RC4558

RC4558 is a dual general-purpose operational amplifier integrated circuit commonly used in audio and instrumentation applications. It was originally produced by Philips Semiconductors (now NXP) and is functionally similar to other widely used dual op-amps such as the uA4558 and LM4558. The RC4558 remains available from multiple manufacturers in common packages such as DIP-8 and SOIC-8.

The device contains two independent op-amps in a single package. For the standard DIP-8 pinout (as with many dual op-amps): pin 1 is output of amplifier A, pin 2 is inverting input A, pin 3 is non-inverting input A, pin 4 is V−, pin 5 is non-inverting input B, pin 6 is inverting input B, pin 7 is output of amplifier B, and pin 8 is V+. The RC4558 is not rail-to-rail and typically requires dual supplies or a sufficiently high single supply to accommodate input and output ranges.

Electrical characteristics are similar to other general-purpose dual op-amps of its era. It offers relatively low noise for an older design, a gain-bandwidth product around 1 MHz, and a slew rate on the order of several tenths of a volt per microsecond. Input-offset voltages are typically a few millivolts, and input bias currents are in the tens of nanoamps range, with exact values dependent on manufacturer and temperature. The part is designed for stable operation in closed-loop configurations and is widely used in feedback amplifiers, filters, and mixers.

Applications include audio preamplifiers, tone controls, active filters, and generic instrumentation circuits. Variants and cross-compatibles exist from different manufacturers, and some labeling may include RC4558P or RC4558N designations.