Output timing measurement using an Idd method

The exact placement of the data output eye for high speed single and double data rate (SDR, DDR) synchronous dynamic random access memories (SDRAM) allows high speed operation. For the timing measurement method via current presented in this paper the tester drives data at the same time as the device. The current consumption of the device is depending on the overlap of the tester output waveform and the waveform of the data driven by the device under test (DUT). This paper presents the measurement method and results from a 128M x4 SDRAM and compares them to a traditional approach using a data strobe.