SM72445 Datasheet, PDF (7/19 Pages) Texas Instruments – Programmable Maximum Power Point Tracking Controller With Adjustable PWM Frequency

Operation Description
OVERVIEW
The SM72445 is a programmable MPPT controller capable of
outputting four PWM gate drive signals for a 4 switch buck-
boost converter with an independent Panel Mode. The typical
application circuit is shown in Figure 2. The SM72445 does
not require a dedicated switch to implement Panel Mode. The
four buck-boost switches can be controlled to implement PM.
A dedicated switch may be used for higher efficiency. Setting
the voltage on pin A2 selects between the options.
The SM72445 uses an advanced digital controller to generate
its PWM signals. A maximum power point tracking (MPPT)
algorithm monitors the input current and voltage and controls
the PWM duty cycle to maximize energy harvested from the
photovoltaic module. MPPT performance is very fast. Con-
vergence to the maximum power point of the module typically
occurs within 0.01s. This enables the controller to maintain
optimum performance under fast-changing irradiance condi-
tions.
Transitions between buck, boost, and Panel Mode are
smoothed. Output voltage and current limiting functionality
are integrated into the digital control logic. The controller is
capable of handling both shorted and no-load conditions and
will recover smoothly from both conditions.
FIGURE 4. High Level State Diagram for Startup
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