MULTIPLE INPUT ANALOG TO DIGITAL CONVERTER

• US 20100238058A1
• Filed: 03/17/2010
• Published: 09/23/2010
• Est. Priority Date: 03/17/2009
• Status: Abandoned Application

• Current Assignee: OHAUS Corp. (Mettler-Toledo International Inc.)
• Original Assignee: OHAUS Corp. (Mettler-Toledo International Inc.)
• Inventors: Scaduto, John B.
• Application Number:
  US12/726,197
• Publication Number:
  US 20100238058A1
• Time in Patent Office: Days
• US Class Current: 341/141
• CPC Class Codes: H03M 1/0607 Offset or drift compensation removal of offset already present on the analogue input signal H03M1/1295
• CPC Class Codes: H03M 1/0682 using a differential network structure, i.e. symmetrical with respect to ground
• CPC Class Codes: H03M 1/1225 using time-division multiplexing

Abstract

A multi-input analog to digital converter (“ADC”) to accept and process multiple inputs. The analog multiplexer is integrated with an amplifier chopper circuit to form a high precision, temperature stable, ADC circuit with multiple inputs.

Claims

1. A system for converting or amplifying signals from a plurality of load cells, comprising:

a first multiplexer circuit electrically connected to the plurality of load cells to receive output signals from the load cells;

an amplifier circuit electronically connected to the first multiplexer circuit;

a control signal in electrical communication with the first multiplexer circuit for selecting one of the load cells and wherein said system is configured to output signals from the selected load cell; and

wherein the system is configured to shift the amplifier circuit from a positive side to a negative side.

2. The system according to claim 1, further comprising:

a chopper signal in electrical communication with the first multiplexer circuit for shifting the amplifier circuit from a positive side to a negative side.

3. The system according to claim 1, wherein the amplifier circuit is an analog to digital converter circuit.

4. The system according to claim 1, wherein the control signal originates from a load cell operator station wherein a load cell operator can switch between two or more load cells by the touch of a button.

5. The system according to claim 1, wherein the amplifier circuit is a precision sigma-delta analog to digital converter.

6. The system according to claim 1, wherein the first multiplexer circuit is comprised of a plurality of multiplexers, one for each of the load cells connected to the system.

7. The system according to claim 2, further comprising:

a second multiplexer circuit connected to an output of the amplifier circuit; and

wherein the chopper signal is in electrical communication with the second multiplexer circuit and controls the signal output from the second multiplexer circuit.

8. A system for converting or amplifying signals from a plurality load cells, comprising:

a first multiplexer circuit electrically connected to the plurality of load cells to receive output signals from the load cells;

an amplifier circuit electronically connected to the first multiplexer circuit;

a control signal in electrical communication with the first multiplexer circuit for selecting one of the load cells and wherein said system is configured to output signals from the selected load cell;

a chopper signal in electrical communication with the first multiplexer circuit for shifting the amplifier circuit from a positive side to a negative side;

a second multiplexer circuit connected to an output of the amplifier circuit; and

wherein the chopper signal is in electrical communication with the second multiplexer circuit and controls the signal output from the second multiplexer circuit.

9. The system according to claim 8, wherein the amplifier circuit is an analog to digital converter circuit.

10. The system according to claim 8, wherein the control signal originates from a load cell operator station wherein a load cell operator can switch between two or more load cells by the touch of a button.

11. The system according to claim 8, wherein the amplifier circuit is a precision sigma-delta analog to digital converter.

12. The system according to claim 8, wherein the first multiplexer circuit is comprised of a plurality of multiplexers, one for each of the load cells connected to the system.

13. A method for amplifying signals from a plurality load cells, comprising the steps of:

receiving signals output from a plurality of load cells at a first multiplexer circuit;

providing an amplifier circuit electronically connected to the first multiplexer circuit;

providing a control signal in electrical communication with the first multiplexer circuit for selecting one of the load cells;

outputting signals from the selected load cell at the output of the first multiplexer circuit; and

providing a chopper signal for shifting the amplifier circuit from a positive side to a negative side.

14. The system according to claim 13, wherein the amplifier circuit is an analog to digital converter circuit.

15. The system according to claim 13, wherein the control signal originates from a load cell operator station wherein a load cell operator can switch between two or more load cells by the touch of a button.

16. The system according to claim 13, wherein the amplifier circuit is a precision sigma-delta analog to digital converter.

17. The system according to claim 13, wherein the first multiplexer circuit is comprised of a plurality of multiplexers, one for each of the load cells connected to the system.

18. The system according to claim 13, further comprising:

providing a second multiplexer circuit connected to an output of the amplifier circuit; and

providing the chopper signal to the second multiplexer circuit for controlling the signal output from the second multiplexer circuit.