Fully differential non-inverted parallel amplifier for detecting biology electrical signal

• US 7,863,977 B1
• Filed: 09/14/2009
• Issued: 01/04/2011
• Est. Priority Date: 09/14/2009
• Status: Active Grant

• Current Assignee: Edan Instruments, Inc.
• Original Assignee: Edan Instruments, Inc.
• Inventors: Xiang, Xiaofei, Xie, Xicheng, Hu, Xunqiao
• Primary Examiner(s): NGUYEN, PATRICIA T
• Application Number:
  US12/558,609
• Time in Patent Office: 477 Days
• Field of Search: 330/69, 330/258, 330/124.R, 330/147, 600/509
• US Class Current: 330/69
• CPC Class Codes: A61B 5/30 Input circuits therefor
• CPC Class Codes: A61B 5/305 Common mode rejection
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: H03F 2200/261 Amplifier which being suitable for instrumentation applications
• CPC Class Codes: H03F 2203/45134 the whole differential amplifier together with other coupled stages being fully differential realised
• CPC Class Codes: H03F 2203/45138 Two or more differential amplifiers in IC-block form are combined, e.g. measuring amplifiers
• CPC Class Codes: H03F 2203/45528 the FBC comprising one or more passive resistors and being coupled between the LC and the IC
• CPC Class Codes: H03F 3/45475 using IC blocks as the active amplifying circuit
• CPC Class Codes: H03F 3/45928 using IC blocks as the active amplifying circuit
• CPC Class Codes: H03F 3/68 Combinations of amplifiers, e.g. multi-channel amplifiers for stereophonics power amplifiers using a combination of several semiconductor amplifiers H03F3/211; combinations of amplifiers using coupling networks with distributed constants H03F3/602

Abstract

This invention relates to a fully differential non-inverting parallel amplifier for detecting biology electrical signal, including input buffer circuits, differential filter circuits, data selector, non-inverting parallel amplifying circuits and analog-digital circuits. The biology electrical signal, first impeded and converted by the input buffer circuits, and then low-pass filtered by the differential filter circuits, shall be amplified with its common mode signal rejected by passing through the data selector and non-inverting parallel amplifier circuits. At last, the amplified biology electrical signal is output by analog to digital conversion in the analog-digital circuits after its noises beyond signal high frequency band are filtered by anti-aliasing filter net. This invention, with low noise and high common mode rejection ratio, stable baseline, large signal input dynamic range, is reliable and not easy to be saturated. Furthermore, it can support mature PACE Detecting with a low cost. It is notable in social and economical benefits for its simple electrical circuits and easy use in any biology electrical testing equipments and controlling system.

Claims

1. A fully differential non-inverting parallel amplifier for detecting biology electrical signal, characterized in that it includes input buffer circuits, differential filter circuits, data selector, non-inverting parallel amplifying circuits and analog-digital circuits;

wherein the biology electrical signal, first impeded and converted by the input buffer circuits, and then low-pass filtered by the differential filter circuits, shall be amplified with its common mode signal rejected by passing through the data selector and non-inverting parallel amplifier circuits;

then, the amplified biology electrical signal is output by analog to digital conversion in the analog-digital circuits after its noises beyond signal high frequency band are filtered by anti-aliasing filter net.

2. A fully differential non-inverting parallel amplifier for detecting biology electrical signal as set forth in claim 1, characterized in that the foresaid input buffer has nine circuits U1˜

U9;

each circuits is comprised by one low-noise single operational amplifier which is connected like voltage follower; and

its non-inverting input is connected with the circuits current limiting resistance while the inverting input is connected with output end and the input end of differential filtering circuits.

3. A fully differential non-inverting parallel amplifier for detecting biology electrical signal as set forth in claim 1, characterized in that the differential filtering circuits has eight circuits;

each circuits has first order differential low pass filter comprised by two resistances and one capacitor;

one end of the resistance is connected with the output end of buffer circuits while the other is connected with capacitor filter and data selector input as well; and

both ends of the capacitor filter are connected with resistance filter separately.

4. A fully differential non-inverting parallel amplifier for detecting biology electrical signal as set forth in claim 1, characterized in that the foresaid data selector is an analog switch of analog-digital converter internal integration with high resolution which can be equipped as one choosing from eight differential input and output, and 8 differential input ends shall be connected with conductor I and II and the outputs of differential filter V1-V6.

5. A fully differential non-inverting parallel amplifier for detecting biology electrical signal as set forth in claim 1, characterized in that the foresaid differential non-inverting parallel amplifying circuits is one circuits;

the circuits mainly includes double operational amplifier U10, U11, resistance R19-R23 and capacitor C9;

wherein the non-inverting end of U10 is connected with the normal phase output MUXP of U12;

the non-inverting end of U11 is connected with the negative output MUXN of U12;

the inverting end of U10 and U11 is connected with resistance R19;

the inverting end of U10 and U11 are connected with output of U10 and U11 through R20 and R21 separately;

the output of U10 and U11 are connected with one end of R22 and R23 in filtering net, while the other end of R22 and R23 are connected with capacitor filter C9 and the positive input IN+ and negative input IN−

of analog-digital converter at the same time.

6. A fully differential non-inverting parallel amplifier for detecting biology electrical signal as set forth in claim 5, characterized in that the IN+ and IN−

of analog-digital converter are connected with R22 and R23 separately, and the digital signal output is connected with microprocessor through SPI or LVDS.