A digital-to-time converter (DTC) converts a digital code into a time delay using a capacitor digital-to-analog converter (CDAC) that functions as a charging capacitor. The DTC includes a switched capacitor voltage-to-current converter for the formation of a charging current (or a discharging current) for charging (or for discharging) the charging capacitor responsive to a triggering clock edge that begins the time delay. A comparator compares a voltage on the charging capacitor to a threshold voltage to determine an end of the time delay.

A method for checking a message in a communication system, in which multiple users are connected to a communication medium that includes two signal lines and exchange messages via same. A time difference between points in time of reception of a message that is sent on the communication medium is ascertained at two different, predefined positions on the communication medium, and based on a comparison of the time difference to at least one reference time difference, it is determined whether the message originates from a verified user. During the ascertainment of the time difference at the two positions, in each case a difference signal is formed from signals that have resulted on the two signal lines due to the message.

A method for checking a message in a communication system, in which multiple users are connected to a communication medium that includes two signal lines and exchange messages via same. A time difference between points in time of reception of a message that is sent on the communication medium is ascertained at two different, predefined positions on the communication medium, and based on a comparison of the time difference to at least one reference time difference, it is determined whether the message originates from a verified user. During the ascertainment of the time difference at the two positions, in each case a difference signal is formed from signals that have resulted on the two signal lines due to the message.

A pulse width modulation (PWM) digital-to-analog conversion circuit includes switches 102, 104, 114, 116 controlled by a first PWM signal, and switches 106, 108, 110, 112 controlled by a second PWM signal. A first operational amplifier (op-amp) includes a first input coupled to an output of a filter, and a second input coupled to an output of the first op-amp. During a first time period, an output of a second op-amp is coupled to an input of the filter via switches 102 and 104, and an output of a third op-amp is coupled to the output of the first op-amp via switches 114 and 116. During a second time period, the output of the second op-amp is coupled to the output of the first op-amp via switches 106 and 108, and an output of the third op-amp is coupled to the input of the filter via switches 110 and 112.

In certain aspects, a method for providing a first drive clock signal and a second drive clock signal to a first sub-digital-to-analog converter (sub-DAC) and a second sub-DAC includes receiving an input clock signal, and dividing the input clock signal to generate a first divided clock signal and a second divided clock signal. The method also includes gating the input clock signal using the first divided clock signal to generate the first drive clock signal, and inputting the first drive clock signal to a clock input of the first sub-DAC. The method further includes gating the input clock signal using the second divided clock signal to generate the second drive clock signal, and inputting the second drive clock signal to a clock input of the second sub-DAC.

In certain aspects, a method for providing a first drive clock signal and a second drive clock signal to a first sub-digital-to-analog converter (sub-DAC) and a second sub-DAC includes receiving an input clock signal, and dividing the input clock signal to generate a first divided clock signal and a second divided clock signal. The method also includes gating the input clock signal using the first divided clock signal to generate the first drive clock signal, and inputting the first drive clock signal to a clock input of the first sub-DAC. The method further includes gating the input clock signal using the second divided clock signal to generate the second drive clock signal, and inputting the second drive clock signal to a clock input of the second sub-DAC.

An apparatus for interpolating between a first signal and a second signal is provided. The apparatus includes a first plurality of interpolation cells configured to generate a first interpolation signal at a first node. At least one of the first plurality of interpolation cells is configured to supply, based on a first number of bits of a control word, at least one of the first signal and the second signal to the first node. The apparatus further includes a second plurality of interpolation cells configured to generate a second interpolation signal at a second node. At least one of the second plurality of interpolation cells is configured to supply, based on a second number of bits of the control word, at least one of the first signal and the second signal to the second node. The apparatus additionally includes an interpolation circuit configured to weight the second interpolation signal based on a weighting factor, and to combine the first interpolation signal and the weighted second interpolation signal to generate a third interpolation signal.

An apparatus for interpolating between a first signal and a second signal is provided. The apparatus includes a first plurality of interpolation cells configured to generate a first interpolation signal at a first node. At least one of the first plurality of interpolation cells is configured to supply, based on a first number of bits of a control word, at least one of the first signal and the second signal to the first node. The apparatus further includes a second plurality of interpolation cells configured to generate a second interpolation signal at a second node. At least one of the second plurality of interpolation cells is configured to supply, based on a second number of bits of the control word, at least one of the first signal and the second signal to the second node. The apparatus additionally includes an interpolation circuit configured to weight the second interpolation signal based on a weighting factor, and to combine the first interpolation signal and the weighted second interpolation signal to generate a third interpolation signal.

An apparatus is configured to generate, from a stream of periodic digital samples, a first sub-stream of periodic analog samples and a second sub-stream of periodic analog samples, each sub-stream comprising substantially stable time intervals. The apparatus is further configured to generate a sign-modulated sub-stream by applying to the second sub-stream a sign modulation operation effecting a sign transition during a stable time interval of the second sub-stream. The apparatus is further configured to generate an output stream of periodic analog samples based on a sum of the first sub-stream and the sign-modulated sub-stream, wherein a period of the output stream is shorter than periods of the first and second sub-streams.

An apparatus is configured to generate, from a stream of periodic digital samples, a first sub-stream of periodic analog samples and a second sub-stream of periodic analog samples, each sub-stream comprising substantially stable time intervals. The apparatus is further configured to generate a sign-modulated sub-stream by applying to the second sub-stream a sign modulation operation effecting a sign transition during a stable time interval of the second sub-stream. The apparatus is further configured to generate an output stream of periodic analog samples based on a sum of the first sub-stream and the sign-modulated sub-stream, wherein a period of the output stream is shorter than periods of the first and second sub-streams.