ECE 153-B Homework Set 2: Sensor Interface Design with ADC Problems, Assignments of Hispanic American Literature

Download ECE 153-B Homework Set 2: Sensor Interface Design with ADC Problems and more Assignments Hispanic American Literature in PDF only on Docsity! . ECE 153-B — Sensor & Peripheral Interface Design University of California Santa Barbara Homework Set #2 (due Thursday February 5, 2009) Problem 1: Assume that an A/D converter is supplying samples at 44.1 KHz (this is a typical sampling rate used for CD-quality audio). The system uses a timer interrupt to trigger the A/D conversions. a. How much time is available per sample for CPU operations? b. If the interrupt handler executes for too long such that the next interrupt occurs before the current call to the handler has finished, what happens? c. If the interrupt handler executes 100 instructions for obtaining the sample and passing it on to an application routine, how many instructions can be executed by that application routine between interrupts on a 20 MHz processor that executes one instruction per clock cycle? Problem 2: Assume that you are interfacing your digital system to an analog signal that swings between -2V and +2V using an 8-bit unipolar ADC with a signal range of 0-5V. a. What is the resolution of this ADC? b. What digital code will represent -2V? c. What digital code will represent 0V? d. In order to get an accurate representation of the signal being converted, what relation- ship must hold between its frequency content and your system sampling rate? Problem 3: Assume that we have a successive approximation style ADC with 12 bits of accuracy. a. What is a minimum number of clock cycles required for this ADC to convert an analog signal to digital form? b. Assuming a 0-10V unipolar range (and 12-bit accuracy) what will be the final converted value when the input signal is 4.25V ? c. Describe the conversion method, showing each of the digital patterns considered during the successive approximation above.