Digitally Programmable Microphone Preamp Boosts Dynamic Range

A digitally programmable microphone preamplifier offers high performance and flexibility for designers of pro audio equipment. The THAT1570/5171 paired chipset comprises a low-noise differential audio preamplifier (1570) and a separate high-performance digital preamplifier controller (5171). Compared to competing single-chip implementations that operate from only ±5-V supplies, the 1570/5171 enables much greater flexibility with up to 130-dB dynamic range when operating from ±17-V supplies, allowing designers to tradeoff power consumption versus dynamic range. The duo enables gain to be programmed over 56 1-dB steps from 13.6 dB to 68.6 dB. An additional gain setting of +5.6 dB allows the combination to accept line inputs up to +22 dBu. Other high-performance specifications and features include: low noise of 1.5 nV/vHz at 68.6-dB gain, and 20 nV/vHz at 5.6-dB gain; low THD+N of 0.0003% at 21.6-dB gain; and wide bandwidth of 1.8 MHz at 40.6-dB gain. The THAT1570/5171 chipset is available now and costs less than $10 each in lots of 1000. The 1570 is housed in a tiny 4 x 4-mm QFN16 package, and the 5171 in a 7 x 7-mm QFN32. A demo board is also available for $250 each. THAT CORP., Milford, MA. (508) 478-9200.