Why FRAMs go well with information logging in EDR for airbags, ADAS


Occasion information recorders (EDRs) in automotive functions like airbag security techniques and superior driver help techniques (ADAS) more and more demand specialised data-logging reminiscence gadgets that may immediately seize and reliably retailer vital information for many years.

To handle the necessity for steady information logging in automotive designs, Infineon has expanded its portfolio by including two new ferroelectric RAM (FRAM) reminiscence gadgets in 1-Mbit and 4-Mbit densities to its EXCELON household. The German chipmaker claims that its 1-Mbit gadgets are the business’s first automotive-qualified serial FRAMs.

The brand new FRAM gadgets declare to realize steady information logging with prompt non-volatility to shortly seize pre- and post-collision occasion information and retailer immediately on energy loss. Consequently, it minimizes reliance on giant backup capacitors which will fail throughout a collision or present inadequate cost.

 

Determine 1 Knowledge logging is increasing in automotive functions pushed by growing electrification and superior security techniques. Supply: Infineon

FRAM, a non-volatile reminiscence that makes use of a ferroelectric capacitor product of lead zirconate titanate (PZT) to retailer information, has the traits of each a ROM and a RAM. So, it may be purpose-built for mission-critical information logging, and its ample non-volatile information storage may be tailor-made for automotive EDR functions.

FRAMs in airbags and ADAS

In EDR settings, Infineon’s Auto FRAM gadgets complement high-density storage like eMMC flash, which can not retailer constantly in real-time and depend on backup capacitors to switch after the collision, risking the lack of vital information. Repeatedly logging FRAM reminiscence may also ease the load on the embedded SRAM buffer.

Determine 2 FRAMs can seize as much as 20 ms of time-stamped EDR information forward of a collision occasion. Supply: Infineon

Take the case of airbag EDRs that seize from 5 to twenty seconds of time-stamped information metrics in a collision occasion to help in accident reconstruction and car security analysis (Determine 2). And automakers and regulators require that EDRs report a minimum of three occasions which will happen in a crash or roadway departure.

Then there are ADAS functions that seize front-facing digicam photos constantly for 4 seconds earlier than and after a collision-like occasion to help in accident reconstruction and car security analysis. Right here, an FRAM can seize real-time digicam photos earlier than and after collision-like occasions and retailer them immediately on energy loss (Determine 3).

Determine 3 FRAMs can seize real-time digicam photos earlier than and after collision-like occasions and retailer immediately on energy loss. Supply: Infineon

That clearly makes the case for reminiscence densities tailor-made to particular use circumstances requiring information logging. “Knowledge logging necessities are rising quickly in automotive techniques, as traits towards broader use of digital techniques and business rules have inspired using high-reliability non-volatile reminiscences in airbag security techniques, together with engine management and battery administration techniques,” stated Ramesh Chettuvetty, VP of RAM Options at Infineon.

He added that the zero delay write functionality of those FRAMs permits system information to be captured and recorded as much as the final prompt earlier than an accident or different user-defined set off occasion. Right here, zero delay write implies that it facilitates the write information to reminiscence cells at bus speeds with no soak time to realize prompt non-volatility. In different phrases, it eliminates “soak time” by immediately backing up information on energy loss.

Learn/write endurance and pace

Infineon’s portfolio of automotive FRAM reminiscence gadgets ranges from 4 Kbit to 16 Mbit densities. These FRAMs characteristic quick and dependable learn/write efficiency at speeds as much as 50 MHz in SPI mode and as much as 108 MHz in quad SPI (QSPI) mode. This information switch can match or exceed conventional parallel interfaces whereas lowering pin rely dramatically.

Subsequent, these FRAMs present limitless write cycle endurance to log information each 10 µs over 20 years. Meaning automotive techniques like airbags and ADAS can log information constantly over a 20-year product lifespan.

Right here, it’s necessary to notice that low endurance reminiscences like EEPROMs can not retailer constantly in real-time and depend on backup capacitors to switch after the collision, risking the lack of vital information. However, these FRAMs declare 10 trillion learn/write cycles of endurance and devour 200 instances decrease energy than EEPROMs for lively writes.

Each 1 Mbit (CY15B201QN-50SXE) and 4 Mbit (CY15B204QN-40SXE) EXCELON FRAM gadgets at the moment are in quantity manufacturing.

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