# US 2018/0123515 A1 · Mixer of a near field communication (nfc) receiver device supporting single-ended and differential inputs > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0123515 A1 - Document ID: US20180123515A1 - Status: Published application - Kind: A1 - Application number: 15/341,629 - Filed: 2016-11-02 - Published: 2018-05-03 - Earliest claimed: 2016-11-02 - Assignees: NXP B.V. - Applicants: NXP B.V. - Inventors: Jingfeng Ding; Helmut Kranabenter; Gernot Hueber - Web page: https://patentgrep.com/patent/US20180123515A1 ## CPC - H03D 7/125: {with field effect transistors} - G11C 27/02: Sample-and-hold arrangements (G11C27/04 takes precedence) - G11C 27/024: {using a capacitive memory element (G11C27/04 takes precedence)} - H03D 7/1441: {using field-effect transistors (H03D7/145 takes precedence)} - H03D 7/1466: {Passive mixer arrangements} - H03D 7/165: {at least two frequency changers being located in different paths, e.g. in two paths with carriers in quadrature (combined with amplitude demodulation H03D1/2245, combined with angle demodulation H03D3/007; N-path filters H03H19/002)} - H04B 5/70: specially adapted for specific purposes - H03D 2200/0082: Quadrature arrangements - H03D 2200/0086: Reduction or prevention of harmonic frequencies - H03D: DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER (masers, lasers H01S; circuits capable of acting both as modulator and demodulator H03C; details applicable to both modulators and frequency-changers H03C; demodulating pulses H03K9/00; transforming types of pulse modulation H03K11/00; coding, decoding or code conversion, in general H03M; repeater stations H04B7/14; demodulators adapted for AC systems of digital information transmission H04L27/00; synchronous demodulators adapted for colour television H04N9/66) - G11C: STATIC STORES (semiconductor memory devices H10B) - H04B: TRANSMISSION ## Abstract Embodiments of a mixer of a Near field communication (NFC) receiver device and a method for operating a mixer of an NFC receiver device are disclosed. In an embodiment, a mixer of an NFC receiver device includes an input unit from which an input signal is received, a sample and hold circuit configured to sample the input signal and to store electrical charge based on the sampled input signal in order to generate a differential output signal, a control unit configured to switch the sample and hold circuit between different operational modes based on whether the input signal is a single-ended input signal or a differential input signal, and a differential output unit from which the differential output signal is output. Other embodiments are also described. ## Claims ### Claim 1 A mixer of a Near field communication (NFC) receiver device, the mixer comprising: an input unit from which an input signal is received; a sample and hold circuit configured to sample the input signal and to store electrical charge based on the sampled input signal in order to generate a differential output signal; a control unit configured to switch the sample and hold circuit between different operational modes based on whether the input signal is a single-ended input signal or a differential input signal; and a differential output unit from which the differential output signal is output, wherein the control unit is configured to set the sample and hold circuit to a single-ended input operational mode in response to the input signal being a single-ended input signal and to set the sample and hold circuit to a differential input operational mode in response to the input signal being a differential input signal, wherein the input unit comprises a first input terminal and a second input terminal, wherein the sample and hold circuit comprises a first switch connected between the first input terminal and the second input terminal, wherein the differential output unit comprises a first output terminal and a second output terminal, and wherein the sample and hold circuit further comprises a second set of switches and a plurality of capacitors connected between the first and second input terminals and the first and second output terminals. ### Claim 2 (canceled) ### Claim 3 (depends on 1) The mixer of claim 1, wherein the control unit is configured to control the first switch based on whether the input signal is a single-ended input signal or a differential input signal. ### Claim 4 (depends on 3) The mixer of claim 3, wherein the control unit is configured to switch the first switch on when in the single-ended input operational mode. ### Claim 5 (depends on 4) The mixer of claim 4, wherein the control unit is configured to switch the first switch off when in the differential input operational mode. ### Claim 6 (canceled) ### Claim 7 (depends on 1) The mixer of claim 1, wherein the second set of switches comprises a second switch, a third switch, a fourth switch, and a fifth switch, wherein the plurality of capacitors comprise a first capacitor, a second capacitor, a third capacitor, and a fourth capacitor, wherein the second switch is connected to the first input terminal and to the first capacitor, and wherein the third switch is connected to the second input terminal and to the second capacitor. ### Claim 8 (depends on 7) The mixer of claim 7, wherein a first terminal of the first switch is connected to the first input terminal and to the second switch, wherein a second terminal of the first switch is connected to the third switch and to the second capacitor, and wherein the control unit is configured to switch the second switch off in response to the input signal being a single-ended input signal. ### Claim 9 (depends on 8) The mixer of claim 8, wherein the fourth switch is connected to the second switch, to the first capacitor, and to the first output terminal, and wherein the fifth switch is connected to the third switch, to the second capacitor, to the fourth capacitor, and to the second output terminal. ### Claim 10 (depends on 8) The mixer of claim 8, further comprising a sixth switch, wherein a first terminal of the sixth switch is connected to the second input terminal and to the third switch, wherein a second terminal of the sixth switch is connected to the second switch and to the first capacitor. ### Claim 11 (depends on 8) The mixer of claim 8, wherein the first, second, third, and fourth capacitors are connected to a node, and wherein the second input terminal is connected to the node if the input signal is a single-ended input signal. ### Claim 12 (depends on 1) The mixer of claim 1, wherein the mixer is an in-phase mixer or a quadrature mixer of an I/Q mixer system. ### Claim 13 (depends on 12) The NFC receiver device of claim 12, wherein the NFC receiver device further comprises the I/Q mixer system, an amplifier connected to the I/Q mixer system, an Analog to Digital Converter (ADC) connected to the amplifier, and a digital signal processor (DSP) connected to the ADC. ### Claim 14 (canceled) ### Claim 15 (canceled) ### Claim 16 (canceled) ### Claim 17 (canceled) ### Claim 18 (canceled) ### Claim 19 (canceled) ### Claim 20 A method for operating a mixer of a Near field communication (NFC) receiver device, the method comprising: receiving an input signal from an input unit; sampling the input signal and storing electrical charge based on the sampled input signal in order to generate a differential output signal using a sample and hold circuit; switching the sample and hold circuit between different operational modes based on whether the input signal is a single-ended input signal or a differential input signal, wherein switching the sample and hold circuit between the different operational modes comprises setting the sample and hold circuit to a single-ended input operational mode in response to the input signal being a single-ended input signal and setting the sample and hold circuit to a differential input operational mode in response to the input signal being a differential input signal; and outputting the differential output signal from a differential output unit, wherein the input unit comprises a first input terminal and a second input terminal, wherein the sample and hold circuit comprises a first switch connected between the first input terminal and the second input terminal, wherein the differential output unit comprises a first output terminal and a second output terminal, and wherein the sample and hold circuit further comprises a second set of switches and a plurality of capacitors connected between the first and second input terminals and the first and second output terminals.