The SSM2212 is a dual, NPN-matched transistor pair that is specifically designed to meet the requirements of ultralow noise audio systems.With its extremely low input base spreading resistance (rbb' is typically 28 Ω) and high current gain (hFEtypically exceeds 600 at IC= 1 mA), 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 VOSof less than 10 μV 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.The SSM2212 is also an ideal choice for accurate and reliable current biasing and mirroring circuits. Furthermore, because the accuracy of a current mirror degrades exponentially with mismatches of VBEbetween transistor pairs, the low VOSof the SSM2212 does not need offset trimming in most circuit applications.The SSM2212 SOIC performance and characteristics are guaranteed over the extended temperature range of −40°C to +85°C.The SSM2212 is available in 8-lead SOIC and 16-lead LFCSP packages.