Texas Instruments ISO154XEVM - ISO154xEVM Evaluation Module ISO154XEVM ISO154XEVM Datenbogen
Produktcode
ISO154XEVM
EVM Setup and Operation
illustrates SDA2 and SCL2 of U1 being treated as inputs and driven by an I
2
C transmitter
connected to J3B/J4B (for SDA2) and J5B/J6B (for SCL2). The output waveforms for SDA1 and SCL1 are
captured on the oscilloscope at J3A/J4A and J5A/J6A respectively. Note the low level of the SDA1 and
SCL1 outputs offset from the ground level. This is due to the high output low level on side 1 designed to
prevent a latch-up state.
captured on the oscilloscope at J3A/J4A and J5A/J6A respectively. Note the low level of the SDA1 and
SCL1 outputs offset from the ground level. This is due to the high output low level on side 1 designed to
prevent a latch-up state.
Note the offset of the output low level voltage from ground on SDA1 and SCL1.
Figure 6. Typical Waveforms, Inputs on Side 2
In addition to the cases shown here, the SDA and SCL signals also propagate in mutually opposing
directions. However, if using ISO1541, the SCL line is unidirectional and only allows the signal to
propagate from SCL1 to SCL2 and not vice-versa.
directions. However, if using ISO1541, the SCL line is unidirectional and only allows the signal to
propagate from SCL1 to SCL2 and not vice-versa.
8
SLLU166 – June 2012
ISO154xEVM Low-Power Bidirectional I
2
C Isolators Evaluation Module
Copyright © 2012, Texas Instruments Incorporated