Integrated circuit and reference voltage generation circuit

• US 10,547,320 B1
• Filed: 02/11/2019
• Issued: 01/28/2020
• Est. Priority Date: 07/16/2018
• Status: Active Grant

• Current Assignee: SK Hynix Inc.
• Original Assignee: SK Hynix Inc.
• Inventors: Seo, Young-Suk
• Primary Examiner(s): Williams, Howard
• Application Number:
  US16/272,549
• Publication Number:
  US 20200021303A1
• Time in Patent Office: 351 Days
• CPC Class Codes: H03F 3/45632 in differential amplifiers with FET transistors as the active amplifying circuit H03F3/4578 takes precedence
• CPC Class Codes: H03M 1/46 with digital/analogue converter for supplying reference values to converter

Abstract

An integrated circuit includes: a first differential buffer suitable for receiving a primary signal through a primary input terminal thereof, and receiving a secondary signal through a secondary input terminal thereof, wherein the secondary signal has a phase opposite to a phase of the primary signal; a second differential buffer suitable for receiving a first reference voltage through primary and secondary input terminals thereof; and an operational amplifier suitable for receiving a first common mode voltage of the primary and secondary output terminals of the first differential buffer and a second common mode voltage of the primary and secondary output terminals of the second differential buffer, to output the first reference voltage.

Claims

1. An integrated circuit comprising:

a first differential buffer suitable for receiving a primary signal through a primary input terminal thereof, and receiving a secondary signal through a secondary input terminal thereof, wherein the secondary signal has a phase opposite to a phase of the primary signal;

a second differential buffer suitable for receiving a first reference voltage through primary and secondary input terminals thereof; and

an operational amplifier suitable for receiving a first common mode voltage of the primary and secondary output terminals of the first differential buffer and a second common mode voltage of the primary and secondary output terminals of the second differential buffer, to output the first reference voltage.

2. The integrated circuit of claim 1, further comprising:

an analog-to-digital converter (ADC) suitable for analog-to-digital converting the first reference voltage to generate a digital code; and

a digital-to-analog converter (DAC) suitable for digital-to-analog converting the digital code to generate a second reference voltage.

3. The integrated circuit of claim 2, further comprising a third differential buffer suitable for receiving an input signal based on the second reference voltage.

4. The integrated circuit of claim 3, further comprising a fourth differential buffer suitable for receiving the primary signal through a primary input terminal thereof, and receiving the secondary signal through a secondary input terminal thereof.

5. The integrated circuit of claim 4, wherein the primary signal and the secondary signal comprise data strobe signals or clock signals.

6. The integrated circuit of claim 5, wherein the input signal comprises data.

7. The integrated circuit of claim 3, wherein the first differential buffer, the second differential buffer and the operational amplifier are enabled in a reference voltage generation period, and

the ADC holds a value of the digital code when the reference voltage generation period ends.

8. The integrated circuit of claim 7, wherein the primary and secondary signals toggle in the reference voltage generation period.

9. The integrated circuit of claim 7, wherein the reference voltage generation period is included in the initial period of the operation of the integrated circuit.

10. The integrated circuit of claim 4, wherein each of the first to fourth differential buffers comprises a current mode logic (CML) buffer.

11. The integrated circuit of claim 2, wherein the ADC comprises a successive approximation register (SAR) ADC.

12. The integrated circuit of claim 7, wherein the input signal is received after the reference voltage generation period ends.

13. A reference voltage generation circuit comprising:

a first differential buffer suitable for receiving a primary signal and a secondary signal, and outputting a first common mode voltage, wherein the secondary signal has a phase opposite to a phase of the primary signal;

a second differential buffer suitable for receiving a first reference voltage through primary and secondary input terminals, and outputting a second common mode voltage;

an operational amplifier suitable for comparing the first common mode voltage and the second common mode voltage to output the first reference voltage;

an analog-to-digital converter (ADC) suitable for analog-to-digital converting the first reference voltage to generate a digital code; and

a digital-to-analog converter (DAC) suitable for digital-analog converting the digital code to generate a second reference voltage.

14. The reference voltage generation circuit of claim 13, wherein the primary and secondary signals are data strobe signals or clock signals.

15. The reference voltage generation circuit of claim 13, wherein the DAC is enabled after the first differential buffer, the second differential buffer, the operational amplifier and the ADC are disabled.

16. The reference voltage generation circuit of claim 14, wherein the second reference voltage is used for a differential input buffer.