| 摘要 |
PROBLEM TO BE SOLVED: To provide a logarithmic compression type current-voltage conversion circuit which has linearity even for a very low current value. SOLUTION: The current-voltage conversion circuit includes a current input terminal 1, a reference voltage input terminal 2, a voltage output terminal 3, and an operational amplifier 4 and an NPN-type transistor 5 which are formed on a P-type semiconductor substrate. The operational amplifier 4 has an inverting input terminal connected to the current input terminal 1 and has a non-inverting input terminal connected to the reference voltage input terminal 2 and has an output terminal connected to the voltage output terminal 3. The NPN-type transistor 5 has a collector connected to the current input terminal 1 and has a base connected to the reference voltage input terminal 2 and has an emitter connected to the voltage output terminal 3. The NPN-type transistor 5 comprises an N-type epitaxial layer corresponding to the emitter, a P-type diffusion layer selectively formed on the N-type epitaxial layer and corresponding to the base, and an N-ype diffusion layer selectively formed on the P-type diffusion layer and corresponding to the collector. COPYRIGHT: (C)2011,JPO&INPIT
|
