Infineon Technologies Ag

Stefan Sommer

Volker Kilian

Richard Roth

Lenart Hauptner

Wolfgang Anton Spirkl

A tuning circuit for setting a signal propagation time on a signal line in an integrated circuit, particularly a DRAM circuit, has a transistor and a capacitor. A control connection of the transistor is connected to a control unit for the purpose of switchably connecting the capacitor to the signal line through the transistor in order to set the signal propagation time on the signal line on the basis of application of a control signal, generated in the control unit, to the control connection on the transistor.

Circuit for setting a signal propagation time for a signal on a signal line and method for ascertaining timing parameters

For testing or for characterizing output drivers of output circuits of high-speed semiconductor memory devices under conditions close to an application, scan elements are provided at the inputs of the output circuits. The scan elements in each case have a register function and are cascaded to form a scan chain. Via the scan chain, test data signals are applied to the inputs of the output circuits whilst bypassing a memory cell array of the semiconductor memory devices. The characterization of data signals of the high-speed semiconductor memory devices that are output by the output circuits requires only a test memory controller not connected to the data signal terminals and a passive load simulation of the application memory controller.

Method and arrangement for testing output circuits of high speed semiconductor memory devices

In the case of the present-day trend of miniaturizing housed electronic devices, there is the problem that the contact spacings between the terminal pins becomes smaller and smaller and are no longer visible optically. As a result, it also becomes more difficult to solder the contacts of correspondingly designed contact bases, which for example, are designed as test bases, to the individual conductor tracks of the printed circuit board. Possible faulty soldering points, short circuits or interruptions have hitherto been tracked down by laborious manual measurement using the TDR method. The invention proposes producing a test device in which in each case two terminal pins are connected to a short-circuiting bridge. The test device is inserted into the contact base and connects two signal paths of the printed circuit board on which the propagation time of a reflected wave can be measured.

Growing community of inventors

Fürth, Germany

Stefan Sommer