bq76PL536A Battery Monitor

General Features

  • supports 3 - 6 lithium-ion cells (stackable up to 192 cells)

  • SPI comm

  • Supply Voltage Range from 6 V to 30 V Continuous and 36-V Peak

  • Has built on comparators for protections

  • Integrates an analog front end (AFE) along with a precision analog-to-digital converter (ADC), used to precisely measure battery cell voltages

  • Non-volatile memory stores the user-programmable protection thresholds and delay times

Cell Balancing

  • Six outputs (CB1 to CB6) control the external N-FETs in series with a power resistor

  • A 1 activates the external balance FET by placing a high on the associated pin.

Internal Voltage Regulators

  • The bq76PL536A derives power from the BAT pin using several internal low dropout (LDO) voltage regulators.

  • The BAT pin should be connected to the most-positive cell input from cell 3, 4, 5, or 6, depending on the number of cells connected.

Application Requirements (See page 55 for the Diagram)

  • An anti-aliasing filter is required for each VCn input VC6–VC1, consisting of a 1-kΩ, 1% series resistor and 100- nF capacitor

  • Place filter capacitors as close to the IC as possible.

  • Select the RC filter closest to the cell for filter requirements

  • Select Zener diode for lowest possible reverse leakage.

  • A balance FET gate-protection diode is required (RESEARCH THIS)

  • MOSFET with low turn-on threshold voltage (must turn on with the lowest cell voltage)

  • The LDOA, LDOD1, LDOD2 and REG50 pins all require a 2.2-µF ceramic capacitor to be placed as closely as possible to the respective pins to optimize stability.

  • The bq76PL536A requires a power supply with between 7.2 V to 27 V inputs.

  • VREF and AGND pins require a high-quality 10-µF capacitor be connected between them, in very close physical proximity to the device pins, using short track lengths to minimize the effects of track inductance on signal quality.

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