Dual, 16-Bit, 1000 MSPS, TxDAC+® Digital-to-Analog Converter
Features and Benefits
- 16-bit resolution, 160 MSPS/400 MSPS input/output data rate
- Selectable 2×/4×/8× interpolating filter
- Programmable channel gain and offset adjustment
- fS/4, fS/8 digital quadrature modulation capability
- Direct IF transmission mode for 70 MHz + IFs
- Enables image rejection architecture
- Fully compatible SPI® port
- Excellent ac performance SFDR −73 dBc @ 2 MHz to 35 MHz WCDMA ACPR 71 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
- Please see data sheet for additional features
The AD9777 is the 16-bit member of a new pin-compatible family of high-speed dual Interpolating TxDAC+® converters with a maximum input data rate of 160 MSPS (no interpolation) and maximum DAC update rate of 400 MSPS (8x interpolation). They feature a selectable interpolation rate (2x/4x/8x) and a complex modulator that can mix at Fs/2, Fs/4 or Fs/8. All configuration is accomplished through an easy to use 3- or 4-wire SPI interface.
When used with an external quadrature modulator (such as the AD8345/AD8346/AD8349) the AD977X can be used implement a more traditional baseband I/Q architecture or an image reject upconversion architecture by using its internal complex (I&Q) mixer. The latter architecture may be well suited for those applications demanding high modulation accuracy (i.e. 64 QAM) that digital modulation inherently provides. This offers the added benefit of suppressing the image inherent in an analog mixing operation, consequently reducing the number of filtering stages, and therefore the cost of the hardware required to achieve 3G and broadband spectral emission specifications. User-accessible Gain and Offset correction is accessed through the SPI port and improves sideband suppression and LO feedthrough, respectively. A direct IF mode allows synthesis of intermediate frequencies (IFs) above 70 MHz.
TxDAC+ is a registered trademark of Analog Devices, Inc.
- Analog quadrature modulation architecture
- 3G, multicarrier GSM, TDMA, CDMA systems
- Broadband wireless, point-to-point microwave radios
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Application Notes (11)
Tools & Simulations
AD9777 Companion Parts
Recommended Quadrature Modulators
- For an IQ modulator with integrated PLL and VCO: ADRF6701, ADRF6702, ADRF6703, ADRF6704.
- For 3V power supplies: AD8345, AD8346.
- In wideband communication systems: ADL5370, ADL5371, ADL5372, ADL5373, ADL5374, ADL5375, AD8349, ADL5385, ADL5386.
Recommended Clock Drivers
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.