fs3862 Fortune Semiconductor Corporation, fs3862 Datasheet - Page 9

• Manufacturer Part Number: fs3862
• Description: 8-bit Mcu With 1k Program Eprom, 64-byte Sram, 5-bit I/o Port, Intelligent Charger Management Controller
• Manufacturer: Fortune Semiconductor Corporation

Rev. 1.3
The FS3862 uses flexible control schemes of charger’s current and voltage regulations in conjunction with the
built-in 8-bit RISC-type MCU core running at typical 100kHz for desired charge sequence controls during its
operations. It is embedded with the constant-current and constant-voltage regulations as well as the additional
facilities of PWM voltages for user-defined intermediate voltage levels used for various applications.
The external sensing resistors together with built-in parameters of the 8-bit MCU enable the device performing
charge cycle operations through selections of small to larger charge current’s amounts primarily for Li+ battery’s
linear mode charge applications, where the pulse-mode charging can be implemented using the internal
hardware to control the charge sequences as implemented by the built-in MCU program code for various
charger applications.
The typical Li+ charge steps are mainly four stages to conduct:
˙Pre-charge conditioning (or called trickle-mode charge, as the Phase-0 stage): where the low-voltage
discharged battery typical lower than 3.0v (or 2.8v, depending on how the battery’s parameters are set) gets
wake-up by applying typical 1/10 of full-rate charge current (a small amount of selectable charge current, also
called trickle current, such as 85mA of 850mA charge current ) until reaching the threshold voltage 3.0v. If the
trickle current has been applied to the battery for more than 30 minutes by timer’s measurement and not
reaching the required 3.0v, it could be detected as bad battery without continuing to the next step of charge
operations.
8.
8.1
Typical Charging Conditions and Phases
Functional Description
Fig.8-1 Typical Charge Profile
FS3862
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