AD9953-PCB Analog Devices, Inc., AD9953-PCB Datasheet - Page 13

• Manufacturer Part Number: AD9953-PCB
• Description: 400 Msps 14-bit, 1.8v Cmos Direct Digital Synthesizer
• Manufacturer: Analog Devices, Inc.

DAC Output
The AD9953 incorporates an integrated 14-bit current output
DAC. Unlike most DACs, this output is referenced to AVDD,
not AGND.
Two complementary outputs provide a combined full-scale
output current (I
common-mode noise that might be present at the DAC output,
offering the advantage of an increased signal-to-noise ratio. The
full-scale current is controlled by an external resistor (R
connected between the DAC_R
(AGND_DAC). The full-scale current is proportional to the
resistor value as follows:
The maximum full-scale output current of the combined DAC
outputs is 15 mA, but limiting the output to 10 mA provides the
best spurious-free dynamic range (SFDR) performance. The DAC
output compliance range is AVDD + 0.5 V to AVDD – 0.5 V.
Voltages developed beyond this range will cause excessive DAC
distortion and could potentially damage the DAC output circuitry.
Proper attention should be paid to the load termination to keep the
output voltage within this compliance range.
OUT
). Differential outputs reduce the amount of
R
SET
=
39
SET
.
19
pin and the DAC ground
/
I
OUT
SET
)
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Serial IO Port
The AD9953 serial port is a flexible, synchronous serial communi-
cations port that allows easy interface to many industry-standard
microcontrollers and microprocessors. The serial I/O port is com-
patible with most synchronous transfer formats, including both the
Motorola 6905/11 SPI® and Intel® 8051 SSR protocols.
The interface allows read/write access to all registers that configure
the AD9953. MSB first or LSB first transfer formats are supported.
The AD9953’s serial interface port can be configured as a single pin
I/O (SDIO), which allows a 2-wire interface or two unidirectional
pins for in/out (SDIO/SDO), which in turn enables a 3-wire inter-
face. Two optional pins, IOSYNC and CS , enable greater flexibility
for system design in the AD9953.
Register Map and Descriptions
The register map is listed in Table 5.
AD9953