AD7992 Analog Devices, AD7992 Datasheet - Page 23

• Manufacturer Part Number: AD7992
• Description: 2-Channel, 12-Bit ADC with I2C Compatible Interface in 10-Lead MSOP
• Manufacturer: Analog Devices

Specifications of AD7992

• Resolution (bits): 12bit
• # Chan: 2
• Sample Rate: 79kSPS
• Interface: I²C/Ser 2-Wire,Ser
• Analog Input Type: SE-Uni
• Ain Range: Uni (Vref),Uni Vdd
• Adc Architecture: SAR
• Pkg Type: SOP

READING DATA FROM THE AD7992
Reading data from the AD7992 is a 1- or 2-byte operation.
Reading back the contents of the alert status register, the config-
uration register, or the cycle timer register is a single-byte read
operation, as shown in Figure 28. This assumes the particular
register address has previously been set up by a single-byte write
operation to the address pointer register (see Figure 25). Once
the register address has been set up, any number of reads can
be performed from that particular register without having to
write to the address pointer register again. If a read from a
different register is required, the relevant register address has
to be written to the address pointer register, and again any
number of reads from this register may then be performed.
SDA
SCL
SDA
SCL
START BY
START BY
MASTER
MASTER
0
1
0
1
1
1
SERIAL BUS ADDRESS BYTE
SERIAL BUS ADDRESS BYTE
0
0
A3
FRAME 1
A3
Figure 29. Reading Two Bytes of Data from the Conversion Result Register
FRAME 1
Figure 28. Reading a Single Byte of Data from a Selected Register
A2
A2
SCL (CONTINUED)
SDA (CONTINUED)
A1
A1
A0
A0
ACK. BY
AD7992
R/W
R/W
Rev. 0 | Page 23 of 28
ACK. BY
AD7992
9
9
ALERT-
FLAG
D7
1
D7
1
1
Reading data from the conversion result register, DATA
registers, DATA
operation, as shown in Figure 29. The same rules apply for a
2-byte read as a 1-byte read.
When reading data back from a register, such as the conversion
result register, if more than two read bytes are supplied, the
same or new data is read from the AD7992 without the need to
re-address the device. This allows the master to continuously
read from a data register without having to re-address the
AD7992.
ZERO
D6
D6
MOST SIGNIFICANT DATA BYTE FROM
MOST SIGNIFICANT DATA BYTE FROM
ZERO CH
D5
SINGLE DATA BYTE FROM AD7992
D5
D4
D4
ID
FRAME 2
FRAME 2
FRAME 2
AD7992
LOW
AD7992
D11
D3
D3
registers, or hysteresis registers is a 2-byte
D2
D10
D2
D1
D1/0
D9
D0
D0/0
D8
NO ACK. BY
NO ACK. BY
MASTER
MASTER
MASTER
ACK. BY
9
9
9
STOP BY
MASTER
STOP BY
MASTER
AD7992
HIGH