STMicroelectronics EVAL5973D

Overview

EVAL5973D from STMicroelectronics is an evaluation board for the L5973D 2.5 A step-down switching regulator IC, designed to demonstrate adjustable DC-DC conversion from 4 V to 36 V input to 1.235–35 V output with 250 kHz fixed frequency, internal P-channel MOSFET (R_DS(on) = 250 mΩ), and thermal shutdown protection - used in power supply validation for LCD monitors, car radios, and industrial DC-DC modules.

For engineers reviewing the EVAL5973D datasheet, EVAL5973D pinout, EVAL5973D application, or EVAL5973D equivalent, this board enables rapid functional verification of the L5973D's voltage feedforward control, synchronization capability, zero-load operation, and feedback disconnection protection under real-world thermal and load conditions.

Technical Context

The EVAL5973D implements a complete reference design for the L5973D monolithic buck regulator, featuring an HSOP8-exposed-pad package layout with optimized thermal path (R_th(j-amb) ≈ 40 °C/W), 15 µH power inductor (Coilcraft DO3316P-153), and STPS2L25U Schottky output diode. It supports adjustable output via external resistor divider (R1/R2/R3) and includes SYNC, INH, COMP, and FB terminals for full control loop evaluation.

It validates key L5973D behaviors: pulse-by-pulse current limiting (2.5–3.5 A trip), 3.3 V ±2% reference accuracy, 100% duty-cycle low-dropout mode, and stable operation down to 0 A load - all verified across -40°C to +125°C junction temperature range per DS2671 Rev 17.

Key Specifications

Availability

EVAL5973D is available at Aetrix Electronics and suitable for LCD monitor power supplies, automotive infotainment systems, and industrial DC-DC converter development requiring stable component supply and full-function evaluation capability.

Supply support for EVAL5973D 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 power management, microcontrollers, and analog ICs for industrial, automotive, and consumer markets.

The EVAL5973D belongs to ST's power evaluation board portfolio, developed specifically to accelerate adoption of the L5973D buck regulator in high-reliability, thermally constrained applications such as set-top boxes, printers, and battery-powered DC-DC systems.

FAQ

What input voltage range is supported on the EVAL5973D board?

The EVAL5973D board supports 4.4 V to 25 V DC input, constrained by the 25 V rating of C1 (GRM32DR61E106KA12L ceramic capacitor) and 6.3 V rating of C2 (POSCAP 6TPB330M). Operation beyond 25 V risks capacitor overvoltage and is not validated per DS2671 Rev 17 Figure 12.

Can the EVAL5973D be used to test output voltages below 1.235 V?

Yes - the board supports sub-1.235 V outputs using the external circuit in Figure 19 of DS2671 Rev 17, where V_OUT = V_FB – [(V_REF – V_FB) × (R2/R1)], enabling minimum output of 0.6 V with proper resistor selection and load bleed resistor.

Does the EVAL5973D provide synchronization capability for multi-rail designs?

Yes - the board exposes the SYNC pin (Pin 2) of the L5973D, allowing master-slave configuration with external clock signals between 212–280 kHz. Slave sink current is specified at 0.11–0.45 mA, and master output amplitude reaches 2.75–3 V with 3 mA source load per Table 4.

How is thermal performance validated on this evaluation board?

Thermal performance is validated using the HSOP8-exposed-pad layout per Figure 20 and Table 6, achieving R_th(j-amb) ≈ 40 °C/W. Figure 8–9 in DS2671 Rev 17 show junction temperature vs. output current up to 2.6 A at V_IN = 12 V, confirming safe operation within -40°C to +125°C T_J range.