The bq76PL536 is a stackable three to six series cell lithium-ion battery pack protector and analog front end (AFE) that incorporates a precision analog-to-digital converter (ADC); independent cell voltage and temperature protection; cell balancing, and a precision 5-V regulator to power user circuitry.
The bq76PL536 integrates a voltage translation and precision analog-to-digital converter system to measure battery cell voltages with high accuracy and speed.
The bq76PL536 provides full protection (secondary protection) for overvoltage, undervoltage, and overtemperature conditions. When safety thresholds are exceeded, the bq76PL536 sets the FAULT output. No external components are needed to configure or enable the protection features.
Cell voltage and temperature protection functions are independent of the ADC system. Programmable protection thresholds and detection delay times are stored in Error Check/Correct (ECC) OTP EPROM, which increases the flexibility and reliability of the battery management system.
The bq76PL536 is intended to be used with a host controller to maximize the functionality of the battery management system. However, the protection functions do not require a host controller.
The bq76PL536 can be stacked vertically to monitor up to 192 cells without additional isolation components between ICs. A high-speed serial peripheral interface (SPI) bus operates between each bq76PL536 to provide reliable communications through a high-voltage battery cell stack.
The host microcontroller controls cell balancing of individual cells by setting the registers (via SPI) which control the appropriate CBx outputs. These outputs can be turned off via the same control, or automatically by the internal programmable safety timer. The balancing bypass current is set via an external series resistor and FET.