AD7623AST Analog Devices Inc, AD7623AST Datasheet - Page 26

• Manufacturer Part Number: AD7623AST
• Description: IC ADC 16BIT 1.33MSPS DFF 48LQFP
• Manufacturer: Analog Devices Inc
• Series: PulSAR®r

Specifications of AD7623AST

• Number Of Bits: 16
• Sampling Rate (per Second): 1.33M
• Data Interface: Serial, Parallel
• Number Of Converters: 1
• Power Dissipation (max): 55mW
• Voltage Supply Source: Analog and Digital
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 48-LQFP
• For Use With: EVAL-AD7623CBZ - BOARD EVALUATION FOR AD7623
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

AD7623
MICROPROCESSOR INTERFACING
The AD7623 is ideally suited for traditional dc measurement
applications supporting a microprocessor, and ac signal
processing applications interfacing to a digital signal processor.
The AD7623 is designed to interface with a parallel 8-bit or
16-bit wide interface, or with a general-purpose serial port or
I/O ports on a microcontroller. A variety of external buffers can
be used with the AD7623 to prevent digital noise from coupling
into the ADC. The SPI Interface (ADSP-219x) section shows
the use of the AD7623 with an ADSP-219x SPI-equipped DSP.
SPI Interface (ADSP-219x)
Figure 42 shows an interface diagram between the AD7623 and
an SPI-equipped DSP, ADSP-219x. To accommodate the slower
speed of the DSP, the AD7623 acts as a slave device, and data
must be read after conversion. This mode also allows the daisy-
chain feature. The convert command could be initiated in
response to an internal timer interrupt.
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The reading process can be initiated in response to the end-of-
conversion signal (BUSY going low) using an interrupt line of
the DSP. The serial peripheral interface (SPI) on the ADSP-219x
is configured for master mode (MSTR) = 1, clock polarity bit
(CPOL) = 0, clock phase bit (CPHA) = 1, and SPI interrupt
enable (TIMOD) = 00 by writing to the SPI control register
(SPICLTx).
It should be noted that to meet all timing requirements, the SPI
clock should be limited to 17 Mb/s allowing it to read an ADC
result in less than 1 μs. When a higher sampling rate is desired,
use one of the parallel interface modes.
DVDD
Figure 42. Interfacing the AD7623 to SPI Interface
*ADDITIONAL PINS OMITTED FOR CLARITY
SER/PAR
EXT/INT
RD
INVSCLK
AD7623*
SDOUT
CNVST
BUSY
SCLK
CS
PFx
SPIxSEL (PFx)
MISOx
SCKx
PFx OR TFSx
ADSP-219x*