onsemi SA9V0A

Overview

SA9V0A from Fairchild Semiconductor is a unidirectional 500 W transient voltage suppressor (TVS) diode designed for primary-level overvoltage protection in DC power lines and signal interfaces. It features a 9.0 V reverse stand-off voltage (VRWM), 10.0–11.1 V breakdown voltage (VBR) at 1.0 mA, 15.4 V clamping voltage (VC) at 32.5 A peak pulse current (IPPM), and operates up to +175 °C junction temperature - deployed in industrial power supplies and automotive body control modules.

For engineers reviewing the SA9V0A datasheet, pinout, applications, or equivalent options, key selection criteria include clamping performance under 10/1000 μs surge, low leakage (<5 μA at VRWM), fast response time (<1.0 ps), DO-15 package compatibility, and unidirectional polarity for DC rail protection.

Technical Context

The SA9V0A employs a glass-passivated PN junction optimized for high-energy transient suppression on 10/1000 μs waveforms. Its low incremental surge resistance ensures stable clamping during repetitive surges, while its <1.0 ps response time enables effective protection of downstream ICs against ESD and lightning-induced transients.

Designed for unidirectional operation, the device conducts only in reverse bias above VBR and blocks up to 9.0 V in normal operation. It meets JEDEC-standard non-repetitive surge testing (8.3 ms half-sine, 70 A IFSM) and supports thermal derating to 1.0 W at 75 °C with 0.375" lead length.

Key Specifications

Pinout & Package

SA9V0A uses the DO-15 axial-leaded package with cathode indicated by a color band. The device has two terminals: anode and cathode. No internal pins - leads serve as direct connection points.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ9.0A and P6KE9.0A, the SA9V0A offers optimal balance of axial-leaded manufacturability, 500 W surge handling, and tight 15.4 V clamping - making it preferred for legacy-compatible industrial and automotive repairs where DO-15 footprint must be retained.

Availability

SA9V0A is available at Aetrix Electronics and suitable for industrial power supplies, automotive body control modules, telecom DC feeder lines, and point-of-load DC-DC converter inputs requiring stable component supply across extended production lifecycles.

Supply support for SA9V0A 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 leading designer and manufacturer of power semiconductors, analog ICs, and discrete devices, acquired by ON Semiconductor in 2016. Its legacy TVS portfolio remains widely deployed in industrial and automotive systems.

The SA9V0A belongs to Fairchild's SAxV0(C)A series of 500 W unidirectional/bidirectional TVS diodes, engineered specifically for robust, cost-effective overvoltage protection in DC power distribution networks and interface lines.

FAQ

What is the clamping voltage of the SA9V0A at its rated peak pulse current?

The SA9V0A has a maximum clamping voltage (VC) of 15.4 V at its rated peak pulse current (IPPM) of 32.5 A, measured on a 10/1000 μs waveform. This value defines the upper voltage limit imposed on the protected circuit during a standardized surge event and is critical for ensuring compatibility with downstream components' absolute maximum ratings. The SA9V0A maintains this clamping performance consistently across its operating temperature range.

Is the SA9V0A bidirectional or unidirectional?

The SA9V0A is a unidirectional transient voltage suppressor, indicated by the absence of the "C" suffix in its part number. It functions as a reverse-biased avalanche diode, conducting only when the cathode-to-anode voltage exceeds its breakdown range (10.0–11.1 V). Unlike bidirectional variants (e.g., SA9V0CA), the SA9V0A does not conduct in forward bias beyond typical diode drop and is intended for DC line protection with defined polarity.

What package type does the SA9V0A use, and how is polarity marked?

The SA9V0A uses the DO-15 axial-leaded package. Polarity is marked by a colored band (typically black or dark gray) on the cathode end of the device body. This band aligns with standard diode marking conventions and must be oriented toward the higher-potential side of the protected line. The DO-15 outline and lead spacing comply with industry-standard mechanical specifications for through-hole mounting and manual or wave soldering.

Can the SA9V0A replace the P6KE9.0A in an existing design?

The SA9V0A can serve as a functional replacement for the P6KE9.0A in many cases due to identical DO-15 packaging, matching 9.0 V VRWM, and comparable thermal ratings. However, the SA9V0A offers tighter clamping (15.4 V vs. 16.0 V) and faster response (<1.0 ps vs. ~1 ns), which may improve system-level surge immunity. Layout and soldering processes remain unchanged, but validation against IEC 61000-4-5 or ISO 7637-2 is recommended.

What is the maximum junction temperature rating for the SA9V0A?

The SA9V0A is rated for a maximum operating junction temperature (TJ) of +175 °C, enabling reliable operation in high-temperature environments such as engine compartments, industrial enclosures, and sealed power supplies. This rating is supported by its glass-passivated junction structure and thermal design for 0.375" lead length at 75 °C ambient. Derating curves confirm usable power dissipation down to 0 W at 175 °C case temperature.