Differential transistor and method therefor

A method of forming a differential transistor comprising:

• forming an enhancement mode transistor of a first conductivity type having a source coupled to a source of a depletion mode transistor of a second conductivity type;
• forming a threshold voltage of the enhancement mode transistor so that an absolute value of the threshold voltage of the enhancement mode transistor is no greater than an absolute value of a threshold voltage of the depletion mode transistor;
• coupling a gate of the enhancement mode transistor to a gate of another enhancement mode transistor, coupling a drain of the depletion mode transistor to a voltage return, coupling a gate of the depletion mode transistor to a gate and a source of another depletion mode transistor and to a drain of the another enhancement mode transistor, coupling a source of the another enhancement mode transistor to receive a voltage from a voltage source;
• and
• coupling a drain of the enhancement mode transistor to a first terminal of a resistor and to a signal input of a microprocessor, and coupling a second terminal of the resistor to receive the voltage from the voltage source.

A method of forming a differential transistor comprising:

• forming an enhancement mode transistor of a first conductivity type having a source coupled to a source of a depletion mode transistor of a second conductivity type;
• forming a threshold voltage of the enhancement mode transistor so that an absolute value of the threshold voltage of the enhancement mode transistor is no greater than an absolute value of a threshold voltage of the depletion mode transistor;
• coupling a drain of the enhancement mode transistor to receive a voltage from a voltage source;
• coupling a gate of the enhancement mode transistor to a gate of another enhancement mode transistor, coupling a drain of the depletion mode transistor to a signal mode, coupling a gate of the depletion mode transistor to a gate and a source of another depletion mode transistor and to a drain of the another enhancement mode transistor, coupling a source of the another enhancement mode transistor to receive the voltage from the voltage source;
• and
• coupling a drain of the another depletion mode transistor to a drain of a lower output transistor and coupling a source of the lower output transistor to a voltage return.

A method of forming a differential transistor comprising:

• forming an enhancement mode transistor of a first conductivity type having a source coupled to a source of a depletion mode transistor of a second conductivity type;
• and
• forming a threshold voltage of the enhancement mode transistor so that an absolute value of the threshold voltage of the enhancement mode transistor is no greater than an absolute value of a threshold voltage of the depletion mode transistor;
• and
• coupling the drain of the depletion mode transistor to receive a first signal, coupling a gate of the depletion mode transistor to a gate of another enhancement mode transistor, coupling the drain of the enhancement mode transistor to a voltage return, coupling a gate of the enhancement mode transistor to a drain of another depletion mode transistor and to a drain of the another enhancement mode transistor, coupling a source of the another depletion mode transistor to a gate of the another depletion mode transistor, and coupling a source of the another enhancement mode transistor to receive a voltage from a voltage source.