STMicroelectronics STTH1R04A

Overview

STTH1R04A from STMicroelectronics is a 1 A, 400 V ultrafast recovery diode in SMA package, featuring 14 ns typical reverse recovery time (trr), 0.9 V typical forward voltage (VF) at 150 °C, and 175 °C maximum junction temperature - optimized for high-frequency switching in telecom power supplies and base-drive circuits.

For engineers reviewing the STTH1R04A datasheet, STTH1R04A pinout, STTH1R04A application, or STTH1R04A equivalent, key selection criteria include ultrafast trr performance under dIF/dt = −100 A/µs, low conduction loss (P = 0.9 × IF(AV) + 0.250 × IF²(RMS)), thermal resistance Rth(j-l) = 35 °C/W (SMA), and ECOPACK-compliant lead-free packaging.

Technical Context

The STTH1R04A employs ST's planar platinum-doped silicon technology to achieve ultrafast soft recovery with negligible switching losses and stable dynamic behavior across temperature. Its trr remains ≤30 ns up to 125 °C and dIF/dt = −50 A/µs, while IRM stays below 3.5 A under harsh conditions (VR = 320 V, Tj = 125 °C).

Designed for unidirectional current control in hard-switched topologies, it delivers low VF across operating temperatures (0.9–1.25 V at 1 A, 100–150 °C) and supports surge currents up to 30 A (10 ms, sinusoidal), enabling robust operation in transient-prone telecom and industrial DC-DC stages.

Key Specifications

Pinout & Package

STTH1R04A is housed in an SMA (DO-214AC) surface-mount package with two terminals: anode and cathode. The package features UL94 V0 epoxy, lead-free construction, and is optimized for conduction cooling via PCB copper pads.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultrafast diode applications.

Compared with MUR140 and VS-1EJH04-M3/5AT, STTH1R04A offers the fastest trr (14 ns), lowest VF at elevated temperature, and highest surge rating - making it optimal for high-efficiency, high-frequency telecom and industrial power stages where thermal and dynamic performance are prioritized.

Availability

STTH1R04A is available at Aetrix Electronics and suitable for telecom AC-DC front-ends, industrial DC-DC converter outputs, and motor drive snubber networks requiring stable component supply and long-term manufacturability.

Supply support for STTH1R04A 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, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.

The STTH1R04 series belongs to ST's high-performance ultrafast diode product line, engineered specifically for high-frequency switching power conversion where low trr, low VF, and high thermal robustness are essential.

FAQ

What is the maximum allowable junction temperature for STTH1R04A?

The absolute maximum junction temperature (Tj) for STTH1R04A is 175 °C, as specified in Table 1 of the official datasheet DS5848. This rating applies under steady-state and transient conditions, and operation beyond this limit risks permanent device degradation. Thermal design must ensure junction temperature remains within this bound using Rth(j-l) = 35 °C/W and appropriate PCB copper area.

Does STTH1R04A have a built-in guard ring or soft recovery characteristic?

Yes - STTH1R04A uses platinum-doped planar technology that provides inherently soft reverse recovery, confirmed by low IRM (≤3.5 A) and controlled QRR (<20 nC) across dIF/dt and temperature. While no explicit "guard ring" structure is described in the datasheet, the soft recovery behavior is intrinsic to the doping profile and eliminates need for external snubbers in most 100–500 kHz applications.

Can STTH1R04A be used in place of a Schottky diode in low-voltage applications?

No - STTH1R04A is a PN junction ultrafast diode, not a Schottky. Its VF (0.9 V typ. at 150 °C) is higher than typical Schottky diodes (<0.5 V), and it exhibits reverse recovery charge (QRR), unlike Schottky devices. It replaces standard fast or ultrafast diodes (e.g., UF4007), not Schottkys - use only where 400 V blocking and soft recovery are required over ultra-low VF.

What is the recommended footprint for STTH1R04A in SMA package?

The official recommended SMA footprint is provided in Figure 19 of DS5848: pad length 5.43 mm (0.214″), pad width 2.63 mm (0.104″), center-to-center spacing 5.84 mm (0.230″), with inner pad width 1.4–1.64 mm (0.065″). Copper area under each pad should exceed 1 cm² for optimal thermal performance, per AN5088 guidelines.