Selectable Programmable Gain Or Operational Amplifier

A microcontroller integrated circuit, comprising:

• a digital processor and memory;
• an analog-to-digital converter (ADC) having a digital output coupled to the digital processor;
• a configurable analog amplifier, comprising:
• a differential input stage;
• a first output block;
• a second output block;
• a plurality of switches coupled to the differential input stage, the first output block and the second output block;
• wherein
• the differential input stage and the first output block are coupled together as a programmable gain amplifier when certain ones of the plurality of switches are arranged in a first mode, and
• the differential input stage and the second output block are coupled together as an operational amplifier when the certain ones of the plurality of switches are arranged in a second mode;
• and
• the processor controls the first and second modes.

A method for configuring an amplifier as a programmable gain amplifier or an operational amplifier, said method comprising the steps of:

• providing a differential input stage;
• providing a first output block having an input switchably coupled to an output of the differential input stage;
• providing a second output block having an input switchably coupled to the output of the differential input stage;
• and
• providing a plurality of switches coupled to the differential input stage, and the first and second output blocks;
• coupling the differential input stage and the first output block together as a programmable gain amplifier when the plurality of switches are arranged in a first mode;
• and
• coupling the differential input stage and the second output block together as an operational amplifier when the plurality of switches are arranged in a second mode.