Patent classifications
H03M1/765
D/A CONVERTER
A high-order converter generates a first high-order voltage V.sub.U_P and a second high-order voltage V.sub.U_N that monotonously change with mutually opposite polarities with respect to high-order m bits (1≤m<n) of the digital signal. A low-order converter generates a first low-order voltage and a second low-order voltage that monotonously change with mutually opposite polarities with respect to low-order (n−m) bits of the digital signal. A first amplifier receives one of the first and the second high-order voltages and one of the first and the second low-order voltages to output one differential analog signal. Having a configuration in common with the first amplifier, a second amplifier receives another of the first and the second high-order voltages and another of the first and the second low-order voltages to output another differential analog signal.
SELF CALIBRATING DIGITAL-TO-ANALOG CONVERTER
A self-calibrating digital-to-analog converter (DAC) is disclosed. The self-calibrating DAC includes a DAC including a least significant bit (LSB) side resistor network and a most significant bit (MSB) side resistor network. At least the MSB side resistor network includes a plurality of trimmable resistors. A resistance to frequency converter coupled with an output of the DAC is included to generate a frequency f.sub.L based on a value of the LSB side resistor network or the MSB side resistor network. A monitor is included to generate a counter value by comparing f.sub.L with a high frequency clock having a constant frequency f.sub.H. A memory is included to store at least two counter values generating by comparing f.sub.L and f.sub.H once when the LSB side resistor network is connected while the MSB side resistor network is floating and once when the LSB side resistor network is floating while only one of the resistors in the MSB side resistor network is connected and all other resistors in the MSB side resistor network are floating. A comparator is included to compare the at least two counter values. A trimming controller is included to generate a trimming signal to trim one of the plurality of trimmable resistors based on an output of the comparator.
MATCHED DIGITAL-TO-ANALOG CONVERTERS
A voltage ladder is used to generate reference voltages. The voltage ladder is used by multiple digital-to-analog converters (DACs). In particular, the voltage ladder is used by multiple pulse-width modulation (PWM) DACs. Having multiple DACs utilize a common voltage ladder for their reference voltages reduces mismatched output voltages between DACs. Having multiple DACs utilize the common voltage ladder helps ensure that the reference voltages used by different DACs are not affected by process, voltage, and/or temperature variations in the reference voltages that would occur when using different voltage ladders for each DAC.
SEMICONDUCTOR DEVICE
A semiconductor device using a pass transistor is provided. The semiconductor device includes a first circuit, a second circuit, a plurality of input terminals, and an output terminal. The first circuit includes a plurality of first transistors functioning as pass transistors, and the second circuit includes a plurality of second transistors functioning as pass transistors. Note that the number of the first transistors is larger than the number of the second transistors, a gate of the first transistor is supplied with a first signal, and a gate of the second transistor is supplied with a second signal. The first circuit is supplied with grayscale signals through x input terminals, and the first circuit selects y grayscale signals of the grayscale signals with the first signal. The second circuit is supplied withy (y<x) grayscale signals, the second circuit outputs z (z<y) grayscale signals of they grayscale signals to the output terminal with the second signal.
DETECTION CIRCUIT FOR DETECTING THE AMPLITUDE OF A CLOCK SIGNAL AND DETECTION METHOD THEREOF
A detection circuit for detecting a clock signal includes a multiplexer, a digital-to-analog converter, a comparator, and a counter. The multiplexer outputs either a first signal or a second signal as a selection signal. The digital-to-analog converter outputs a reference voltage according to the selection signal. The comparator compares the clock signal to the reference voltage to generate a comparison signal. The counter counts a reference clock signal to generate an overflow signal, and resets the overflow signal according to the comparison signal. The overflow signal indicates the amplitude of the clock signal.
SEMICONDUCTOR DEVICE, ANALOG-TO-DIGITAL CONVERTER AND ANALOG-TO-DIGITAL CONVERTING METHOD
A semiconductor device includes an analog-to-digital converter configured to perform a process of sampling an analog input signal and a successive-approximation process, execute an AD conversion process, and output a digital output signal. The AD converter includes an upper DAC, a redundant DAC, a lower DAC, a comparator configured to compare a comparative reference voltage and output voltages of the upper DAC, the redundant DAC and the lower DAC, a control circuit configured to control successive approximations by the upper DAC, the redundant DAC and the lower DAC based on the comparison result of the comparator, and generate a digital output signal, and a correction circuit. The correction circuit includes an error correction circuit configured to correct an error of the upper bit with the redundant bit, and an averaging circuit configured to calculate an average value of conversion values of a plurality of the lower bits supplied multiple times.
SYSTEM FOR TESTING AN ELECTRONIC CIRCUIT COMPRISING A DIGITAL TO ANALOG CONVERTER AND CORRESPONDING METHOD AND COMPUTER PROGRAM PRODUCT
A digital-to-analog converter (DAC) includes a switching network and built-in-self-test (BIST) circuitry. The DAC, in operation, generates analog output signals in response to input codes of a set of input codes of the DAC. The BIST circuitry sequentially applies codes of a determined subset of codes of the set of input codes to test the plurality of switches. The determined subset of codes has fewer codes than the set of input codes. The BIST circuitry detects failures of switches of the plurality of switches based on responses of the DAC to the applied codes. In response to detecting a failure of a switch, the BIST generates a signal indicating a failure of the switching network.
SYSTEM AND METHOD FOR DIGITAL-TO-ANALOG CONVERTER WITH SWITCHED RESISTOR NETWORKS
A digital-to-analog converter for generating an analog output voltage in response to a digital value comprising a plurality of bits, the converter including: (i) a first switched resistor network having a first configuration and for converting a first input differential signal into a first analog output in response to a first set of bits in the plurality of bits; and (ii) a second switched resistor network, coupled to the first switched resistor network, having a second configuration, differing from the first configuration, and for converting a second input differential signal into a second analog output in response to a second set of bits in the plurality of bits.
System for and method of cancelling a transmit signal echo in full duplex transceivers
The systems and methods discussed herein utilized a wireless or wired transceiver having a transmitter and a receiver. The transceiver is configured to reduce distortion contributions associated with echo cancelling. The transmitter provides a replica signal and a transmit signal. The replica signal and the transmit signal can be provided using a common switch.
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.