The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 16, 2003
Filed:
Mar. 11, 2002
Clemens Gerhardus Johannes De Haas, Nijmegen, NL;
Hendrik Boezen, Nijmegen, NL;
Aloysius Johannes Maria Boomkamp, Nijmegen, NL;
Gerrit Jan Bollen, Nijmegen, NL;
Abraham Klaas Van Den Heuvel, Nijmegen, NL;
Ruurd Anne Visser, Nijmegen, NL;
Koninklijke Philips Electronics N.V., Eindhoven, NL;
Abstract
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.