MAX8819应用电路 (集成了充电器和智能电源的选择

The MAX8819_ is a complete power solution for MP3 players and other handheld applications. The IC includes a battery charger, step-down converters, and WLED power. It features an input current-limit switch to power the IC from an AC-to-DC adapter or USB port, a 1-cell lithium ion (Li+) or lithium polymer (Li-Poly) charger, three step-down converters, and a step-up converter with serial step dimming for powering two to six white LEDs. All power switches for charging and switching the system load between battery and external power are included on-chip. No external MOSFETs are required. The MAX8819C/MAX8819D offer a sequenced power-up/power-down of OUT1, OUT2, and then OUT3.Maxim's Smart Power Selector makes the best use of AC-to-DC adapter power or limited USB power. Battery charge current and input current limit are independently set. Input power not used by the system charges the battery. Charge current is resistor programmable and the input current limit can be selected as 100mA, 500mA, or 1A. Automatic input selection switches the system load from battery to external power. In addition, on-chip thermal limiting reduces the battery charge rate to prevent charger overheating.