# US 2014/0191782 A1 · On-chip r and c calibration using on-board supply bypass capacitance > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0191782 A1 - Document ID: US20140191782A1 - Status: Published application - Kind: A1 - Application number: 13/734,805 - Filed: 2013-01-04 - Published: 2014-07-10 - Earliest claimed: 2013-01-04 - Assignees: Broadcom Corporation - Applicants: Broadcom Corporation - Inventors: Mohyee MIKHEMAR; Hooman DARABI - Web page: https://patentgrep.com/patent/US20140191782A1 ## CPC - H03B 21/00: Generation of oscillations by combining unmodulated signals of different frequencies (H03B19/00 takes precedence; frequency changing circuits in general H03D) - G01L 9/12: by making use of variations in capacitance {, i.e. electric circuits therefor} - H03B 5/20: with frequency-determining element comprising resistance and either capacitance or inductance, e.g. phase-shift oscillator - H03B 5/32: being a piezoelectric resonator (selection of piezoelectric material H10N30/00) - G01R 27/2605: {Measuring capacitance (capacitive sensors G01D5/24)} - G01R 31/016: {Testing of capacitors (measuring capacitance G01R27/2605)} - H03K 3/0231: Astable circuits {(H03K3/0315 takes precedence)} - H03K 3/354: Astable circuits - H03B: GENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS (generators adapted for electrophonic musical instruments G10H; masers or lasers H01S; generation of oscillations in plasma H05H) - G01L: MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE (weighing G01G) - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M) ## Abstract A technique for calibration of on-chip resistance (R) and capacitance (C) values using an on-board bypass capacitor may include configuring an on-chip switch to selectively couple an on-chip calibration circuit to an on-chip port. The on-chip calibration circuit may include an RC oscillator having an RC time constant (RCTC). The on-board bypass capacitor may be coupled to the on-chip calibration circuit, by using the on-chip port. The on-chip R and C values may be calibrated using the on-chip calibration circuit and the on-board bypass capacitor. ## Claims ### Claim 1 A device for calibration of on-chip resistance (R) and capacitance (C) values using an on-board bypass capacitor, the device comprising: an on-chip calibration circuit, including an RC oscillator having an RC time constant (RCTC), disposed to calibrate the on-chip R and C values; an on-chip switch configurable to selectively couple the on-chip calibration circuit to an on-chip port, the on-chip port being used for coupling the on-board bypass capacitor to the on-chip calibration circuit; and a calibration module configured to calibrate the on-chip R and C values using the on-chip calibration circuit and the on-board bypass capacitor. ### Claim 2 (depends on 1) The device of claim 1, wherein an RCTC module is configured to perform: a first RCTC measurement, while the switch is configured to uncouple the on-board bypass capacitor from the on-chip calibration circuit; and a second RCTC measurement, while the switch is configured to couple the on-board bypass capacitor to the on-chip calibration circuit, wherein the RCTC module is further configured to perform the first and the second RCTC measurements by measuring a period associated with an oscillation frequency of the oscillator using a reference oscillator. ### Claim 3 (depends on 2) The device of claim 2, wherein the measured period is a measure of the RCTC of the on-chip calibration circuit. ### Claim 4 (depends on 2) The device of claim 2, further comprising an on-board crystal oscillator, and wherein the RCTC module is configured to use the on-board crystal oscillator as the reference oscillator, and wherein the on-board crystal oscillator comprises a crystal oscillator used by one or more on-chip circuits including at least one synthesizer. ### Claim 5 (depends on 2) The device of claim 2, wherein the RCTC module is configured to perform the second RCTC measurement by measuring a combined RCTC that includes a known capacitance value of the on-board bypass capacitor. ### Claim 6 (depends on 5) The device of claim 5, wherein the calibration module is configured to determine the resistance R and the capacitance C of the on-chip calibration circuit by using the measured RCTC of the on-chip calibration circuit, the measured combined RCTC, and the known capacitance value of the on-board bypass capacitor. ### Claim 7 (depends on 6) The device of claim 6, wherein the calibration module is further configured to determine the on-chip unit resistance (Ru) and unit-capacitance (Cu) values based on the determined resistance Rcal and capacitance Ccal of the on-chip calibration circuit, and wherein the calibration module is further configured to calibrate the on-chip R and C values based on the determined Ru and Cu values. ### Claim 8 A method for calibration of on-chip resistance (R) and capacitance (C) values using an on-board bypass capacitor, the method comprising: configuring an on-chip switch to selectively couple an on-chip calibration circuit to an on-chip port, the on-chip calibration circuit including an RC oscillator having an RC time constant (RCTC); coupling the on-board bypass capacitor to the on-chip calibration circuit, by using the on-chip port; and using the on-chip calibration circuit and the on-board bypass capacitor to calibrate the on-chip R and C values. ### Claim 9 (depends on 8) The method of claim 8, wherein using the on-chip calibration circuit and the on-board bypass capacitor to calibrate the on-chip R and C values comprises using an RCTC module to perform: a first RCTC while the switch uncouples the on-board bypass capacitor from the on-chip calibration circuit; and a second RCTC measurement while the switch couples the on-board bypass capacitor to the on-chip calibration circuit, wherein the reference oscillator is used by the RCTC module to measure a period associated with an oscillation frequency of the oscillator. ### Claim 10 (depends on 9) The method of claim 9, wherein the measured period is a measure of the RCTC of the on-chip calibration circuit. ### Claim 11 (depends on 9) The method of claim 9, wherein performing the first RCTC measurement includes using, as the reference oscillator, an already available on-board crystal oscillator. ### Claim 12 (depends on 11) The method of claim 11, wherein the already available on-board crystal oscillator comprises a crystal oscillator used by one or more on-chip circuits including at least one synthesizer. ### Claim 13 (depends on 9) The method of claim 9, wherein performing the second RCTC measurement comprises measuring, using the RCTC module, a combined RCTC that includes a known capacitance value of the on-board bypass capacitor. ### Claim 14 (depends on 13) The method of claim 13, wherein determining the resistance Rcal and the capacitance Ccal of the on-chip calibration circuit comprises using, by a calibration module, the measured RCTC of the on-chip calibration circuit, the measured combined RCTC, and the known capacitance value of the on-board bypass capacitor. ### Claim 15 (depends on 14) The method of claim 14, further comprising determining, by the calibration module, the on-chip unit-resistance (Ru) and unit-capacitance (Cu) values based on the determined resistance R and capacitance C of the on-chip calibration circuit. ### Claim 16 (depends on 15) The method of claim 15, further comprising calibrating, by the calibration module, the on-chip R and C values based on the determined on-chip unit-resistance (Ru) and unit-capacitance (Cu) values. ### Claim 17 A system for calibration of on-chip resistance (R) and capacitance (C) values using an on-board bypass capacitor, the system comprising: an on-chip calibration circuit, including an RC oscillator having an RC time constant (RCTC), disposed to calibrate the on-chip R and C values; an on-chip switch configurable to selectively couple the on-chip calibration circuit to an on-chip port, the on-chip port being used for coupling the on-board bypass capacitor to the on-chip calibration circuit; an RCTC module configured to perform a first RCTC measurement while the switch is configured to uncouple the on-board bypass capacitor from the on-chip calibration circuit, and to perform a second RCTC measurement while the switch is configured to couple the on-board bypass capacitor to the on-chip calibration circuit; and a calibration module to determine a resistance Rcal and a capacitance Ccal of the on-chip calibration circuit by using a result of the first and the second RCTC measurements, and to calibrate the on-chip R and C values based on the determined resistance Rcal and capacitance Ccal of the on-chip calibration circuit. ### Claim 18 (depends on 17) The system of claim 17, wherein: the RCTC module is configured to perform the first RCTC measurement by measuring a period associated with an oscillation frequency of the oscillator using a reference oscillator, the measured period is a measure of the RCTC of the on-chip calibration circuit, and the RCTC module is configured to perform the second RCTC measurement by measuring a combined RCTC that includes a known capacitance value of the on-board bypass capacitor. ### Claim 19 (depends on 18) The system of claim 18, further comprising an already available on-board crystal oscillator disposed to be used as the reference oscillator, and wherein the already available on-board crystal oscillator comprises a crystal oscillator used by one or more on-chip circuits including at least one synthesizer. ### Claim 20 (depends on 18) The system of claim 18, wherein the calibration module is configured to determine the resistance R and the capacitance C of the on-chip calibration circuit by using the measured RCTC of the on-chip calibration circuit, the measured combined RCTC, and the known capacitance value of the on-board bypass capacitor, wherein the calibration module is further configured to determine the on-chip unit resistance (Ru) and unit-capacitance (Cu) values based on the determined resistance Rcal and capacitance Ccal of the on-chip calibration circuit, and wherein the calibration module is further configured to calibrate the on-chip R and C values based on the determined Ru and Cu values.