The DDS3-PC is a 12 MHz synthesizer that comes in PC card format and uses direct digital synthesis to produce low-noise sinusoidal signals. The DDS3-PC series produces simultaneous sine and clock signals (ACMOS/TTL) that can be set from 2 Hz to 12 MHz in 2 Hz steps. The DDS3-PCs are fast instruments that allow the frequency to be changed in approximately 1 ms to 10 ms. (Frequency switching time is limited only by ISA bus speed). The user can automatically sweep through a set of frequency, attenuation, and dwell time settings.