摘要:
An adjustment circuit for use with a resistive reference ladder that establishes nominal reference steps and a common mode voltage for a plurality of comparators, such as used in a flash converter. An “H” arrangement of current sources injects current at a first node, VH, and sinks at a second node, VL. with VH, and VL. being coupled to ends of the ladder. The voltage difference between these two nodes thus controls the scale applied to the reference ladder, without affecting a common mode voltage reference Vcm. Alternatively, the current source may inject current at VL and sink current at VH to decrease the reference for each comparator.
摘要:
A differential reference ladder with an auto zero circuit that can be used as part of a flash analog to digital converter. The auto zero operation is performed relative to a common mode voltage of the ladder. The resistive ladder is disconnected from the rest of the circuit during auto zero mode. As a result, the auto zero adjustment is more accurate, since the offsets are stored under the same common mode connection as when the circuit is in a compare mode. This permits auto zeroing to proceed quickly unencumbered by the parasitic capacitance of the ladder or other components.
摘要:
Electronic circuitry supports utilization of a series of pulses of varying width to tune a transducer (e.g., a coil that produces or receives a magnetic field) for transmitting or receiving. For example, a control voltage generator generates a sequence of digital pulses of varying pulse widths to produce respective control voltages. The control voltage generator applies a produced control voltage to a varactor element whose capacitance changes depending on a magnitude of the produced control voltage. The varactor element forms part of a tank circuit. Consequently, the series of pulse widths controls an operating frequency of the tank circuit at different times. The tank circuit includes an inductive coil that is tuned to produce or receive a magnetic or inductive field.
摘要:
One aspect of the present invention is generally directed towards a system and method of tuning a transducer for transmitting and receiving a wireless signal. In an illustrative embodiment, a single transducer is coupled to a first or second circuit for either transmitting or receiving, respectively. Generally, electrical characteristics of the first circuit are adjusted to increase a magnetic field generated by the transducer. Conversely, electrical characteristics of the second circuit are adjusted to increase a signal generated by the transducer for receiving a magnetic field. Accordingly, a single transducer device can be tuned for either transmitting or receiving a corresponding wireless signal.
摘要:
A differential reference ladder with an auto zero circuit that can be used as part of a flash analog to digital converter. The auto zero operation is performed relative to a common mode voltage of the ladder. The resistive ladder is disconnected from the rest of the circuit during auto zero mode. As a result, the auto zero adjustment is more accurate, since the offsets are stored under the same common mode connection as when the circuit is in a compare mode. This permits auto zeroing to proceed quickly unencumbered by the parasitic capacitance of the ladder or other components.
摘要:
An adjustment circuit for use with a resistive reference ladder that establishes nominal reference steps and a common mode voltage for a plurality of comparators, such as used in a flash converter. An “H” arrangement of current sources injects current at a first node, VH, and sinks at a second node, VL, with VH, and VL, being coupled to ends of the ladder. The voltage difference between these two nodes thus controls the scale applied to the reference ladder, without affecting a common mode voltage reference Vcm. Alternatively, the current source may inject current at VL and sink current at VH to decrease the reference for each comparator.
摘要:
Electronic circuitry supports utilization of a series of pulses of varying width to tune a transducer (e.g., a coil that produces or receives a magnetic field) for transmitting or receiving. For example, a control voltage generator generates a sequence of digital pulses of varying pulse widths to produce respective control voltages. The control voltage generator applies a produced control voltage to a varactor element whose capacitance changes depending on a magnitude of the produced control voltage. The varactor element forms part of a tank circuit. Consequently, the series of pulse widths controls an operating frequency of the tank circuit at different times. The tank circuit includes an inductive coil that is tuned to produce or receive a magnetic or inductive field.
摘要:
One aspect of the present invention is generally directed towards a system and method of tuning a transducer for transmitting and receiving a wireless signal. In an illustrative embodiment, a single transducer is coupled to a first or second circuit for either transmitting or receiving, respectively. Generally, electrical characteristics of the first circuit are adjusted to increase a magnetic field generated by the transducer. Conversely, electrical characteristics of the second circuit are adjusted to increase a signal generated by the transducer for receiving a magnetic field. Accordingly, a single transducer device can be tuned for either transmitting or receiving a corresponding wireless signal.