ltc4151 Linear Technology Corporation, ltc4151 Datasheet - Page 11

• Manufacturer Part Number: ltc4151
• Description: High Voltage I2c Current And Voltage Monitor
• Manufacturer: Linear Technology Corporation

Table 1. LTC4151/LTC4151-1 Device Addressing*
*H = Tie High; L = Tie to GND; NC = Open; X = Don’t Care
Acknowledge
The acknowledge signal is used for handshaking between
the transmitter and the receiver to indicate that the last
byte of data was received. The transmitter always releases
the SDA line during the acknowledge clock pulse. The
LTC4151/LTC4151-1 pull the SDA line low on the 9th clock
cycle to acknowledge receipt of the data. If the slave fails
to acknowledge by leaving SDA high, then the master can
abort the transmission by generating a Stop condition.
When the master is receiving data from the slave, the
master must pull down the SDA line during the clock pulse
to indicate receipt of a data byte, and that another byte is
to be read. After the last byte has been received the master
will leave the SDA line high (not acknowledge) and issue
a Stop condition to terminate the transmission.
Write Protocol
The master begins a write operation with a Start condi-
tion followed by the seven bit slave address and the R/W
bit set to zero. After the addressed LTC4151/LTC4151-1
acknowledge the address byte, the master then sends a
command byte which indicates which internal register
the master wishes to write. The LTC4151/LTC4151-1
acknowledge this and then latches the lower three bits of
the command byte into its internal register address pointer.
The master then delivers the data byte and the LTC4151 or
LTC4151-1 acknowledges once more and latches the data
APPLICATIONS INFORMATION
DESCRIPTION
Mass Write
0
1
2
3
4
5
6
7
8
HEX DEVICE
ADDRESS
CC
CE
D0
D2
D4
D6
D8
DA
DC
DE
h
a6
1
1
1
1
1
1
1
1
1
1
a5
1
1
1
1
1
1
1
1
1
1
a4
0
0
0
0
0
0
0
0
0
0
BINARY DEVICE ADDRESS
a3
0
0
1
1
1
1
1
1
1
1
into its internal register. If the master continues sending a
second byte or more data bytes, as in a Write Word or Write
Page command, the second byte or more data bytes will
be acknowledged by the LTC4151/LTC4151-1, the internal
register address pointer will increment automatically, and
each byte of data will be latched into an internal register
corresponding to the address pointer. The write operation
terminates and the register address pointer resets to 00h
when the master sends a Stop condition.
Read Protocol
The master begins a read operation with a Start condition
followed by the seven bit slave address and the R/W bit set to
zero. After the addressed LTC4151/LTC4151-1 acknowledge
the address byte, the master then sends a command byte
that indicates which internal register the master wishes to
read. The LTC4151/LTC4151-1 acknowledge this and then
latches the lower three bits of the command byte into its
internal register address pointer. The master then sends
a repeated Start condition followed by the same seven bit
address with the R/W bit now set to one. The LTC4151/
LTC4151-1 acknowledge and send the contents of the
requested register. The transmission terminates when the
master sends a Stop condition. If the master acknowledges
the transmitted data byte, as in a Read Word command,
the LTC4151/LTC4151-1 will send the contents of the next
register. If the master acknowledges the second data byte
a2
1
1
0
0
0
0
1
1
1
1
a1
1
1
0
0
1
1
0
0
1
1
LTC4151/LTC4151-1
a0
0
1
0
1
0
1
0
1
0
1
R/W
X
X
X
X
X
X
X
X
X
0
LTC4151/LTC4151-1
ADR1
ADDRESS PINS
NC
NC
NC
X
H
H
H
L
L
L
11
ADR0
NC
NC
NC
H
H
H
X
L
L
L
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