ST Life.augmented


Up to 2.5 W solar USB supply based on the SPV1040 and LD39050
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The STEVAL-ISV015V1 demonstration board is a solar harvester system designed to supply USB devices and is based on the ST devices SPV1040 (solar voltage boost converter) and LD39050 (voltage regulator with low quiescent current and low noise). The SPV1040 is a high efficiency, low power and low voltage monolithic step-up converter that operates over a 0.3 V to 5 V input voltage range, therefore allowing the use of even a few solar cells in all portable applications where the capability of handling low input voltages is of utmost importance. Despite the variation of several conditions throughout the day (such as irradiation, dirt, temperature, etc.) the SPV1040 allows the achievement of maximum efficiency (90% typ.) in terms of power harvested from the cells and transferred to the output thanks to the embedded MPPT algorithm. The SPV1040 allows the output voltage to be regulated by using an external resistive divider up to 5.2 V, limiting the current supplied to protect the battery and the measuring of input current and voltage to research the maximum power point through a dedicated input pin. Furthermore, the device can be shut off by driving an XSHUT pin to a logic level low, in order to save power when its working mode is not required. Self protection features like overtemperature and overcurrent at the input are implemented. The LD39050 provides 500 mA maximum current from an input voltage ranging from 1.5 V to 5.5 V with a typical dropout voltage of 200 mV. It is available in a fixed output voltage version from 0.8 V up to 4.5 V (100 mV steps), or adjustable between 0.8 V and Vin- Vdrop. The ultra low drop-voltage, low quiescent current and low noise features make it suitable for low power battery-powered applications. Stability is ensured using ceramic capacitors. The power supply rejection is 65 dB at low frequencies and starts to roll off at 10 kHz. An enable logic control function puts the LD39050 in shut-down mode allowing a total current consumption of lower than 1 μA. The device also includes short-circuit constant current limiting and thermal protection.

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Data Brief

Key Features

  • Proprietary “Perturb and Observe” embedded MPPT algorithm
  • Very low input voltage (down to 0.3 V)
  • Input reverse polarity protection
  • Fully integrated solution with power MOSFET, reverse blocking, diode and output current sense resistor
  • Ultra low dropout and low noise, low quiescent current LDO
  • RoHS compliant


Design Resources


Technical Documentation

Product Specifications

Description Version Size
DB1661: Up to 2.5 W solar USB supply based on the SPV1040 and LD39050
2.0 228 KB

Application Notes

Description Version Size
AN4123: STEVAL-ISV015V1 up to 2.5 W solar USB charger
2.0 990 KB

Hardware Resources

Board Manufacturing Specification

Description Version Size
STEVAL-ISV015V1 gerber files
1.0 133 KB

Bill of Materials

Description Version Size
1.0 60 KB

Schematic Pack

Description Version Size
STEVAL-ISV015V1 schematics
1.0 31 KB

Sample & Buy

Part Number Marketing StatusCore ProductOrder From STUnit Price (US$)*
@ 1
Distributor AvailabilityRoHS Compliance GradeDownload
Material Declaration**
STEVAL-ISV015V1ActiveSPV1040T; LD39050-103No availability reported, please contact our Sales officeEcopack2-

(*) Suggested Resale Price per unit (USD) for BUDGETARY USE ONLY. For quotes, prices in local currency, please contact your local ST Sales Office or our Distributors
(**) The Material Declaration forms available on may be generic documents based on the most commonly used package within a package family. For this reason, they may not be 100% accurate for a specific device. Please contact our sales support for information on specific devices.