Many Microchip customers ask us for help when designing their oscillator circuits. Due to the great num- ber of combinations of VDD and temperature ranges, crystal or resonator, loading capacitors, circuit layout and circuit board materials, it is not practical to provide a cookbook process that would work well for everyone or even for most users. However, there are measures that can be used to develop and test for good working oscillator circuits. This application note breaks down the oscillator design process into the following three parts: specifying the operating conditions, selecting the components and testing oscillator performance. Other concerns are also discussed that may be helpful during layout and testing. AN949 Making Your Oscillator Work Temperature Author: Brett Duane The product is expected to operate over some temper- Microchip Technology Inc. ature range. Testing of oscillator operation will be conducted over the same or slightly larger range. The temperature affects transistor gain, capacitor values INTRODUCTION and the crystal/resonator frequency. Many Mic……