EVAL-AD7747EBZ Analog Devices Inc, EVAL-AD7747EBZ Datasheet - Page 13

• Manufacturer Part Number: EVAL-AD7747EBZ
• Description: 24-Bit Capacitance-to-Digital Converter Eval. Board
• Manufacturer: Analog Devices Inc

Specifications of EVAL-AD7747EBZ

• Silicon Manufacturer: Analog Devices
• Application Sub Type: Capacitance-to-Digital Converter
• Kit Application Type: Data Converter
• Silicon Core Number: AD7747
• Sensor Type: Touch, Capacitive
• Interface: I²C
• Voltage - Supply: 2.7 V ~ 5.25 V
• Embedded: No
• Utilized Ic / Part: AD7747
• Kit Contents: Board
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Sensitivity: -
• Sensing Range: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

the bus, allowing another master device to take control of the
bus. Therefore, a master wanting to retain control of the bus
issues successive start conditions known as repeated start
conditions.
AD7747 RESET
To reset the AD7747 without having to reset the entire I
an explicit reset command is provided. This uses a particular
address pointer word as a command word to reset the part and
upload all default settings. The AD7747 does not respond to the
I
values upload for approximately 150 μs (max 200 μs).
The reset command address word is 0xBF.
2
C bus commands (do not acknowledge) during the default
SEQUENCE
SEQUENCE
WRITE
READ
S SLAVE ADDR A(S)
S SLAVE ADDR A(S)
S = START BIT
P = STOP BIT
SCLOCK
SDATA
LSB = 0
A(S) = ACKNOWLEDGE BY SLAVE
A(M) = ACKNOWLEDGE BY MASTER
START ADDR
S
SUB ADDR
SUB ADDR
1–7
R/W
Figure 23. Write and Read Sequences
8
A(S)
A(S) S SLAVE ADDR
2
C bus,
Figure 22. Bus Data Transfer
ACK
9
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SUBADDRESS
DATA
1–7
LSB = 1
8
A(S)
A(S) = NO ACKNOWLEDGE BY SLAVE
A(M) = NO ACKNOWLEDGE BY MASTER
GENERAL CALL
When a master issues a slave address consisting of seven 0s with
the eighth bit (R/W bit) set to 0, this is known as the general call
address. The general call address is for addressing every device
connected to the I
address and read in the following data byte.
If the second byte is 0x06, the AD7747 is reset, completely
uploading all default values. The AD7747 does not respond to
the I
values upload for approximately 150 μs (200 μs maximum).
The AD7747 does not acknowledge any other general call
commands.
ACK
A(S)
9
2
C bus commands (do not acknowledge) during the default
1–7
DATA
DATA
8
DATA
ACK
A(M)
9
2
C bus. The AD7747 acknowledges this
STOP
P
A(S)
P
DATA
A(M)
P
AD7747