ABLIC launches automotive window voltage detectors

The automobile industry is endeavouring to improve the quality of automobile parts in order to proactively prevent traffic accidents while simultaneously implementing functional safety (*1) initiatives in order to reduce the impact of any accidents which may occur in the rare event of a failure

Automobiles contain a wide variety of safety devices, such as EPS (Electric Power Steering) which provides power via an electric motor to assist with steering. EPS is essential for lane keep assist, parking assist, and other ADAS/autonomous driving systems to provide fine-tuned control via an electric motor. Voltage detectors are used to monitor EPS voltage for greater safety.

In the past, it was the general practice that voltage detectors were used only for voltage monitoring of undervoltage, while protective elements (Zener diodes) were connected for handling of overvoltage. Although overvoltage is less frequent than undervoltage, overvoltage also poses a risk of failure, and therefore there is a rising demand for functional safety to not only provide protection from overvoltage, but to detect voltage anomalies in order to determine whether a failure has occurred and take necessary control measures accordingly. In addition, in EPS and other applications which require more granular functional safety support, there is increased demand for faster detection of anomalies and greater care for non-safe faults (*2).

The S-191A Series window voltage detector launched is a window monitoring voltage detector which monitors both undervoltage and overvoltage. The product features the industry's highest class (*3) 10μs typ. response time from detection of an undervoltage or overvoltage anomaly to output and is also equipped with a manual reset function (*4) which enables diagnosis of non-safe IC faults. The product is able to achieve higher functional safety and contribute to better automotive safety thanks to these features.

The S-191A Series is also PPAP (Production Part Approval Process) capable and planned for compliance with Grade 1 of the AEC (*)-Q100 (*Automotive Electronics Council) quality standard for automotive ICs.

Major features

Window detection

The S-191A Series is a window voltage detector which is capable of both undervoltage and overvoltage monitoring. In addition, the product allows for detection voltage for both undervoltage and overvoltage detection to be set separately. This allows for more flexible accommodation of customer requirements than systems where detection voltage is set according to monitored voltage and vertically equalised window width.

Industry’s highest class (*3) fast detection

The S-191A Series delivers a fast response time of 10μs typ. from undervoltage or overvoltage detection to output, which places it in the industry’s highest class for fast detection. Quick detection of voltage anomalies ensures fast output of detection signals to the microcontroller and improves system safety.

The manual reset function (*4) enables diagnosis of non-safe faults

The S-191A Series is capable of diagnosing non-safe IC faults using a manual reset function. Misinterpreting a voltage fault as normal voltage (=incorrect release) would be a non-safe fault for a voltage detector. The product forcibly sets detection status in the IC when manual reset is enabled, which makes it possible to determine that a failure which could lead to incorrect release is occurring when the output does not switch to ‘detected’ and remains ‘released’ when manual reset is enabled.

The ultra-compact package contributes to a smaller footprint

The S-191A Series is housed in an ultra-compact automotive HSNT-8(1616)B (1.6 x 1.6 x t0.41mm) package making it 70% smaller than ABLIC's conventional products.

Major specifications

• Operating voltage range: 2.5 to 6.0V
• Voltage detection range:
  • Undervoltage detection voltage 0.6 to 4.9V
  • Overvoltage detection voltage 0.7 to 5.5V
• Detection voltage accuracy:
  • Undervoltage detection voltage: ±1.5%
  • Overvoltage detection voltage: ±1.5%
• Hysteresis width: Selectable Off (0%), On (3.0%, 5.0%, 10.0%)
• Detection response time: 10.0µs typ.
• Manual reset function: MR pin input logic: Active “L”
• Release delay time accuracy: ±15% (CD = 3.3 nF)
• Output format: Nch open drain output
• Current consumption: 1.5μA typ.
• Operation temperature range: Ta = -40°C to +125°C
• Lead-free (Sn 100%), halogen-free
• AEC-Q100 in process (*5)

(*1) Functional safety : The incorporation of functional innovations to maintain an acceptable level of safety

(Reference: https://www.ablic.com/en/semicon/products/automotive/asil/)

(*2) Non-safe faults : A failure that impacts safety. For a voltage detector, this is the failure to detect a fault which should have been detected.

(*3) As a window voltage detector for 6V operation. Based on our research as of October 2023

(*4) Manual reset function : A function which can forcibly output a reset signal based on signal input to the reset IC MR (Manual Reset) pin.

(Reference: https://www.ablic.com/en/semicon/support/faq/power-management-ic/voltage-detector-reset-ic/record-391/)

(*5) Contact our sales office for further details.

Application examples

• Voltage monitoring of automotive ECUs, ADAS, and other systems that require failure detection
• For automotive use (engine, transmission, suspension, ABS, related-devices for EV/HEV/PHEV, etc.)