Rail-to-rail steering for 3.3V signal lines
The CM1213A-04S7 is a 4-channel steering TVS array from onsemi, designed to clamp ESD transients on 3.3V I/O lines without loading the signal. Its 10V typical clamping voltage keeps the protected node well below the breakdown of most 3.3V CMOS inputs, while the 3.3V reverse standoff sits just above the rail so the diode stays off during normal operation. Four unidirectional channels in a single SC-70-6 package replace four discrete diodes, saving placement cost and board area on HDMI, USB, or LVDS data lines where every pF of capacitance matters.
Clamp voltage and peak pulse current
With a 1A peak pulse current rating (8/20 µs waveform), the part handles the IEC 61000-4-2 ESD contact discharge level common in consumer and industrial interfaces. The 6V minimum breakdown voltage provides a guard band against the 3.3V rail plus ripple, so the steering diodes do not conduct during normal transients on the supply.