| US 7,561,000 B2 | ||
| Oscillator circuit for a sensor | ||
| Melnrad Sauter, Neukirch (Germany); and Jean-Luc Lamarche, Mittelhausbergen (France) | ||
| Assigned to i f m electronic GmbH, Essen (Germany) | ||
| Filed on Jul. 14, 2005, as Appl. No. 11/180,904. | ||
| Claims priority of application No. 10 2004 034 190 (DE), filed on Jul. 14, 2004. | ||
| Prior Publication US 2006/0012443 A1, Jan. 19, 2006 | ||
| Int. Cl. H03B 5/08 (2006.01) | ||
| U.S. Cl. 331—167 [331/117 R; 331/117 FE; 324/655] | 16 Claims |
| 1. Oscillator circuit for a sensor, comprising:
a tuned circuit having a first terminal and a second terminal, and
an operational amplifier having an inverting input and a noninverting input, the electrical oscillation of the tuned circuit
being tapped between the first terminal and the second terminal of the tuned circuit, and the first terminal of the tuned
circuit being connected to the noninverting input of the operational amplifier and an output of the operational amplifier
being fed back to the noninverting input of the operational amplifier,
wherein the second terminal of the tuned circuit, at least in terms of AC voltage, is directly connected to the inverting
input of the operational amplifier, and
wherein the output of the operational amplifier is fed back via a voltage-controlled power source to the noninverting input
of the operational amplifier.
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