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US 5,757,211 AGranted
IC precision resistor ratio matching with different tub bias voltages
AssigneeSGS-Thomson Microelectronics S.A.
InventorWilliam Aidan Phillips
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Abstract
An integrated circuit motor controller having two or more integrated resistor dividers which produce signals to be compared with each other is disclosed. The circuit is designed to substantially reduce the dependency of the comparison on the reverse bias of the junctions between diffused resistors in the integrated resistor dividers and the silicon into which they are diffused.
Claims20
A controller for controlling a system including a circuit comprising:
- a command signal input for inputting a command signal;
- a feedback signal input for inputting a feedback signal from said system;
- a first resistor divider circuit including first and second resistors for outputting a first signal in response to said command and feedback signals;
- a second resistor divider circuit including third and fourth resistors, responsive to said command and feedback signals for outputting a second signal for comparison to said first signal to generate a comparison signal;
- tub tie contacts operably associated with said first and second resistor divider circuits for introducing bias voltages for biasing said first, second, third, and fourth resistors of said first and second resistor divider circuits;
- and wherein
- at least one of said command signal or feedback signal inputs is coupled to at least one of said tub tie contacts for biasing at least one of said first, second, third, or fourth resistors with either said command or feedback signal so as to minimize error introduced by said bias voltages in a comparison of said first and second signals.
4 more elements
A method for controlling a system, said method comprising the steps of:
- providing a first resistor divider circuit including first and second resistors having first and second tub ties for outputting a first signal in response to command and feedback signals;
- providing a second resistor divider circuit including third and fourth resistors having third and fourth tub ties, responsive to said command and feedback signals, for outputting a second signal for comparison to said first signal to generate a comparison signal;
- introducing bias voltages to said first, second, third, and fourth tub ties for biasing said first, second, third, and fourth resistors of said first and second resistor divider circuits;
- and
- biasing at least one of said first, second, third, or fourth tub ties of said first, second, third, and fourth resistors with at least one of said command or feedback signals so as to minimize error introduced by said bias voltages in a comparison of said first and second signals.
2 more elements
An integrated circuit for controlling a motor comprising:
- a command signal input for inputting a command signal for controlling said motor;
- a feedback signal input for inputting a feedback signal from said motor;
- a first resistor divider circuit having first and second resistors for outputting a first signal in response to said command and feedback signals;
- a second resistor divider circuit having third and fourth resistors for outputting a second signal for comparison to said first signal;
- a comparator/amplifier for comparing said first and second signals;
- each of said resistors including a tub tie contact for introducing a bias voltage wherein said bias voltage of said first, second, and third resistors are fixed;
- and
- switch means for selectively biasing said fourth resistor with one of said command or feedback signals so as to minimize error introduced by said bias voltage in a comparison of said first and second signals.
5 more elements
Dependencies are inferred from the claim text.