The SSM2212RZ is a dual NPN-matched Transistor Pair. It is specifically designed to meet the requirements of ultralow noise audio systems. With its extremely low input base spreading resistance (rbb' is typically 28R) and high current gain (hFE typically exceeds 600 at IC = 1mA), the SSM2212 can achieve outstanding signal-to-noise ratios. The high current gain results in superior performance compared to systems incorporating commercially available monolithic amplifiers. Excellent matching of the current gain (ΔhFE) to approximately 0.5% and low VOS of less than 10μV typical make the SSM2212 ideal for symmetrically balanced designs, which reduce high order amplifier harmonic distortion. Stability of the matching parameters is guaranteed by protection diodes across the base-emitter junction. These diodes prevent degradation of beta and matching characteristics due to reverse biasing of the base-emitter junction.