The ESOP-8 package, when properly soldered to a PCB copper pad, can dissipate ~1.2W. For a 1A charge at 5V input vs 4.0V battery, dissipation is only (5.0-4.0)*1 = 1W, keeping the chip within safe limits.
In a market flooded with PMICs like the TP4056 (charge-only) or MT3608 (boost-only), the Yc2019 offers distinct advantages. Firstchip Yc2019
With only a USB power source connected and no load on the 5V output, the Yc2019 functions as a standard linear charger. It charges the battery in three stages: The ESOP-8 package, when properly soldered to a