Nxp B.v.

Gerard Arie De Wit

Johannes Petrus Antonius Frambach

Cornelis Klaas Waardenburg

Stefan Paul Van Den Hoek

A transmitter circuit including an impedance setting circuit having first and second legs, wherein each leg includes an adjustable pull-up resistance and an adjustable pull-down resistance connected in series between a supply terminal and a reference terminal. A first-leg-node, between the adjustable resistances of the first leg, is connected to a first bus terminal. A second-leg-node, between the adjustable resistances of the second leg, is connected to a second bus terminal. The controller detects a transition in a transmission data signal, and in response to a dominant to recessive transition the controller controls a voltage setting circuit to set the differential driver voltage on the bus to a recessive value; adjusts each of the adjustable pull-up resistances and the adjustable pull-down resistances with the same target impedance profile such that the transmitter circuit drives the bus with a target driver impedance for an active recessive period of a bit time.

Transmitter circuit

A Controller Area Network (CAN) transmitter, in which transitions between output levels are smoothed through use of multiple Digital to Analog Converters (DACs) switched by a multi-phase clock signal. Example embodiments include a CAN transmitter () comprising: an oscillator () configured to generate a clock signal having n equally spaced phases (clk_0, clk_120, clk_240), where n is an integer greater than 1; n Digital to Analog Converters, DACs (-), each DAC having an input connected to one of the n phases of the clock signal and to a common data input line, each DAC being configured to provide an output signal that transitions between first and second output levels in M discrete steps upon being triggered by a transition of a signal on the data input line synchronized with the one of the n phases of the clock signal; and an output amplifier stage () configured to provide a differential CAN output signal from a combination of output signals from each of the n DACs (-).

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Wijchen, Netherlands

Gerard Arie De Wit