The PCI2CH24BIT is a high-resolution wide band acoustic data acquisition card in PCIe form factor which enables a variety of acoustic and ultrasound signal processing functions, including active or passive sonar, vibration analysis, geophysics, and other test and measurement applications. The card provides two “high speed” (2.5MSPS) analog input channels, and four “low speed” (144kSPS) channels, which it converts to digital data with 24-bit resolution. Anti-aliasing inherent in the Sigma-Delta converters simplifies analog signal conditioning elsewhere in the signal path. The analog front end includes adjustable gain and two pole anti-alias filtering. All other processing is performed using the on-board FPGA resources. The PCI2CH24BIT includes a high precision frequency synthesizer which allows the user to generate a sample clock of virtually any frequency, with high precision. It can also accept an external clock for frequency coherent synchronization to peripheral equipment. When using the PCI2CH24BIT, data acquisition may be performed in either capture or continuous mode. In capture mode a specific number of samples are acquired following a trigger event, while in continuous mode the amount data acquired is virtually unlimited. In this mode acquisition is initiated and terminated by software commands. 256MB of DDR3 DRAM (configured as a ring buffer) is included for on board data storage, and the card includes a DMA engine for efficient data transfer to host memory