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LTC3552 - Standalone Linear Li-Ion Battery Charger and Dual Synchronous Buck Converter

The LTC3552 is a complete constant-current/constantvoltage linear charger with a dual DC/DC converter for single cell lithium-ion batteries. Its DFN package and low external component count make the LTC3552 ideally suited for portable applications. Furthermore, the LTC3552 is designed to work within USB power specifi cations.

No external sense resistor or external blocking diode is required due to the internal MOSFET architecture. The charge voltage is fixed at 4.2V and the charge current is programmed with a resistor. The charge cycle terminates when the charge current drops below the programmed termination threshold after the final float voltage is reached. When the input supply (wall adapter or USB supply) is removed, the LTC3552 enters a low current state dropping the battery drain current to less than 2µA. Thermal regulation maximizes charge rate without risk of overheating.

The synchronous step-down switching regulators generate adjustable output voltages from 5V down to 0.6V. The switching frequency is set at 2.25MHz, allowing the use of small surface mount inductors and capacitors.

特点 高达 950mA 的可设置充电电流 完整的线性充电器和双信道 DC/DC 稳压器 0.6V 至 5V 的降压型转换器输出电压 无需 MOSFET、检测电阻器或隔断二极管 热调整功能可在无过热危险的情况下实现充电速率的最大化* 直接从一个 USB 端口进行充电 可设置充电电流终止 准确度达 ±1% 的 4.2V 预设充电电压 用于电池电量测量的充电电流监视器输出* 自动再充电 充电状态输出 “电源接入”输出 2.9V 涓流充电门限 软起动功能限制了浪涌电流 低静态电流降压型转换器 (40µA) 电流模式操作，恒定频率 (2.25MHz) 扁平 (5mm x 3mm x 0.75mm) DFN 封装 典型应用

应用 蜂窝电话、PDA、MP3 播放机 蓝牙应用 封装信息

演示电路板