STMicroelectronics L9820D

Overview

L9820D from STMicroelectronics is a high-side power switch IC designed for driving resistive or inductive loads with one terminal grounded. It operates up to 25 V supply voltage, delivers 0.3 A continuous output current, features on-resistance < 0.8 Ω at 25°C, and integrates diagnostic feedback and thermal/overcurrent/overvoltage protection. It is used in automotive body control modules for lamp and solenoid actuation.

For engineers reviewing the L9820D datasheet, L9820D pinout, L9820D application, or L9820D equivalent, key selection criteria include its TTL-compatible enable input, active-low diagnostic output with 30 µs fault detection delay, integrated short-circuit current limiting (1.5 A), thermal shutdown at 150°C, and SO8 package compatibility with PCB layout constraints in space-constrained ECUs.

Technical Context

The L9820D implements a monolithic high-side driver using ST's Multipower BCD technology, integrating a power MOSFET stage, charge pump, protection logic, and diagnostic circuitry. Its enable input controls both power stage and internal biasing, reducing quiescent current to ≤300 µA in standby mode.

Diagnostic feedback is active only when ENABLE is high and reports overvoltage (>25 V), overtemperature (≥150°C), or short-circuit events via open-drain low-active output. Fault detection includes 2–5 V hysteresis for overvoltage and 25–50°C hysteresis for thermal events to prevent chatter during transient conditions.

Key Specifications

Pinout & Package

Package: SO8 (Small Outline, 8-pin, 150 mil width), compliant with JEDEC MS-012, thermal resistance R_{th j-amb} = 200 °C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS27081A and VND5E025AK, the L9820D offers balanced protection integration and diagnostic simplicity at lower system cost-ideal for cost-sensitive automotive body electronics where 0.3 A drive and basic fault reporting meet functional safety requirements.

Availability

L9820D is available at Aetrix Electronics and suitable for automotive lighting control, solenoid actuation, body control module outputs, and industrial PLC digital output stages requiring stable component supply across production lifecycles.

Supply support for L9820D 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, designing and manufacturing analog, power, MCU, and sensor solutions for automotive, industrial, and consumer markets.

The L9820D belongs to ST's "VIPower" family of intelligent power switches, engineered specifically for robust, protected high-side load control in automotive body electronics and industrial I/O applications.

FAQ

What is the maximum load voltage the L9820D can safely switch?

The L9820D supports a maximum forward supply voltage of 50 V (absolute max), but its overvoltage protection triggers at 25 V. For reliable operation in automotive 12 V systems-including load-dump transients per ISO 7637-2-it is rated for continuous use up to 25 V, with built-in clamping and hysteresis to avoid nuisance trips.

Does the L9820D require an external pull-up resistor on the DIAG pin?

Yes-the DIAG pin is an open-drain output and must be pulled up externally (typically to 5 V or V_S) with a resistor between 4.7 kΩ and 10 kΩ. This ensures proper logic-level recognition by the host microcontroller and guarantees sufficient sink current (up to 10 mA) during fault conditions.

Can the L9820D drive inductive loads without external flyback protection?

No-while the device includes internal clamp diodes for limited energy dissipation, it does not integrate full flyback suppression. An external freewheeling diode (e.g., 1N4007) must be placed across inductive loads (e.g., solenoids, relays) to prevent voltage spikes exceeding 50 V and ensure long-term reliability.

How does the ENABLE pin reduce power consumption in standby mode?

When ENABLE is driven low, the L9820D disables its internal charge pump, power stage, and diagnostic circuitry, reducing total supply current to ≤300 µA at 85°C. This ultra-low quiescent state allows integration into always-on vehicle networks (e.g., CAN wake-up nodes) without excessive battery drain over extended parking periods.