AD5363 Analog Devices, AD5363 Datasheet - Page 26

• Manufacturer Part Number: AD5363
• Description: 8-Channel, 14-Bit, Serial Input, Voltage-Output DAC
• Manufacturer: Analog Devices

Specifications of AD5363

• Resolution (bits): 14bit
• Dac Settling Time: 20µs
• Single-supply: No
• Dac Type: Voltage Out
• Dac Input Format: Ser,SPI

AD5362/AD5363
APPLICATIONS INFORMATION
POWER SUPPLY DECOUPLING
In any circuit where accuracy is important, careful considera-
tion of the power supply and ground return layout helps to
ensure the rated performance. The printed circuit boards on
which the AD5362/AD5363 are mounted should be designed so
that the analog and digital sections are separated and confined
to certain areas of the board. If the AD5362/AD5363 are in a
system where multiple devices require an AGND-to-DGND
connection, the connection should be made at one point only.
The star ground point should be established as close as possible
to the device. For supplies with multiple pins (V
it is recommended that these pins be tied together and that each
supply be decoupled only once.
The AD5362/AD5363 should have ample supply decoupling of
10 μF in parallel with 0.1 μF on each supply located as close to
the package as possible, ideally right up against the device. The
10 μF capacitors are the tantalum bead type. The 0.1 μF capacitor
should have low effective series resistance (ESR) and low effective
series inductance (ESI)—typical of the common ceramic types
that provide a low impedance path to ground at high frequencies—
to handle transient currents due to internal logic switching.
Digital lines running under the device should be avoided because
they can couple noise onto the device. The analog ground plane
should be allowed to run under the AD5362/AD5363 to avoid
noise coupling. The power supply lines of the AD5362/AD5363
should use as large a trace as possible to provide low impedance
paths and reduce the effects of glitches on the power supply line.
Fast switching digital signals should be shielded with digital
ground to avoid radiating noise to other parts of the board, and
they should never be run near the reference inputs. It is essential
to minimize noise on the VREF0 and VREF1 lines.
Avoid crossover of digital and analog signals. Traces on oppo-
site sides of the board should run at right angles to each other.
This reduces the effects of feedthrough through the board. A
microstrip technique is by far the best approach, but it is not
always possible with a double-sided board. In this technique,
the component side of the board is dedicated to ground plane,
while signal traces are placed on the solder side.
As is the case for all thin packages, care must be taken to avoid
flexing the package and to avoid a point load on the surface of
this package during the assembly process.
POWER SUPPLY SEQUENCING
When the supplies are connected to the AD5362/AD5363, it
is important that the AGND and DGND pins be connected
to the relevant ground plane before the positive or negative
supplies are applied. In most applications, this is not an issue
because the ground pins for the power supplies are connected
to the ground pins of the AD5362/AD5363 via ground planes.
When the AD5362/AD5363 are to be used in a hot-swap card,
SS
, V
DD
, DV
CC
Rev. A | Page 26 of 28
),
care should be taken to ensure that the ground pins are
connected to the supply grounds before the positive or negative
supplies are connected. This is required to prevent currents
from flowing in directions other than toward an analog or
digital ground.
INTERFACING EXAMPLES
The SPI interface of the AD5362/AD5363 is designed to allow
the parts to be easily connected to industry-standard DSPs and
microcontrollers. Figure 25 shows how the AD5362/AD5363 can
connect to the Analog Devices, Inc., Blackfin® DSP. The Blackfin
has an integrated SPI port that can be connected directly to the
SPI pins of the AD5362 or AD5363, and programmable I/O
pins that can be used to set or read the state of the digital input
or output pins associated with the interface.
The Analog Devices
two serial ports (SPORTs). Figure 26 shows how one SPORT can
be used to control the AD5362 or AD5363. In this example, the
transmit frame synchronization (TFSx) pin is connected to the
receive frame synchronization (RFSx) pin. Similarly, the transmit
and receive clocks (TCLKx and RCLKx) are also connected. The
user can write to the AD5362/AD5363 by writing to the transmit
register of the ADSP-21065L. A read operation can be accom-
plished by first writing to the AD5362/AD5363 to tell the part
that a read operation is required. A second write operation with
an NOP instruction causes the data to be read from the
AD5362/AD5363. The DSP receive interrupt can be used to
indicate when the read operation is complete.
ADSP-BF531
ADSP-21065L
Figure 26. Interfacing to an ADSP-21065L DSP
Figure 25. Interfacing to a Blackfin DSP
RCLKx
TCLKx
FLAG
FLAG
FLAG
FLAG
DRxA
RFSx
DTxA
TFSx
ADSP-21065L
SPISELx
0
1
2
3
MOSI
MISO
PF10
SCK
PF9
PF8
PF7
is a floating-point DSP with
SYNC
SCLK
SDI
SDO
RESET
LDAC
CLR
BUSY
AD5362/
AD5363
SYNC
SCLK
SDI
SDO
RESET
LDAC
CLR
BUSY
AD5362/
AD5363