STMicroelectronics STPS40L45CT

Overview

STPS40L45CT from STMicroelectronics is a dual center-tap Schottky barrier rectifier in TO-220AB package, rated for 45 V repetitive peak reverse voltage, 2 × 20 A average forward current per diode, and maximum junction temperature of 150 °C. It delivers low forward voltage drop (0.49 V max at 20 A, 125 °C), enabling high-efficiency operation in low-voltage DC-DC converters and SMPS freewheeling paths.

For engineers reviewing the STPS40L45CT datasheet, STPS40L45CT pinout, STPS40L45CT application, or STPS40L45CT equivalent, key selection criteria include thermal resistance (1.5 °C/W junction-to-case per diode), avalanche capability (8100 W peak, 1 µs), dV/dt rating (10,000 V/µs), and conduction loss modeling (P = 0.28 × IF(AV) + 0.0105 × IF²(RMS)).

Technical Context

This dual-diode Schottky rectifier integrates two independent anode-cathode junctions sharing a common cathode terminal (center-tap configuration), enabling synchronous rectification or dual-output DC-DC topologies. Its low VF and negligible reverse recovery charge eliminate switching losses typical of PN junction diodes.

The device operates with specified avalanche energy handling (PARM = 8100 W, tp = 1 µs), validated under controlled transient conditions. Thermal coupling between diodes is quantified via Rth(c) = 0.1 °C/W, allowing accurate power derating when both diodes conduct simultaneously.

Key Specifications

Pinout & Package

Package: TO-220AB - Through-hole, single-ended heat-transfer package with insulated tab; mounting torque 0.4–0.6 N·m; UL94 V0 epoxy; designed for conduction cooling via heatsink attachment.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual Schottky rectifier applications.

Compared with VS-40CPH045 and MBR4045CT, STPS40L45CT offers the lowest VF in TO-220AB form factor, enabling higher power density in space-constrained designs while maintaining compatibility with legacy ST-compatible layouts and thermal interface materials.

Availability

STPS40L45CT is available at Aetrix Electronics and suitable for server VRMs, industrial DC-DC converters, and solar microinverter output stages requiring stable component supply, long-lifecycle availability, and consistent parametric performance across production batches.

Supply support for STPS40L45CT 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, designing and manufacturing analog, digital, and mixed-signal ICs, discrete devices, and MEMS sensors for industrial, automotive, and consumer markets.

The STPS40L45CT belongs to ST's low-drop Schottky rectifier product line, engineered specifically for high-frequency, high-efficiency power conversion in space- and thermally-constrained applications such as telecom rectifiers and embedded power supplies.

FAQ

What is the maximum continuous forward current per diode for STPS40L45CT at 130 °C case temperature?

The STPS40L45CT is rated for 20 A average forward current per diode at Tc = 130 °C, as specified in Table 2 of the official datasheet (DocID6857 Rev 5). This value assumes proper heatsinking and accounts for thermal derating above 25 °C ambient. Exceeding this current without adequate thermal management risks junction temperature exceeding 150 °C, triggering thermal runaway.

Is the cathode (K) terminal electrically isolated from the TO-220AB metal tab?

No - the K terminal is directly bonded to the metal tab in the TO-220AB package. The tab serves as the common cathode connection and must be electrically isolated from the PCB ground plane using an insulating washer or thermal pad unless the circuit design intentionally references the cathode to chassis ground. This is confirmed in Figure 11 and Package Information section of the datasheet.

Can STPS40L45CT replace STPS30L45CG in a D2PAK-based design?

No - STPS40L45CT uses TO-220AB packaging with different pin spacing, thermal interface, and mounting torque (0.4–0.6 N·m), whereas STPS30L45CG is in D2PAK with surface-mount footprint and no through-hole leads. Mechanical incompatibility prevents direct replacement; board redesign and thermal validation would be required due to differing Rth(j-c) (1.5 vs. 1.2 °C/W) and power handling profiles.

What is the typical reverse leakage current at 125 °C and 45 V reverse bias?

At Tj = 125 °C and VR = VRRM = 45 V, the reverse leakage current (IRRM) is specified as 140–280 mA (max 2 A per Table 2). This wide range reflects process variation; typical behavior shown in Figure 7 indicates ~200 mA at 45 V and 125 °C. This leakage contributes directly to standby power loss and must be factored into battery-life calculations for always-on systems.