Koninklijke Philips Corporation N.V.

Nxp B.v.

Ruurd Anne Visser

Hendrik Boezen

Abraham Klaas Van Den Heuvel

Aloysius Johannes Maria Boomkamp

Clemens Gerhardus Johannes De Haas

Gerrit Jan Bollen

Cornelis Klaas Waardenburg

Patrick Willem Hubert Heuts

Cecilius Gerardus Kwakernaat

Peter Michael Buehring

Gerrit Bollen

Nico Berckmans

Martinus Bredius

Marcellinus W M Oosterhuis

Egon Joehnk

Maarten Teunis Visser

In order to provide a circuit arrangement () for use in a data transmission system comprising at least one input stage (IS) being connected downstream of at least one bus system (CB), in particular of at least one C[ontroller]A[rea]N[etwork] bus system, the input stage (IS) comprising at least one resistive ladder (RL) for dividing the input signals; and at least one amplifier stage (AS) connected downstream of the input stage (IS), as well as a corresponding method with improved common mode range and with better H[igh]F[requency] performance, it is proposed that that the voltage range of the amplifier stage (AS) is limitated to a defined maximum voltage, in particular to the supply voltage (VCC).

Circuit arrangement and method of operating such circuit arrangement

An electronic circuit contains a driver circuit () with an output coupled to a digital communication conductor (), for driving changes of a potential at the digital communication conductor () to and from a digital signal level. The driver circuit () comprises a control circuit (), to generate selection signals that select increasingly stronger drive strengths and increasingly weaker drive strengths during changes to and from the digital level respectively. A controllable current supply circuit (), has a current control input coupled to the control circuit () for receiving the selection signals and a current supply output coupled to the digital communtication conductor (). A detector circuit () has an input coupled to the digital communtication conductor () and an output coupled to the control circuit (), and arranged to detect whether a potential at the digital communication conductor () has reached a required range. The control circuit () stores information about the drive strength that was selected when the detector circuit () indicated that the range was reached during the change to the digital level, and during the change it restores the drive strength to the last stored drive strength as a first step during the change away from the digital level.

Driver circuit for reducing the effects of disturbances on the duty cycle of a digital signal on a bus conductor

A bus communication system contains a pair of communication conductors and a driver. The driver contains a plurality of pairs of controlled current source circuit, each pair comprising current source circuits of a first and second, mutually opposite polarity, and a control circuit for matching currents drawn by the current sources in each pair. The current source circuit of the first polarity have outputs coupled to a first one of the communication conductors, the current source circuits of the second polarity have outputs coupled to a second one of the communication conductors. A delay line is provided, with taps coupled to control inputs of the current sources of the first and second polarity, so that the pairs are switched on successively with mutual delays between successive pairs, as determined by the delay line.

Line driver with reduced interference

Line driver for a LIN-bus. The line driver has a current source output transistor (T) for pulling down the LIN-bus wire (LB) to ground (GND). The LIN-bus wire (LB) is connected to a positive supply voltage (VBAT) through a pull-up resistor (R). The output transistor (T) is driven by a driver stage (DRV) in response to an input current (J) at an input node (X). The driver stage has a further resistor (R) connected between the gate of the output transistor (T) and a reference terminal (GND), a reference transistor (T) which has its source connected to the reference terminal (GND) and its drain coupled to the input node (X); the gates of the output transistor (T) and the reference transistor (T) are connected to an output (DAO) of a differential amplifier (DA) which has an inverting input (DAN) coupled to a bias voltage source (E) and a non-inverting input (DAP) coupled to the input node (X). The further resistor (R) stage provides a low-impedance path to ground for RF disturbances reaching the gate of the output transistor (T) through the drain-gate capacitance of the output transistor (T) and prevents these disturbances from penetrating the driver stage.

Line driver with current source output and high immunity to RF signals

Line driver for a LIN-bus. The line driver has a current source output transistor (T ) for pulling down the LIN-bus wire (LB) to ground (GND). The LIN-bus wire (LB) is connected to a positive supply voltage (VBAT) through a pull-up resistor (R ). The output transistor (T ) provides a ramp shaped output current under control of a ramp generator (RG). The ramp shaped output current in combination with the pull-up resistor (R ) asserts a ramp shaped output voltage on the LIN-bus wire (LB). According to the LIN-bus specifications the resistance of the pull-up resistor may vary between 500 Ohm and 1 kOhm. When the resistance is 1 kOhm, the output voltage is clamped to signal ground (GND) and a delay occurs between the edge in the data signal (TXD) and the corresponding rising ramp in the output voltage. This delay is reduced considerably by a comparator (CMP, T ) which monitors the output voltage and which increases the slew rate of the ramp generator (RG) when the output voltage is clamped and drops below a certain threshold.

Line driver with current source output and low sensitivity to load variations

A fault tolerant air bag system needs a floating supply, which supply conventionally is made by means of a DC-DC converter with a transformer. By splitting the main energy reserve capacitor ( ) into two capacitors ( ), and coupling one of the capacitors ( ) to the other ( ) by means of switches ( ) which open during a crash, no transformer is needed any more.

Fault tolerant air bag bus system without transformer

Growing community of inventors

Nijmegen, Netherlands

Ruurd Anne Visser