Miscellaneous active electrical nonlinear devices – circuits – and – Specific signal discriminating without subsequent control – By amplitude
Patent
1997-08-19
1999-11-02
Tran, Toan
Miscellaneous active electrical nonlinear devices, circuits, and
Specific signal discriminating without subsequent control
By amplitude
327337, G11C 2702
Patent
active
059778032
ABSTRACT:
In an interface circuit connected to a capacitance type sensor having two sets of capacitors C1 and C2 whose capacitances are varied, this interface circuit is equipped with an OP amplifier A1 where a feedback/sampling capacitor C3 is connected between its output terminal and its inverting input terminal; and a holding capacitor C4 connected between a non-inverting terminal of the OP-amplifier A1 and a reference voltage source; one ends of the respective capacitors C1, C2, C3 are connected to the inverting input terminal of the OP amplifier A1; at timing .phi.1 of a switching cycle, the other ends of the respective capacitors C1, C2 are connected to a power source and the capacitor C3 is shortcircuited; at timing .phi.2 thereof, the other ends of the capacitors C1, C2 and an output terminal of the OP amplifier A1 are connected to the non-inverting input terminal of the OP amplifier A1; and the switched capacitor type interface interface circuit further includes: a multiplexer for sequentially connecting a plurality of the capacitance type sensors to the capacitance type sensor interface circuit in a second switching cycle having a time period longer than time periods of the switching cycles .phi.1 and .phi.2; and a plurality of sample/hold circuits whose quantity is equal to those of the plural capacitance type sensors, which are sequentially connected to the capacitive type sensor interface circuit in response to the connections of the plural capacitance type sensors in the second switching cycle.
REFERENCES:
patent: 4375595 (1983-03-01), Ulmer et al.
patent: 5281860 (1994-01-01), Krenik et al.
patent: 5425650 (1995-06-01), Frick
patent: 5633594 (1997-05-01), Okada
patent: 5724095 (1998-03-01), Shyu et al.
patent: 5751154 (1998-05-01), Tsugai
patent: 5751189 (1998-05-01), Shyu et al.
Leuthold, H.; Rudolf, F., An ASIC for High-resolution Capacitive Microacelerometer, Sensors and Actuators A21-A23 (1990) pp. 278-281.
Mitsubishi Denki & Kabushiki Kaisha
Tran Toan
LandOfFree
Capacitance type sensor interface circuit does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Capacitance type sensor interface circuit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Capacitance type sensor interface circuit will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2140490