BQ24251YFFT - English Editing Encyclopedia Entry

Product Overview

Category

The BQ24251YFFT belongs to the category of integrated circuits (ICs) specifically designed for battery charging applications.

Use

This product is primarily used for charging lithium-ion batteries in various electronic devices such as smartphones, tablets, and portable electronics.

Characteristics

• The BQ24251YFFT is a highly efficient charging IC that offers fast and reliable charging capabilities.
• It supports multiple charging modes, including constant current (CC), constant voltage (CV), and trickle charge.
• The IC incorporates advanced safety features to protect the battery from overcharging, overvoltage, and overcurrent conditions.
• It is designed to operate with a wide input voltage range, making it suitable for various power sources.
• The BQ24251YFFT also includes thermal regulation to prevent overheating during charging.

Package and Quantity

This product is available in a small form factor package, typically a 20-pin QFN (Quad Flat No-Lead) package. The exact dimensions may vary depending on the manufacturer. It is commonly sold in reels or trays containing multiple units.

Specifications

• Input Voltage Range: 4.35V to 6.45V
• Charging Current Range: Up to 3A
• Charging Voltage Range: 3.5V to 4.44V
• Operating Temperature Range: -40°C to 85°C
• Efficiency: Up to 95%
• Protection Features: Overvoltage, Overcurrent, Overtemperature, Short Circuit

Pin Configuration

The BQ24251YFFT has a total of 20 pins, each serving a specific function. Here is a detailed pin configuration:

1. VIN: Input voltage pin
2. VBUS: USB input voltage pin
3. ISET: Charging current setting pin
4. TS: Temperature sense pin
5. STAT: Charging status indicator pin
6. PG: Power good indicator pin
7. CE: Charge enable pin
8. SDA: I2C data pin
9. SCL: I2C clock pin
10. INT: Interrupt output pin
11. BAT: Battery voltage sense pin
12. SRN: System reset input pin
13. VSS: Ground pin
14. VSS: Ground pin
15. VSS: Ground pin
16. VSS: Ground pin
17. VSS: Ground pin
18. VSS: Ground pin
19. VSS: Ground pin
20. VSS: Ground pin

Functional Features

The BQ24251YFFT offers several functional features that enhance its performance and usability:

1. High Efficiency: The IC incorporates advanced charging algorithms to maximize the charging efficiency, resulting in faster charging times.
2. Input Current Limiting: It includes a programmable input current limit feature, allowing users to set the maximum current drawn from the power source.
3. Thermal Regulation: The IC monitors the temperature during charging and adjusts the charging current accordingly to prevent overheating.
4. USB OTG Support: It supports USB On-The-Go (OTG) functionality, enabling the device to act as a host or peripheral depending on the connected device.
5. I2C Interface: The BQ24251YFFT can be controlled and monitored through an I2C interface, providing flexibility and customization options.

Advantages and Disadvantages

Advantages

• Fast and efficient charging capabilities
• Multiple charging modes for versatile applications
• Advanced safety features protect the battery
• Wide input voltage range for compatibility with various power sources
• Compact form factor for space-constrained designs

Disadvantages

• Requires additional external components for complete charging circuit implementation
• Limited availability of alternative models from different manufacturers

Working Principles

The BQ24251YFFT operates based on a switching regulator topology. It utilizes a combination of constant current and constant voltage charging techniques to efficiently charge lithium-ion batteries. The IC continuously monitors the battery voltage, temperature, and charging current to ensure safe and optimal charging conditions.

During the initial charging phase, the IC provides a constant current to the battery until it reaches a predefined voltage threshold. Once this threshold is reached, the IC switches to constant voltage mode, maintaining a steady voltage while reducing the charging current. This prevents overcharging and extends the battery's lifespan.

Application Field Plans

The BQ24251YFFT is widely used in various portable electronic devices that require efficient and reliable battery charging. Some potential application fields include:

1. Smartphones and Tablets: The IC can be integrated into mobile devices to provide fast and safe charging capabilities.
2. Wearable Devices: It can be utilized in smartwatches, fitness trackers, and other wearable gadgets to ensure optimal battery performance.
3. Portable Gaming Consoles: The IC enables quick charging of gaming consoles, allowing users to