Rail-to-rail steering topology for high-speed signal protection
The CM1213A-02SR is a steering (rail-to-rail) TVS diode array from onsemi, designed to clamp transients on two unidirectional signal lines. The rail-to-rail architecture steers the overvoltage to the supply or ground rail, keeping the clamping voltage low — 10V typical at Ipp — which matters when protecting 3.3V logic with thin gate oxides. Each channel handles a peak pulse current of 1A (8/20µs waveform), adequate for ESD and small surge events on interfaces like USB, HDMI, or LVDS. The 3.3V reverse standoff matches the nominal rail of common low-voltage ASICs and FPGAs.
SOT-143 package and industrial temperature range
Housed in a SOT-143 (TO-253AA) surface-mount package, the CM1213A-02SR occupies a compact footprint suitable for space-constrained PCBs. Power line protection is built in, meaning the device can clamp transients on power rails as well as signal lines, though the 1A peak pulse current limits it to low-power auxiliary rails rather than main supply buses.
The base product number CM1213 covers a family of rail-to-rail clamp arrays; the -02SR suffix denotes the 2-channel variant in SOT-143 on tape-and-reel.