摘要:
An arrangement for improving the operation of an analog to digital converter (A/D), which can form part of an integrated circuit, the A/D converter being coupled to a reference voltage and having a plurality of input pins associated therewith comprises: a resistor divider having a plurality of resistors coupled in series, the resistor divider having an upper node coupled to a source of voltage to be converted, having a lower node coupled to a source of reference potential and having a plurality of intermediate nodes; and, each of the upper intermediate nodes being coupled to a respective one of the input pins of the A/D converter. The A/D converter can have enhanced resolution and/or an extended dynamic range when the voltage level being tested is divided arid the reference voltage is reduced. A corresponding method comprises the steps of: successively scaling down a voltage to be converted to a series of stepped down voltage levels; applying the successively stepped down voltage levels to respective ones of the input pins; and, sequentially scanning and acquiring a plurality of scaled A/D converter values from the input pins.
摘要:
A single antenna transmits and receives signals. The single antenna has first and second antenna loops substantially lying in a common plane and partially overlapping. First and second transceiver circuits are coupled to the first and second antenna loops respectively, for respectively generating in a first mode of operation first and second pulsed magnetic fields together defining an interrogation zone for a marker generating a characteristic response to the magnetic fields in the interrogation zone, and for receiving signals from the interrogation zone in a second mode of operation. The first and second transceiver circuits alternately generate the first and second magnetic fields substantially in phase with one another and substantially out of phase with one another. The partially overlapping antenna loops prevent detuning of the transceivers otherwise resulting from the phase alternating. Each of the first and second transceiver circuits has a phase controllable transmitter section and a phase controllable receiver section. A controller independently phase controls the transmitter and receiver sections. Each receiver section is coupled across the tuned circuit of its respective transceiver circuit.