A fully integrated solution is offered by NCP1835B, providing high stability of the charging voltage (4.2 ± 0.05 V).
Perhaps the only drawback of this microcircuit is its too tiny size (DFN-10 case, size 3×3 mm). Not everyone is able to provide high-quality soldering of such miniature elements.
Of the indisputable advantages I would like to note the following:
1. The minimum number of parts underweight.
2. The ability to charge a fully discharged battery (30mA precharge);
3. Definition of the end of charging.
4. Programmable charging current – up to 1000 mA.
5. Indication of charge and error (capable of detecting non-chargeable batteries and signaling this).
6. Protection against prolonged charge (by changing the capacitor capacitance C t , you can set the maximum charge time from 6.6 to 784 minutes).