General Description
The MAX5894 programmable interpolating, modulating,
500Msps, dual digital-to-analog converter (DAC) offers
superior dynamic performance and is optimized for high-
performance wideband, single-carrier transmit applica-
tions. The device integrates a selectable 2x/4x/8x
interpolating filter, a digital quadrature modulator, and
dual 14-bit, high-speed DACs on a single integrated cir-
cuit. At 30MHz output frequency and 500Msps update
rate, the in-band SFDR is 86dBc while consuming 1.1W.
The device also delivers 73dB ACLR for two-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. Individual offset and
gain programmability allow the user to calibrate out local
oscillator (LO) feedthrough and sideband suppression
errors generated by analog quadrature modulators.
The MAX5894 features a f
IM
/4 digital image-reject mod-
ulator. This modulator generates a quadrature-modulat-
ed 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 f
IM
/2 or f
IM
/4.
The MAX5894 features a standard 1.8V CMOS, 3.3V tol-
erant data input bus for easy interface. A 3.3V SPI™ port
is provided for mode configuration. The programmable
modes include the selection of 2x/4x/8x interpolating fil-
ters, f
IM
/2, f
IM
/4 or no digital quadrature modulation with
image rejection, channel gain and offset adjustment, and
offset binary or two’s complement data interface.
Pin-compatible 12- and 16-bit devices are also available.
Refer to the MAX5893 data sheet for the 12-bit version
and the MAX5895 data sheet for the 16-bit version.
Applications
Base Stations: 3G UMTS, CDMA, and GSM
Broadband Wireless Transmitters
Broadband Cable Infrastructure
Instrumentation and Automatic Test Equipment (ATE)
Analog Quadrature Modulation Architectures
Features
o 74dB ACLR at f
OUT
= 61.44MHz (Single-Carrier
WCDMA)
o Meets 3G UMTS, cdma2000
®
, GSM Spectral Masks
(f
OUT
= 122MHz)
o Noise Spectral Density = -154dBFS/Hz at
f
OUT
= 16MHz
o 91dBc SFDR at Low-IF Frequency (10MHz)
o 88dBc SFDR at High-IF Frequency (50MHz)
o Low Power: 886mW (f
CLK
= 250MHz)
o User Programmable
Selectable 2x, 4x, or 8x Interpolating Filters
< 0.01dB Passband Ripple
> 99dB Stopband Rejection
Selectable Real or Complex Modulator Operation
Selectable Modulator LO Frequency: OFF, f
IM
/2
or f
IM
/4
Selectable Output Filter: Lowpass or Highpass
Channel Gain and Offset Adjustment
o EV Kit Available (Order the MAX5894 EV Kit)
MAX5894
14-Bit, 500Msps, Interpolating and Modulating
Dual DAC with CMOS Inputs
________________________________________________________________
Maxim Integrated Products
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