Field effect transistor circuits

A sine wave to triangle wave converter circuit including a first field effect transistor, a second field effect transistor, a third field effect transistor and fourth field effect transistor wherein each of the first, second, third, and fourth field effect transistors include a drain terminal, a gate terminal, and source terminal comprising:

• a sinusoidal signal source coupled to the gate terminals of the first and third field effect transistors;
• coupling to a first voltage potential the gate terminals of the second and fourth field transistors;
• coupling the drain terminal of the first field effect transistor to the drain terminal of the second field effect transistor;
• coupling the drain terminal of the third field transistor to the drain terminal of the fourth field effect transistor;
• coupling the source terminal of the first field effect transistor to the source terminal of the fourth field effect transistor;
• coupling the source terminal of the second field transistor to the source terminal of the third field effect transistor;
• coupling a first current source to the source terminals of the first field effect transistor and the fourth field effect transistor;
• coupling a second current source to the source terminals of the second field effect transistor and the third field effect transistor;
• providing a first output current terminal coupled to the drain terminals of the first and second field effect transistors;
• setting the current of the first current source not equal to the current of the second current source;
• providing a triangle waveform current at the first output current terminal with the sinusoidal signal source.