6.002 Demo# 19: Crosstalk

6.002 Demo# 19 Crosstalk Lectures 13 and 25 Agarwal Fall 00 Purpose: This demo shows the capacitive coupling between signals on two separate wires in proximity. It is used as a case where 6.002 abstractions are violated. The coupling can be modeled as a capacitor, but the effect is due to physical implementation, not the design. Steps: 1. With a sine wave applied to one circuit, and a square wave to the other, note on the scope the “spikes” riding on the sine wave circuit output, corresponding to the transitions in the square wave. 2. Remove the spikes from the sine wave output by switching the square wave to a triangle wave. Sinusoid + Square wave / triangle - Description: Crosstalk demonstration See schematic diagram next page for more detail Oscilloscope Setup CH V/DIV 1 on 5 2 on OFFSET MODE FUNC DC off 2 -80 mV DC off 3 off 0 DC off 4 on 1 DC off Horizontal: 200 us -13.31 2.3 Acquisition: MATH AUTO AUTO VERTICAL 4 HORIZONTAL Trigger: CH2 Cite as: Anant Agarwal and Jeffrey Lang, course materials for 6.002 Circuits and Electronics, Spring 2007. MIT OpenCourseWare (http://ocw.mit.edu/), Massachusetts Institute of Technology. Downloaded on [DD Month YYYY]. Waveform Generator Setup UNIT WAVE Power Supply Setup AMP OFFSET FG1 Sq 5 0 FG2 1 0 Sine FREQ 10 Khz 2.5 Khz +6 off +25 off -25 OUTPUT off Trigger: INT Cite as: Anant Agarwal and Jeffrey Lang, course materials for 6.002 Circuits and Electronics, Spring 2007. MIT OpenCourseWare (http://ocw.mit.edu/), Massachusetts Institute of Technology. Downloaded on [DD Month YYYY].