
Analog Devices
GENERAL DESCRIPTION
The AD9773 is the 12-bit member of the AD977x pin compatible, high performance, programmable 2×/4×/8× interpolating TxDAC+® family. The AD977x family features
a serial port interface (SPI) that provides a high level of programmability, thus allowing for enhanced system-level options. These options include selectable 2×/4×/8× interpolation filters; fS/2, fS/4, or fS/8 digital quadrature modulation with image rejection; a direct IF mode; programmable channel gain and offset control; programmable internal clock divider;
straight binary or twos complement data interface; and a single port or dual-port data interface.
The selectable 2×/4×/8× interpolation filters simplify the requirements of the reconstruction filters while simultaneously enhancing the TxDAC+ family’s pass-band noise/distortion
performance. The independent channel gain and offset adjust registers allow the user to calibrate LO feedthrough and side band suppression errors associated with analog quadrature
modulators. The 6 dB of gain adjustment range can also be used to control the output power level of each DAC.
FEATURES
12-bit resolution, 160 MSPS/400 MSPS
input/output data rate
Selectable 2×/4×/8× interpolating filter
Programmable channel gain and offset adjustment
fS/2, fS/4, fS/8 digital quadrature modulation capabilit
Direct IF transmission mode for 70 MHz + IFs
Enables image rejection architecture
Fully compatible SPI port
Excellent ac performance
SFDR −69 dBc @ 2 MHz to 35 MHz
WCDMA ACPR −69 dB @ IF = 19.2 MHz
Internal PLL clock multiplier
Selectable internal clock divider
Versatile clock input
Differential/single-ended sine wave or
TTL/CMOS/LVPECL compatible
Versatile input data interface
Twos complement/straight binary data coding
Dual-port or single-port interleaved input data
Single 3.3 V supply operation
Power dissipation: typical 1.2 W @ 3.3 V
On-chip 1.2 V reference
80-lead thin quad flat package, exposed pad (TQFP_EP)
APPLICATIONS
Communications
Analog quadrature modulation architecture
3G, multicarrier GSM, TDMA, CDMA systems
Broadband wireless, point-to-point microwave radios
Instrumentation/ATE