Apparatus for performing capacitor amplification in an electronic device

Patent metadata

Field	Value
Publication number	US-9800219-B2
Application number	US-201615147902-A
Country	US
Kind code	B2
Filing date	May 5, 2016
Priority date	Sep 23, 2015
Publication date	Oct 24, 2017
Grant date	Oct 24, 2017

Abstract

An apparatus for performing capacitor amplification in an electronic device may include a first resistor and a second resistor that are connected in series and coupled between a set of input terminals of a receiver in the electronic device, a common mode capacitor having a first terminal coupled to a common mode terminal and having a second terminal, and an alternating current (AC)-coupled amplifier that is coupled between the common mode terminal and the second terminal of the common mode capacitor. The first resistor and the second resistor may be arranged for obtaining a common mode voltage at the common mode terminal between the first resistor and the second resistor. In addition, the common mode capacitor may be arranged for reducing a common mode return loss. Additionally, the AC-coupled amplifier may be arranged for performing capacitor amplification for the common mode capacitor.

First claim

What is claimed is:

1. An apparatus for performing capacitor amplification in an electronic device, the apparatus comprising:
a first resistor and a second resistor, connected in series and coupled between a set of input terminals of a receiver in the electronic device, arranged for obtaining a common mode voltage at a common mode terminal between the first resistor and the second resistor, wherein the set of input terminals is arranged to input signals into the receiver;
a common mode capacitor, having a first terminal coupled to the common mode terminal and having a second terminal, arranged for reducing a common mode return loss; and
an alternating current (AC)-coupled amplifier, coupled between the common mode terminal and the second terminal of the common mode capacitor, arranged for performing capacitor amplification for the common mode capacitor, wherein an inverter within the AC-coupled amplifier is coupled between the common mode terminal and the second terminal of the common mode capacitor.

2. The apparatus of claim 1 , wherein the set of input terminals comprises two differential input terminals.

3. The apparatus of claim 1 , wherein all input terminals of the set of input terminals are voltage input terminals.

4. The apparatus of claim 1 , wherein the AC-coupled amplifier has an input terminal and an output terminal; and the input terminal of the AC-coupled amplifier is coupled to the common mode terminal, and the output terminal of the AC-coupled amplifier is coupled to the second terminal of the common mode capacitor.

5. The apparatus of claim 4 , further comprising:
an AC-coupling capacitor, arranged for coupling the input terminal of the AC-coupled amplifier to the common mode terminal, wherein the AC-coupling capacitor has a first terminal coupled to the common mode terminal, and has a second terminal coupled to the input terminal of the AC-coupled amplifier.

6. The apparatus of claim 4 , wherein a gain of the AC-coupled amplifier is equal to −A, wherein the parameter A is a positive value that is equal to or greater than one.

7. The apparatus of claim 4 , wherein the AC-coupled amplifier comprises:
the inverter, having an input terminal coupled to the input terminal of the AC-coupled amplifier, and having an output terminal coupled to the output terminal of the AC-coupled amplifier; and
a resistor, having a first terminal coupled to the input terminal of the AC-coupled amplifier, and having a second terminal coupled to the output terminal of the AC-coupled amplifier.

8. The apparatus of claim 7 , wherein the output terminal of the AC-coupled amplifier and the second terminal of the common mode capacitor are electrically connected to each other, directly.

9. The apparatus of claim 7 , further comprising:
a source follower, coupled between the output terminal of the AC-coupled amplifier and the second terminal of the common mode capacitor.

10. The apparatus of claim 7 , wherein the inverter comprises:
a first Metal Oxide Semiconductor Field Effect Transistor (MOSFET) and a second MOSFET, coupled between a set of predetermined voltage levels, wherein the input terminal of the inverter is electrically connected to a gate terminal of the first MOSFET and a gate terminal of the second MOSFET, and the output terminal of the inverter is electrically connected to another terminal of the first MOSFET and another terminal of the second MOSFET, wherein yet another terminal of the first MOSFET is electrically connected to one of the set of predetermined voltage levels, and yet another terminal of the second MOSFET is electrically connected to another of the set of predetermined voltage levels.

11. The apparatus of claim 10 , wherein the inverter further comprises:
a third MOSFET, having a gate terminal electrically connected to the output terminal of the inverter and having other terminals, wherein one of the other terminals of the third MOSFET is electrically connected to the one of the set of predetermined voltage levels, and another of the other terminals of the third MOSFET is electrically connected to the output terminal of the inverter.

12. The apparatus of claim 1 , wherein the apparatus comprises the receiver.

Assignees

• Mediatek Inc

Inventors

• Wang Huai-Te

Classifications

• H03F2200/42

  the input to the amplifier being made by capacitive coupling means · CPC title

• H03F2203/45061

  the common mode reference signal being taken or deducted from the one or more inputs of the differential amplifier · CPC title

• H03F3/505 Primary

  with field-effect devices · CPC title

• H03F2203/45084

  the common mode signal circuit comprising one or more inductive or capacitive elements, e.g. filter circuitry · CPC title

• H03F1/342

  in field-effect transistor amplifiers · CPC title