AD7150 Analog Devices, AD7150 Datasheet - Page 22

• Manufacturer Part Number: AD7150
• Description: Ultra-Low Power, 2-Channel, Capacitance Converter for Proximity Sensing
• Manufacturer: Analog Devices

Specifications of AD7150

• Resolution (bits): 12bit
• # Chan: 2
• Sample Rate: n/a
• Interface: I²C/Ser 2-Wire,Ser
• Analog Input Type: SE-Uni
• Ain Range: 0.5 pF,1 pF,2 pF,4 pF
• Adc Architecture: Sigma-Delta
• Pkg Type: SOP

AD7150
If a repeated start condition is encountered after the address
pointer byte, all peripherals connected to the bus respond
exactly as outlined previously for a start condition; that is, a
repeated start condition is treated the same as a start condition.
When a master device issues a stop condition, it relinquishes
control of 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.
AD7150 RESET
To reset the AD7150 without having to reset the entire serial
bus, 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 AD7150 does not respond to the
serial bus commands (do not acknowledge) during the default
values upload for approximately 2 ms.
The reset command address word is 0xBF.
SEQUENCE
SEQUENCE
WRITE
READ
S SLAVE ADDR A(S)
S SLAVE ADDR A(S)
S = START BIT
P = STOP BIT
SCLOCK
SDATA
LSB = 0
START ADDR R/W ACK SUBADDRESS ACK
A(S) = ACKNOWLEDGE BY SLAVE
A(M) = ACKNOWLEDGE BY MASTER
S
SUB ADDR
SUB ADDR
1–7
Figure 43. Write and Read Sequences
8
A(S)
A(S) S SLAVE ADDR
Figure 42. Bus Data Transfer
9
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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 serial bus. The AD7150 acknowledges this
address and reads in the following data byte.
If the second byte is 0x06, the AD7150 is reset, completely
uploading all default values. The AD7150 does not respond to
the serial bus commands (do not acknowledge) during the
default values upload for approximately 2 ms.
The AD7150 does not acknowledge any other general call
commands.
9
A(S)
1–7
DATA
DATA
8
DATA
ACK
A(M)
9
STOP
P
A(S)
P
DATA
A(M)
P