AEC-Q PSU Monitoring IC with Self-Diagnostics for ADAS/Automated Driving Functional Safety
Rohm released a power supply monitoring IC, the BD39040MUF-C, with BIST (Built-In Self Test) that supports functional safety. This IC is suitable for automotive application power supply systems requiring fail-safe measures such as electric power steering as well as sensors and cameras for ADAS and autonomous driving.
The PSU monitoring IC is useful for radars, cameras, and sensors for ADAS/automated driving, ECUs, electric power steering, dashboard cluster LCD panels, infotainment, lamps, and other power systems requiring functional safety measures beyond ASIL-B.
Rohm points out that rapid progress in ADAS and automated driving in the automotive sector have encouraged demand for functions such as collision prevention and lane assist that reduce the accident risk.
Consequently, product development for mounted semiconductors has to ensure functional safety (fail-safe) in the event of failure with self-diagnostic and other functions.
Rohm cites its recent developments which supported functional safety. In 2017 ROHM developed an LCD chipset comprised of LCD drivers and power supply ICs which supported functional safety. Then, in 2018 the company acquired certification of the development process under the international functional safety development standard ISO26262.
Now, when judging the safety and redundancy of systems, incorporating various self-test and monitoring functions Rohm claims its created the industry's first power supply monitoring IC with a built-in self-diagnostic function that makes it easy to add functional safety to existing systems.
The BD39040MUF-C is a power monitoring IC that offers monitoring functions required for functional safety in the power supply systems of ADAS sensor modules. In addition to voltage monitoring functions (Power Good, reset) and a watchdog timer for monitoring the ECU essential for functional safety, Rohm also asserts that its power supply monitoring IC is the first in the industry to introduce a self-diagnostic function.
By utilizing original technology, this IC makes enables the detection of potential failure of the power supply IC without affecting existing systems.
The integration of these functions into a compact 3mm square package makes it suitable for ADAS applications demanding miniaturization.
Samples are available now and OEM quantities will be available in August 2019.
(Click on image to enlarge)
Key Features
The BD39040MUF-C is the first power supply monitoring IC in the industry to include a self-diagnostic function along with additional features that make it ideal for functional safety systems required for ADAS and automated driving.
1. Self-diagnostic function provides the reliability needed for functional safety
For functional safety, to clear the highest safety requirement level (ASIL), detection of potential failures of the power supply monitoring functions themselves are needed. For example, if a failure occurs when a monitoring function (such as over-voltage) cannot detect an abnormality, the failed monitoring function becomes a hidden fault that masks the breakdown, creating a dangerous situation.
In order to overcome this, the BD39040MUF-C with self-diagnostic function employs original circuit technology that enables the detection of potential failures beforehand. Both the reference voltage and oscillator circuits are multiplexed for continuous mutual monitoring between systems to improve safety during regular operation.
2. Provides flexible support for existing systems
Rohm says that the BD39040MUF-C easily supports functional safety in existing systems without any changes of power supply sequences. Additionally, the watchdog timer for ECU can be adjusted via external resistance and the effective monitoring timing arbitrarily set ON/OFF.
Moreover, the IC comes in a compact 3mm square package suitable for ADAS and automated driving applications demanding a smaller form factor.
3. Integrates various monitoring functions required by automotive power supplies and ECUs
The BD39040MUF-C combines a range of monitoring functions, including over-voltage and under-voltage monitoring (Power Good) required for power supplies, and watchdog timer and reset functions demanded by ECUs. Among these, the watchdog timer is a window-type that monitors whether the ECU is stuck in a loop within a programmable timeout period.
Product Overview
- Input Voltage Range: 2.7V to 5.5V
- Self-diagnostic function
- Reset function (over-voltage/under-voltage monitoring)
- 4ch voltage monitoring function (overvoltage/undervoltage)
- Reference voltage self-monitoring function
- Oscillation frequency self-monitoring function
- Window-type watchdog timer (WDT)
- (Monitoring time can be set via external resistor; effective WDT timing can be turned ON/OFF)
- Enables air/ground fault detection of the WDT input signal using the WDOUT pin
- AEC-Q100 (Grade 1) qualified
