Tuan-Shu Ho

2 (From Wikimedia) DisplayTrigger Input

3 Graphed by Dong-Yo Vertical Amplifier Horizontal Amplifier AC/DC/GND Attenuator Trigger System Sweep Generator Vertical position Volts/Div Time/DivHorizontal position Ext. trigger Ext. sweep Signal Input Deflection Electrodes In CRT

 Input impedance selection ◦ 1MΩ : general purpose, for sample under test  Preventing system damage  50Ω : smaller RC time constant, larger bandwidth  The standard impedance of coaxial cable  Triggering ◦ External trigger  External pulse signal ◦ Edge trigger  Level: amplitude of signal  Slope: derivative of signal ◦ Trigger hold-off 4 Trigger hold-off

 Categorized by data type ◦ Analog oscilloscope ◦ Digital oscilloscope  Categorized by sampling method ◦ Real-time sampling (RTS) ◦ Equivalent-time sampling (ETS)  Sometimes it’s just called “sampling oscilloscope”  History ◦ Analog RTS > Analog ETS (~1950) > Digital RTS and ETS 5

 Digital “storage” oscilloscope ◦ Analog storage: Allows the traces to remain on the screen for several minutes or longer. ◦ Digital storage: Traces are stored in digital memories after analog-to- digital conversion.  Post-acquisition manipulation and pre-trigger viewing is available.  Drawback: dynamic range and sampling rate are limited by the additional ADC. 6

 a repetitive train of pulses (strobes) is applied to sample the input signal.  Firing the strobe during each repetition of the input pulse train at a time Δt later than it fired in the previous.  The original signal can be reconstructed after T/Δt cycles. 7 Kate et al, Sampling Oscilloscope Models and Calibrations

 ETS Pro ◦ Larger bandwidth  BW limit of RTS: BW of Amplifier and ADC  BW limit of ETS: limited by temporal resolution and frequency accuracy of system. ◦ Better SNR  ETS Con ◦ Can only observe only repetitive events ◦ Lower dynamic range  Sampling unit before amplifier and attenuator  Both RTS and ETS can achieve tens of GHz BW. ◦ Agilent DSAX96204Q (RTS):~USD$420,000 ◦ Agilent 86100D (ETS):~USD$20,000 8

 Agilent DSAX96204Q ◦ Real-time Sampling ◦ Analog Bandwidth: 63GHz ◦ Max. Sampling rate: 160GS/s ◦ Max memory depth: 2 Gpts  Agilent 86100D ◦ Equivalent-time sampling ◦ Analog bandwidth: 80GHz ◦ Max. Sampling rate: 40kS/s  Other manufacturers ◦ Tektronix ◦ Lecroy (65GHz RTS, 100GHz ETS) 9

 LeCroy WaveExpert ◦ Equivalent-time sampling ◦ Analog bandwidth: 100GHz ◦ Max. Sampling rate: 10MS/s 10

Thank you for your attention! 11