| 摘要 |
<p>A logarithmic convertor based on a nonlinear successive detection principle has a temperature-compensated biassing arrangement and a large operating range due to a d.c. feedback network for offset reduction and an attenuating input stage permitting large input voltages. The log convertor exploits the exponential relationship between the collector current and base-emitter voltage of a bipolar transistor to render the convertor insensitive to temperature and process parameter variations. The converter is a cascade of sections, each having a constant-gain differential amplifier having a particularized current source. The constant-gain amplifier may include a Darlington differential pair, and the current sources have outputs that are either temperature-independent or proportional to temperature.</p> |
