ST公司的SPV1040是嵌入了MPPT的高效太陽能電池充電器,輸入電壓0.3V到5.5V,內部集成140 mΩ同步整流器, 120 mΩ功率開關,100kHz固定PWM頻率,占空比有MPPT算法來控制,輸出電壓具有穩壓,過流和超溫保護,主要用在智能手機和GPS系統,無線手機,小型電器和傳感器,手持媒體播放器(PMP),數碼相機,玩具和手持保健設備.本文介紹了SPV1040主要特性, 方框圖,典型應用電路,輸出并聯和串聯連接圖,以及太陽能電池充電器STEVAL-ISV006V2電路圖和材料清單與PCB布局圖.
High efficiency solar battery charger with embedded MPPT
The SPV1040 is a high efficiency, low power and low voltage monolithic step-up converter that operates over a 0.3 V to 5.5 V input voltage range which allows providing power supply to products using even down to one photovoltaic cell or fuel cells where the capability of handling low input voltages is of utmost importance.
Despite the variation of several conditions over the day (like irradiation, dirt, temperature, etc.) the SPV1040 allows to achieve the maximum efficiency in terms of power harvested from the cells and transferred to the output thanks to the embedded MPPT algorithm.
It employs an input voltage regulation loop, which fixes the charging battery voltage, set with a resistor divider and a maximum output current set with a current sense resistor according to charging current constraints.
The SPV1040 guarantees safety of application devices and of the converter itself stopping the PWM switching in case either of reached maximum input current peak threshold set up to 1.8 A or maximum temperature limit set up to 155 ℃.
As additional feature the IC build-in an input source reverse polarity protection which prevents damaging in case of reverse connection of solar panel at the input.
SPV1040主要特性:
■ 0.3 V to 5.5 V operating input voltage
■ 140 mΩ internal synchronous rectifier
■ 120 mΩ internal power active switch
■ 100 kHz fixed PWM frequency
■ Duty cycle controlled by MPPT algorithm
■ Output voltage regulation, overcurrent and overtemperature protection
■ Input source reverse polarity protection
■ Built in soft-start
■ Up to 95% efficiency
■ 3 mm x 4.4 mm TSSOP8 package
SPV1040應用:
■ Smart phones and GPS systems
■ Wireless headsets
■ Small appliances, sensors
■ Portable media players
■ Digital still cameras
■ Toys and portable healthcare
圖1.SPV1040方框圖
圖2.SPV1040簡化應用電路圖
圖3.SPV1040輸出并聯連接圖
圖4.SPV1040輸出串聯連接圖
采用SPV1040的太陽能電池充電器STEVAL-ISV006V2
STEVAL-ISV006V2: solar battery charger using the SPV1040
The SPV1040 is a high efficiency, low power and low voltage DC-DC converter that provides a single output voltage up to 5.2 V. Startup is guaranteed at 0.3 V and the device operates down to 0.45 V when coming out from MPPT mode. It is a 100 kHz fixed frequency PWM step-up (or boost) converter able to maximize the energy generated by few solar cells (polycrystalline or amorphous). The duty cycle is controlled by an embedded unit running an MPPT algorithm with the goal of maximizing the power generated from the panel by continuously tracking its output voltage and current.
The SPV1040 guarantees the safety of overall application and of converter itself by stopping the PWM switching in the case of an overcurrent or overtemperature condition.
The IC integrates a 120 mΩ N-channel MOSFET power switch and a 140 mΩ P-channel
MOSFET synchronous rectifier.
圖5.采用SPV1040的典型應用電路
圖6.太陽能電池充電器STEVAL-ISV006V2外形圖
圖7. STEVAL-ISV006V2電路圖
太陽能電池充電器STEVAL-ISV006V2材料清單:
圖8. STEVAL-ISV006V2 PCB布局圖
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