The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 31, 2002
Filed:
Jul. 07, 2000
Reiner Bidenbach, Vörstetten, DE;
Ulrich Theus, Gundelfingen, DE;
Micronas GmbH, Freiburg, DE;
Abstract
In integrators which integrate the analog photocurrent of a photodiode (PD), the amplification-bandwidth product is relatively small on account of the parallel parasitic capacitance (Cp) of the photodiode (PD). However, in a design with a switched capacitor (C ), the bandwidth and at the same time the DC amplification must be large, so as to assure the integrator function even at low frequencies. So as to fulfill both of these mutually contradictory requirements for large bandwidth and high DC amplification, a reference voltage (V ) is present at a voltage divider that includes a resistor (R ) and a circuit section (R ) connected in series thereto, as well as at the photodiode (PD). The connection point of the voltage divider is connected to the inverting input of the transconductance amplifier (V). In a preferred embodiment, the circuit section (R ) is realized as a switched capacitor (C ), and the resistance (R ) is realized as an MOS transistor (T ). As an integrated switching circuit, the invention is especially suited for sigma-delta-analog converters.