STMicroelectronics A5973D013TR

Overview

A5973D013TR from STMicroelectronics is a monolithic step-down (buck) switching regulator IC designed for automotive power systems, featuring an internal P-channel DMOS switch (R_DS(on) = 250 mΩ), 2 A DC output capability, 4–36 V input range, and AEC-Q100 qualification for under-hood applications including engine control units and body electronics.

For engineers reviewing the A5973D013TR datasheet, A5973D013TR pinout, A5973D013TR application, or A5973D013TR equivalent, key selection criteria include cold-crank operation down to 4 V, 250 kHz fixed-frequency PWM with synchronization support, thermal shutdown at 150 °C ± 10 °C, and feedback disconnection protection - all critical for functional-safety-compliant 12 V/24 V automotive subsystems.

Technical Context

The A5973D013TR implements voltage-mode PWM control with an integrated transconductance error amplifier (g_m = 2.3 mS, gain = 65 dB), internal 3.3 V reference (±0.3% over temperature), and feedforward-enhanced oscillator for line regulation stability. Its pulse-by-pulse current limiting (2.25–3.5 A min/max) combines with frequency foldback to maintain safe inductor current during short-circuit events.

Thermal performance is enabled by the HSOP8 package with exposed thermal pad (R_th(JA) = 40 °C/W on evaluation board), supporting continuous 2 A output at ambient temperatures up to +70 °C without forced airflow. The inhibit (INH) pin provides <100 µA standby current when pulled high (>2.2 V), enabling low-power sleep modes in infotainment and ADAS modules.

Key Specifications

Pinout & Package

Package: HSOP8 with exposed thermal pad (JEDEC MO-220 variant), optimized for automotive PCB layouts requiring low R_th(JA) and mechanical robustness.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar step-down regulator applications.

Compared with LM2678SD-5.0/NOPB, A5973D013TR adds AEC-Q100 compliance, cold-crank operation, and integrated VREF - essential for automotive deployment. Versus TPS54240DGQR, it trades higher switching frequency for superior line transient response via feedforward and lower component count via internal reference and gate driver.

Availability

A5973D013TR is available at Aetrix Electronics and suitable for engine control units, ADAS camera modules, body control modules, and infotainment systems requiring stable component supply across extended automotive temperature ranges and long production lifecycles.

Supply support for A5973D013TR 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 vertical manufacturing and AEC-Q100-aligned quality systems.

The A5973D belongs to ST's automotive-grade power management portfolio, engineered specifically for under-hood and safety-critical subsystems demanding high reliability, wide input range, and integrated protection features.

FAQ

What is the maximum recommended PCB copper area for the HSOP8 thermal pad?

The datasheet specifies mounting on an evaluation board with R_th(JA) = 40 °C/W, achieved using a 20 mm² exposed pad connected to a 2-layer internal ground plane with ≥6 thermal vias (0.3 mm diameter). For production boards, ST recommends ≥30 mm² copper area with ≥8 vias to sustain 2 A continuous output at +70 °C ambient.

Can the A5973D013TR operate with an input voltage below 4 V?

No - the absolute minimum operating input voltage is 4 V, verified across -40 °C to +125 °C junction temperature. Below this, UVLO disables the regulator to prevent erratic switching or insufficient gate drive for the internal P-MOSFET. This threshold ensures reliable cold-crank operation in 12 V automotive systems.

How does the feedback disconnection protection trigger?

When the FB pin voltage rises above 1.8 V (indicating open-circuit feedback divider), the internal comparator forces the COMP pin low and halts switching within one cycle. This prevents uncontrolled output voltage rise - a critical safeguard when powering sensitive 3.3 V or 5 V logic that lacks overvoltage tolerance.

Is external compensation mandatory for stable operation?

Yes - the COMP pin requires an external Type II or Type III compensation network (typically RC + C network) to set loop crossover frequency and phase margin. ST provides design equations and example values in Section 7.1 of the datasheet; omitting compensation causes oscillation or poor transient response, especially with ceramic output capacitors.