AD7739BRU Analog Devices Inc, AD7739BRU Datasheet - Page 25

• Manufacturer Part Number: AD7739BRU
• Description: IC ADC 24BIT 8-CH 24-TSSOP
• Manufacturer: Analog Devices Inc

Specifications of AD7739BRU

• Rohs Status: RoHS non-compliant
• Number Of Bits: 24
• Sampling Rate (per Second): 15.1k
• Data Interface: DSP, MICROWIRE™, QSPI™, Serial, SPI™
• Number Of Converters: 1
• Power Dissipation (max): 100mW
• Voltage Supply Source: Analog and Digital
• Operating Temperature: -40°C ~ 105°C
• Mounting Type: Surface Mount
• Package / Case: 24-TSSOP (0.173", 4.40mm Width)
• For Use With: EVAL-AD7739EBZ - BOARD EVAL FOR AD7739

CONTINUOUS READ (CONTINUOUS CONVERSION)
MODE
When the Cont RD bit in the mode register is set, the first write
of 0x48 to the communications register starts the continuous
read mode. As shown in Figure 22, subsequent accesses to the
part sequentially read the channel status and data registers of
the last completed conversion without any further configuration
of the communications register being required.
Note that the continuous conversion bit in the mode register
should be set when entering the continuous read mode.
Note that the continuous read mode is a dump mode reading of
the channel status and data registers regardless of the dump bit
value. Use the channel bits in the channel status register to
check/recognize which channel data is actually being
shifted out.
DOUT
SCLK
RDY
DIN
CS
REGISTER
COMM.
WRITE
0x38
REGISTER
WRITE
MODE
0x48
REGISTER
COMM.
WRITE
0x48
Figure 22. Continuous Conversion, CH0 and CH1, Continuous Read
CONVERSION
COMPLETE
ON CH0
Rev. 0 | Page 25 of 32
STATUS
STATUS
(0x00)
READ
CH0
(0x00)
DATA
Note that the last completed conversion result is being read.
Therefore, the RDYFN bit in the I/O port register should be 0,
and reading the result should always start before the next
conversion is completed.
The AD7739 will stay in continuous read mode as long as the
DIN pin is low while the CS pin is low; therefore, write 0 to the
AD7739 while reading in continuous read mode. To exit
continuous read mode, take the DIN pin high for at least 100 ns
after a read is complete. (Write 0x80 to the AD7739 to exit
continuous reading.)
Taking the DIN pin high does not change the Cont RD bit in
the mode register. Therefore, the next write of 0x48 starts the
continuous read mode again. To completely stop the continuous
read mode, write to the mode register to clear the Cont RD bit.
READ
DATA
CH0
(0x00)
DATA
CONVERSION
COMPLETE
ON CH1
STATUS
(0x00)
STATUS
READ
CH1
(0x00)
DATA
READ
DATA
CH1
(0x00)
DATA
03742-0-022
AD7739