外置mos5V输入升压8.4v充电两节锂电池芯片
External mos5V input boost 8.4v charging two lithium battery chip
5v升压8.4v芯片是一款工作于4V到28V的PFM升压型电池充电控制集成电路。5v升压8.4v芯片
内部集成有基准电压源，＋5V电压调制单元，电感电流检测单元，电池电压检测电路和片外N沟道MOSFET驱动电路等，具有外部元件少，电路简单等优点。当接通输入电源时， 5v升压8.4v芯片进入充电状态，控制
片外N沟道MOSFET导通，电感电流上升，当上升到外部电流检测电阻设置的上限时，片外N沟道
MOSFET截止，电感电流下降，电感中的能量转移到电池中。当电感电流下降到外部电流检测电
阻设置的下限时，片外N沟道MOSFET再次导通，如此循环。电池电压通过电阻分压网络反馈到FB
管脚，当FB管脚电压达到1.205V(典型值)时，充电过程结束，片外N沟道MOSFET保持截止状态。
当FB管脚电压下降到再充电阈值时，5v升压8.4v芯片 再次进入充电状态。 最高工作频率可达1MHz，
工作温度范围从－40到＋85。
5v升压8.4v芯片采用6管脚的SOT23封装。
The 5v boost 8.4v chip is a PFM boost battery charge control IC that operates from 4V to 28V. 5v boost 8.4v chip
The internal integration of the reference voltage source, +5V voltage modulation unit, inductor current detection unit, battery voltage detection circuit and off-chip N-channel MOSFET driver circuit, etc., has the advantages of fewer external components and simple circuit. When the input power is turned on, the 5v boost 8.4v chip enters the charging state, and the control
The off-chip N-channel MOSFET is turned on, the inductor current rises, and when it rises to the upper limit of the external current sense resistor setting, the off-chip N-channel
The MOSFET is turned off, the inductor current drops, and the energy in the inductor is transferred to the battery. When the inductor current drops to the external current sense
When the lower limit of the resistor is set, the off-chip N-channel MOSFET is turned on again, and thus cycles. Battery voltage is fed back to FB via resistor divider network
Pin, when the FB pin voltage reaches 1.205V (typ.), the charging process ends and the off-chip N-channel MOSFET remains off.
When the FB pin voltage drops to the recharge threshold, the 5v boost 8.4v chip enters the charging state again. The maximum operating frequency is up to 1MHz.
Operating temperatures range from -40°C to +85°C.
The 5v boost 8.4v chip is available in a 6-pin SOT23 package.
