STMicroelectronics STIL04-T5

Overview

STIL04-T5 from STMicroelectronics is an AC inrush current limiter IC designed for off-line power supplies, replacing two bridge diodes in steady state with dual unidirectional switches integrated in a single Pentawatt package. It delivers 4 A average output current, supports 700 V repetitive off-state voltage, and features instantaneous response after AC line dropout with dV/dt immunity >1000 V/µs at 125°C - deployed in high-density server and telecom power supplies.

For engineers reviewing the STIL04-T5 datasheet, STIL04-T5 pinout, STIL04-T5 application, or STIL04-T5 equivalent, key selection criteria include inrush limiting capability, surge robustness per IEC61000-4-5 (500 A peak), driver trigger current (10–20 mA), thermal resistance (2 °C/W junction-to-case), and compatibility with PFC boost preregulators requiring fast recovery after brownout.

Technical Context

The STIL04-T5 operates as a dual unidirectional switch connected in parallel with the AC input bridge and inrush resistor. During startup, internal switches remain open, routing inrush current through the external resistor and bridge diodes; once the auxiliary supply powers the integrated driver, both switches close to bypass the diodes and conduct full AC current.

In PFC boost preregulator configurations, the device enables power-fail recovery: upon AC dropout, switches open and allow bulk capacitor discharge to sustain the main converter; upon line recovery, inrush is limited through the same resistor before switches re-enable - all without external control logic or timing components.

Key Specifications

Pinout & Package

Packaged in Pentawatt (standard variant, not HV2), the STIL04-T5 uses a 5-pin through-hole package with isolated tab for heatsinking. Pin 1 (L) and Pin 5 (N) connect to AC line and neutral; Pin 3 (OUT) is the common output node; Pins 2 and 4 (Pt1, Pt2) are dedicated gate drivers for each internal unidirectional switch.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar inrush current limitation applications.

Compared with STIL06-T5, the STIL04-T5 offers lower thermal mass and tighter dV/dt margin for compact 300–500 W systems; versus PGB10SA, it eliminates four external components and guarantees sub-10 µs recovery latency after brownout - critical for uninterrupted operation in real-time embedded power systems.

Availability

STIL04-T5 is available at Aetrix Electronics and suitable for server power supplies, telecom rectifiers, and high-end TV displays requiring stable component supply, long-term lifecycle support, and RoHS-compliant ECOPACK® packaging.

Supply support for STIL04-T5 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 reliability heritage.

The STIL series belongs to ST's Application-Specific Devices (ASD) portfolio, engineered specifically for intelligent inrush current control in off-line AC-DC converters - targeting efficiency, space, and transient resilience in high-power-density power supplies.

FAQ

Does STIL04-T5 require external gate resistors?

No. The STIL04-T5 integrates fully self-contained driver circuitry for both internal unidirectional switches. External gate resistors are unnecessary because the driver output stage is optimized for direct connection to the power switch gates and includes built-in current limiting and slew rate control. This eliminates layout sensitivity and ensures consistent switching behavior across temperature and voltage ranges.

Can STIL04-T5 be used without a PFC stage?

Yes, but with functional limitations. While the device will limit inrush current in non-PFC topologies using an external auxiliary supply to drive Pt1/Pt2, its power-fail recovery feature relies on PFC-generated auxiliary power. Without PFC, manual reset or external control logic is needed to re-enable switches after AC dropout - negating the core auto-recovery advantage.

What is the role of the tab on the STIL04-T5 package?

The exposed metal tab is electrically connected to the OUT (Pin 3) terminal and serves as the primary thermal path. It must be mounted to a heatsink using the specified 0.8 Nm torque and thermally conductive interface material. Electrical isolation from chassis ground is required unless system-level safety analysis confirms OUT node grounding is permissible per IEC62368-1.

How does STIL04-T5 compare to mechanical NTC thermistors for inrush limiting?

Unlike NTC thermistors, STIL04-T5 provides consistent inrush limiting across repeated cycles without cooldown delay, delivers lower steady-state losses (<1.4 V drop vs ~0.5 Ω NTC resistance), and enables precise brownout recovery timing. It also avoids NTC aging effects and ambient temperature drift - making it superior for high-reliability, high-cycling applications like telecom and server power.