STMicroelectronics L9733CN

Overview

L9733CN from STMicroelectronics is an AEC-Q100 qualified automotive octal self-configuring low/high-side driver IC. It integrates eight MOSFET output drivers capable of automatic high- or low-side configuration per channel, supports 4.5–5.5 V supply, delivers ≤0.7 Ω R_ON at 25 °C, and provides 1 A minimum current limit per output with integrated diagnostics via SPI. It is deployed in HVAC actuators, powertrain solenoids, and body control modules requiring robust fault management.

For engineers reviewing the L9733CN datasheet, L9733CN pinout, L9733CN application, or L9733CN equivalent, key selection considerations include its self-configuring topology, -40 °C to +125 °C junction temperature operation, 50 V clamp voltage for low-side outputs, -14 V clamp for high-side outputs, and daisy-chainable 16-bit SPI interface with latched fault reporting.

Technical Context

The L9733CN implements a monolithic medium-current driver architecture with internal charge pump eliminating external capacitors, enabling independent high/low-side operation on all eight outputs without configuration pins. Each channel features programmable fault detection-open load, short-to-GND, short-to-V_b, and overcurrent-in latched or unlatched mode.

Outputs 6–8 accept external PWM signals (IN6–IN8) for real-time duty-cycle control, while outputs 1–5 are SPI-only. The device operates across V_bat = 4.5–18 V and tolerates jump-start (up to 27 V/1 min) and load-dump (up to 40 V) conditions, with thermal shutdown triggered at 151–200 °C and 10 °C hysteresis.

Key Specifications

Pinout & Package

Package: PowerSSO-28 (exposed pad), thermally enhanced surface-mount package requiring exposed slug soldered to PCB ground plane for thermal and EMI performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal configurable driver applications.

Compared with TLE9201SE and BD82002FV-M, the L9733CN uniquely combines self-configuring high/low-side flexibility, integrated clamping, and external PWM inputs-making it optimal for mixed-topology automotive body and powertrain modules where layout reuse and diagnostic depth are critical.

Availability

L9733CN is available at Aetrix Electronics and suitable for HVAC actuator control, engine cooling fan driving, and transmission solenoid management requiring stable component supply across automotive production lifecycles.

Supply support for L9733CN 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 headquartered in Geneva, Switzerland, specializing in automotive, industrial, and power management ICs with broad AEC-Q100 product coverage.

The L9733CN belongs to ST's automotive smart-power driver family, designed specifically for robust, fault-tolerant control of inductive and resistive loads in harsh vehicle environments.

FAQ

What is the maximum allowable V_bat during load dump, and how long can it be sustained?

The L9733CN withstands V_bat up to 40 V during load dump events, as specified in absolute maximum ratings. However, internal protection circuits-including overtemperature shutdown and overcurrent detection-are not guaranteed functional above 27 V. Sustained operation beyond 27 V should be limited to transient durations defined by ISO 7637-2 Pulse 5a, and external TVS clamping is recommended for system-level robustness.

How does self-configuration determine high-side versus low-side topology?

Self-configuration relies on internal voltage sensing at SRCx and DRNx pins during power-up and fault detection cycles. If SRCx is detected near GND potential and DRNx near V_bat, the channel configures as low-side; if SRCx is near V_bat and DRNx near GND, it configures as high-side. No external components or register writes are required-the decision is hardware-autonomous and verified per channel.

Can outputs 1–5 be controlled by PWM, or only via SPI?

Outputs 1–5 are SPI-only and cannot accept external PWM signals. Only outputs 6, 7, and 8 feature dedicated IN6, IN7, and IN8 pins for direct PWM modulation. This partitioning enables time-critical actuation on three channels while retaining SPI-based sequencing and diagnostics for the remaining five-supporting mixed-control strategies in complex subsystems.

Is the exposed thermal pad electrically connected, and what is its voltage potential?

Yes, the exposed pad is internally connected to GND and must be soldered to a PCB copper pour tied to system analog ground. It serves both thermal dissipation (R_th(j-case) = 3 °C/W) and EMI suppression. Floating or connecting the pad to any other net-including V_bat or chassis ground-violates the thermal and electrical design and may cause malfunction or reliability failure.