SM72445 Datasheet, PDF (11/19 Pages) Texas Instruments – Programmable Maximum Power Point Tracking Controller With Adjustable PWM Frequency

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FIGURE 9. Equivalent Input Circuit
DIGITAL INPUTS and OUTPUTS
The digital input signals have an operating range of 0V to
V_A, where V_A = VDDA – VSSA. They are not prone to latch-
up and may be asserted before the digital supply V_D, where
V_D = VDDD – VSSD, without any risk. The digital output sig-
nals operating range is controlled by V_D. The output high
voltage is V_D – 0.5V (min) while the output low voltage is 0.4V
(max).
SCL and SDA
SCL is an input, and SDA is bidirectional with an open-drain
output. SCL and SDA do not have internal pull-ups. A “high”
level will not be observed on this pin until pull-up current is
provided by some external source, typically a pull-up resistor.
The choice of resistor value depends on many system factors
such as load capacitance and trace length. A typical value of
pull-up resistor for SM72445 ranges from 2 kΩ to 10 kΩ. For
more information, refer to the I2C Bus specification for se-
lecting the pull-up resistor value. The SCL and SDA outputs
can operate while being pulled up to 5V and 3.3V.
I2C CONFIGURATION REGISTERS
The operation of the SM72445 can be configured through its
I2C interface. Complete register settings for I2C lines are
shown below.
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