Model 4906 Supercap Feather Wing
Need to transmit occasional LoRaWAN® data, or occasionally power up a high-power sensor, using a high-impedance battery like a coin cell or lithium thionyl chloride battery? The 100 mW needed for a typical transmission can overwhelm a high-impedance power supply; and many battery chemistries will give much lower life when discharged at a high rate than at a low rate.
The Model 4906 Supercap Feather Wing is designed to bridge this gap. It includes a 1 farad CAP-XX HW103 supercap, charge-control circuitry to manage the supercap, and a 2.7 V buck regulator that operates from any 2.4 V to 5 V power supply to create a low-impedance 2.7 V power supply. In between transmissions, the charge controller trickle-charges the supercap, storing energy while keeping the instantaneous load low. Then, while your board is transmitting, the supercap provides burst of low power to allow you to do your work before going back to a low power state.
Supercaps, like batteries, store charge. Unlike batteries, supercaps store charge on the plates of a capacitor, rather than storing charge chemically. Supercaps won't hold charge nearly as long as batteries; but they charge and discharge much more efficiently, with very little energy lost to heat. They also retain their performance over many more charge / discharge cycles, and have a design life of ten years.
The output voltage drops as the supercap is discharged, and therefore this module is intended for use with Feather form-factor boards that contain integrated boost regulators, such as MCCI's Catena 4801, Catena 4612 and Catena 4618. Such boards can work with input voltages from 1.8 V to 2.7 V.
Specifications and Features
- Dimensions: 2" x 0.9"
- Input voltage 3 V nominal (2.4V to 5V)
- Input impedance: 1k ohms.
- Output voltage 2.7 V nominal, 2.75 V max
- Input connector JST-PH2
- Output connector JST-PA3 (center pin no-connect)
- Test points are provided for monitoring performance during prototyping
- Open-source hardware: schematics available on GitHub.
Volume discounts and custom variants are available. Contact MCCI via email (email@example.com) for assistance.