1 Features

• Two fast pack voltage measurements

– Dedicated single-ended measurements; ASIL-D

– HV Measurement Accuracy <0.4% ; 0.3-5v

single ended

– 0uS VI sync within BQ79881; fast 5uS typical

VI Sync with cell measurements

• Accurate Single-Ended Measurements

– Up to 18 single ended ADC inputs; ASIL-D

– HV Measurement Accuracy <0.4%; 0-5V single

ended

– Usable as ratiometric temperature sense inputs

– Configurable 1.8V/2.5V/3.3V reference for HV

measurements

• Four Current Sense ADCs

– Measure up to two separate currents; ASIL-D

– Input range = +/-275mV differential, +/-750mV

common mode; ASIL-D

– 0.1% accuracy. 10mA (50u Rshunt)

• Over Current Comparators

– Dedicated fast overcurrent digital comparator

per CS ADC; ASIL-D

– Response : 100uS to 1mS. Accuracy: 1%

– Thresholds: 0mV to +/-300mV.

– OC response on GPIO pins.

– Majority voting option

• Upgraded Daisy Chain Interface

– 2x parallel SPI ports to MCU to support split

chain with single bridge device

– 2-wire isolated interface, SPI to MCU

– 2Mbps single chain/ring, 4Mbps split chain for

up to 4x speed improvement

– Closed Loop BCI: 200mA; Open Loop BCI:

300mA

– Isolation: Transformer or capacitor-only

– FDTI Time: <100ms for 800V packs or 250 cells

– Support for ring architecture

– Reverse wakeup available without ring

architecture

• Smart EIS Engine

– Integrated Electrochemical Impedance

Spectroscopy measurement engine

– Impedance Accuracy: 1% with 1A excitation,

>200uΩ impedance

– Excitation frequency: 0.01Hz – 3.5kHz

– < 5us I/V synchronization from device to device

– Support for global excitation

• Other

– 12V switch drive pins to drive NMOSFET or

Opto-MOS switches

– Package: 48-pin QFN, 0.5mm pitch

– Meets AEC-Q100 and ISO26262 ASIL-D

Functional Safety

• – Power Consumption

• Active mode: < 100mW

• Sleep mode: < 0.5mW

• Deep sleep mode: < 0.05mW

2 Applications

• Battery Management System (BMS) in hybrid and

electric powertrain systems

• Energy storage battery packs with Battery

Management Systems

3 Description

The device can be used to measure divided down

high voltage nodes in a battery system. It can

measure voltages across Fuses and Contactors, and

it can check isolation voltages in battery junction box

(BJB) systems. The device has four integrated current

sense paths supporting low side shunt resistors.

Coulomb counting is available for accurate SOC

calculation. There are 18 GPIOs/auxiliary inputs

that can be used for HV measurements, thermistor

measurements and driving relays. There are 4 SW

outputs that can be used to drive MOSFET switches

in the measurement path. The device can function

as a SPI and I2C HUB and interface with up

to 8 separate SPI devices/groups. Over current

protection response can be achieved autonomously

using OC Pins for fast reaction in dangerous over

current events. The isolated bi-directional daisy chain

ports support both capacitor and transformer based

isolation. The device can also communicate with MCU

over SPI.