up to six external temperature inputs (two available on GPIO) and includes fault detection and diagnostics for all key internal functions.
 
The ISL78714 meets the stringent reliability and performance requirements of battery systems for all electric vehicle variants, including HEV/PHEV, with safety features that allow automakers to achieve ISO 26262 Automotive Safety Integrity Level (ASIL D). In addition, the ISL78714 monitors and rereads over/under voltage, temperature, open wire conditions, and fault status for 112 cells in less than 10 ms, or 70 cells in 6.5 ms.
 
Multiple ISL78714s can be daisy-chained, supporting systems of up to 420 cells (30 ICs) and providing transient and EMC/EMI immunity. The ISL78714's daisy-chain architecture uses low-cost capacitive or transformer isolation, or a combination of both, with twisted-pair wiring to stack multiple battery packs while protecting against hot connections and high-voltage transients. A watchdog timer automatically powers down a daisy-chain IC if communication with the master MCU is lost.
 
Key Features:
Monitors and manages up to 14 cell voltages with a measurement accuracy of ±2mV.
Robust two-wire daisy chain communication system using capacitor or coupling transformer up to 1 Mbps.
Fully differential ±5V cell input range accommodates fuel cell and bus bar measurement requirements for legacy battery packs.
15-year plate-level accuracy (long-term drift) of ±6mV @ ±6σ.
High diagnostic coverage for cell voltage and temperature measurements.
AEC-Q100 Grade-2 qualified and specified to operate from -40°C to +105°C.
 
A battery management system (BMS) reference design is available, including five ISL78714 ICs and one RH850/P1M MCU to form a complete 70-cell evaluation platform for external balancing. The reference design kit provides configuration and data logging via CAN and UART. A GUI, Altium design files, and low-level drivers for the RH850 and ISL78714 peripherals are also provided. Hardware, software, and interface reference manuals are included, along with an EMC report. Together, the reference design kit makes it easy for electric vehicle system designers to port their software to the RH850 MCU, scale to any battery pack size, and save up to a year of development time.

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