CDS 53A-243 Arbitrary Waveform Generator Card

The Aeroflex / Tektronix / CDS 53A-243 Arbitrary Waveform Generator (ARB) Card is a printed circuit board assembly for use in a Aeroflex / Tektronix / CDS 53/63 Series System. The card produces a programmable series of output-voltage steps that can be used to create precise sinusoidal, triangular, square, or other user-defined arbitrary waveforms. The ARB Card produces an analog output of either 15.11 V, programmable in 10-mV steps, when driving a 50-Ohm load; or t 10.22 V, programmable in 20-mV steps, when driving a high-impedance load.

Sample rates are programmable from a period of 40 nanoseconds to a period of 671 milliseconds in 40 nanosecond steps, using the internal clock.

A waveform consisting of up to 16,384 10-bit voltage points can be programmed into the on-card memory. The waveform may be of any length up to 16,384 samples. The output waveform may be programmed to repeat from 1 through 255 times, or continuously. Break points may be programmed in any nonconsecutive memory locations except the first location in memory. A break point causes the waveform to pause until it is retriggered by software or by a TTL trigger from an external source. This feature is particularly useful in applications where it is desirable to coordinate portions of the output waveform with other portions of the test.

Multiple ARB Cards can be slaved to a single card or to a common external clock source to allow output waveforms to be phase synchronized. This feature gives greater flexibility in using the ARB. For example, the phase relationship between waveforms that have been synchronized in this manner can be varied under program control by specifying a new starting memory location for each individual output waveform.

Memory locations are easily programmed using a string of numeric ASCII characters which directly specify the output voltage for each sample. An editing capability allows individual points in the waveform to be changed without requiring a complete memory reload. In addition, memory loading is further optimized during a block waveform load by an auto-increment feature. With this, the user need only program the starting waveform address at the beginning of the block waveform load.

Auxiliary inputs provide for an external clock input (up to 25 MHz), and for an external trigger. Auxiliary outputs provide a clock output at a frequency equivalent to the programmed sample rate, and a synchronization pulse that is generated at the end of each waveform cycle.