INTRODUCTION
Waveform or function generators capable of producing AM/FM modulated sine wave outputs find a wide range of applications in electrical measurement and laboratory instrumentation. This application note describes the design, construction and performance of such a complete function generator system suitable for laboratory usage or hobbyist applications. The entire function generator is comprised of a single XR-2206 monolithic IC and a limited number of passive circuit components. It provides the engineer, student, or hobbyist with a highly versatile laboratory instrument for waveform generation, at a very small fraction of the cost of conventional function generators available today.

GENERAL DESCRIPTION
The basic circuit configuration and the external components necessary for the high-quality function generator system is shown in Figure 1. The circuit shown is designed to operate with either a 12V single power supply, or with 16V split supplies. For most applications, split-supply operation is preferred since it results in an output dc level which is nearly at ground potential.