Hardware / Microprocessor Interview Questions
1 Apr, 2007
- Explain why & how a MOSFET works
- Draw Vds-Ids curve for a MOSFET. Now, show how this curve changes (a) with increasing Vgs (b) with increasing transistor width (c) considering Channel Length Modulation
- Explain the various MOSFET Capacitances & their significance
- Draw a CMOS Inverter. Explain its transfer characteristics
- Explain sizing of the inverter
- How do you size NMOS and PMOS transistors to increase the threshold voltage?
- What is Noise Margin? Explain the procedure to determine Noise Margin
- Give the expression for CMOS switching power dissipation
- What is Body Effect?
1 Apr, 2007
- For CMOS logic, give the various techniques you know to minimize power consumption
- What is Charge Sharing? Explain the Charge Sharing problem while sampling data from a Bus
- Why do we gradually increase the size of inverters in buffer design? Why not give the output of a circuit to one large inverter?
- In the design of a large inverter, why do we prefer to connect small transistors in parallel (thus increasing effective width) rather than lay out one transistor with large width?
1 Apr, 2007
- Give two ways of converting a two input NAND gate to an inverter
- Given a circuit, draw its exact timing response. (I was given a Pseudo Random Signal Generator; you can expect any sequential ckt)
- What are set up time & hold time constraints? What do they signify? Which one is critical for estimating maximum clock frequency of a circuit?
- Give a circuit to divide frequency of clock cycle by two
- Design a divide-by-3 sequential circuit with 50% duty circle. (Hint: Double the Clock)
10 Feb, 2007
- Are you familiar with the term MESI?
- Are you familiar with the term snooping?
- Describe a finite state machine that will detect three consecutive coin tosses (of one coin) that results in heads.
- In what cases do you need to double clock a signal before presenting it to a synchronous state machine?
- You have a driver that drives a long signal & connects to an input device. At the input device there is either overshoot, undershoot or signal threshold violations, what can be done to correct this problem?
10 Feb, 2007
- What is D-FF?
- What is the basic difference between Latches and Flip flops?
- What is a multiplexer?
- How can you convert an SR Flip-flop to a JK Flip-flop?
- How can you convert an JK Flip-flop to a D Flip-flop?
- What is Race-around problem? How can you rectify it?
- Which semiconductor device is used as a voltage regulator and why?
- Explain an ideal voltage source?
- Explain zener breakdown and avalanche breakdown?
- What are the different types of filters?
- What is the need of filtering ideal response of filters and actual response of filters?
