21V, 3.5A/5.5A 1-Cell Li+ Battery Charger with USB Type-C/BC1.2 Detection

The MAX77884/MAX77885 is a high-performance, high-input 3.5/5.5A fast charger with Smart Power SelectorTM. The IC can operate as a reverse boost without an additional inductor, allowing the battery to share its power through the charging port, and offers programmable output voltage from 4.3V to 12V. The device features fully integrated low-loss power switches to provide a small solution size and high efficiency, even at high input voltage and high charging current. Its high switching frequency allows the use of a smaller-sized inductor. The IC features true load disconnection in reverse-boost mode and an adjustable output-current protection limit. The device is highly flexible and programmable through I2C configuration. Li-ion, Li-polymer, and LiFePO4 battery chemistries are supported. It can also provide fast, programmable, unplugged source detection for dynamic management of system load. To support a variety of legacy USB and proprietary adapters, the device also integrates BC1.2 detection using the D+ and D- pins.

The battery charger includes a Smart Power Selector to accommodate various battery sizes and system loads. The Smart Power Selector allows the system to start up gracefully when an input source is available, even when the battery is deeply discharged (dead battery) or missing. It can be configured so that the battery charging can automatically start when power is applied to the charger input.

APPLICATIONS

* Gaming Devices

* VR Applications

* mPOS

* Tablet PCs

* High-Efficiency Single-Cell Switching Charger

* Up to 5.5A Charging with MAX77885

* Up to 3.5A Charging with MAX77884

* +26V Absolute Maximum Input Voltage Rating

* 4.4V to 21V Input Operating Voltage Range

* Reverse Boost with Programmable Output Voltage Options from 4.3V to 12V

* Up to 18W with MAX77785

* Up to 12W with MAX77884

* Integrated Battery True-Disconnect FET

* RDSON = 7.7mΩ

* Programmable Discharge Current Limit up to 10A

* Shipping Mode and Low Battery Leakage Current

* 0.9MHz Switching Frequency with 1.5μH Inductor

* 1.3MHz Switching Frequency with 1μH Inductor