Patent classifications
H03M1/80
DIGITAL SLOPE ANALOG TO DIGITAL CONVERTER AND SIGNAL CONVERSION METHOD
A digital slope analog to digital converter includes a charge injection digital to analog converter (DAC) circuit, a comparator circuit, a detector circuit, and a control logic circuitry. The charge injection DAC circuit respectively samples input signals via first and second capacitors and generates a first signal via the first capacitor and a second signal via the second capacitor. The comparator circuit compares the first signal with the second signal to generate decision signals. The detector circuit generates a flag signal according to the decision signals. The control logic circuitry generates an enable signal according to the flag signal and generates a digital output when the comparator circuit detects a crossing point of the first and second signals. The charge injection DAC circuit gradually adjusts charges stored in the first and/or the second capacitor according to the enable signal until the crossing point is detected.
Constant current digital to analog converter systems and methods
An electronic device may include a digital to analog converter receiving digital signals and outputting analog signals based on the received digital signals. The electronic device may also include a power source to supply current to the digital to analog converter. The digital to analog converter may include a first resistor ladder section to electrically couple an output node of the digital to analog converter to the power source via a first number of resistors in series. The digital to analog converter may also include a second resistor ladder section to electrically couple the output node to a reference voltage via a second number of resistors in series. The sum of the first number of resistors in series and the second number of resistors in series may be the same for each of the different analog signals.
Digital to analog converter for performing digital to analog conversion with current source arrays
A digital to analog converter is provided, including a buffer circuit, a current switch circuit, and a weighted current generating circuit. The buffer circuit receives an N-bit digital signal and a clock signal, accordingly outputs N switch control signals. The current switch circuit includes N switches which are connected or disconnected according the switch control signals. The weighted current generating circuit includes M current source arrays, where each current source array outputs K output currents. Current values of each output current of each current source array respectively ascend in a binary-weighted manner. A minimum output current of an mth current source array is two times of a maximum output current of a (m−1)th current source array, N is obtained by multiplying M by K, and 1≦m≦M. An output of the digital to analog converter is a total current value of the output currents outputted by the M current source arrays.
Successive approximation register analog to digital converter with multiple split digital to analog convertors
A digital to analog convertor comprises an output line; first, second and third pluralities of capacitors; and first and second bridge capacitors. The first plurality of capacitors is coupled in parallel with one another, coupled with the output line, and comprises a first least significant bit capacitor of a first capacitance value. The second plurality of capacitors is coupled in parallel with one another, coupled with the output line, and comprises a second capacitor of the first capacitance value. The third plurality of capacitors is coupled in parallel with one another, coupled with the output line, and comprises a third capacitor of the first capacitance value. The first bridge capacitor bridges the output line between the first plurality of capacitors and the second plurality of capacitors. The second bridge capacitor bridges the output line between the second plurality of capacitors and the third plurality of capacitors.
METHODS AND DEVICES FOR AN ENERGY EFFICIENT DIGITAL TO ANALOG CONVERSION
Methods and devices for an energy efficient digital to analog conversion are disclosed. With the achievable sampling rates and output voltage levels, high power RF signals can be synthesized. A plurality of pulses are generated and coupled onto transmission lines. On the other end of the transmission line the pulses are either reflected or transmitted to a load line depending on the status of a termination element. In one embodiment the reflected pulses are collected and sent to a load. The energy in the transmitted pulses can be recovered and reused. In another embodiment the transmitted pulses are collected and transmitted to a load and the energy in the reflected pulses is recovered and reused.
Two-capacitor digital-to-analog converter
A two-capacitor digital-to-analog converter circuit having circuitry to compensate for an unwanted capacitance is disclosed. The converter is configured to generate an average voltage on two capacitors for a sequence of bits in a digital word so that when the final bit is reached, the average voltage corresponds to an analog level of the digital word. The converter is configured to input and average the voltage on the two capacitors using different modes to minimize the effects of capacitor mismatch and switching capacitance on the accuracy of the conversion. The converter includes a buffer amp that has an input capacitance that can affect the conversion. Accordingly, the converter further includes capacitance compensation circuitry configured to provide a replica input capacitance that can be charged and discharged according to the bits of the digital word and coupled to the input capacitor to prevent the input capacitance from affecting the conversion.
DIGITAL-TO-ANALOG CONVERSION CIRCUIT
A digital-to-analog conversion circuit, comprising: an R−2R resistive network (10) configured to be connected between an output end and a ground end; an output voltage selection unit (20) configured to be connected between the output end of the R−2R resistive network (10) and a voltage output terminal; an output voltage trimming unit (30), wherein the output voltage trimming unit (30) is provided between a 2R resistor on at least one branch of the R−2R resistive network (10) and the ground end.
Successive approximation register analog-to-digital converter
A successive approximation register analog-to-digital converter includes a capacitance digital-to-analog converter (CDAC) having, a voltage storing circuit connected to an output terminal of the CDAC and including a plurality of capacitors connected in parallel, an output voltage of the CDAC being stored in a selected one of the capacitors, a selector configured to output a voltage stored in the selected one of the capacitors, a comparator configured to compare a voltage input to an input terminal thereof, which is connected to an output terminal of the CDAC, with a reference voltage, and a successive approximation register configured to control the CDAC based on an output of the comparator, and cyclically control the voltage storing circuit and the selector, such that the output of the selector is output to the output terminal one or more cycles after the output voltage was stored in the selected one of the capacitors.
DTC DEVICE AND METHOD BASED ON CAPACITIVE DAC CHARGING
A DTC circuit, includes: a DAC connected to a first node; a first switch connected between a first power source and a second node, and to provide a charge current to the second node according to a first switching signal; and a second switch connected between the first node and the second node, and to electrically connect the DAC to the second node according to a second switching signal. The DAC is to be charged to generate a voltage ramp corresponding to the charge current during a first DTC operational phase when the first and second switching signals have an active level to turn on the first and second switches, and to generate an input control word dependent voltage according to an input control word during a second DTC operational phase when the first and second switching signals have an inactive level to turn off the first and second switches.
Sensor device including a capacitive charge output device connected to an A/D converter
A sensor device includes an A/D converter including an adder that computes a difference between an analog input signal and a predicted value, the adder includes a capacitive adder defined by a series circuit including a capacitive charge output device and a capacitor. A capacitive component in the charge output device defines a portion of the capacitance of the capacitive adder. A digital prediction filter generates the predicted value based on an output from a quantizer. The capacitive adder computes the difference between the analog input signal from the charge output device and the predicted value. The quantizer quantizes and encodes the difference. The A/D converter performs a Δ modulation on the analog input signal which is converted into a digital signal.