Preamplifier for electrostatic type electro-acoustic converter

Abstract

Abstract PURPOSE:To extend the dynamic range, by connecting a pair of FETs of complementary constitution having small gate leakage current to the source follower and connecting the load circuit of high input impedance to the output. CONSTITUTION:As the complementary FET31, 32, small gate leakage current IG, small drain current IDSS when the voltage between the gate and source is zero, are selected and as FET41, 42 of the post stage, greater current IDSS is selected. With this constitution, since the load of FET31, 32 is FET41 of the source follower, the load impedance is high and the dynamic range is broad even with small current IDSS of FET31, 32. Further, in this case, since greater current IDSS is used for FET41, 42, the dynamic range is broad even with low load impedance. Accordingly, the dynamic range as a whole is greatly extended.

Inventors

• 👤 Takeshi Matsudaira
• 👤 Osamu Kono
• 👤 Makoto Ishikawa

Bibliographic Details