NE5532P

The NE5532P from Texas Instruments is the industry-standard dual low-noise operational amplifier, renowned for its 5nV/√Hz equivalent input noise voltage at 1kHz—among the lowest of any bipolar op-amp in its class. With a 10MHz gain-bandwidth product and 9V/µs slew rate, it handles audio bandwidth with ample margin. The 100dB CMRR and 0.002% THD+N at 1kHz ensure pristine signal quality in professional audio applications. The 38mA output drive capability per channel allows it to directly drive 600Ω balanced lines without buffering. The device is internally compensated for unity-gain stability, simplifying circuit design. The bipolar input stage provides lower voltage noise than CMOS alternatives, though at the cost of higher input bias current (800nA max). The NE5532 has been the go-to audio op-amp for decades, used in mixing consoles, preamplifiers, equalizers, and hi-fi equipment worldwide. The P suffix denotes the PDIP-8 through-hole package.

The NE5532P consists of two independent high-performance operational amplifiers on a single die. Each amplifier uses a bipolar input stage with a differential pair, providing the low voltage noise (5nV/√Hz) that is the hallmark of this device. The input stage feeds a voltage gain stage with active current-mirror load, followed by a class-AB output stage capable of sourcing and sinking 38mA. Internal compensation capacitance ensures stability at unity gain without external components. The input protection diodes clamp excessive differential input voltages, and the output stage has short-circuit protection that limits output current during fault conditions. In a typical audio preamp application, the non-inverting input receives the audio signal, and the feedback network from output to inverting input sets the closed-loop gain. At audio frequencies, the open-loop gain of 100dB (100V/mV) provides abundant loop gain for low-distortion amplification. At 1kHz with 20dB (×10) closed-loop gain, the loop gain is approximately 80dB, meaning distortion is reduced by a factor of 10,000 from the open-loop value, resulting in the measured 0.002% THD+N.

NE5532P uses the PDIP-8 package with standard dual op-amp pinout: Pin 1 = Output A, Pin 2 = Inverting Input A (-), Pin 3 = Non-inverting Input A (+), Pin 4 = VEE (-V), Pin 5 = Non-inverting Input B (+), Pin 6 = Inverting Input B (-), Pin 7 = Output B, Pin 8 = VCC (+V). This is the same pinout as LM358, TL072, and RC4558. The NE5532 differs from LM358 in requiring dual supplies (±3V to ±22V) and providing superior audio performance with 5nV/√Hz input noise density. The output can drive 600Ω loads directly. For surface-mount, NE5532DR (SOIC-8) provides identical pinout. The NE5532AP is the premium-grade version with tighter noise and offset specifications.

• Audio Preamp: Non-inverting gain stage for microphone or line-level; 5nV/√Hz noise preserves dynamic range below -100dBu
• RIAA Phono Stage: Two-stage equalizer with feedback RIAA network; low noise critical for cartridge signals
• Active Crossover: Linkwitz-Riley filters split audio into frequency bands; 10MHz GBW ensures flat response to 100kHz+
• Line Driver: 38mA output drives 600Ω balanced line; two amplifiers per channel for differential output
• Headphone Amp: ±15V supply, 32Ω load; NE5532 delivers ~400mW per channel with 0.002% THD

NE5532 is the industry-standard dual low-noise audio op-amp with 10MHz GBW, 9V/µs slew rate, and 5nV/rtHz input noise. It is the de facto choice for audio mixing consoles, preamps, and equalizers. For higher performance, the LM4562 offers 55MHz GBW and 2.7nV/rtHz noise. For JFET-input applications, OPA2134 provides ultra-low distortion in phono and microphone preamps.