Input/output multiplexer bus

• US 9,863,988 B1
• Filed: 10/31/2016
• Issued: 01/09/2018
• Est. Priority Date: 03/27/2006
• Status: Active Grant

• Current Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Original Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Inventors: Seguine, Dennis R.
• Primary Examiner(s): Nguyen, Hoai-An D
• Application Number:
  US15/339,634
• Time in Patent Office: 435 Days
• Field of Search: 324 7611, 324 7659, 324519, 324600, 324649, 324658, 324673, 324678, 324686, 32476201, 710100, 710305, 710306, 710313
• CPC Class Codes: G01D 5/24 by varying capacitance
• CPC Class Codes: G01D 5/2417 by varying separation
• CPC Class Codes: G01R 27/26 Measuring inductance or capacitance; Measuring quality factor, e.g. by using the resonance method; Measuring loss factor; Measuring dielectric constants ; Measuring impedance or related variables
• CPC Class Codes: G01R 27/2605 Measuring capacitance capacitive sensors G01D5/24
• CPC Class Codes: G01R 31/2829 Testing of circuits in sensor or actuator systems testing of apparatus for measuring electric or magnetic variables G01R35/00; testing of indicating or recording apparatus G01D; in airbag systems B60R21/0173; checking gas analysers G01N33/007; monitoring or fail-safe circuits for electromagnets H01F7/1844
• CPC Class Codes: G01R 31/64 Testing of capacitors

Abstract

One embodiment includes and I/O bus including a signal line coupled to a signal source and multiple line switches, each line switch to couple a corresponding I/O port to the signal line. Switch logic coupled to the I/O bus may programmatically switch the multiple line switches to couple at least one of the signal source and measurement circuitry to the respective I/O port.

Claims

1. A capacitance measurement device comprising:

a plurality of inputs/outputs (I/Os), each coupled to a capacitance measurement electrode;

a first capacitance measurement circuit coupled to the plurality of I/Os through a switch matrix, the switch matrix, the switch matrix to provide a plurality of signal sources to the plurality of I/Os and to the first capacitance measurement circuit.

2. The capacitance measurement device of claim 1, wherein the plurality of signal sources includes a voltage signal and a current signal.

3. The capacitance measurement device of claim 1, further comprising a second capacitance measurement circuit coupled to the plurality of I/Os through a switch matrix.

4. The capacitance measurement device of claim 1, further comprising switch logic to operatively control connections between the I/Os and the first measurement circuit.

5. The capacitance measurement device of claim 1, wherein the switch matrix couples at least two I/Os to the first capacitance measurement circuit simultaneously.