Texas Instruments SM72445EVM Evaluation Module SM72445EVM/NOPB SM72445EVM/NOPB 数据表
产品代码
SM72445EVM/NOPB
User's Guide
SNVA649A – May 2012 – Revised May 2013
AN-2241 SM72445 Evaluation Board
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Introduction
The SolarMagic™ SM72445 Evaluation Board is designed to demonstrate the operation and the
capabilities of the SM72445 MPPT controller. The board consists of a high efficiency, four-switch Buck-
Boost DC/DC converter and a bidirectional FET based switch designed to bypass the DC/DC converter for
cases when DC/DC conversion is not needed and during failure of the DC/DC converter (over-current
protection, over-temperature, and so forth). The board also includes auxiliary circuits such as driver,
current sensor, temperature sensor and additional OVP circuitry.
capabilities of the SM72445 MPPT controller. The board consists of a high efficiency, four-switch Buck-
Boost DC/DC converter and a bidirectional FET based switch designed to bypass the DC/DC converter for
cases when DC/DC conversion is not needed and during failure of the DC/DC converter (over-current
protection, over-temperature, and so forth). The board also includes auxiliary circuits such as driver,
current sensor, temperature sensor and additional OVP circuitry.
The SM72445 is designed to maximize the energy production of a photovoltaic panel through the control
of a four switch buck-boost converter as well as an optional FET bi-directional switch (two FETs) designed
to maximize the efficiency at 1:1 conversion ratios. The maximum voltage and power transferred depend
on the component choice (driver, passive components, FET, and so forth). The SM72445 performs
optimization of the operating point of the solar panel through a high speed Perturb&Observe algorithm.
The input voltage and current are sampled at a high rate and digitally filtered while the algorithm updates
the output PWM waveform at a rate up to 1.2ms/step. The PWM waveforms include dead-time and can be
directly fed to the drivers controlling the DC/DC converter’s switches. The SM72445 is designed to
operate at 110kHz, 137kHz and 220kHz depending on the operating mode set. The SM72445 includes
and I2C slave module with 8 address settings to communicate monitoring information and to allow remote
shut-down and configuration modifications.
of a four switch buck-boost converter as well as an optional FET bi-directional switch (two FETs) designed
to maximize the efficiency at 1:1 conversion ratios. The maximum voltage and power transferred depend
on the component choice (driver, passive components, FET, and so forth). The SM72445 performs
optimization of the operating point of the solar panel through a high speed Perturb&Observe algorithm.
The input voltage and current are sampled at a high rate and digitally filtered while the algorithm updates
the output PWM waveform at a rate up to 1.2ms/step. The PWM waveforms include dead-time and can be
directly fed to the drivers controlling the DC/DC converter’s switches. The SM72445 is designed to
operate at 110kHz, 137kHz and 220kHz depending on the operating mode set. The SM72445 includes
and I2C slave module with 8 address settings to communicate monitoring information and to allow remote
shut-down and configuration modifications.
The SolarMagic™ SM72445 Evaluation Board is based on of the SM3320-1A1 power optimizer, and
shares all of its best-in-class power optimization features. This includes its ability to mitigate real-world
mismatch, its 99.5% peak efficiency, and its Panel-Mode operation. In addition, the same ultra-low profile
form factor of the original SM3320-1A1 is maintained so that it can be integrated into the same junction
box designs.
shares all of its best-in-class power optimization features. This includes its ability to mitigate real-world
mismatch, its 99.5% peak efficiency, and its Panel-Mode operation. In addition, the same ultra-low profile
form factor of the original SM3320-1A1 is maintained so that it can be integrated into the same junction
box designs.
This evaluation module is fully operational and can be used with panels from 15V up to 50V (absolute)
operating voltage and up to 300W of power. Proper heat-sinking of the Power FETs must be achieved for
power levels above 50W at room temperature.
operating voltage and up to 300W of power. Proper heat-sinking of the Power FETs must be achieved for
power levels above 50W at room temperature.
The absolute maximum output voltage is 50V. The maximum operating current is 11A.
2
System Overview
depicts how the SM72445 design would be implemented in its intended application. In this
example, the SM72445 senses the input and output voltages and currents, filters them digitally and
calculates power. It then issues four PWM pulses to the gate drivers to control the converter's switches.
The SM72445 also operates an additional switch (called Panel-Mode or PM switch) to optimize efficiency
when operating close to a 1:1 conversion ratio. Optionally, the switch can be omitted for reduced cost. The
SM72445 then utilizes the converter at a 1:1 conversion ratio and increases efficiency by reducing the
switching frequency of the converter
calculates power. It then issues four PWM pulses to the gate drivers to control the converter's switches.
The SM72445 also operates an additional switch (called Panel-Mode or PM switch) to optimize efficiency
when operating close to a 1:1 conversion ratio. Optionally, the switch can be omitted for reduced cost. The
SM72445 then utilizes the converter at a 1:1 conversion ratio and increases efficiency by reducing the
switching frequency of the converter
shows the detailed schematic with component references.
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SNVA649A – May 2012 – Revised May 2013
AN-2241 SM72445 Evaluation Board
Copyright © 2012–2013, Texas Instruments Incorporated