STMicroelectronics L9822N

Overview

L9822N from STMicroelectronics is an octal low-side solenoid driver in PowerSO-20 package, featuring eight 0.53 Ω (typ.) DMOS outputs rated for 1 A continuous current at 25°C, SPI serial interface, and integrated diagnostic feedback via 8-bit serial output. It drives automotive solenoids, relays, and lamps with internal 35 V clamping, short-circuit protection, and open-load detection.

For engineers reviewing the L9822N datasheet, L9822N pinout, L9822N application, or L9822N equivalent, key selection criteria include R_DS(on) stability across temperature, fault reset timing (75–250 µs), SO diagnostic bit alignment with output states, and CE-controlled latch/shift register handshaking for daisy-chained configurations.

Technical Context

The L9822N implements a three-block architecture: an 8-bit SPI shift register for serial data ingestion and diagnostic readback, a parallel latch that holds output control bits and resets on overvoltage faults (>1.6 V), and eight independent low-side DMOS drivers with integrated 36 V zener clamps and voltage-sense comparators.

Operation relies on precise CE edge sequencing: CE falling edge captures real-time output voltage status into the shift register; CE rising edge latches new control data to outputs while initiating a 160 µs fault-protection inhibit window. SCLK edges are gated by CE, ensuring no spurious clocking during deselection.

Key Specifications

Pinout & Package

Package: PowerSO-20 (thermally enhanced surface-mount, R_th(j-case) = 1.5 °C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-side solenoid driver applications.

Compared with TLE6232GP and ULN2803A, the L9822N uniquely combines SPI configurability, per-channel digital diagnostics, and integrated clamping in a single PowerSO-20 package - making it optimal for space-constrained, safety-aware automotive and industrial systems requiring traceable fault logging.

Availability

L9822N is available at Aetrix Electronics and suitable for automotive body control modules, industrial PLC output stages, HVAC zone actuators, and medical infusion pump drive circuits requiring stable component supply and long-term lifecycle support.

Supply support for L9822N 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, designing and manufacturing microcontrollers, power ICs, sensors, and automotive-grade analog devices.

The L9822N belongs to ST's Automotive Smart Power portfolio, engineered specifically for robust, diagnostic-capable load driving in harsh environments - emphasizing functional safety, thermal resilience, and EMI-hardened interfaces.

FAQ

What is the maximum continuous current per channel for the L9822N?

The L9822N supports 500 mA continuous current per channel under standard operating conditions (T_j ≤ 125°C, V_CC = 5 V). At 1 A, R_DS(on) is specified at 25°C but requires careful thermal design due to power dissipation; derating applies above 85°C ambient.

How does the L9822N detect open-circuit conditions?

When an output is programmed OFF (SI = high), the internal comparator pulls the corresponding SO bit LOW if the output pin floats - indicating no external load connection. A HIGH SO bit in this state signals an open-circuit fault, confirmed by comparing diagnostic bits against prior control data.

Can multiple L9822N devices be cascaded on a single SPI bus?

Yes - the SO pin of one L9822N connects directly to the SI pin of the next, forming a daisy chain. All devices share SCLK and CE lines; CE must be asserted simultaneously. Diagnostic and control data shift through the entire chain in 8-bit increments per device.

Is the L9822N compliant with automotive AEC-Q100 standards?

No - the L9822N is not AEC-Q100 qualified. It was designed for industrial and commercial automotive applications (e.g., non-safety-critical BCM functions) and operates across –40°C to +150°C junction temperature, but lacks formal qualification documentation for passenger vehicle safety-critical systems.