AN2370

STC4054 description

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STC4054 description

The STC4054 is a constant current/constant voltage charger for single cell Li-Ion battery. No

external sense resistor or blocking diode is required and its ThinSOT package make it

ideally suited for portable applications.

Its power dissipation can range from 0.2 W to 1.68 W because of Trickle charge mode. In

The STC4054 is designed to work within USB power specifications. An internal block

regulates the current when the junction temperature increases in order to protect the device

when it operates in high power or high ambient temperature environments.

The charge voltage is fixed at 4.2 V, and the charge current limitation can be programmed

using a single resistor connected between the PROG pin and GND. The charge cycle

finishes when the current flowing to the battery is 1/10 of the programmed value. If the

external adaptor is removed, the STC4054 turns off and just 2 µA can flow from the battery

to the device. The device can be put into Shutdown mode, reducing the supply current to 25

µA. The device is delivered in a TSOT23-5L ThinSOT package.

Figure 2.

Block diagram