onsemi SA7.0CA

Overview

SA7.0CA from ON Semiconductor is a bidirectional MiniMOSORB™ Zener transient voltage suppressor (TVS) in an axial-leaded Surmetic package, designed for clamping high-energy transients in DC power rails and signal lines. It features a 7.0 V working peak reverse voltage (VRWM), 12 A maximum reverse peak pulse current (IPP), 12.0 V clamping voltage (VC) at IPP, 500 W peak pulse power (1 ms), and <1 ns response time.

For engineers reviewing the SA7.0CA datasheet, pinout, applications, or equivalent options, key selection criteria include clamping performance under 10/1000 µs surge, UL 497B recognition for isolated loop protection, low zener impedance, ESD robustness (>16 kV HBM), and thermal derating behavior above 75°C lead temperature.

Technical Context

The SA7.0CA operates as a bidirectional voltage-clamping device, leveraging avalanche breakdown across both polarities to protect sensitive circuitry from fast-rising transients such as ESD, lightning-induced surges, and inductive switching spikes. Its design centers on low dynamic impedance and minimal leakage (<150 µA @ VRWM = 7 V) to avoid loading during normal operation.

It complies with UL 497B for isolated loop circuit protection and meets Class 3 ESD immunity (>16 kV per Human Body Model). Thermal performance is defined by a junction-to-lead thermal resistance of 33.3°C/W and steady-state power dissipation of 3.0 W at TL ≤ 75°C with 3/8″ lead length.

Key Specifications

Pinout & Package

SA7.0CA uses a bidirectional axial-leaded configuration in ON Semiconductor's CASE 59 (Surmetic) package. The device has no polarity-dependent terminals - the cathode band denotes orientation only and does not indicate unidirectional conduction. Leads are tinned and solderable per industry standards, rated for 230°C for 10 seconds at 1/16″ from case.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ7.0A and P6KE7.0CA, the SA7.0CA offers superior ESD robustness (>16 kV HBM vs. ~8–12 kV), UL 497B certification for isolated loops, and tighter leakage control (150 µA), making it preferred for medical and telecom applications demanding certified reliability and low standby impact.

Availability

SA7.0CA is available at Aetrix Electronics and suitable for industrial power supplies, telecom line interfaces, medical equipment input stages, and automotive body control modules requiring stable component supply and long-term lifecycle support.

Supply support for SA7.0CA 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

ON Semiconductor (now onsemi) is a global semiconductor manufacturer specializing in power management, analog, sensor, and discrete solutions for automotive, industrial, cloud, and consumer markets.

The SA7.0CA belongs to the MiniMOSORB™ TVS family, engineered specifically for high-surge, low-leakage transient suppression in safety-critical and regulated environments including UL 497B-compliant systems.

FAQ

What is the clamping voltage of the SA7.0CA under maximum surge conditions?

The SA7.0CA exhibits a maximum clamping voltage (VC) of 12.0 V when subjected to its rated peak pulse current (IPP) of 12 A, measured using the standard 10/1000 µs double-exponential surge waveform. This value is guaranteed across temperature and ensures protected circuits remain below critical overvoltage thresholds. The SA7.0CA achieves this with low dynamic impedance and fast avalanche response, making it suitable for safeguarding 5–12 V logic and interface ICs.

Is the SA7.0CA suitable for bidirectional signal line protection?

Yes, the SA7.0CA is explicitly designed as a bidirectional TVS diode, indicated by the "CA" suffix. It provides symmetrical clamping for both positive- and negative-going transients, enabling safe use on AC-coupled lines, differential buses like RS-485, or floating grounds where polarity cannot be assumed. Unlike unidirectional variants (e.g., SA7.0A), the SA7.0CA requires no orientation-specific placement, simplifying layout and reducing assembly risk.

Does the SA7.0CA have UL recognition for safety-critical applications?

Yes, the SA7.0CA carries UL 497B recognition under file #E116110, classified as a protector (QVGV2) for isolated loop circuits. This certification covers rigorous testing including strike voltage breakdown, endurance conditioning, dielectric withstand, and discharge validation - exceeding basic flammability requirements. The SA7.0CA is approved for use in telecom, medical, and industrial systems where regulatory compliance for surge protection is mandatory.

What is the maximum steady-state power dissipation for the SA7.0CA?

The SA7.0CA supports a steady-state power dissipation (PD) of 3.0 W at a lead temperature (TL) of ≤75°C with 3/8″ lead length. Above 75°C, PD derates linearly at 30 mW/°C, reaching zero at TL = 175°C. This thermal profile is defined by its junction-to-lead thermal resistance (RJL) of 33.3°C/W and must be considered alongside PCB copper area and airflow when designing for continuous leakage current or frequent surge events.

How does the SA7.0CA compare to the SA7.5CA in terms of breakdown voltage and clamping performance?

The SA7.0CA has a lower breakdown voltage range (7.78–8.6 V at 10 mA) and clamps at 12.0 V under 12 A surge, whereas the SA7.5CA breaks down at 8.33–9.21 V and clamps at 12.9 V under 10.3 A. The SA7.0CA thus provides tighter voltage margin for 7 V nominal rails and faster response due to lower VBR, making it preferable where headroom below 12 V is critical. Both share identical package, UL recognition, and surge ratings.