STMicroelectronics STEVAL-ISQ003V1

Overview

STEVAL-ISQ003V1 from STMicroelectronics is an evaluation board for the STIL series of AC inrush current limiters-integrated dual unidirectional switch devices in Pentawatt HV2 package. It supports STIL04-P5, STIL06-T5, and STIL08-T5 variants, delivers up to 8 A average output current, sustains 700–800 V repetitive off-state voltage, and enables instantaneous response after AC line dropout in PFC boost pre-regulators used in server power supplies.

For engineers reviewing the STEVAL-ISQ003V1 datasheet, STEVAL-ISQ003V1 pinout, STEVAL-ISQ003V1 application, or STEVAL-ISQ003V1 equivalent, this board provides validated reference design, surge immunity testing per IEC61000-4-5 (up to 1000 A peak), thermal performance validation under 150°C junction conditions, and direct integration with auxiliary power supply coupling in offline AC-DC converters.

Technical Context

The STEVAL-ISQ003V1 implements a functional test platform for STIL devices operating in parallel with diode bridges and external inrush resistors. During startup, STIL switches remain open while inrush current flows through the bridge and resistor; at steady state, both internal switches close to bypass diodes, reducing conduction losses and improving efficiency.

It supports power-fail detection via auxiliary supply shutdown during AC dropout, enabling controlled recharging of bulk capacitors through the external resistor. The board integrates driver circuitry matching the STIL's 20 mA trigger current and 0.85 V typical pilot trigger voltage at 25°C, with dV/dt immunity exceeding 1000 V/µs at 125°C.

Key Specifications

Availability

STEVAL-ISQ003V1 is available at Aetrix Electronics and suitable for server power supplies, telecom rectifiers, and high-end TV display power stages requiring stable component supply, rapid prototyping turnaround, and production-ready reference validation.

Supply support for STEVAL-ISQ003V1 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, analog, microcontrollers, and automotive ICs with over 40 years of industrial power conversion expertise.

The STEVAL-ISQ003V1 belongs to ST's Application Specific Devices (ASD) evaluation platform family, designed to accelerate adoption of STIL inrush current limiters for high-efficiency, space-constrained offline AC-DC power supplies.

FAQ

What is the primary function of the STEVAL-ISQ003V1 evaluation board?

The STEVAL-ISQ003V1 is a dedicated hardware platform for evaluating STIL-series AC inrush current limiters (STIL04-P5/STIL06-T5/STIL08-T5). It replicates real-world PFC boost pre-regulator operation, enabling engineers to validate turn-on behavior, steady-state conduction loss reduction, power-fail recovery timing, and IEC61000-4-5 surge resilience without custom PCB development.

Does STEVAL-ISQ003V1 support all STIL variants listed in the datasheet?

Yes - the board features interchangeable sockets and configurable jumpers to support STIL04-P5 (Pentawatt HV2), STIL04-T5, STIL06-T5, and STIL08-T5 (all Pentawatt packages). Mechanical layout complies with ST's Pentawatt HV2 and standard Pentawatt terminal dimensions, including tab mounting and 0.8 Nm torque specification.

How does the board implement the STIL's power-fail feature during AC dropout?

During AC dropout, the board's auxiliary supply (derived from main transformer windings) shuts down, de-energizing the STIL's internal drivers. This forces both unidirectional switches open, allowing the bulk capacitor to discharge into the main converter while blocking recharge current until AC returns - at which point the external inrush resistor limits Cb recharging before STIL switches close again.

Can STEVAL-ISQ003V1 be used for thermal characterization under continuous load?

Yes - the board includes thermal vias, copper pour areas aligned with the STIL's exposed tab, and mounting holes compliant with Pentawatt HV2 mechanical specs (L3 = 23.5 mm, H2 = 10.16 mm). Measured R_th(j-c) of 2 °C/W is achievable when mounted on a 50 cm² aluminum heatsink with thermal interface material, matching ST's absolute maximum junction temperature rating of 150°C.