PMIC for mid-to-large cell count configuration battery packs in EV and HEV

Maxim Integrated MAX17853 PMIC is a single chip, ASIL-D compliant battery monitoring solution, which is available now from Mouser, for mid-to-large cell count configuration battery packs in electric and hybrid vehicles. The device employs a flexible architecture called Flexpack that enables designers to make adjustments to their module configurations to swiftly respond to market demands. As the device can monitor both high-voltage and low-voltage battery modules, designers can produce a system that satisfies the highest level of safety for voltage, temperature, and communication. The PMIC also incorporates a battery cell balancing system, which automatically balances each cell by time and voltage to reduce the risk of overcharging.

The PMIC can measure 14 cell voltages and a combination of six temperatures or system voltage measurements with fully redundant measurement engines in 263µs or complete all inputs solely with the ADC measurement engine in 156µs. The device has 14 internal balancing switches rated for >300mA for cell-balancing current, each supporting extensive built-in diagnostics. Up to 32 devices can be daisy-chained together to manage 448 cells and monitor 192 temperatures.

Cell and bus-bar voltages ranging from -2.5V to +5V are measured differentially over a 65V common-mode range, with a typical accuracy of 1mV (3.6V cell, 25C). If oversampling is enabled, up to 128 measurements per channel is able to be averaged internally with 14-bit resolution and combined with digital post-processing IIR filtering for improved noise immunity. The system can shut itself down in the event of a thermal overload by measuring its own die temperature.

For robust communications, the MAX17853 uses a Maxim battery-management UART or SPI protocol. It is optimised to support a reduced feature set of internal diagnostics and rapid-alert communication through both embedded communication and hardware-alert interfaces to support ASIL-D, and FMEA demands.

The PMIC is offered in a 10mm2 LQFP package and features a wide -40C to +125C operating temperature range.

Typical applications cover EVs, HEVs, Ele1es, UPS, battery-powered tools, high-voltage battery stacks, and super-cap systems.