STMicroelectronics L9658TR

Overview

L9658TR from STMicroelectronics is an octal squib driver and quad satellite sensor interface ASIC designed for automotive airbag control units (ACUs). It delivers ≥1.2 A for ≥2 ms and ≥1.75 A for ≥1 ms under 35 V load-dump conditions, supports Manchester protocol decoding for up to four satellite sensors (two with Hall effect capability), and integrates SPI-controlled diagnostics including squib resistance measurement, short-to-battery/ground detection, and MOSFET health monitoring.

For engineers reviewing the L9658TR datasheet, L9658TR pinout, L9658TR application, or L9658TR equivalent, this device is selected for high-reliability safety-critical deployment sequencing, real-time satellite sensor data acquisition, and fault-isolated squib actuation in ISO 26262-compliant ACU designs - requiring precise current delivery timing, diagnostic coverage per channel, and robust SPI register-level control.

Technical Context

The L9658TR implements dual-domain SPI control: one interface (CS_D) manages eight independent deployment drivers with programmable arming/deployment timing and per-channel fault reporting; another (CS_S) handles four satellite channels supporting variable-bit-rate Manchester decoding, FIFO buffering, and raw Hall sensor signal capture on CH3/CH4. Each satellite channel features independent current-limit shutdown, continuity check, and protocol-specific error detection ("A" fixed-length or "B" variable-length).

Deployment drivers use independently controlled high-side and low-side MOSFETs enabling open-load, short-to-ground, and short-to-battery diagnostics via SPI-accessible registers. The device includes internal voltage regulation (V8BUCK), analog output (AOUT) for squib resistance readback, and loss-of-ground detection - all operating across a 6.9–18 V supply range with 2 kV HBM ESD protection on all pins.

Key Specifications

Pinout & Package

Package: 64-lead LQFP (10 × 10 mm, 0.5 mm pitch), RoHS-compliant, with exposed thermal pad for enhanced heat dissipation in safety-critical modules.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar squib driver and satellite sensor interface applications.

Compared with MC33816 and RAA215210, the L9658TR uniquely combines octal squib drive, Manchester satellite decoding, and dual Hall-capable inputs in a single LQFP64 package - enabling compact, self-contained ACU designs without external signal conditioning or protocol translation.

Availability

L9658TR is available at Aetrix Electronics and suitable for automotive airbag control units, occupant classification systems, and seat belt pretensioner modules requiring stable component supply, long-term lifecycle assurance, and ASIL-B/D-compliant sourcing.

Supply support for L9658TR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader specializing in automotive-grade ICs, power management, and safety-critical analog/mixed-signal solutions.

The L9658TR belongs to ST's automotive safety ASIC product line, engineered specifically for airbag electronic control units needing integrated squib actuation, satellite sensor interfacing, and comprehensive hardware-level diagnostics per ISO 26262 requirements.

FAQ

What is the minimum VRES voltage required to achieve 1.2 A squib drive current?

The L9658TR guarantees ≥1.2 A squib drive current at VRES = 6.9 V, validated under cold-crank conditions. This specification ensures reliable deployment even during engine start-up when battery voltage dips below 7 V, meeting ISO 16750-2 requirements for automotive electrical systems.

How does the L9658TR handle Manchester protocol bit-rate variation across satellite nodes?

The L9658TR implements automatic bit-rate detection for Manchester-encoded satellite messages, supporting variable rates from 10 kbps to 1 Mbps without reconfiguration. Its decoder synchronizes to incoming edges and adapts sampling windows dynamically, eliminating need for pre-negotiated timing parameters.

Can the Hall effect inputs on CH3 and CH4 be used simultaneously with Manchester decoding?

No - CH3 and CH4 are multiplexed: they operate either as Manchester data inputs (satellite mode) or as analog Hall sensor inputs (Hall mode), selected via SPI configuration register CCR3/CCR4. Both modes cannot be active concurrently on the same channel.

What fault conditions trigger automatic shutdown of a satellite channel?

Each satellite channel shuts down independently upon detecting overcurrent (exceeding programmable trip point), open circuit, short-to-ground, or short-to-battery. Shutdown is enforced by dedicated fault timers and latched until cleared via SPI command, ensuring no spurious reactivation during transient faults.