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LTC3652 Solar Power Management Module

SKU: DFR0535

The LTC3652 Solar Power Management Module provides an efficient solution for harnessing solar energy with a wide input range of 7V to 30V and supports 3.7V Li-Polymer/Li-ion batteries. It offers multi-phase charging including constant current and voltage modes, ensuring optimal battery health and performance. The module incorporates Maximum Power Point Tracking (MPPT) settings to enhance solar energy conversion efficiency, available in OFF, 9V, 12V, and 18V options. Designed to output regulated power supplies at various voltages (5V, 3.3V, 9V/12V), the LTC3652 ensures high efficiency across different loads. With a comprehensive set of protection features, including overcharge, over-discharge, over-current, and reverse connection protection, it safeguards both the battery and connected devices. Operating efficiently within a temperature range of -40℃ to 85℃, the module is ideal for diverse applications requiring reliable solar power management.

Front of black circuit board with green/red connectors for solar power management-DFRobot product sku:DFR0535 image.

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  • Tech Specs

    • Specification

    Parameter Details
    Solar Power Management IC LTC3652
    Solar Input Voltage (SOLAR IN) 7V~30V
    Battery Input (BAT IN) 3.7V Li-Polymer/Li-ion Battery
    Charge Current (USB/SOLAR IN) 2A Max Trickle Charging, Constant Current, Constant Voltage Three Phases Charging
    Charge Cutoff Voltage (USB/SOLAR IN) 4.2V±1%
    MPPT Setting Voltages OFF/9V/12V/18V
    USB IN Voltage 5V
    Regulated Power Supply OUT1=5V 1.5A; OUT2=3.3V 1A; OUT3=9V/12V 0.5A
    Regulated Power Supply Efficiency (3.7V battery IN) OUT1: 90%@10%Load, 86%@50%Load, 80%@90%Load
    OUT2: 96%@10%Load；92%@50%Load；87%@90%Load
    OUT3 (9V OUT): 88%@10%Load, 89%@50%Load, 86%@90%Load
    OUT3 (12V OUT): 87%@10%Load, 88%@50%Load, 82%@90%Load
    USB Charge Efficiency 84%@1A；74%@1.8A
    Solar Charge Efficiency (18V SOLAR IN) 78%@1A；72%@1.8A
    Maximum Quiescent Current Overall: <3 mA
    OUT1: <760 uA
    OUT2: <560 uA
    OUT3: <1.72 mA
    Protections BAT IN: Over Charge Voltage (4.3V)/Over Discharge Voltage (2.4V) /Over Current (3A) /Reverse Connection Protection
    OUT1-OUT3/USB OUT: Short Circuit/Over Current/Over Heat Protection
    SOLAR IN: Backflow/Reverse Connection Protection
    Operation Temperature -40℃～85℃
    Dimension 78.0mm*68.0mm

    FAQ

    • Is there anything that can be done to reduce the quiescent current? I'm measuring about 0.5 mA quiescent current when powering only one of the power supplies (OUT2). The sensor I am powering only consumes about 20 uA when it's in sleep mode, and I need a lower overall quiescent current or I'll deplete my battery during periods when I don't have solar input (polar night in the Arctic).

      Thank you for your sharing. We will carry out corresponding tests. If it is practical, we will update at the next version.

    • Can I connect two battery to each of the BAT IN connectors?
      Yes. But pay attention that these two batteries are in direct parallel connection. It is required that these two batteries are of the same (or near) specifications. The two connectors are designed to be compatible with more battery interfaces. Usually, pick one to connect a single Li battery.
    • In MPPT SET, I can't find a suitable voltage for my solar panel. What can I do?

      Two solutions are available:

      1. Shut down the MPPT function: Turn the last bit of the MPPT SET to ON to shut down MPPT function.

      2. Choose a similar MPPT voltage: Over a relative wide range at the vicinity of MPP point VMP, the output power can still keep a high level. The MPPT voltage setting can be not so accurate. Use a MPPT SET voltage close but not larger than the nominal (maximum power) voltage, i.e. for solar panel (norminal voltage) within 9V~11.9V, use the 9V MPPT SET bit. For 12V-16.9V solar panel, use the 12V MPPT SET bit. For 17V-24V solar panel, use the 18V MPPT SET bit.

    • Can I charge the battery while using the regulated outputs?
      Yes.
    • Why the regulated outputs automatically shut down while all the outputs are still within the nominal value?
      The maximum output power of OUT1/USB OUT, OUT2 and OUT3 are 5V*1.5A+3.3V*1A+12V*0.5A=16.8W. If the module is only power by the battery, the maximum output power is determined by the battery 3A over current threshold. Take the battery voltage as 3.7V and an average 85% efficiency. The maximum output power of the module will not exceed 3.7V*3A*85%=9.4W (when the battery is fully charged, the battery voltage can reach 4.2V, max output power turns out to be 10.7W) . When total the output power exceed this value (though OUT1-OUT3 are still within their nominal value), the battery protection IC will take it as over current error and cut off the connection between battery and the regulated outputs. To push the regulated outputs to its limit, use the USB or SOLAR IN to externally power the module.

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