# US 9,438,190 B1 · Amplification circuit adjusting duty cycle of output signal and receiver including the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,438,190 B1 - Document ID: US9438190B1 - Status: Granted - Kind: B1 - Application number: 15/146,961 - Filed: 2016-05-05 - Published: 2016-08-25 - Granted: 2016-09-06 - Earliest claimed: 2014-05-08 - Assignees: SK hynix Inc. - Applicants: SK hynix Inc. - Inventors: Jae Mo Yang - Web page: https://patentgrep.com/patent/US9438190B1 ## CPC - H03F 3/45183: {Long tailed pairs (H03F3/4521, H03F3/45237 take precedence)} - H03F 3/45188: {Non-folded cascode stages} - H03F 3/45744: {by offset reduction} - H03K 5/1565: {the output pulses having a constant duty cycle} - H03F 2200/375: Circuitry to compensate the offset being present in an amplifier - H03F 2203/45212: the differential amplifier being designed to have a reduced offset - H04B 1/16: Circuits - H03F: AMPLIFIERS - 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) - H04B: TRANSMISSION ## Abstract A receiver includes a first stage buffer, a second stage buffer and a third stage buffer. The first stage buffer includes an input portion electrically coupled to a first voltage node, and configured to change a voltage level of an output node in response to an input signal, first and second load portions electrically coupled between a second voltage node and the output node, and electrically coupled to each other and a duty cycle adjustment portion electrically coupled between the first and second load portions, and configured to provide a correction current to the output node through the first load portion. ## Claims ### Claim 1 A receiver comprising: a first stage buffer configured to amplify an input signal; a second stage buffer configured to amplify an output signal of the first stage buffer; and a third stage buffer configured to amplify an output signal of the second stage buffer, wherein the first stage buffer includes: an input portion electrically coupled to a first voltage node, and configured to change a voltage level of an output node in response to the input signal; first and second load portions electrically coupled between a second voltage node and the output node, and electrically coupled to each other; and a duty cycle adjustment portion electrically coupled between the first and second load portions, and configured to provide a correction current to the output node through the first load portion. ### Claim 2 (depends on 1) The receiver of claim 1, wherein one node of the first load portion is electrically coupled to the output node, and the other node of the first load portion is electrically coupled to one node of the second load portion, and the other node of the second load portion is electrically coupled to the second voltage node. ### Claim 3 (depends on 1) The receiver of claim 1, wherein a resistance value of the first load portion is greater than a resistance value of the second load portion. ### Claim 4 (depends on 1) The receiver of claim 1, wherein the second load portion has a resistance value variable according to a variable resistance code. ### Claim 5 (depends on 1) The receiver of claim 1, wherein each of the first stage buffer and the second stage buffer includes a P-type amplifier, and the third stage buffer includes a N-type amplifier. ### Claim 6 (depends on 1) The receiver of claim 1, wherein the second stage buffer has a higher common mode voltage than a common mode voltage of each of the first and third stage buffers. ### Claim 7 A receiver comprising: a first stage buffer configured to amplify an input signal; a second stage buffer configured to amplify an output signal of the first stage buffer; and a third stage buffer configured to amplify an output signal of the second stage buffer, wherein the second stage buffer includes: an input portion electrically coupled to a first voltage node, and configured to change voltage levels of output nodes in response to the output signal of the first stage buffer; first and second load portions electrically coupled between a second voltage node and the output nodes, and electrically coupled to each other; and a duty cycle adjustment portion electrically coupled between the first and second load portions, and configured to provide correction currents to the output nodes through the first load portion. ### Claim 8 (depends on 7) The receiver of claim 7, wherein a resistance value of the first load portion is greater than a resistance value of the second load portion. ### Claim 9 (depends on 7) The receiver of claim 7, wherein the output nodes include a first output node and a second output node, wherein the first load portion includes: a first resistance having one end electrically coupled to the first output node; a second resistance having one end electrically coupled to the second output node, and the other end electrically coupled to the other end of the first resistance; a first transistor having a gate electrically coupled to the other ends of the first and second resistances, a drain electrically coupled to the one end of the first resistance, and a source electrically coupled to the second load portion; and a second transistor having a gate electrically coupled to the other ends of the first and second resistances, a drain electrically coupled to the one end of the second resistance, and a source electrically coupled to the second load portion. ### Claim 10 (depends on 7) The receiver of claim 7, wherein the second load portion has a resistance value variable according to a variable resistance code. ### Claim 11 (depends on 7) The receiver of claim 7, wherein each of the first stage buffer and the second stage buffer includes a P-type amplifier, and wherein the third stage buffer includes a N-type amplifier. ### Claim 12 (depends on 7) The receiver of claim 7, wherein the second stage buffer has a higher common mode voltage than a common mode voltage of each of the first and third stage buffers. ### Claim 13 A receiver comprising: a first stage buffer configured to amplify an input signal; a second stage buffer configured to amplify an output signal of the first stage buffer; and a third stage buffer configured to amplify an output signal of the second stage buffer, wherein the third stage buffer includes: a first amplifier having: a first input portion electrically coupled to a second voltage node, and configured to generate a first output in response to the output signal of the second stage buffer; a first current mirror configured to provide an amplified current to the first input portion; and first and second load portions serially coupled between a first voltage node and the first current mirror; a second amplifier having: a second input portion electrically coupled to a second voltage node, and configured to generate a second output in response to the output signal of the second stage buffer; a second current mirror configured to provide an amplified current to the second input portion; and third and fourth load portions serially coupled between the first voltage node and the second current mirror; and a duty cycle adjustment portion electrically coupled between the first and second load portions and the third and fourth load portions. ### Claim 14 (depends on 13) The receiver of claim 13, wherein the first load portion having one end electrically coupled between the first current mirror and the second load portion, wherein the second load portion electrically coupled between the first load portion and the first voltage node, wherein the third load portion having electrically coupled between the second current mirror and the fourth load portion, and wherein the fourth load portion electrically coupled between the third load portion and the first voltage node. ### Claim 15 (depends on 13) The receiver of claim 13, wherein a resistance value of the first load portion is greater than a resistance value of the second load portion, and wherein a resistance value of the third load portion is greater than a resistance value of the fourth load portion. ### Claim 16 (depends on 13) The receiver of claim 13, wherein each of the second and fourth load portions has a resistance value variable according to a variable resistance code. ### Claim 17 (depends on 13) The receiver of claim 13, wherein each of the first stage buffer and the second stage buffer includes a P-type amplifier, and wherein each of the first and second amplifiers is a N-type amplifier. ### Claim 18 (depends on 13) The receiver of claim 13, wherein the second stage buffer has a higher common mode voltage than a common mode voltage of each of the first and third stage buffers.