英特爾MCS-51、MCS-48微控制器的振蕩器的設(shè)計

CONTENTS PAGE
INTRODUCTION? 1
FEEDBACK OSCILLATORS? 1
Loop Gain? 1
How Feedback Oscillators Work? 2
The Positive Reactance Oscillator? 2
QUARTZ CRYSTALS? 3
Crystal Parameters? 3
Equivalent Circuit? 3
Load Capacitance? 4
``Series'' vs. ``Parallel'' Crystals? 4
Equivalent Series Resistance? 4
Frequency Tolerance? 5
Drive Level? 5
CERAMIC RESONATORS? 5
Specifications for Ceramic Resonators? 6
OSCILLATOR DESIGN
CONSIDERATIONS? 6
On-Chip Oscillators? 6
Crystal Specifications? 6
Oscillation Frequency? 7
Selection of CX1 and CX2? 7
Placement of Components? 7
Clocking Other Chips? 7
External Oscillators? 8
Gate Oscillators vs. Discrete Devices? 10
Fundamental vs. Overtone
Operation? 11
``Series'' vs. ``Parallel'' Operation? 11
CONTENTS PAGE
MORE ABOUT USING THE ``ON-CHIP''
OSCILLATORS? 11
Oscillator Calculations? 11
Start-Up Characteristics? 13
Steady-State Characteristics? 15
Pin Capacitance? 16
MCSé-51 Oscillator? 16
MCSé-48 Oscillator? 16
CONTENTS PAGE
Pre-Production Tests? 19
Troubleshooting Oscillator Problems? 20
APPENDIX A: QUARTZ AND CERAMIC
RESONATOR FORMULAS? A-1
APPENDIX B: OSCILLATOR ANALYSIS
PROGRAM? B-1