2. Electronics Principles & Applications Sixth Edition Chapter 13 Integrated Circuits (student version) ©2003 Glencoe/McGraw-Hill Charles A. Schuler

3. IC Fabrication The 555 Timer Analog ICs Mixed-signal ICs Troubleshooting INTRODUCTION

4. Dear Student: This presentation is arranged in segments. Each segment is preceded by a Concept Preview slide and is followed by a Concept Review slide. When you reach a Concept Review slide, you can return to the beginning of that segment by clicking on the Repeat Segment button. This will allow you to view that segment again, if you want to.

5. Concept Preview Photolithography is the base process used in making monolithic integrated circuits. Impurities are diffused into the substrate to form PN junctions. ICs are batch processed. One wafer will yield many devices. A probe test identifies defective ICs before the wafer is cut apart. An aluminum metalization layer interconnects the various IC components.

6. The base process in making ICs is photolithography. Silicon wafer (the substrate) oxidized on its surface Coated with photoresist Covered with a photomask Exposed to light and developed Etched to expose the substrate Impurity diffusion into the substrate Repeat eight to twenty times

7. Silicon substrate Start with a silicon substrateCoat with silicon dioxide Coat with photoresist Cover with photomask Expose with light Develop Etch Diffusion Dopant A P-N junction has been formed.

8. Batch Processing Each wafer will yield dozens of ICs (or more). Wafer

9. Probe Test

10. During the probe test, the defective ICs are marked. After the wafer is separated, the defective ICs are discarded.

11. Using photolithography to form an NPN BJT 1. P- type substrate 2. N+ diffusion layer 3. N epitaxial layer 4. Silicon dioxide layer 5. Expose and etch 6. Boron diffusion 7. Silicon dioxide layer 8. Expose and etch 9. Boron base diffusion 10. Emitter diffusion

12. Using photolithography to form an NPN BJT 11. Coat, expose and etch 12. Aluminum metalization layer 13. Coat, expose and etch away extra aluminum Collector contact Emitter contact Base contact

13. IC Fabrication Quiz The base process in making monolithic Ics is __________. photolithography The wafer is coated with photoresist and exposed through a __________. photomask Etching produces windows through which impurities are __________. diffused The electrical performance of each chip on the wafer is checked during the __________ test. probe Individual sections are electrically connected with a film of __________. aluminum

14. Concept Review Photolithography is the base process used in making monolithic integrated circuits. Impurities are diffused into the substrate to form PN junctions. ICs are batch processed. One wafer will yield many devices. A probe test identifies defective ICs before the wafer is cut apart. An aluminum metalization layer interconnects the various IC components. Repeat Segment

15. Concept Preview The 555 timer IC has two comparators, a discharge transistor and a digital output. One-shot operation provides an output pulse width controlled by an external resistor and capacitor. Astable operation provides a continuous rectangular waveform at the output. Time-delay operation provides an output delay that is RC controlled. Pulse position modulation uses an external signal to control the comparator trip points.

16. 5 k  R SQ Q Gnd1 Out 3 +V CC 8 Discharge Threshold Control Trigger 7 6 5 2 555 Reset4 UTP 2/3 V CC LTP 1/3 V CC A popular timer IC

17. S R Q Q R SQ Q How the RS flip-flop in the 555 timer works: Once set, the Q output remains high until the flip-flop is reset. Outputs are in opposite states.

18. 1 3 +V CC 7 6 2 8 One-shot Operation R C 1/3 V CC The input trigger resets the flip-flop and C then charges until the top comparator trips and sets the flip-flop. S R input trigger output pulse Discharge transistor

19. + V CC 555 48 7 6 1 3 2 R C t = 1.1RC Output pulse Trigger 1/3 V CC The external components determine the output pulse width.

20. 1 3 +V CC 7 6 2 8 Free-running or Astable Operation RBRB C RARA S R 2/3 V CC 1/3 V CC C charges through R A + R B and discharges through R B.

21. + V CC 555 48 7 6 1 3 2 RARA C Astable Mode Duty Cycle > 50% RBRB f = 1.45 (R A + 2R B )C Duty Cycle = R A + 2R B x 100% R A + R B

22. + V CC 555 48 7 6 1 3 2 RARA C Astable Mode Duty Cycle < 50% RBRB f = 1.45 (R A + R B )C RARA Duty Cycle = R A + R B x 100% C charges through R A and discharges through R B.

23. + V CC 555 48 6 1 3 2 R C Trigger Time-delay Mode Time delay = 1.1 RC Output

24. Pulse-position Modulation Modulation

25. 555 Timer Quiz The voltage of the trigger signal must be less than 1/3 __________. V CC The threshold and trigger comparators control the __________. RS flip-flop The Q output of the RS flip-flop controls the __________ transistor. discharge In one-shot mode, the external R and C set the __________ of the output pulse. width In astable mode, the 555 timer acts as an __________. oscillator

26. Concept Review The 555 timer IC has two comparators, a discharge transistor and a digital output. One-shot operation provides an output pulse width controlled by an external resistor and capacitor. Astable operation provides a continuous rectangular waveform at the output. Time-delay operation provides an output delay that is RC controlled. Pulse position modulation uses an external signal to control the comparator trip points. Repeat Segment

27. Concept Preview There are three IC categories: analog, digital and mixed signal. The most widely-applied analog ICs are amplifiers and voltage regulators. Phase locked loops can be used for FM detection and for frequency synthesis. A sample and hold circuit is usually required for analog to digital conversion. The number of bits sets the output resolution for digital to analog converters. Switched capacitor ICs can provide voltage conversion and integration.

28. Analog ICs include: Linear voltage regulators Differential amps High-speed amps Op amps RF and IF amps Modulators and mixers Demodulators Power amps

29. The LM3876 delivers up to 56W of audio output power to an 8  load. V+ V- Out V IN + V IN - Mute Gnd 11-lead TO220 plastic package 0.1% THD 20 Hz – 20 kHz 95 dB SNR Load, voltage and temperature protected 100 W peak output

30. Mixed signal ICs contain or use both digital and analog circuit functions. 1 2 3 4 5 6 GND U/D CS W H V CC MAX5468 This Maxim digital potentiometer is an example. It provides 32 output levels from pin 5 for volume control applications. It is adjusted by applying digital pulses to pin 3. Pin 4, along with pin 3, selects either a volume up or a volume down mode.

31. Error Amplifier Phase Detector LPF VCO Phase-locked loops are mixed signal ICs. The phase detector is usually digital.

32. Error Amplifier Phase Detector LPF VCO Phase-locked Loop In VCO The VCO locks onto the input phase.

33. Error Amplifier Phase Detector LPF VCO In The VCO also locks onto the input frequency. Out Output voltage Input frequency Lock range

34. Error Amplifier Phase Detector LPF VCO In PLLs can serve as FM detectors. Out

35. Error Amplifier Phase Detector LPF VCO f REF PLL Frequency Synthesizer f OUT Digital divide by N f OUT = N(f REF )

36. A sample and hold can be a separate circuit or part of an analog to digital converter. hold capacitor analog input clock switch A/D occurs when signal voltage is not changing to A/D

37. 4-bit D/A Converter V out R R 2R 4R 8R Output states = 2 N = 2 4 = 16 N = 4 5 V 8 0 V -9.375 V

38. 1 ms -10 0 time volts 0 Switched Capacitor Voltage Inverter

39. 1 ms 0 20 time volts 0 Switched Capacitor Voltage Doubler

40. Conventional and Switched Capacitor Integrators 1 ms 10 time volts 0 0 C1C1 C2C2 C R Slope of V out = -V in x RC 1 Slope of V out = -V in x C2C2 C 1 x f clock

41. Mixed Signal IC Quiz When a PLL is locked, the VCO tracks the input __________. signal PLLs can be used as FM __________. detectors With a divide by N, a PLL serves as a frequency __________. synthesizer The output of a 6-bit D/A converter has __________ possible output levels. 64 The output slope of a switched capacitor __________ depends on the clock frequency. integrator

42. Troubleshooting Be sure to take a system point of view. Is there any software involved? Supply voltages may be critical. Waveform analysis is often used. Check clock frequency.

43. Concept Review There are three IC categories: analog, digital and mixed signal. The most widely-applied analog ICs are amplifiers and voltage regulators. Phase locked loops can be used for FM detection and for frequency synthesis. A sample and hold circuit is usually required for analog to digital conversion. The number of bits sets the output resolution for digital to analog converters. Switched capacitor ICs can provide voltage conversion and integration. Repeat Segment

44. REVIEW IC Fabrication The 555 Timer Analog ICs Mixed-signal ICs Troubleshooting