Logarithmic current to voltage converters

A photocurrent detection system comprising:

• a photodetector configured to generate an input current;
• and
• a semiconductor die comprising a first logarithmic converter, wherein the first logarithmic converter comprises:
• an input terminal configured to receive the input current;
• an output terminal configured to provide a first logarithmic output voltage;
• a first field-effect transistor (FET) having a gate connected to the input terminal;
• a first bipolar transistor having a collector connected to the input terminal and an emitter connected to the output terminal;
• and
• a stacked transistor connected to the output terminal and to the first FET.

A method of logarithmic current to voltage conversion, the method comprising:

• providing an input current from an input terminal to a collector of a first bipolar transistor;
• providing a logarithmic output voltage from an emitter of the first bipolar transistor to an output terminal;
• and
• providing feedback from the output terminal to the input terminal through a stacked transistor and a first field-effect transistor (FET), a gate of the first field-effect transistor (FET) connected to the input terminal and the stacked transistor connected to the output terminal and a source of the first FET.