onsemi SA7V5A

Overview

SA7V5A from Fairchild Semiconductor is a unidirectional 500 W transient voltage suppressor (TVS) diode in DO-15 package, with 7.5 V reverse stand-off voltage (VRWM), 8.33–9.21 V breakdown voltage (VBR) at 1.0 mA test current, and 12.9 V clamping voltage (VC) at 38.8 A peak pulse current (IPPM) on 10/1000 μs waveform. It provides robust ESD and surge protection for DC power rails and low-speed signal lines in industrial control and automotive body electronics.

For engineers reviewing the SA7V5A datasheet, pinout, applications, or equivalent options, key selection criteria include clamping performance under 38.8 A surge, unidirectional polarity with cathode band marking, DO-15 mechanical compatibility, and junction temperature rating up to +175°C for high-reliability environments.

Technical Context

The SA7V5A employs a glass-passivated silicon junction optimized for fast transient response-typically less than 1.0 ps from 0 V to breakdown for unidirectional operation-and low incremental surge resistance to minimize voltage overshoot during 500 W peak pulse events. Its electrical behavior is defined by strict VRWM (7.5 V), VBR (min 8.33 V, max 9.21 V), and VC (12.9 V @ IPPM) parameters under standardized 10/1000 μs waveform conditions.

Designed for single-pulse or low-duty-cycle surge suppression, the device supports non-repetitive forward surge current up to 70 A (8.3 ms half-sine), operates with junction temperatures up to +175°C, and exhibits reverse leakage <50 μA at VRWM-verified per Rev. D datasheet specifications for the SA5V0(C)A–SA170(C)A family.

Key Specifications

Pinout & Package

SA7V5A is housed in a DO-15 axial-leaded package with cathode indicated by a color band on the unidirectional variant. Lead length is specified at 0.375 inches for thermal derating calculations.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ7.5A and P6KE7.5A, the SA7V5A offers identical clamping performance and DO-15 compatibility but targets cost-sensitive, high-volume through-hole designs where 500 W rating meets validated surge profiles-making it optimal for automotive body electronics and industrial controls with established DO-15 layouts.

Availability

SA7V5A is available at Aetrix Electronics and suitable for automotive body control modules, industrial PLC digital inputs, DC motor drive protection, smart sensor node power rails, and telecom power interface circuits requiring stable component supply and long-term obsolescence management.

Supply support for SA7V5A 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

Fairchild Semiconductor was a U.S.-based semiconductor company specializing in power management, analog, and discrete components before its acquisition by ON Semiconductor in 2016; its legacy TVS portfolio remains widely deployed in automotive and industrial systems.

The SA7V5A belongs to Fairchild's SAxVxC(A) family of 500 W unidirectional TVS diodes, engineered specifically for robust, cost-effective overvoltage protection in DC power distribution networks and low-speed signal interfaces.

FAQ

What is the clamping voltage of the SA7V5A under maximum rated surge current?

The SA7V5A has a clamping voltage (VC) of 12.9 V when subjected to its rated peak pulse current of 38.8 A on a 10/1000 μs waveform, as specified in the Rev. D datasheet. This value ensures downstream components see no more than 12.9 V during surge events, protecting ICs with 13.5 V absolute maximum ratings. The SA7V5A maintains this clamping performance consistently across its qualified operating temperature range.

Is the SA7V5A unidirectional or bidirectional, and how is polarity identified?

The SA7V5A is a unidirectional TVS diode, meaning it clamps only in reverse bias and conducts forward like a standard rectifier. Polarity is marked by a color band on the cathode end of the DO-15 package-this band must be oriented toward the higher-potential side of the protected circuit. Bidirectional variants in the same family use the "C" suffix (e.g., SA7V5CA), which SA7V5A does not carry.

What is the maximum operating junction temperature for the SA7V5A?

The SA7V5A has a maximum operating junction temperature (TJ) of +175°C, allowing reliable operation in high-temperature environments such as engine compartments or enclosed industrial enclosures. This rating is validated per JEDEC standards and supports continuous operation at full power dissipation (1.0 W) up to +75°C ambient with 0.375″ lead length, with linear derating above that temperature.

How does the SA7V5A compare to the SA7V5CA in terms of electrical behavior?

The SA7V5A is unidirectional and clamps only in reverse bias, while the SA7V5CA is bidirectional and clamps symmetrically in both directions-its electrical characteristics apply identically for positive and negative transients. Both share identical VRWM (7.5 V), VBR (8.33–9.21 V), and VC (12.9 V) values, but SA7V5CA lacks a cathode band and is used where AC-coupled or dual-polarity surge protection is required.

Can the SA7V5A be used in place of the P6KE7.5A without layout changes?

No-the SA7V5A and P6KE7.5A share the DO-15 package and pin-compatible axial-leaded form factor, but they are not guaranteed drop-in replacements due to differences in surge lifetime endurance and qualification testing. While both meet 7.5 V VRWM and 12.9 V VC specs, P6KE7.5A is rated for 600 W peak pulse power and may exhibit different aging behavior under repetitive surges. System validation is required before substitution.