onsemi SA8V5CA

Overview

SA8V5CA from Fairchild Semiconductor is a bidirectional 500 W transient voltage suppressor (TVS) diode in DO-15 package, designed for clamping ESD and surge transients in power and signal lines. It features 8.5 V reverse stand-off voltage (VRWM), 9.44–10.4 V breakdown voltage (VBR), 14.4 V clamping voltage at 34.7 A peak pulse current, and operates up to +175 °C junction temperature - used in DC power input protection for industrial controllers.

For engineers reviewing the SA8V5CA datasheet, pinout, applications, or equivalent options, key selection criteria include clamping performance under 10/1000 μs surge, low leakage (<10 μA at 8.5 V), bidirectional symmetry, DO-15 mechanical compatibility, and thermal robustness in high-ambient environments.

Technical Context

The SA8V5CA is a glass-passivated, bidirectional TVS diode optimized for fast transient suppression on DC rails and unidirectional/bidirectional data lines. Its junction structure delivers sub-nanosecond response time (<5.0 ns) and low incremental surge resistance, enabling effective clamping before downstream ICs experience overvoltage stress.

Rated for 500 W peak pulse power on the standardized 10/1000 μs waveform, it sustains 70 A non-repetitive forward surge current and maintains stable clamping across -65 °C to +175 °C operating junction range - supporting reliability-critical applications where thermal derating must be minimized.

Key Specifications

Pinout & Package

SA8V5CA uses a DO-15 axial-leaded package with no polarity marking - consistent with bidirectional TVS construction. Leads are electrically symmetric; either terminal may serve as anode or cathode depending on transient polarity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ8.5CA and P6SMB8.5CA, the SA8V5CA offers proven thermal margin in high-ambient through-hole deployments, while P6SMB8.5CA provides seamless second-source assurance without layout or qualification impact.

Availability

SA8V5CA is available at Aetrix Electronics and suitable for industrial PLC power inputs, automotive BCM CAN bus protection, telecom RRU DC feeds, and medical infusion pump motor drivers requiring stable component supply across multi-year production cycles.

Supply support for SA8V5CA 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 of high-performance analog and discrete semiconductors, acquired by ON Semiconductor in 2016; its TVS portfolio remains widely deployed in industrial and automotive systems.

The SAxxxCx series was engineered specifically for robust, cost-effective transient suppression in DC power distribution networks - emphasizing clamping accuracy, thermal resilience, and bidirectional symmetry for harsh-environment applications.

FAQ

What is the clamping voltage of SA8V5CA at its rated peak pulse current?

The SA8V5CA has a maximum clamping voltage (VC) of 14.4 V when subjected to its rated peak pulse current (IPPM) of 34.7 A on the 10/1000 μs waveform. This value is measured per JEDEC standards and guarantees that protected downstream circuitry will not experience voltages exceeding 14.4 V during specified surge events. The SA8V5CA maintains this clamping performance across its full operating temperature range.

Is SA8V5CA unidirectional or bidirectional, and how does that affect its circuit placement?

The SA8V5CA is a bidirectional TVS diode, indicated by the "CA" suffix, meaning it provides symmetrical clamping for both positive and negative transients. Unlike unidirectional variants, it requires no polarity orientation during placement - either lead connects to the line being protected, and the other to ground. This simplifies layout and eliminates risk of reverse installation in differential or AC-coupled applications.

Can SA8V5CA replace SA8V0CA in an existing design?

Yes, the SA8V5CA can replace SA8V0CA in most cases, but with attention to voltage margins: SA8V0CA has VRWM = 8.0 V and VBR = 8.89–9.83 V, while SA8V5CA specifies VRWM = 8.5 V and VBR = 9.44–10.4 V. If the protected circuit operates near 8.0–8.5 V, the higher stand-off voltage of SA8V5CA reduces leakage risk but may delay clamping onset slightly. Verify timing margin under worst-case surge conditions before substitution.

What is the maximum steady-state power dissipation for SA8V5CA at 75°C ambient?

The SA8V5CA is rated for 1.0 W steady-state power dissipation at 75°C ambient temperature with 0.375" lead length, per its Absolute Maximum Ratings table. This rating assumes free-air convection and standard PCB pad geometry. Derating is required above 75°C - e.g., ~0.67 W at 100°C ambient - as defined in the Pulse Derating Curve (Figure 2) of the original Fairchild datasheet Rev. D.

Does SA8V5CA meet any industry surge immunity standards out-of-the-box?

The SA8V5CA itself is not certified to IEC 61000-4-5 or ISO 7637-2, but its 500 W 10/1000 μs rating and 14.4 V clamping voltage make it a common choice for meeting Level 3 (1 kV line-to-ground, 2 kV line-to-line) surge requirements in industrial and automotive applications when properly integrated into a full protection network with series impedance and filtering. System-level validation remains required.