16-Bit, 500Msps, Interpolating and Modulating Dual DAC with Interleaved LVDS Inputs

The MAX5898 programmable interpolating, modulating, 500Msps, dual digital-to-analog converter (DAC) offers superior dynamic performance and is optimized for high-performance wideband, single- and multicarrier transmit applications. The device integrates a selectable 2x/4x/8x interpolating filter, a digital quadrature modulator, and dual 16-bit, high-speed DACs on a single integrated circuit. At 30MHz output frequency and 500Msps update rate, the in-band SFDR is 81dBc, while only consuming 1.2W. The device also delivers 71dB ACLR for four-carrier WCDMA at a 61.44MHz output frequency.

The selectable interpolating filters allow lower input data rates while taking advantage of the high DAC update rates. These linear-phase interpolation filters ease reconstruction filter requirements and enhance the passband dynamic performance. Each channel includes offset and gain programmability, allowing the user to calibrate out local oscillator (LO) feedthrough and sideband suppression errors generated by analog quadrature modulators.

The MAX5898 features a fIM / 4 digital image-reject modulator. This modulator generates a quadrature-modulated IF signal that can be presented to an analog I/Q modulator to complete the upconversion process. A second digital modulation mode allows the signal to be frequency-translated with image pairs at fIM / 2 or fIM / 4.

The MAX5898 features a standard LVDS interface for low electromagnetic interference (EMI). Interleaved data is applied through a single 16-bit bus. A 3.3V SPI™ port is provided for mode configuration. The programmable modes include the selection of 2x/4x/8x interpolating filters, fIM / 2, fIM / 4 or no digital quadrature modulation with image rejection, individual channel gain and offset adjustment, and offset binary or two's-complement data interface.

Compatible versions with CMOS interfaces and 12-, 14-, and 16-bit resolutions are also available. Refer to the MAX5893 data sheet for 12-bit CMOS, MAX5894 for 14-bit CMOS, and the MAX5895 for 16-bit CMOS versions.

Applications

* Analog Quadrature Modulation Architectures

* Base Stations: 3G Multicarrier UMTS, CDMA, and GSM

* Broadband Cable Infrastructure

* Broadband Wireless Transmitters

* Instrumentation and Automatic Test Equipment (ATE)

* 71dB ACLR at fOUT = 61.44MHz (Four-Carrier WCDMA)

* Meets Multicarrier UMTS, cdma2000®, GSM Spectral Masks (fOUT = 122MHz)

* Noise Spectral Density = -160dBFS/Hz at fOUT = 16MHz

* 90dBc SFDR at Low-IF Frequency (10MHz)

* 88dBc SFDR at High-IF Frequency (50MHz)

* Low Power: 831mW (fCLK = 250MHz)

* User Programmable

* Selectable 2x, 4x, or 8x Interpolating Filters

* < 0.01dB Passband Ripple

* > 95dB Stopband Rejection

* Selectable Real or Complex Modulator Operation

* Selectable Modulator LO Frequency: OFF, fIM / 2, or fIM / 4

* Selectable Output Filter: Lowpass or Highpass

* Per Channel Gain and Offset Adjustment

* EV Kit Available (Order the MAX5898EVKIT)