DAC8803 Datasheet, PDF (21/30 Pages) Texas Instruments – Quad, Current Output, Serial Input 14-Bit Multiplying Digital-to-Analog Converter

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TYPICAL CHARACTERISTICS: V_DD = +2.7 V (continued)
At T_A = +25°C, +V_DD = +2.7 V, unless otherwise noted.
LINEARITY ERROR
vs DIGITAL INPUT CODE
DAC8803
SBAS340A – JANUARY 2005 – REVISED APRIL 2005
DIFFERENTIAL LINEARITY ERROR
vs DIGITAL INPUT CODE
Graphic
Forthcoming
Graphic
Forthcoming
Figure 51.
Figure 52.
PARAMETER MEASUREMENT INFORMATION
SDI
CLK
CS
LDAC
A1 A0 D13 D13 D12 D11 D10 D9 D8 D7
D2 D1 D0
t_CSS
t_ds
t_dh
t_ch
t_cl
t_csh
Input REG. LD
t_pd
SDO
t_lds
t_LDAC
t_LDH
Figure 53. DAC8803 Timing Diagram
CIRCUIT OPERATION
The DAC8803 contains four 14-bit, current-output, digital-to-analog converters respectively. Each DAC has its
own independent multiplying reference input. The DAC8803 uses a 3-wire SPI compatible serial data interface,
with a configurable asynchronous RS pin for half-scale (MSB = 1) or zero-scale (MSB = 0) preset. In addition, an
LDAC strobe enables four channel simultaneous updates for hardware synchronized output voltage changes.
D/A Converter
The DAC8803 contains four current-steering R-2R ladder DACs. Figure 54 shows a typical equivalent DAC.
Each DAC contains a matching feedback resistor for use with an external I-to-V converter amplifier. The R_FBX pin
is connected to the output of the external amplifier. The I_OUTX terminal is connected to the inverting input of the
external amplifier. The A_GNDX pin should be Kelvin-connected to the load point in the circuit requiring the full
14-bit accuracy.
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