Integrated current mirror in output stage of operational amplifier

A chopper stabilized current mirror configuration comprising:

• a first integrated current mirror circuit comprising a first transistor and a second transistor, said first transistor and said second transistor having gates connected together and having sources coupled together;
• a first switch network coupled to drains of said first transistor and said second transistor, said first switch network configured for chopper stabilizing said first transistor and said second transistor;
• a second integrated current mirror circuit comprising a third transistor and a fourth transistor, said third transistor and said fourth transistor having gates connected together and having sources coupled together;
• a second switch network coupled to drains of said third transistor and said fourth transistor, said second switch network configured for chopper stabilizing said third transistor and said fourth transistor;
• and
• wherein said first switch network and said second switch network are configured to permit said first transistor and said third transistor to drive current to a first output terminal and said second transistor and said fourth transistor to drive current to a load device during a first phase of operation, and are configured to permit said second transistor and said fourth transistor to drive current to said first output terminal and said first transistor and said third transistor to drive current to the load device during a second phase of operation.

An amplifier circuit configured for providing full rail-to-rail output performance, said amplifier circuit comprising:

• an amplifier having a gain stage configured for receiving an input signal;
• at least one current mirror configuration integrated within said amplifier, said at least one current mirror comprising a first transistor device and a second transistor device;
• and
• at least one switching network, said at least one switching network configured such that said first transistor device is coupled in a feedback arrangement with said amplifier and said second transistor device is configured to mirror said input signal to an output load during a first phase, and said second transistor device is coupled in a feedback arrangement with said amplifier and said first transistor device is configured to mirror said input signal to the output load during a second phase.

A method for chopper stabilizing a current mirror configuration to facilitate full rail-to-rail output performance in an amplifier circuit, said method comprising the steps of:

• receiving an input current signal in an amplifier having an output stage configured within a first current mirror circuit and a second current mirror circuit;
• switching a first transistor of said first current mirror circuit and a third transistor of said second current mirror circuit to be in a feedback arrangement with said amplifier during a first phase of operation;
• switching a second transistor of said first current mirror circuit and a fourth transistor of said second current mirror circuit to be connected with a load device during said first phase of operation;
• switching said second transistor of said first current mirror circuit and said fourth transistor of said second current mirror circuit to be in said feedback arrangement with said amplifier device during a second phase of operation;
• and
• switching a first transistor of said first current mirror circuit and a third transistor of said second current mirror circuit to be connected with the load device during said first phase of operation.