hardware Interview questions

Hardware Board design Interview questions 1. How do you select following 1. Freewheeling diode purpose selection 2. Micro controller Crystal accuracy 3. Crystal load capacitance 4. R, L, C, FET and BJT selection 2. How do you limit surge voltage and inrush current? 3. How do you choose Instrumentation amplifier? 4. Design considerations for Instrument amplifier? 5. Relation between CMRR and frequency? 6. Design square wave generator using inverters/opamp 7. Power dissipations in LDO and switching regulators 8. How do you interface analog sensor to controller? 9. What is pinch off voltage? 10. What are the ADC errors and how to minimize? 11. What are accuracy, resolution and precision? 12. Decupling capacitors use? How to choose the required decoupling capacitance value for a given controller/PLD 13. Differences between EEPROM and FLASH 14. What will happen if the two trace lengths of differential signals are not same? 15. Draw voltage double circuit 16. Draw charge pump circuit 17. Draw an op-amp based circuit to obtain 0-3V from +/-10V input 18. Important parameters to select op-amp 19. What is virtual GND how it is happening in op-amp? 20. Current mirror circuit and explain 21. I2c timing diagram 22. Flash/SRAM Read timing diagram 23. What is clock stretching? 24. Why do we use pull-ups on I2C bus and how to calculate resistance values? 25. What is noise margin? 26. What is IB, Beta and IC relation for saturated BJT? 27. What is the maximum phase shift you get with capacitor/RC ckt ? 28. Draw BJT amplifier ckt with equations and Output characteristics 29. Draw Schmitt rigger ckt with equations 30. How do you protect circuit from reverse polarity? 31. Differences between RS232 and RS485 communication 32. What is MultiMaster Communication? 33. Frequency response of RC LPF with equations 34. What type of simulations you have done in PSPICE? 35. Compare BJT and FET 36. Draw constant current amplifier using BJT 37. What are the error sources for op-amp? 38. What is slew rate and unity gain bandwidth? 39. How do you select controller for typical application 40. How do you interface 7segment LED’s with controller 41.Serial communications SPI, I2C, RS232,RS485 and RS422 42. Draw BJT amplifier and Derive Gain formula Continental 1. CLK oscillator design using Inverter 2. Inverting and non inverting amplifier design 3. Protection circuits for Surge and inrush current 4. Controller selection 5. Block diagram Power consumption of your board 6. In I2C communication which side (Device or master) is open collector? Honeywell Bangalore: 1. How the isolating amplifier provides impedance matching 2. Instrumentation amplifier practical design considerations 3. EMI/EMC standards 4. Flash and EEPROM differences 5. Differences between LDO and STD LDO 6. Constant current amplifier design 7. How the virtual gnd will happen in opamp 8. OPamp internal diagram 9. Current mirror circuit with equations 10. CMRR and PSRR relation with frequency? 11. How do you select instrument amplifier and advantages of Instrument amp 12. Which source is best for far communication I souce or V source ? and how? 13. Types of simulations in SPICE 14. MTBF and Error budjet calculations 15. ADC types and operations 16. Schmittriger ckt with equations 17. ADC error types and how do we minimize 18. Under/over sampling advantages and disadvantages 19. Aliasing effect in an ADC 1. boost regulator operation 2. +ve and –ve amplifier design using opamp 3. BJT amplifier gain calculations 4. BJT and fet differences 5. how do we select an ADc for 10V i/p with noise environment 6. How will you measure 50V on a board by ADC, Hint: Do not use resistor divider,it loads supply. use a differential amplifier 7. Battery present indication using opamp like how it glows in LAPtop 8. Use of RE resistor in BJT amp 9. BJT amplifier design 10. how do you control ADC errors 11. RC LPF design calculations and frequency response with angle calculations 12. RS232 communication protections 13. Difference between normal diode and surge protection diode 14. Impulse , step ramp equations and if we give thse to RC lpf wht will be the output? Goodrich: 1. Design an Half wave rectifier 2. How do you select frequency of operation in buck regulator 3. what is the significance of schottkey diode in buck regulator, advantages over normal diode 4. L&T: 1. Design a opamp ckt to convert +/-10V to 0-3V 2. buck regulator function 3. optical isolator selection GE: