DACs Enable Direct RF Upconversion

Said to employ simpler direct RF upconversion architectures that require fewer external components, the AD977x family of dual interpolating TxDAC+ d/a converters target multi-carrier 3G and HDTV transmitters and satellite systems. The AD9777, AD9775 and AD9773 provide 16-, 14- and 12-bit resolutions, respectively, input data rates up to 160 Msamples/s with 1x interpolation, and support a maximum d/a conversion update rate of 400 Msamples/s with 8x interpolation. They provide selectable 2x, 4x and 8x interpolation filters to improve noise performance and reduce input data-rate requirements. The AD9777 features a W-CDMA ACPR of -71 dBc at IF=71 MHz and an IMD of -80 dBc up to 30 MHz. And the AD9775 and AD9773 are pin-compatible with each other. Available in thermally enhanced, 80-lead TQFPs, prices for the AD9777/75/73 are $39.95, $35, and $24.95, respectively, each/1,000. ANALOG DEVICES INC., Wilmington, MA. (800) 262-5643.