SM72445 Datasheet, PDF (15/19 Pages) Texas Instruments – Programmable Maximum Power Point Tracking Controller With Adjustable PWM Frequency

FIGURE 12. I2C Write Sequence
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Noise coupling into digital lines greater than 400 mVp-p (typ-
ical hysteresis) and undershoot less than 500 mV below GND,
may prevent successful I2C communication with SM72445.
I2C no acknowledge is the most common symptom, causing
unnecessary traffic on the bus. Although the I2C maximum
frequency of communication is rather low (400 kHz max), care
still needs to be taken to ensure proper termination within a
system with multiple parts on the bus and long printed board
traces. Additional resistance can be added in series with the
SDA and SCL lines to further help filter noise and ringing.
Minimize noise coupling by keeping digital traces out of
switching power supply areas as well as ensuring that digital
lines containing high speed data communications cross at
right angles to the SDA and SCL lines.
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