| 摘要 |
PURPOSE:To improve the linearity and the temperature, characteristic of the titled amplifier by making the circuit of a logarithmic amplifier into IC formation, combining a logarithmic converting section and a differential amplifier section to compensate the temperature characteristic of a logarithmic converting section with the temperature characteristic of a differential amplifier. CONSTITUTION:The logarithmic amplifier consists of a logarithmic converting section 3 inputting an input current Ic and a reference current Ig, and the differential amplifier section 4 inputting output voltages V1, V2 from the converting section 3. The converting section 3 consists of input transistors TRQ31, Q32 and operational amplifiers A1, A2, the differential amplifier section 4 consists of TRQ41, Q42 and a constant power supply 13, and the output voltages V1, V2 from the converting section 3 are inputted to each base of the TRQ41, Q42. Further, the output voltages V1, V2 nearly proportional to the temperature characteristic from the converting section 3 are compensated by the temperature characteristic of the differential amplifier section 4 so as to improve the linearity and the temperature characteristic. |
