
MAX5877
14-Bit, 250Msps, High-Dynamic-Performance,
Dual DAC with LVDS Inputs
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13
SELIQP
CLKP-CLKN
DATAIN
I0
Q2
I2
Q1
I1
I3
Q3
Q0
tS
tH
OUTI
OUTQ
tPD
I0 - 5
I0 - 4
I0 - 2
I0 - 3
I0 - 6
Q0 - 6
Q0 - 5
Q0 - 4
Q0 - 3
Q0 - 2
SELIQN
Figure 4. Timing Diagram
Data Timing Relationship
Figure 4 displays the timing relationship between digital
LVDS data, clock, and output signals. The MAX5877
features a 2.0ns hold, a -1.2ns setup, and a 1.1ns prop-
agation delay time. A nine (eight)-clock-cycle latency
exists between CLKP/CLKN and OUTIP/OUTIN
(OUTQP/OUTQN).
LVDS-Compatible Digital Inputs
(B13P/B13N–B0P/B0N, XORP, XORN,
SELIQP, SELIQN)
The MAX5877 latches B13P/N–B0P/N, XORP/N, and
SELIQP/N data on the rising edge of the clock. A logic-
high signal on SELIQP and a logic-low signal on
SELIQN directs data onto the I-DAC inputs. A logic-low
signal on SELIQP and a logic-high signal on SELIQN
directs data onto the Q-DAC inputs.
The MAX5877 features LVDS receivers on the bus input
interface with internal 110
termination resistors. See
Figure 5. XORP and XORN are not internally terminated.
These LVDS inputs (B13P/N–B0P/N) allow for a low differ-
ential voltage swing with low constant power consump-
tion. A 1.25V common-mode level and 250mV differential
input swing can be applied to the B13P/N–B0P/N,
XORP/N, and SELIQP/N inputs.
The MAX5877 includes LVDS-compatible exclusive-OR
inputs (XORP, XORN). Input data (all bits) is compared
with the bits applied to XORP and XORN through exclu-
sive-OR gates. Setting XORP high and XORN low inverts
the input data. Setting XORP low and XORN high leaves
the input data noninverted. By applying a previously
encoded pseudo-random bit stream to the data input
and applying decoding to XORP/XORN, the digital input
data can be decorrelated from the DAC output, allowing
for the troubleshooting of possible spurious or harmonic
distortion degradation due to digital feedthrough on the
printed circuit board (PCB). If XOR functionality is not
required, connect XORP to GND and XORN to DVDD1.8.