Ultra-compact driver with diagnostics, protection, and failsafe limp-home mode

Geneva, Switzerland, June 23, 2025 -- STMicroelectronics’ L9800 8-channel automotive low-side driver is ISO 26262 compliant and housed in a compact, leadless outline that saves space in body-control modules, HVAC and climate controls, and power-domain controls.

The L9800 outputs can drive resistive, capacitive, or inductive loads like relays, solenoids, and LEDs. With continuous real-time diagnostics and open-circuit, short-circuit, overcurrent, and overtemperature protection per channel, the L9800 enhances vehicle reliability and eases system-level ISO 26262 certification up to ASIL-B. The diagnostic signals are available at the L9800’s SPI port, which also provides access to the driver’s internal configuration registers for device set-up. 

The eight output channels can be driven via the SPI interface or alternatively using two dedicated parallel inputs that can be mapped to selected outputs. These pins also allow emergency hardware control of two default channels even if the digital supply voltage is not available. This lets the L9800 operate in limp-home mode, maintaining essential functions for safety and convenience, in the event of system failure such as a microcontroller fault or supply undervoltage.

The L9800 also provides a bulb-inrush mode that allows driving small lamps of about 2W or other electronic loads with high input capacitance, with protection against excessive current. In addition, the driver ensures safe operation during engine cranking with battery voltage as low as 3V.

The L9800 is available in a 4mm x 4mm TFQFN24 package and is in production now, priced at $0.52 for orders of 1000 pieces.

Please visit https://www.st.com/l9800-driver for more information.

About STMicroelectronics 

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