Dimaty,
Thanks for the feedback.
The battery you referenced may have overvoltage protection but it does not have a LiPo charging circuit.
The charging board you referenced should do the trick. It has a USB-C connector that can support > 0.5A input from a USB phone charging device with higher current output.
I figured you would be detaching the KitProg from the 059 kit.
If you would like to keep the charging circuit on the final assembly. It is possible.
There are a few reasons this may not be optimum especially if you are creating a device that requires long battery duration and light-weight.
- The battery charging circuit weighs a few grams.
- The battery always connected to the PsoC and the battery charging circuit will discharge the battery even when not in use. In drones, it is recommended to disconnect the battery when not in use. You can also place an in-line switch to the B+ terminal of the battery.
- The battery charge circuit takes up some space.
If you off-board the charging circuit, you can eliminate the issues above.
The VDD pin on the 059 can take in 1.7V to 5.5V. You do have to be careful what circuits in the PsoC are powered. The analog circuits do not run very accurately if the voltage drops below 2.7V. There is a ScBoost circuit inside the PsoC that can be enabled to allow for operation down to 1.7V
If you're using any ADCs, DO NOT use VDDA, VDDA/2, VDDA*2, etc as a reference.. Since VDDA is dependent on VDD, VDDA will drop with VDD. Use the internal Vref of 1.024V as your reference. This reference is mostly immune to VDDA drops down to 1.7V.
The Digital side of the PSoC is mostly immune to VDD drops. Internally the digital circuits will successfully operate down to 1.7V with the following exceptions: The maximum clocking speeds will be reduced as VDD drops.
Consider what the voltage requirements of externally connected circuits to the PSoC. They might be a more narrow range of operation.
In general, on battery operated applications, there are some highly recommended considerations:
- Avoid using a crystal on ECO if you can. Use the IMO (+/- 1% accuracy) at 3 MHz. The crystal driver consumes more current.
- PSoC active (non-sleep modes) current is highly dependent on the clocking rates to the CPU and the peripherals. The higher the clocking rate, the higher the current consumption. Therefore:
- Do not use the PLL. Feed the IMO directly to the MASTER_CLK and BUS_CLK.
- Keep the input clocks to peripherals (both Fix Function and UDB blocks) as low as practical.
- If you absolutely need crystal accuracy, you can use the WCO with a 32.768 KHz watch crystal. This can be better than +/-200 ppm accurate.
- In your SW application, you might consider going to a low-power sleep mode as often as possible. There are different low-power modes where the CPU can consume <5uA in this mode. If you use even less current if you can tolerate CPU to be turned off and restarted.
Hopefully this covers many of your questions.
