LTC4151
13
4151ff
For more information www.linear.com/LTC4151
address with the R/W bit now set to one. The LTC4151
acknowledges and sends 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 will send the contents of the next register. If
the master acknowledges the second data byte and each
of the following (if more) data bytes, as in a Read Page
command, the LTC4151 will keep sending out each data
byte in the register that corresponds to the incrementing
register pointer. The read operation terminates and the
register address pointer resets to 00h when the master
sends a Stop condition.
Layout Considerations
A Kelvin connection between the sense resistor R
S
and
the LTC4151 is recommended to achieve accurate cur-
rent
sensing (
Figure 10). The minimum trace width for
1oz copper foil is 0.02" per amp to make sure the trace
applicaTions inForMaTion
SENSE
–
GND
SENSE
+
V
IN
ADR1
ADR0
LTC4151
V
IN
GND
R
S
I
LOAD
I
LOAD
Figure 10. Recommended Layout for Kelvin Connection
stays at a reasonable temperature. Using 0.03" per amp
or wider is recommended. Note that 1oz copper exhibits
a sheet resistance of about 530µW per square.
ADINADIN
R1
0.02Ω
LTC4151-2
V
IN
7V TO 80V
V
OUT
V
CC
8
5V
1
2
8
7
6
5
1
2
3
4
ISO_SDA
ISO_SCL
7
5
GND
4
1
2
8
5
C7
1µF
100V
V
IN
V
IN
ADR1
ADR0
SDAO
IN
LT3010-5
SHDN
OUT
SENSE
GND
SDAI
SCL
GND
SENSE
+
SENSE
–
C6
1µF
ISO1
PS9817-2
ISO2
PS9817-2
R3
10k
R4
10k
R11
1k
R13
10k
4151 F11
R12
1k
R14
10k
R8
1k
C4
0.1µF
V
CC
GND
Figure 11. LTC4151-2 I
2
C Opto-Isolation Interface with High Speed Opto-Couplers
