New series of automotive battery monitoring protection ICs released

A new solution for forward-looking functional safety with automotive grade protection ICs for EVs and e-Bikes ～

ABLIC has launched the S-19193 Series of automotive three to six-cell battery monitoring protection ICs.

BMS for EVs, e-bikes, etc., need to be functionally safe and compliant with ISO26262, the standard for functional safety in road vehicles. The acceptance criteria for functional safety are (1) fail-safe (the ability to return to a safe state in the event of a failure or malfunction), (2) fail-operational (the ability to continue operation even in the event of a failure or malfunction), and (3) fail-degraded (the ability to continue operation with decreased functionality). In the past, the conventional method of achieving (1) fail-safe functional safety was to use an MCU with a high-performance IC called an AFE to monitor automotive battery overcharge and overdischarge conditions.

Under the conventional (1) fail-safe methodology, the safety of a driver is ensured by 'returning to a safe state', i.e. stopping the vehicle in the event of an actual failure or malfunction, and there was no requirement for continued monitoring of batteries after the vehicle had safely stopped.

However, with the evolution of automated driving technologies, it is expected that there will be an increase in cases where the system, rather than the driver, handles any problems that occur, so the (2) fail-operational and (3) fail-degraded methodologies, which permit for continued operation even in the event of a failure or malfunction, are becoming increasingly important.

The new series of automotive three- to six-cell battery monitoring protection ICs are products developed in ISO 26262 compliant processes and are equipped with functions for monitoring automotive battery overcharge and overdischarge.

Using the series makes it possible to continue battery monitoring as a secondary system even in the event the conventional monitoring system (primary) fails and to achieve a safer BMS that is (2) fail-operational and (3) fail-degraded compliant.

There are also examples of AFE and MCU internal monitoring functions configured as primary and secondary, but these are primarily for failure and fault detection through mutual monitoring and are insufficient for backup of functionality. Internal redundancy also poses a risk of 'joint failure', where the loss of functionality occurs simultaneously with the occurrence of a failure; however, with the series, the secondary monitoring can be made completely independent from the primary monitoring to mitigate the risk of joint failures.

The new series also makes it possible to configure a stand-alone operation secondary monitoring circuit that does not need MCU control, which can also contribute to reducing the number of design processes.

A Safety Manual is also available for download to support BMS functional safety design using the S-19193 Series. The product is also compliant with the PPAP established by the U.S. Automotive Industry Action Group (AIAG) and planned to be compliant with AEC-Q100 Grade1.