AD7641BSTZ Analog Devices Inc, AD7641BSTZ Datasheet - Page 26

• Manufacturer Part Number: AD7641BSTZ
• Description: IC ADC 18BIT 2MSPS SAR 48-LQFP
• Manufacturer: Analog Devices Inc

Specifications of AD7641BSTZ

• Data Interface: Serial, Parallel
• Number Of Bits: 18
• Sampling Rate (per Second): 2M
• Number Of Converters: 1
• Power Dissipation (max): 92mW
• Voltage Supply Source: Analog and Digital
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 48-LQFP
• Resolution (bits): 18bit
• Sampling Rate: 2MSPS
• Input Channel Type: Differential
• Supply Current: 23mA
• Digital Ic Case Style: QFP
• No. Of Pins: 48
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: EVAL-AD7641CBZ - BOARD EVALUATION FOR AD7641
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

AD7641
MICROPROCESSOR INTERFACING
The AD7641 is ideally suited for traditional dc measurement
applications supporting a microprocessor, and ac signal processing
applications interfacing to a digital signal processor. The
AD7641 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 AD7641 to prevent digital noise from coupling into the
ADC. The SPI Interface (ADSP-219x) section illustrates the use
of the AD7641 with the ADSP-219x SPI-equipped DSP.
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SPI Interface (ADSP-219x)
Figure 40 shows an interface diagram between the AD7641 and
an SPI-equipped DSP, the ADSP-219x. To accommodate the
slower speed of the DSP, the AD7641 acts as a slave device and
data must be read after conversion. This mode also allows the
daisy-chain feature. The convert command can be initiated in
response to an internal timer interrupt. The 18-bit output data
are read with three SPI byte access. 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 the 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, it is
recommended to use one of the parallel interface modes.
DVDD
1
ADDITIONAL PINS OMITTED FOR CLARITY.
Figure 40. Interfacing the AD7641 to ADSP-219x
MODE0
MODE1
EXT/INT
RD
INVSCLK
AD7641
SDOUT
CNVST
BUSY
SCLK
CS
PFx
SPIxSEL (PFx)
MISOx
SCKx
PFx OR TFSx
ADSP-219x
1