AD5570 Analog Devices, AD5570 Datasheet - Page 22

• Manufacturer Part Number: AD5570
• Manufacturer: Analog Devices

Specifications of AD5570

• Resolution (bits): 16bit
• Dac Update Rate: 83kSPS
• Dac Settling Time: 12µs
• Max Pos Supply (v): +16.5V
• Single-supply: No
• Dac Type: Voltage Out
• Dac Input Format: SPI

AD5570
AD5570 to ADSP21xx
An interface between the AD5570 and the ADSP21xx family is
shown in Figure 44. The ADSP21xx must be set up to operate in
the SPORT transmit alternate framing mode. The ADSP21xx is
programmed through the SPORT control register and is con-
figured as follows: internal clock operation, active low framing,
and 16-bit word length.
Transmission is initiated by writing a word to the Tx register, after
the SPORT has been enabled. As the data is clocked out of the
DSP on the rising edge of SCLK, no glue logic is required to inter-
face the DSP to the DAC. In the interface shown, the DAC output
is updated using the LDAC pin via the DSP. Alternatively, the
LDAC input can be tied permanently low, and then the update
is automatic when TFS is taken high.
AD5570 to PIC16C6x/7x
The PIC16C6x/7x synchronous serial port (SSP) is configured as
an SPI master with the clock polarity bit set to 0. This is done
by writing to the synchronous serial port control register, SSPCON
(see documentation on the PIC16/17 microcontroller). In this
example, I/O port RA1 is being used to pulse SYNC and enable
the serial port of the AD5570. This microcontroller transfers only
*ADDITIONAL PINS OMITTED FOR CLARITY.
ADSP21xx
Figure 44. AD5570 to ADSP21xx Interface
SCLK
RFS
TFS
DR
FO
DT
SDO
SDIN
SCLK
SYNC
LDAC
AD5570*
Rev. C | Page 22 of 24
eight bits of data during each serial transfer operation; therefore,
two consecutive write operations are needed.
the connection diagram.
EVALUATION BOARD
The AD5570 comes with a full evaluation board to aid designers
in evaluating the high performance of the part with minimal
effort. The evaluation board requires a power supply, a PC,
and an oscilloscope.
The AD5570 evaluation kit includes a populated and tested
AD5570 printed circuit board. The evaluation board inter-
faces to the parallel interface of a PC. Software is available
with the evaluation board that allows the user to easily pro-
gram the AD5570. A schematic of the evaluation board is
shown in Figure 46. The software runs on any PC installed
with Microsoft® Windows® 95/ Windows® 98/Windows® ME/
Windows® 2000/Windows® XP.
An application note containing full details on operating the
evaluation board comes supplied with the AD5570 evalua-
tion board.
*ADDITIONAL PINS OMITTED FOR CLARITY.
PIC16C6x/7x*
SCLK/RC3
Figure 45. AD5570 to PIC16C6x/7x Interface
SDO/RC5
SDI/RC4
RA1
SDO
SDIN
SCLK
SYNC
AD5570*
Figure 45
shows