NE4558

The NE4558 is a dual operational amplifier integrated circuit that belongs to the 4558 family. It was originally produced by National Semiconductor and later by other manufacturers. It is a general‑purpose, low‑noise op amp intended for audio and signal‑conditioning tasks. The device contains two independent, internally compensated op‑amps in a single 8‑pin package and is suitable for use in single‑ or dual‑supply configurations over a wide supply range. In audio applications it is commonly used in preamplifiers, active filters, tone controls, mixers, and instrumentation, where moderate gain and low noise are desirable. The NE4558 is known for relatively low noise for a bipolar op-amp in its class and for robust closed‑loop performance in standard configurations.

Pinout and packaging: In the common DIP‑8 package, the pins are typically: 1 outputs A, 2 inverting input A, 3 non‑inverting input A, 4 negative supply, 5 non‑inverting input B, 6 inverting input B, 7 output B, 8 positive supply. Many manufacturers also offer the device in surface‑mount formats (e.g., SO‑8) with the same functional pinout, though pin numbers may vary between package styles; always consult the datasheet.

Variants and compatibility: The NE4558 is functionally similar and pin‑compatible with other 4558 family devices such as RC4558 and LM4558. Numerous manufacturers offer NJM4558, JRC4558, and other equivalents, often marketed as low‑noise dual op‑amps suitable for audio.