Wide range input voltage differential receiver

• US 10,277,216 B1
• Filed: 09/27/2017
• Issued: 04/30/2019
• Est. Priority Date: 09/27/2017
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Nguyen, Huy M., Lee, Seong Hoon
• Primary Examiner(s): Houston, Adam D
• Application Number:
  US15/717,865
• Time in Patent Office: 580 Days
• CPC Class Codes: G06F 30/30 Circuit design
• CPC Class Codes: G06F 30/36 Circuit design at the analogue level
• CPC Class Codes: H03F 3/45183 Long tailed pairs H03F3/4521, H03F3/45237 take precedence
• CPC Class Codes: H03F 3/4521 Complementary long tailed pairs having parallel inputs and being supplied in parallel
• CPC Class Codes: H03F 3/45237 Complementary long tailed pairs having parallel inputs and being supplied in series
• CPC Class Codes: H03K 7/08 Duration or width modulation ; Duty cycle modulation

Abstract

A method and apparatus for receiving reduced voltage swing signals is disclosed. A first amplifier may generate a first intermediate signal based on a difference between voltage levels of a first and second input signals, and a second amplifier may generate a second intermediate signal based on a difference in the voltage levels between the second and first input signals. A regenerative amplifier may increase a difference in the voltage level of the first and second intermediate signals using regenerative feedback and the voltage levels of the first and second input signals. A latch circuit may generate first and second output signals using the first and second intermediate signals.

Claims

1. An apparatus, comprising:

a first amplifier circuit configured to generate a first intermediate signal based on a first difference between a voltage level of a first input signal and a voltage level of a second input signal;

a second amplifier circuit configured to generate a second intermediate signal based on a second difference between the voltage level of the second input signal and the voltage level of the first input signal;

a third amplifier circuit configured to increase a difference in a voltage level of the first intermediate signal and a voltage level of the second intermediate signal using feedback and based on the voltage level of the first input signal and the voltage level of the second input signal; and

a latch circuit configured to generate a first output signal and a second output signal using the first intermediate signal and the second intermediate signal.

2. The apparatus of claim 1, further comprising a duty cycle correction circuit configured to generate a corrected output signal using at least one of the first output signal and the second output signal, wherein a duty cycle of the corrected output signal is different from a duty cycle of the at least one of the first output signal and the second output signal.

3. The apparatus of claim 2, wherein an amount of variation in the duty cycle of the corrected output signal from the duty cycle of the at least one of the first output signal and the second output signal is based upon a control signal, wherein the control signal includes a plurality of data bits.

4. The apparatus of claim 2, wherein the duty cycle correction circuit is further configured to provide a high impedance output based on a control signal.

5. The apparatus of claim 1, wherein the third amplifier circuit is further configured to:

set the voltage level of the first intermediate signal to a first voltage based on an enable signal; and

set the voltage level of the second intermediate signal to a second voltage level, based on the enable signal.

6. The apparatus of claim 1, wherein the first amplifier circuit includes a header device and a footer device, and wherein the first amplifier circuit is further configured to disable the header device and the footer device based on a control signal.

7. A method, comprising:

receiving a first input signal and a second input signal by a differential receiver circuit;

generating, by a first amplifier circuit, a first intermediate signal based on a first difference between a voltage level of a first input signal and a voltage level of a second input signal;

generating, by a second amplifier circuit, a second intermediate signal based on a second difference between the voltage level of the second input signal and the voltage level of the first input signal;

increasing, by a third amplifier circuit, a difference in a voltage level of the first intermediate signal and a voltage level of the second intermediate signal using feedback and based on the voltage level of the first input signal and the voltage level of the second input signal; and

generating, by a latch circuit, a first output signal and a second output signal using the first intermediate signal and the second intermediate signal.

8. The method of claim 7, further comprising generating, by a duty cycle correction circuit, a corrected output signal using at least one of the first output signal and the second output signal, wherein a duty cycle of the corrected output signal is different from a duty cycle of the at least one of the first output signal and the second output signal.

9. The method of claim 8, wherein an amount of variation in the duty cycle of the corrected output signal from the duty cycle of the at least one of the first output signal and the second output signal is based upon a control signal, wherein the control signal includes a plurality of data bits.

10. The method of claim 8, further comprising, providing, by the duty cycle correction circuit, a high impedance output based on a control signal.

11. The method of claim 7, further comprising:

setting, by the third amplifier circuit, the voltage level of the first intermediate signal to a first voltage based on an enable signal; and

setting, by the third amplifier circuit, the voltage level of the second intermediate signal to a second voltage level, based on the enable signal.

12. The method of claim 7, further comprising decoupling a local power signal included in the first amplifier circuit from a power supply signal based on an enable signal.

13. The method of claim 7, further comprising decoupling a local ground signal included in the first amplifier circuit from a ground signal based on an enable signal.

14. A non-transitory computer-readable storage medium having design information stored thereon, wherein the design information specifies a design of at least a portion of a hardware integrated circuit in a format recognized by a semiconductor fabrication system that is configured to use the design information to produce the hardware integrated circuit according to the design information, wherein the design information specifies that the hardware integrated circuit comprises:

a first amplifier circuit configured to amplify generate a first intermediate signal based on a first difference between a voltage level of a first input signal and a voltage level of a second input signal;

a second amplifier circuit configured to generate a second intermediate signal based on a second difference between the voltage level of the second input signal and the voltage level of the first input signal;

a third amplifier circuit configured to increase a difference in a voltage level of the first intermediate signal and a voltage level of the second intermediate signal using feedback and based on the voltage level of the first input signal and the voltage level of the second input signal; and

a latch circuit configured to generate a first output signal and a second output signal using the first intermediate signal and the second intermediate signal.

15. The non-transitory computer-readable storage medium of claim 14, wherein the hardware integrated circuit further comprises a duty cycle correction circuit configured to generate a corrected output signal using at least one of the first output signal and the second output signal, wherein a duty cycle of the corrected output signal is different from a duty cycle of the at least one of the first output signal and the second output signal.

16. The non-transitory computer-readable storage medium of claim 15, wherein an amount of variation in the duty cycle of the corrected output signal from the duty cycle of the at least one of the first output signal and the second output signal is based upon a control signal, wherein the control signal includes a plurality of data bits.

17. The non-transitory computer-readable storage medium of claim 15, wherein the duty cycle correction circuit is further configured to provide a high impedance output based on a control signal.

18. The non-transitory computer-readable storage medium of claim 14, wherein the regenerative amplifier circuit is further configured to:

set the voltage level of the first intermediate signal to a first voltage based on an enable signal; and

set the voltage level of the second intermediate signal to a second voltage level, based on the enable signal.

19. The non-transitory computer-readable storage medium of claim 14, wherein the first amplifier circuit includes a header device and a footer device, and wherein the first amplifier circuit is further configured to disable the header device and the footer device based on a control signal.

20. The non-transitory computer-readable storage medium of claim 14, wherein the regenerative amplifier circuit includes a first pull-up device controlled by the first intermediate signal, and a second pull-up device controller by the second intermediate signal.