ISO1540D I2C Isolator Ic

The ISO1540 and ISO1541 devices are low-power,
bidirectional isolators that are compatible with I
2C
interfaces. These devices have logic input and output
buffers that are separated by Texas Instruments
Capacitive Isolation technology using a silicon dioxide
(SiO2
) barrier. When used with isolated power
supplies, these devices block high voltages, isolate
grounds, and prevent noise currents from entering the
local ground and interfering with or damaging
sensitive circuitry.
This isolation technology provides for function,
performance, size, and power consumption
advantages when compared to optocouplers. The
ISO1540 and ISO1541 devices enable a complete
isolated I
2C interface to be implemented within a
small form factor.
The ISO1540 has two isolated bidirectional channels
for clock and data lines while the ISO1541 has a
bidirectional data and a unidirectional clock channel.
The ISO1541 is useful in applications that have a
single master while the ISO1540 is suitable for multimaster applications. For applications where clock
stretching by the slave is possible, the ISO1540
device should be used.
Isolated bidirectional communication is accomplished
within these devices by offsetting the low-level output
voltage on side 1 to a value greater than the highlevel input voltage on side 1, thus preventing an
internal logic latch that otherwise would occur with
standard digital isolators.