US 12,407,311 B2
Readout circuit for high-precision vibration sensor
Pengjun Wang, Zhejiang (CN); Xiangyu Li, Zhejiang (CN); Hao Ye, Zhejiang (CN); and Gang Li, Zhejiang (CN)
Assigned to Wenzhou University, Zhejiang (CN)
Filed by Wenzhou University, Zhejiang (CN)
Filed on May 17, 2023, as Appl. No. 18/319,411.
Claims priority of application No. 202211553264.0 (CN), filed on Dec. 6, 2022.
Prior Publication US 2024/0186969 A1, Jun. 6, 2024
Int. Cl. H03F 3/45 (2006.01); G01P 15/125 (2006.01); G01P 21/00 (2006.01); H03M 3/00 (2006.01)
CPC H03F 3/45475 (2013.01) [G01P 15/125 (2013.01); G01P 21/00 (2013.01); H03M 3/30 (2013.01)] 1 Claim
OG exemplary drawing
 
1. A readout circuit for a high-precision vibration sensor, wherein the readout circuit comprises an on-chip self-test circuit, a low-noise charge amplifier, a correlated double sampling circuit, a proportional integral differential (PID) feedback control circuit, a phase compensation circuit and Sigma-Delta;
the on-chip self-test circuit comprises a thirteenth switch, a fourteenth switch, a fifteenth switch, a sixteenth switch, a twenty-first capacitor and a twenty-second capacitor, wherein one terminal of the thirteenth switch is a first input terminal of the on-chip self-test circuit, the other terminal of the thirteenth switch, one terminal of the fifteenth switch and one terminal of the twenty-first capacitor are connected, the other terminal of the fifteenth switch is grounded, the other terminal of the twenty-first capacitor is a first output terminal of the on-chip self-test circuit, one terminal of the fourteenth switch is a second input terminal of the on-chip self-test circuit, the other terminal of the fourteenth switch, one terminal of the sixteenth switch and one terminal of the twenty-second capacitor are connected, the other terminal of the sixteenth switch is connected to a positive pole of a power supply, and the other terminal of the twenty-second capacitor is a second output terminal of the on-chip self-test circuit;
the low-noise charge amplifier comprises a fifth capacitor, a sixth capacitor, a first operational amplifier, a fifth switch, a sixth switch, a ninth switch and a tenth switch, wherein the first operational amplifier has a positive input terminal, a negative input terminal, a positive output terminal and a negative output terminal, one terminal of the fifth switch is a first input terminal of the low-noise charge amplifier, the other terminal of the fifth switch, one terminal of the sixth switch, one terminal of the fifth capacitor and the negative input terminal of the first operational amplifier are connected, the other terminal of the sixth switch, the other terminal of the fifth capacitor and the positive output terminal of the first operational amplifier are connected and a connecting terminal is a first output terminal of the low-noise charge amplifier, one terminal of the ninth switch is a second input terminal of the low-noise charge amplifier, the other terminal of the ninth switch, one terminal of the tenth switch, one terminal of the sixth capacitor and the positive input terminal of the first operational amplifier are connected, and the other terminal of the tenth switch, the other terminal of the sixth capacitor and the negative output terminal of the first operational amplifier are connected and a connecting terminal is a second output terminal of the low-noise charge amplifier;
the correlated double sampling circuit comprises a seventh capacitor, an eighth capacitor, a ninth capacitor, a tenth capacitor, a second operational amplifier, a third operational amplifier, an eighth switch, an eleventh switch, a thirty-third switch and a thirty-forth switch, wherein the second operational amplifier and the third operational amplifier each have a positive input terminal, a negative input terminal and an output terminal, one terminal of the seventh capacitor is a first input terminal of the correlated double sampling circuit, the other terminal of the seventh capacitor, one terminal of the eighth switch and one terminal of the thirty-third switch are connected, the other terminal of the thirty-third switch, one terminal of the ninth capacitor and the positive input terminal of the second operational amplifier are connected, the other terminal of the eighth switch and the other terminal of the ninth capacitor are both connected to the positive pole of the power supply, the negative input terminal of the second operational amplifier and the output terminal of the second operational amplifier are connected and a connecting terminal is a first output terminal of the correlated double sampling circuit, one terminal of the eighth capacitor is a second input terminal of the correlated double sampling circuit, the other terminal of the eighth capacitor, one terminal of the eleventh switch and one terminal of the thirty-fourth switch are connected, the other terminal of the thirty-fourth switch, one terminal of the tenth capacitor and the positive input terminal of the second operational amplifier are connected, the other terminal of the eleventh switch and the other terminal of the tenth capacitor are both connected to the positive pole of the power supply, and the negative input terminal of the third operational amplifier and the output terminal of the third operational amplifier are connected and a connecting terminal is a second output terminal of the correlated double sampling circuit;
the PID feedback control circuit comprises a seventh switch, a twelfth switch, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, an eleventh capacitor, a twelfth capacitor, a thirteenth capacitor, a fourteenth capacitor and a fourth operational amplifier, wherein the fourth operational amplifier has a positive input terminal, a negative input terminal, a positive output terminal and a negative output terminal, one terminal of the seventh switch is a first output terminal of the PID feedback control circuit, the other terminal of the seventh switch, one terminal of the thirteenth capacitor and the positive output terminal of the fourth operational amplifier are connected, the other terminal of the thirteenth capacitor is connected to one terminal of the third resistor, the other terminal of the third resistor, one terminal of the eleventh capacitor, one terminal of the first resistor and the positive input terminal of the fourth operational amplifier are connected, the other terminal of the eleventh capacitor is connected to one terminal of the second resistor, the other terminal of the second resistor and the other terminal of the first resistor are connected and a connecting terminal is a first input terminal of the PID feedback control circuit, one terminal of the twelfth switch is a second output terminal of the PID feedback control circuit, the other terminal of the twelfth switch, one terminal of the fourteenth capacitor and the negative output terminal of the fourth operational amplifier are connected, the other terminal of the fourteenth capacitor is connected to one terminal of the sixth resistor, the other terminal of the sixth resistor, one terminal of the twelfth capacitor, one terminal of the fourth resistor and the negative input terminal of the fourth operational amplifier are connected, the other terminal of the twelfth capacitor is connected to one terminal of the fifth resistor, the other terminal of the fifth resistor and the other terminal of the fourth resistor are connected and a connecting terminal is a second input terminal of the PID feedback control circuit;
the phase compensation circuit comprises a seventeenth switch, an eighteenth switch, a nineteenth switch, a twentieth switch, a twenty-first switch, a twenty-second switch, a twenty-third switch, a twenty-fourth switch, a twenty-fifth switch, a twenty-sixth switch, a twenty-seventh switch, a twenty-eighth switch, a twenty-ninth switch, a thirtieth switch, a thirty-first switch, a thirty-second switch, a fifteenth capacitor, a sixteenth capacitor, a seventeenth capacitor, an eighteenth capacitor, a nineteenth capacitor, a twentieth capacitor, a fifth operational amplifier and a sixth operational amplifier, wherein the fifth operational amplifier and the sixth operational amplifier each have a positive input terminal, a negative input terminal and an output terminal, one terminal of the seventeenth switch is a first input terminal of the phase compensation circuit, the other terminal of the seventeenth switch, one terminal of the eighteenth switch, one terminal of the fifteenth capacitor and one terminal of the sixteenth capacitor are connected, the other terminal of the eighteenth switch is grounded, the other terminal of the fifteenth capacitor, one terminal of the nineteenth switch and one terminal of the twentieth switch are connected, the other terminal of the twentieth switch is grounded, the other terminal of the sixteenth capacitor, one terminal of the twenty-first switch and one terminal of the twenty-second switch are connected, the other terminal of the twenty-first switch is grounded, the other terminal of the nineteenth switch, the other terminal of the twenty-second switch, one terminal of the twenty-third switch, one terminal of the seventeenth capacitor and the negative input terminal of the fifth operational amplifier are connected, the positive input terminal of the fifth operational amplifier is grounded, the other terminal of the twenty-third switch, the other terminal of the seventeenth capacitor, one terminal of the twenty-fourth switch and the output terminal of the fifth operational amplifier are connected, the other terminal of the twenty-fourth switch is a first output terminal of the phase compensation circuit, one terminal of the twenty-fifth switch is a second input terminal of the phase compensation circuit, the other terminal of the twenty-fifth switch, one terminal of the twenty-sixth switch, one terminal of the nineteenth capacitor and one terminal of the twentieth capacitor are connected, the other terminal of the twenty-sixth switch is grounded, the other terminal of the nineteenth capacitor, one terminal of the twenty-seventh switch and one terminal of the twenty-eighth switch are connected, the other terminal of the twenty-eighth switch is grounded, the other terminal of the twentieth capacitor, one terminal of the thirtieth switch and one terminal of the twenty-ninth switch are connected, the other terminal of the thirtieth switch is grounded, the other terminal of the twenty-seventh switch, the other end of the twenty-ninth switch, one terminal of the thirty-first switch, one terminal of the eighteenth capacitor and the negative input terminal of the sixth operational amplifier are connected, the positive input terminal of the sixth operational amplifier is grounded, the other terminal of the thirty-first switch, the other terminal of the eighteenth capacitor, one terminal of the thirty-second switch and the output terminal of the sixth operational amplifier are connected, and the other terminal of the thirty-second switch is a second output terminal of the phase compensation circuit;
the first input terminal of the on-chip self-test circuit is a first self-test terminal of the readout circuit for a high-precision vibration sensor, to which a positive self-test voltage is input; the second input terminal of the on-chip self-test circuit is a second self-test terminal of the readout circuit for a high-precision vibration sensor, to which a negative self-test voltage is input; the first output terminal of the on-chip self-test circuit and the first input terminal of the low-noise charge amplifier are connected, and a connecting terminal is a positive input terminal of the readout circuit for a high-precision vibration sensor, which is connected to a positive output terminal of a vibration sensor; the second output terminal of the on-chip self-test circuit and the second input terminal of the low-noise charge amplifier are connected, and a connecting terminal is a negative input terminal of the readout circuit for a high-precision vibration sensor, which is connected to a negative output terminal of the vibration sensor; the first output terminal of the low-noise charge amplifier is connected to the first input terminal of the correlated double sampling circuit, the second output terminal of the low-noise charge amplifier is connected to the second input terminal of the correlated double sampling circuit, the first output terminal of the correlated double sampling circuit is connected to the first input terminal of the phase compensation circuit and the first input terminal of the PID feedback control circuit, the second output terminal of the correlated double sampling circuit is connected to the second input terminal of the phase compensation circuit and the second input terminal of the PID feedback control circuit, the first input terminal of the PID feedback control circuit is connected to the positive input terminal of the readout circuit for a high-precision vibration sensor, the second output terminal of the PID feedback control circuit is connected to the negative input terminal of the readout circuit for a high-precision vibration sensor, and the first output terminal and the second output terminal of the phase compensation circuit output a pair of differential signals to Sigma-Delta, which converts the pair of differential signals into digital signals and outputs the digital signals.