McGill Increasing the Time Dynamic Range of Pulse Measurement Techniques in Digital CMOS Applications of Pulse Measurement: Duty-Cycle Measurement Pulsed Radar Digital Applications … Previous Techniques Limitations: Large power dissipation for small pulses Otherwise, very high resolution ADC needed Time walk correction techniques needed in the dual-slope ADC approach Always linearity, power, resolution trade-offs

McGill Proposed System Vin V th,n t1t1 V out1 V out2 TT  T = (t 2 -t 1 ) m.  T Time Amplification Edge Detection Vin t2t2 t1t1 t2t2 Low Power; dynamic current generation techniques in the front-end edge detection while relying on the charge carried by the input edges and a capacitor for a fast discharge of the output node, without the need for a constant biasing current Low-end pulse measurement possible; relies on time amplification which is used to stretch the two input edges, carrying the pulse width, into an amplified version, using simple cross-coupled differential pairs loaded properly and operating in the appropriate mode. Amplification makes the task of digitization simpler The system carries the timing information with two fast edges  More noise immunity and less non-linear errors Unlike the dual-slope ADC circuit, the proposed system does not suffer from the linearity, power, resolution trade-offs (no comparator overdrive concerns here)  Extra degree of freedom to the designer Low- Resolution TDC Serial Shift Out

McGill Summary of Results Before calibration After calibration Offset Simulated/Fitted time amplifier gain Input pulse width, ps TDC shift in bit location