A CMOS op amp is utilized to provide two-channel signal clamping with room-temperature leakage’s typically below 100fA. Costs of the dual clamping two-line circuit of <$3 compare favorably with alternate methods at double to quadruple the cost. Signal lines connect to either of the two op amp input pins, and clamping voltages are applied to the amplifier supply pins to provide bipolar clamping levels of the connected analog signal lines.