The API9221 is a versatile multi-input lithium battery charger designed for use with car/wall adapters or USB power supplies. It is equipped with a range of advanced features including overvoltage protection (OVP), USB bypass functionality, and a low-dropout (LDO) regulator providing 4.9V at 10mA. The charger offers robust protection mechanisms, such as USB overvoltage protection at 5.4V, wall adapter overvoltage protection at 6.9V, and overall input safety up to 28V. It supports a maximum fast charging current of 1.2A and allows for programmable charge current and termination via external resistors. Additionally, it provides reverse current protection and thermal management to ensure safe operation.
This charger is particularly well-suited for a variety of handheld consumer electronics, including smartphones, PDAs, MP3 players, handheld test equipment, digital cameras, and multimedia players. In this article, we explore the key features of the API9221, its functional block diagram, and an example application circuit.
The API9221 boasts two supply inputs, making it ideal for highly integrated portable devices that need to charge from USB hosts, wall adapters, or car adapters. The PPT pin communicates to a host controller whether a safe and valid supply is connected to either VUSB or VDC. If both supplies are connected, the higher current option from VDC takes precedence. The host controller can also manage the charging process via the EN pin.
The API9221 employs a constant current/constant voltage (CC/CV) charging algorithm, ensuring that the connected lithium-based battery is charged to 4.2V with an accuracy of 1%. This charging voltage can be adjusted using an external resistor, RIMIN. The CHG pin signals when the termination current is reached and resets upon EN activation, power-off, or when the battery voltage drops below 3.9V.
The device includes multiple protective measures to safeguard against potential malfunctions. The VUSB pin has an overvoltage protection threshold of 5.4V, while VDC is protected up to 6.9V. For situations exceeding these thresholds, the device shuts down to prevent damage, withstanding input voltages up to 28V. A current-limited linear regulator ensures proper system control and startup.
To avoid overheating, the API9221 integrates thermal monitoring. If the temperature exceeds 125°C, the current is automatically reduced to a safer level, allowing charging to continue but at a reduced rate.
Key features of the API9221 include:
- Linear Lithium-Ion/Lithium Polymer charging IC
- Powered by USB host or car/wall adapter
- Overvoltage protection: USB - 5.4V, Wall - 6.9V
- Safe input up to 28V
- Fast charging capability with up to 1.2A current
- Integrated linear regulator: 4.9V at 10mA with current limiting
- Programmable charging current for wall and USB
- Adjustable charge termination via external resistor
- Current limiting on USB bypass path
- Indicator pins for charging and power presence
- Host-controlled enable pin for flexible charging management
- Reverse current protection
- Thermal protection
- Environmentally friendly packaging: DFN4030-12 in "Green" molding compound (RoHS compliant)
Applications for the API9221 span a wide range of consumer electronics, including:
- Handheld consumer devices
- Smartphones, PDAs, MP3 players
- Portable test equipment
- Digital cameras
- Multimedia players
Figure 1 shows the functional block diagram of the API9221, illustrating its internal architecture and key components. The design ensures reliability, efficiency, and adaptability across various charging scenarios, making it a valuable solution for modern portable devices.
[Image description: A functional block diagram of the API9221, showing its internal components and connections.]
This versatile charger not only meets the needs of today’s demanding portable electronics but also adheres to environmental standards, making it an eco-friendly choice for manufacturers and consumers alike.
99% Ceramic Accessories,99 Porcelain Square Pieces,Ceramic Square Pieces,99 Ceramic Square Pieces
Yixing Guanming Special Ceramic Technology Co., Ltd , https://www.guanmingceramic.com