Vishay Siliconix SIC431EVB

Overview

SIC431EVB from Vishay Siliconix is an evaluation board for the SiC431 24 A synchronous buck DC/DC converter IC, supporting 3 V–24 V input and adjustable 0.6 V–20 V output. It implements voltage-mode constant-on-time (VM-COT) control with programmable 300 kHz–1 MHz switching, integrated high-side (6 mΩ) and low-side (2 mΩ) MOSFETs, and full protection including OVP, UVP, OCP, OTP, and PGOOD. Designed for rapid validation of point-of-load (POL) power stages in server, industrial, and telecom applications.

For engineers reviewing the SIC431EVB datasheet, SIC431EVB pinout, SIC431EVB application, or SIC431EVB equivalent, this board enables fast characterization of transient response, efficiency mapping across load and frequency, soft-start timing, mode selection (forced CCM, power save, ultrasonic), and pre-bias startup behavior - all using the production-grade SiC431AED-T1-GE3 IC in MLP44-24L package.

Technical Context

The SIC431EVB implements a complete microBUCK® reference design centered on the SiC431 controller IC, which integrates gate drivers, VM-COT control logic, internal ramp generation, error amplifier compensation, and protection circuitry. Its layout features optimized power loop routing, separate AGND/PGND planes tied at a single point, and thermal vias under the MLP44-24L footprint to support 24 A continuous operation.

It supports all SiC431 configuration modes via resistor-selectable MODE1/MODE2 pins, includes jumpers for EN control and PGOOD monitoring, and provides test points for VIN, VOUT, SW, FB, and PGOOD signals. Input capacitance uses parallel 22 μF ×2 + 100 nF; output employs four 100 μF ceramic capacitors plus optional bulk electrolytic; inductor is 300 nH with 0.7 mΩ DCR.

Key Specifications

Availability

SIC431EVB is available at Aetrix Electronics and suitable for server power delivery, industrial PLC I/O modules, and telecom base station POL conversion requiring stable component supply and rapid prototyping capability.

Supply support for SIC431EVB 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

Vishay Siliconix is a global leader in discrete semiconductors and passive components, specializing in high-efficiency power management solutions for demanding industrial, computing, and telecom applications.

The SIC431EVB belongs to Vishay's microBUCK® evaluation platform family, engineered to accelerate adoption of their integrated synchronous buck regulators - emphasizing ease of use, layout fidelity, and correlation to production performance.

FAQ

What is the primary function of the SIC431EVB?

The SIC431EVB is an evaluation board designed exclusively for the SiC431 24 A synchronous buck regulator IC. It provides a fully assembled, tested, and characterized reference design enabling engineers to validate electrical performance-including efficiency, transient response, soft-start behavior, and protection functionality-before integrating the SiC431 into end systems. The board uses the production SiC431AED-T1-GE3 IC in MLP44-24L package.

Does the SIC431EVB support all SiC431 variants?

No - the SIC431EVB is configured for the SiC431AED-T1-GE3 variant (ultrasonic mode, internal VDD/VDRV). It does not natively support SiC431B/C/D variants requiring external VDD/VDRV supplies or different light-load modes. While MODE1/MODE2 resistors are user-modifiable, the board's input decoupling and biasing network is optimized for SiC431A/SiC431C operation above 4.5 V VIN.

What output voltage is pre-configured on the SIC431EVB?

The SIC431EVB is factory-configured for 1.2 V output at up to 24 A, achieved using a 9.53 kΩ top feedback resistor (R_{FB_H}) and standard 10 kΩ bottom resistor (R_{FB_L}). This matches common CPU core rail requirements and allows immediate testing without component changes. Output voltage can be adjusted down to 0.6 V or up to 20 V by modifying the feedback divider per the formula V_OUT = 0.6 V × (1 + R_{FB_H}/R_{FB_L}).

How is thermal performance managed on the SIC431EVB?

The SIC431EVB uses a 4-layer PCB with 2 oz copper on power layers, thermal vias under the MLP44-24L pad array, and a dedicated thermal pad connected to internal PGND planes. This achieves ≤2 °C/W junction-to-board thermal resistance, enabling sustained 24 A operation at ambient temperatures up to +70 °C without forced airflow. Vishay's recommended layout guidelines and thermal simulation data are included in the Design Support Kit (Doc #74589).

Can the SIC431EVB be used for pre-bias start-up validation?

Yes - the SIC431EVB supports pre-bias start-up validation out-of-the-box. When the output capacitor is pre-charged, the SiC431 monitors the FB pin voltage and inhibits switching until the sensed voltage falls below the internal reference ramp, preventing negative current spikes and excessive sinking through the low-side MOSFET. This behavior is observable using the provided FB and VOUT test points during controlled start-up sequences.