The PDAC4000 is a very high speed, four channel Digital to Analog Conversion (DAC) board which may be used as an Arbitrary Waveform Generator, a waveform playback device, or for generating multiple communication frequency bands. Output waveforms may be "single shot" or "continuously looped". The DAC4000 is a daughter card that plugs into a PMP1000 base board and takes advantage of its data interfaces and programmability.

The PDAC4000 can accurately produce output signal frequencies up to 400 MHz. Each 16-bit converter can output up to 1000 megasamples per second. On-board there is a total of 512 megabytes of SDRAM.

Data samples may be supplied to the DACs via the on-board memory, or via the Signatec Auxiliary Bus (SAB) or PCI-X bus on the PMP1000. Waveforms captured with either Signatec's 8-bit PDA1000 or 14-bit PDA14 boards may be played back at the same clock rate at which they were acquired or at other programmable clock rates.

The DAC clock source may be selected as either the 1000 MHz or 800 MHz VCXO oscillator or from the external clock input. Any of the three clock sources can be divided by any integer from 1 to 32 times a second integer from 1 to 32 for a total divider range of 2 to 1024. The VCXO oscillators have extremely low jitter and can be synchronized to an external reference input or to the internal TCXO reference. The internal reference is accurate to better than 3ppm.

The PDAC4000 can be programmed to generate continuous, repetitive waveforms by utilizing data “looping” whereby the designated amount of data is played repeatedly without gaps in the waveform.

The PDAC4000 is ideal for playing back extremely long waveforms, such as those previously captured with a Signatec Waveform Recording System. This is particularly useful in testing a system's response to previously recorded real world signals. In such an operation the data is supplied from the high-speed data storage system via the PCI-X bus and the PMP1000's on-board RAM is utilized as a very large FIFO. The PDAC4000's own on-board RAM would not be used in this implementation.