sm72442mtx National Semiconductor Corporation, sm72442mtx Datasheet - Page 6

• Manufacturer Part Number: sm72442mtx
• Description: Programmable Maximum Power Point Tracking Controller For Photovoltaic Solar Panels
• Manufacturer: National Semiconductor Corporation

www.national.com
Operation Description
OVERVIEW
The SM72442 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
The SM72442 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
Figure
2.
FIGURE 4. High Level State Diagram for Startup
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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 and advanced digital PWM dithering techniques
are employed to increase effective PWM resolution. 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.
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