LTC4310CDD-2-PBF View Datasheet(PDF) - Linear Technology
Part Name
Description
Manufacturer
LTC4310CDD-2-PBF Datasheet PDF : 20 Pages
| |||
LTC4310-1/LTC4310-2
Applications Information
Typical Applications
Figure 8 shows the LTC4310-1 providing I2C communica-
tions between an I2C bus referenced to system ground and
an I2C bus using –5V for its ground reference. Ceramic
coupling capacitors, C1-C5, are used to bridge the isolation
barrier. This circuit is recommended for ground isolation
voltages less than 100V and is limited by the voltage rating
of C1-C5. Higher voltage ceramic capacitors may be used
to achieve higher isolation voltages. Because the LTC4310
uses a pseudo-differential transmit scheme, capacitor C5
must be connected between ground and –5V to provide a
return path for the transmitted current.
Figure 9 shows the LTC4310-1 in an application circuit
using its zero current shutdown mode. A microprocessor
only activates the left LTC4310-1 when it needs to com-
municate with the isolated I2C bus. Because the LTC4310-1
contains a STOP bit and bus idle detection circuitry, there
is no danger of connecting in the middle of a message
when the microprocessor asynchronously reenables the
LTC4310-1.
3.3V
CBUS = 100pF
C6
C7
0.01µF 0.01µF
R1 R2 R3
5.1k 5.1k 10k
VCC
TXP
LTC4310-1
–5V
C1
C2
VCC
RXP
LTC4310-1
SDA TXN
SCL
C3
RXN SDA
SCL
READY RXP
EN
RXN
TXP READY
C4
EN
TXN
GND
C5
GND
R4 R5 R6
10k 10k 10k
CBUS = 30pF
431012 F08
–5V
C1 TO C5 = 47pF, 100V
Figure 8. Low Voltage I2C Isolation Between a Ground Referenced Bus and a –5V Referenced Bus
5V
R1
3.3k
CBUS = 200pF
µP
R2 R3
3.3k 10k
VCC
TXP
LTC4310-1
SDA TXN
SCL
READY RXP
EN
OFF ON
RXN
GND
C6
0.01µF
C1
C3
C5
C7
0.01µF
–5V
VCC
RXP
EN
C2
LTC4310-1
RXN READY
SDA
TXP
SCL
C4
TXN
GND
C1 TO C5 = 47pF, 100V
R4 R5 R6
10k 5.1k 5.1k
CBUS = 150pF
SLAVE#1 . . . SLAVE#N
431012 F09
–5V
14
Figure 9. The LTC4310-1 in a Zero Current Shutdown Application
431012fa
Share Link: 