摘要:
Systems, apparatuses and methods may provide for a transmit circuit including a light source and a receive circuit including a photodetector and a transimpedance amplifier (TIA) coupled to the photodetector. Additionally, a calibration circuit may be coupled to the transmit circuit and the receive circuit, wherein the calibration circuit includes a current controller to set an operational current of the light source to a minimum value that results in a target output voltage of the receive circuit. In one example, the gain of the TIA remains substantially constant during calibration of the receive circuit.
摘要:
Described is an apparatus which comprises: a source to generate a first current having AC and DC components; a current-to-voltage converter to convert the first current or a copy of the first current to a first voltage proportional to a resistance, the first voltage having AC and DC components that correspond to the AC and DC components of the first current; a sample-and-hold circuit to filter the AC component from the first voltage and for providing an output voltage with the DC component; and an amplifier to receive the output voltage.
摘要:
A lock detect circuit (FIG. 3) for use in a synthesiser of the type comprising a phase comparator (5), a reference frequency source (11, 13, 15) a variable frequency oscillator (1), a variable divider (3) and a loop amplifier (7). The circuit includes logic gates (31, 33, . . . 41) to monitor the frequency `up` and frequency `down` error signals (C.sub.U, C.sub.D) produced by the comparator (5) and provides an `in-lock` indication (S) when frequency `up` or frequency `down` signals exclusively are detected in a predetermined period ( .sub.D). Accordingly this circuit may comprise a variable delay (31) an inverter (33) an AND-gate (35) and an OR-gate (39) for generating a comparison signal:f'.sub.E =F.sub.N .multidot.C.sub.D +C.sub.Uwhere f.sub.N is the signal from the inverter time delay pair derived from the divider output. This signal is fed to a series of flip-flops (37) clocked by the frequency down signal. The outputs (Q) of the flip-flops (37) are referred to a second AND-gate (41) to generate the `in-lock` signal (S).To accommodate under critical damping a latch (43) may be provided at the signal output. Alternatively two such circuits, one with reversed input connections may be used in tandem to provide both positive to negative detect windows.
摘要:
Apparatus for obtaining programmable threshold extension of an FM demodulator comprises a limiter preamplifier 4 and a variable gain buffer amplifier 6. The buffer amplifier 6 is provided with an external control node 16 such that the signal level fed from the buffer amplifier 6 to an injection locked oscillator/divider 8 can be programmed in dependence upon a control signal applied to the external control node 16. In this manner threshold extension of the FM demodulator can be selectively applied in dependence upon the noise level in an FM input signal to be demodulated. The limiter preamplifier 4 and the buffer amplifier 6 may form part of an automatic gain control circuit.
摘要:
Described is an apparatus which comprises: a first bridge to be coupled to a first load; a first Pulse Width Modulation (PWM) circuit to drive the first bridge; a second bridge to be coupled to a second load; and a second PWM circuit to drive the second bridge, wherein the first PWM circuit is controlled by a first digital word separate from a second digital word, wherein the second PWM circuit is controlled by the second digital, and wherein the second digital word is derived from the first digital word.
摘要:
A memory controller operable for selective memory access to areas of memory exhibiting different attributes leverages different memory capabilities that vary access speed, retention time and power consumption, among others. Different areas of memory have different attributes while remaining available to applications as a single contiguous range of addressable memory. The memory controller employs an operating mode that identifies operational priorities for a computing device, such as speed, power conservation, or efficiency. The memory controller identifies an area of memory based on an expected usage of the data stored in the area, for example an access frequency indicating future retrieval. The memory controller therefore selects areas of memory based on the operating mode and the expected usage of data to be stored in the area according to a heuristic that favors areas of memory based on those exhibiting attributes having a high correspondence to the expected usage of the data.
摘要:
An amplifier includes steering stages to receive a control signal and collectively provide an output signal. Each steering stage receives an associated input signal and contributes to the output signal based on the control signal. The amplifier includes an attenuator to selectively attenuate the input signals to form different gain control ranges for the amplifier.
摘要:
A frequency dividing arrangement 5 comprises a frequency divider 6 coupled to an active filler 7 which is operative to suppress output radiation from the frequency dividing arrangement. The arrangement 5 may be incorporated into a frequency synthesis loop 4 of a television tuner circuit in order to reduce interference between the loop 4 and a down conversion stage of the tuner circuit.
摘要:
Described is an apparatus which comprises: an amplifier to receive a reference voltage; and calibration logic which is operable to receive a first voltage and to provide the reference voltage to the amplifier, wherein the calibration logic is operable to generate a look-up table (LUT) that maps the first voltage to a drive current.
摘要:
Technologies for the sensing of biofeedback signals of a user include a body area network (BAN) system comprising one or more biofeedback sensors and one or more BAN controllers. The biofeedback sensors are configured to sense BAN signals, which may include biofeedback signals and body-coupled communication (BCC) signals. To facilitate communication, the biofeedback sensors may demultiplex the sensed BAN signals into biofeedback signals and incoming BCC signals. Similarly, the biofeedback sensors may multiplex outgoing BCC signals with sensed biofeedback signals. The BAN controller may communicate in a similar manner. Additionally, the BAN controller may process incoming BCC signals and provide feedback to the user based on BCC signals received from the biofeedback sensors.