Analog Electronics In A Day Analog Electronic Design 12. Single-Supply Op Amp Applications 12-1 Biasing calculations Computer calculations 13. Circuits High Speed Amplifier Applications 13-1 Communications circuits Imaging circuits Video/multimedia circuits Instrumentation circuits 14. Converter Basics 14-1 · Digital math Basic DAC theory and configurations Basic ADC theory and configurations Error definitions and curves 112
1-12 Analog Electronics In A Day Analog Electronic Design 1-12 12. Single-Supply Op Amp Applications 12-1 • Biasing calculations • Computer calculations 13. Circuits High Speed Amplifier Applications 13-1 • Communications circuits • Imaging circuits • Video/multimedia circuits • Instrumentation circuits 14. Converter Basics 14-1 • Digital math • Basic DAC theory and configurations • Basic ADC theory and configurations • Error definitions and curves
Analog Electronics In A Day Analog Electronic Design 15. Converter Applications 15-1 Communications circuits FIFO circuits ATS systems circuits WLL circuits Low frequency applications circuits 16. Power Applications 16-1 LDO circuits Power distribution circuits DSP power supplies ·Dc/ DC converters Battery management circuits 113
1-13 Analog Electronics In A Day Analog Electronic Design 1-13 15. Converter Applications 15-1 • Communications circuits • FIFO circuits • ATS systems circuits • WLL circuits • Low frequency applications circuits 16. Power Applications 16-1 • LDO circuits • Power distribution circuits • DSP power supplies • DC/DC converters • Battery management circuits
Analog Electronics In A Day Analog Electronic Design Passive Devices Feedback ensures that circuit performance is determined by passive not active devices Passive device accuracy and stability is paramount when they control circuit performance 1-14 Passive devices are the resistors, capacitors, and inductors required to build electronic hardware, but they always have a gain less than one Passives can multiply a signal by values less than one, as is shown in section four, but they can't multiply by more than one because of theil lack of gain. All the glory goes to the sophisticated high gain amplifiers but they are useless without the resistors and capacitors which control their gain. Good circuit design practice demands accurate and stable amplifiers, but the active devices are by nature unstable, so they are tamed with passives. Feedback is employed in almost all circuit designs to insure that the circuit performance is a function of the passive rather than the active components Passive devices are neglected in the rush to complete the design of an electronic system. Many engineers select passive devices as an after thought; they just pick them from a list of standard components. Although this practice is adequate for some circuits, it does not suffice in the demanding world of high frequency amplifiers, precision sample-holds data converters, or other demanding circuits. The hard must select adequate passives for demanding application ware designer
1-14 Analog Electronics In A Day Analog Electronic Design 1-14 • Feedback ensures that circuit performance is determined by passive, not active, devices. • Passive device accuracy and stability is paramount when they control circuit performance. Passive devices are the resistors, capacitors, and inductors required to build electronic hardware, but they always have a gain less than one. Passives can multiply a signal by values less than one, as is shown in section four, but they can’t multiply by more than one because of their lack of gain. All the glory goes to the sophisticated high gain amplifiers, but they are useless without the resistors and capacitors which control their gain. Good circuit design practice demands accurate and stable amplifiers, but the active devices are by nature unstable, so they are tamed with passives. Feedback is employed in almost all circuit designs to insure that the circuit performance is a function of the passive rather than the active components. Passive devices are neglected in the rush to complete the design of an electronic system. Many engineers select passive devices as an after thought; they just pick them from a list of standard components. Although this practice is adequate for some circuits, it does not suffice in the demanding world of high frequency amplifiers, precision sample-holds, data converters, or other demanding circuits. The hardware designer must select adequate passives for demanding applications
Analog Electronics In A Day Analog Electronic Design Selection Criteria for Passives Accuracy and stability Passive devices must be expensiVe Small -Surface mountable 1-15 The selection criteria for passive devices is very demanding. The first selection criterion for passives is that they must be accurate and stable to insure proper circuit performance. After this criterion is satisfied, there are requirements for low cost, small size and surface mounting. Accuracy normally dictates larger size, so the accuracy and small size requirements often conflict. More new surface mount components are coming out each day; thus it is a constant search to find accurate and stable passives thich meet all the criteria
1-15 Analog Electronics In A Day Analog Electronic Design 1-15 • Accuracy and stability • Passive devices must be: – Inexpensive – Small – Surface mountable The selection criteria for passive devices is very demanding. The first selection criterion for passives is that they must be accurate and stable to insure proper circuit performance. After this criterion is satisfied, there are requirements for low cost, small size and surface mounting. Accuracy normally dictates larger size, so the accuracy and small size requirements often conflict. More new surface mount components are coming out each day; thus it is a constant search to find accurate and stable passives which meet all the criteria
Analog Electronics In A Day Analog Electronic Design Resistors The circuit equation for a resistor is R=V/ Wirewound and power resistors have high inductance Carbon film and metal film resistors are stable with low parasitic effects Use the smallest-value resistor consistent with current floy 116 There are a lot of different resistors available for use, but only a few of them are satisfactory for accurate, stable, or high frequency circuits Wirewound and most power resistors have too much stray inductance and capacitance to operate at high frequencies. Carbon film resistors have less stray capacitance and inductance, but they are limited to about one per cent accuracy. Also, carbon film resistors tend to drift quite a bit with temperature and vibration Metal film resistors share the stray inductance and capacitance problem with carbon films but to a lesser extent. metal film resistors come in closer tolerances approaching 0.05 per cent, and they are more stable under temperature and vibration extremes than the other types Tolerances of 0. 1 per cent and lower are hard to achieve, but there are specialty houses which make precision resistors on a daily basis Film resistors have pretty good noise performance, but some of the old carbon composition types had outstanding noise performance. When noise performance is a critical specification in a design, the resistor selection becomes very complicated Any problems discussed above are complicated with surface mount resistors. Some very good surface mount resistors have come on the market lately, but the surface mount selection still leaves a lot to be desired
1-16 Analog Electronics In A Day Analog Electronic Design 1-16 • The circuit equation for a resistor is R=V/I • Wirewound and power resistors have high inductance • Carbon film and metal film resistors are stable with low parasitic effects • Use the smallest-value resistor consistent with current flow There are a lot of different resistors available for use, but only a few of them are satisfactory for accurate, stable, or high frequency circuits. Wirewound and most power resistors have too much stray inductance and capacitance to operate at high frequencies. Carbon film resistors have less stray capacitance and inductance, but they are limited to about one per cent accuracy. Also, carbon film resistors tend to drift quite a bit with temperature and vibration. Metal film resistors share the stray inductance and capacitance problem with carbon films, but to a lesser extent. Metal film resistors come in closer tolerances approaching 0.05 per cent, and they are more stable under temperature and vibration extremes than the other types. Tolerances of 0.1 per cent and lower are hard to achieve, but there are specialty houses which make precision resistors on a daily basis. Film resistors have pretty good noise performance, but some of the old carbon composition types had outstanding noise performance. When noise performance is a critical specification in a design, the resistor selection becomes very complicated. Any problems discussed above are complicated with surface mount resistors. Some very good surface mount resistors have come on the market lately, but the surface mount selection still leaves a lot to be desired