Vishay General Semiconductor - Diodes Division TPSMA22AHM3_B/I

Overview

TPSMA22AHM3_B/I from Vishay General Semiconductor is a unidirectional surface-mount PAR® transient voltage suppressor (TVS) in SMA (DO-214AC) package, rated for 22 V breakdown voltage (V_BR = 20.9–23.1 V at 1 mA), 400 W peak pulse power (10/1000 µs), and 13.1 A peak pulse current (I_PPM). It protects MOSFETs and ICs in automotive power supply rails against lightning-induced surges and inductive switching transients.

For engineers reviewing the TPSMA22AHM3_B/I datasheet, TPSMA22AHM3_B/I pinout, TPSMA22AHM3_B/I application, or TPSMA22AHM3_B/I equivalent, key selection criteria include its AEC-Q101 qualification, 185 °C maximum junction temperature, unidirectional polarity, low clamping voltage (V_C = 30.6 V at I_PPM), and halogen-free RoHS-compliant construction per HM3 suffix.

Technical Context

This TVS diode uses passivated anisotropic rectifier technology to deliver stable clamping under repetitive surge conditions. Its thermal design supports operation up to T_J = 185 °C, enabling use in under-hood automotive environments without derating penalties beyond those defined in Fig. 2 of the datasheet.

The device exhibits fast response time (<1 ns), low incremental surge resistance, and excellent clamping ratio (V_C/V_BR ≈ 1.39), verified under 10/1000 µs waveform testing. It meets MSL Level 1 per J-STD-020 with 260 °C reflow peak and passes JESD 201 Class 2 whisker testing.

Key Specifications

Pinout & Package

SMA (DO-214AC) package with axial lead configuration: two terminals, cathode marked by color band. Mounting requires 5.0 mm × 5.0 mm copper pads per terminal per JEDEC standard layout.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar transient suppression applications.

Compared with SMAJ22A and TPSMA22AHM3_B/H, the TPSMA22AHM3_B/I offers full automotive qualification, higher junction temperature tolerance, and halogen-free compliance-making it the preferred choice for safety-critical vehicle subsystems and long-lifecycle industrial deployments where traceability and material content matter.

Availability

TPSMA22AHM3_B/I is available at Aetrix Electronics and suitable for automotive power management, industrial sensor interface protection, and telecom DC feeder line surge suppression requiring stable component supply, AEC-Q101 validation, and halogen-free compliance.

Supply support for TPSMA22AHM3_B/I 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 General Semiconductor is a global leader in discrete semiconductors, specializing in diodes, rectifiers, TVS devices, and optoelectronics with emphasis on high-reliability and automotive-grade solutions.

The TPSMAxxA series belongs to Vishay's PAR® family of transient voltage suppressors, engineered specifically for robust surge immunity in harsh environments-including engine compartments, factory floors, and outdoor telecom infrastructure-where sustained high-temperature operation and AEC-Q101 validation are mandatory.

FAQ

What is the breakdown voltage tolerance for TPSMA22AHM3_B/I?

The TPSMA22AHM3_B/I has a specified breakdown voltage range of 20.9 V to 23.1 V at 1 mA test current, representing a ±5% tolerance around the nominal 22 V rating. This tight V_BR distribution ensures consistent clamping behavior across production lots and supports reliable design margining in 24 V systems where overvoltage thresholds must be tightly controlled. The TPSMA22AHM3_B/I datasheet confirms this range in Table 1 under "ELECTRICAL CHARACTERISTICS".

Is TPSMA22AHM3_B/I suitable for bidirectional transient protection?

No, the TPSMA22AHM3_B/I is unidirectional only, as explicitly stated in the Vishay datasheet under FEATURES. It protects against positive-going transients on the cathode side relative to anode (ground). For bidirectional protection-such as AC line or data bus applications-engineers must select a dedicated bidirectional variant like TPSMA22CA or use back-to-back unidirectional devices. The TPSMA22AHM3_B/I marking code "A" and polarity designation confirm its unidirectional function.

Does TPSMA22AHM3_B/I require derating at elevated ambient temperatures?

Yes, the TPSMA22AHM3_B/I must be derated above T_A = 25 °C per Figure 2 in the datasheet. Its peak pulse power (P_PPM) decreases linearly with increasing initial junction temperature, reaching ~50% of 400 W at T_J = 125 °C. However, its 185 °C maximum junction rating allows operation at higher ambient temperatures than standard TVS diodes-enabling use in under-hood locations without additional thermal mitigation, provided PCB copper area meets the 5.0 mm × 5.0 mm pad requirement.

What does the "HM3" suffix indicate in TPSMA22AHM3_B/I?

The "HM3" suffix in TPSMA22AHM3_B/I denotes halogen-free, RoHS-compliant construction with AEC-Q101 qualification. Per Vishay's ordering information table, HM3 devices meet JESD 201 Class 2 whisker resistance and use matte tin-plated leads solderable per J-STD-002. This distinguishes it from HE3 (RoHS + AEC-Q101 but not halogen-free) and standard non-suffixed versions. The TPSMA22AHM3_B/I therefore satisfies strict automotive material compliance requirements including ELV and IMDS reporting.

Can TPSMA22AHM3_B/I replace SMAJ22A in existing designs?

TPSMA22AHM3_B/I is not a direct drop-in replacement for SMAJ22A due to differences in qualification and thermal rating: while both share identical V_BR, V_C, and P_PPM, the TPSMA22AHM3_B/I is AEC-Q101 qualified and rated for 185 °C operation versus SMAJ22A's 150 °C limit. Substitution requires validation of thermal performance and qualification documentation. The TPSMA22AHM3_B/I also carries halogen-free compliance not present in SMAJ22A, impacting material declarations.