Rail-to-rail input linear voltage to current converter
AssigneeCypress Semiconductor Corporation
InventorJonathon Stiff
Life of this patent
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Abstract
A voltage-to-current converter circuit is disclosed. In one embodiment, the present invention includes a first metal oxide semiconductor field effect transistor (MOSFET) stage operable in a low to medium power range. The present invention also includes a second MOSFET stage operable in a medium to high power range. An additive circuit is utilized to add the contributions of both the first MOSFET stage and the second MOSFET stage. A subtractive circuit is further used to subtract either the first MOSFET stage or the second MOSFET stage when both the first MOSFET stage and the second MOSFET stage are operating in the medium power range and outputting current in a voltage-to-current converting circuit.
Claims19
A voltage-to-current converter circuit comprising:
- a first metal oxide semiconductor field effect transistor (MOSFET) stage operable in a low to medium input voltage range;
- a second MOSFET stage operable in a medium to high input voltage range;
- an additive circuit to add current contributions of both the first MOSFET stage and the second MOSFET stage;
- and
- a subtractive circuit for causing said second MOSFET stage contribution to be subtracted from said first MOSFET stage contribution when both said first MOSFET stage and said second MOSFET stage are operating in a portion of the medium voltage range.
A voltage to current converter circuit comprising:
- a positive channel metal-oxide semiconductor (PMOS) stage operable in a low to medium voltage range;
- a negative channel metal-oxide semiconductor (NMOS) stage operable in a medium to high voltage range;
- an additive circuit to add current contributions of both the NMOS stage and the PMOS stage from the low voltage range to the high voltage range to provide a rail-to-rail linear voltage-to-current output;
- and
- a subtractive circuit to subtract said NMOS stage current contribution when both said NMOS stage and said PMOS stage are operating in the medium voltage range.
A voltage-to-current converter circuit comprising:
- a first voltage-to-current converter circuit operational from a low to a mid input voltage range;
- a second voltage-to-current converter circuit operational from a mid to a high input voltage range;
- and
- a current compensation circuit coupled with said first and second voltage-to-current converter circuits, wherein said current compensation circuit removes the input of said second voltage-to-current converter during the mid voltage range when both said first and said second voltage-to-current converters are operational.
Dependencies are inferred from the claim text.