Receiving circuit with ultra-wide common-mode input voltage range

Patent metadata

Field	Value
Publication number	US-9509488-B1
Application number	US-201615063715-A
Country	US
Kind code	B1
Filing date	Mar 8, 2016
Priority date	Oct 2, 2015
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

A receiving circuit with an ultra-wide common-mode input voltage range applies to a controller area network (CAN) and comprises a resistor assembly electrically connected with a CANH and a CANL, a reference amplifier, a first input amplifier assembly, a second input amplifier assembly, and an analog adder. The receiving circuit receives voltages from the CANH and CANL. The resistor assembly bucks voltage, respectively generating CANH and CANL voltage divisions at first and second nodes and outputting the voltage divisions to the first and second input amplifier assemblies. The first and second input amplifier assemblies amplify the differential signal between the first and second nodes and convert the differential signal into single-end signals. The analog adder adds the single-end signals as the output signal. The receiving circuit can receive the signal ranging between the maximum and minimum common-mode voltages and reduce electromagnetic emission.

First claim

What is claimed is:

1. A receiving circuit with an ultra-wide common-mode input voltage range, which is electrically connected with an output end of a receiving circuit of a controller area network (CAN) and applicable to a transceiver integration circuit of said controller area network, comprising:
a resistor assembly electrically connected with a high end and a low end of said controller area network (CANH and CANL) and including a first resistor, a second resistor, a third resistor and a fourth resistor, wherein a first node is arranged between said first resistor and said second resistor, and a second node is arranged between said third resistor and said fourth resistor, and wherein said first resistor is electrically connected with said high end and said first node, and said fourth resistor is electrically connected with said low end and said second node, and wherein said resistor assembly receives a high end voltage (VCANH) from said high end and a low end voltage (VCANL) from said low end and bucks voltage to generate and output a high end voltage division (VCANH DIV ) at said first node and a low end voltage division (VCANL DIV ) at said second node;
a reference amplifier having a reference amplifier input end and a reference amplifier output end, wherein said reference amplifier input end is electrically connected with a reference voltage source, and said reference amplifier output end is electrically connected with a contact between said second resistor and said third resistor;
a first input amplifier assembly and a second input amplifier assembly, wherein said first input amplifier assembly has a first input amplifier assembly output end, and said second input amplifier assembly has a second input amplifier output end, and wherein said first input amplifier assembly is electrically connected with a power source end, said first node and said second node, and wherein said second input amplifier assembly is electrically connected with a ground terminal, said first node and said second node, and wherein each of said first input amplifier assembly and said second input amplifier assembly receives said high end voltage division (VCANH DIV ) from said first node and receives said low end voltage division (VCANL DIV ) from said second node, and wherein said first input amplifier assembly outputs a first single-end output signal from said first input amplifier assembly output end, and wherein said second input amplifier assembly outputs a second single-end output signal from said second input amplifier assembly output end; and
an analog adder having an analog adder input end and an analog adder output end, wherein said analog adder input end is electrically connected with said first input amplifier assembly output end and said second input amplifier assembly output end, and wherein said analog adder output end is electrically connected with said output end of said receiving circuit, and wherein said analog adder receives said first single-end output signal and said second single-end output signal, adds said first single-end output signal and said second single-end output signal to generate a resultant signal, and outputs said resultant signal to said output end of said receiving circuit.

2. The receiving circuit with an ultra-wide common-mode input voltage range according to claim 1 , wherein said reference amplifier transmits a reference voltage generated by said reference voltage source to said resistor assembly.

3. The receiving circuit with an ultra-wide common-mode input voltage range according to claim 2 , wherein said transceiver integration circuit of said controller area network includes a transmitter, and wherein said transmitter is electrically connected with said high end and said low end and transmits a differential signal to said high end and said low end in a dominant state, and wherein a common-mode voltage of said differential signal is supplied to said reference voltage source as said reference voltage.

4. The receiving circuit with an ultra-wide common-mode input voltage range according to claim 1 , wherein said reference amplifier is an inverting closed-loop amplifier.

5. The receiving circuit with an ultra-wide common-mode input voltage range according to claim 1 , wherein said first input amplifier assembly includes:
a first voltage level shifter electrically connected with said power source end and said first node for adjusting a direct-current voltage level of said first node;
a second voltage level shifter electrically connected with said power source end and said second node for adjusting a direct-current voltage level of said second node;
a first differential amplifier electrically connected with said power source end, said first voltage level shifter and said second voltage level shifter, receiving a differential signal, which a direct-current voltage level is adjusted by said first voltage level shifter and said second voltage level shifter from said first node and said second node, to generate a first differential signal; and
a first output amplifier electrically connected said first differential amplifier, receiving said first differential signal from said first differential amplifier, amplifying said first differential signal, converting said first differential signal into a first single-end output signal, and transmitting said first single-end output signal to said analog adder.

6. The receiving circuit with an ultra-wide common-mode input voltage range according to claim 5 , wherein said second input amplifier assembly includes:
a third voltage level shifter electrically connected with said ground terminal and said first node for adjusting a direct-current voltage level of said first node;
a fourth voltage level shifter electrically connected with said ground terminal and said second node for adjusting a direct-current voltage level of said second node;
a second differential amplifier electrically connected with said ground terminal, said third voltage level shifter and said fourth voltage level shifter, receiving a differential signal, which a direct-current voltage level is adjusted by said third voltage level shifter and said fourth voltage level shifter from said first node and said second node, to generate a second differential signal; and
a second output amplifier electrically connected with said second differential amplifier, receiving said second differential signal from said second differential amplifier, amplifying said second differential signal, converting said second differential signal into a second single-end output signal, and transmitting said second single-end output signal to said analog adder.

7. The receiving circuit with an ultra-wide common-mode input voltage range according to claim 6 further comprising a fifth resistor and a sixth resistor cascaded between said first node and said second node and having a third node therebetween, wherein said third node is electrically connected with said fifth resistor, said sixth resistor, said first differential amplifier and said second differential amplifier, and wherein a resistance of said fifth resistor is equal to a resistance of said sixth resistor, and wherein a voltage of said third node is equal to a half of a sum of said high end voltage division (VCANH DIV ) from said first node and said low end voltage division (VCANL DIV ) from said second node.

8. The receiving circuit with an ultra-wide common-mode input voltage range according to claim 7 , wherein a first load and a second load are arranged between said first differential amplifier and said power source end, and wherein each of said first load and said second load is a resistive load, a inductive load or a transistor load.

9. The receiving circuit with an ultra-wide common-mode in

Assignees

• Amazing Microelectronic Corp

Inventors

• Huang Hsun-Hsiu

Classifications

• H04Q1/54 Primary

  Amplifier switched-on automatically in dependence on automatically-selected lines · CPC title

• H04Q2213/401

  DC and voltages of different kinds or values · CPC title

• H04L7/0087 Primary

  Preprocessing of received signal for synchronisation, e.g. by code conversion, pulse generation or edge detection · CPC title

• H04L25/0276 Primary

  Arrangements for coupling common mode signals · CPC title