AN2390 datasheet(17/42 Pages) STMICROELECTRONICS

Part #	AN2390

Description	A flexible universal battery charger

PDF	42 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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17 / 42 page

AN2390

Evaluation board implementation

17/42

2.3

MCU software

2.3.1

Architecture

The software provided in this demo has state machine architecture. To explain more, various

charging states can be defined for each slot. Each slot is driven by its state machine, with

some interactions to implement front slot priority.

In order to measure the charge time, a timekeeper is implemented and counters are

incremented periodically. Most of the time, slot states are unchanged. This implies that the

PWM duty cycle, charge enable signals and LED on/off states are constant. Periodically, the

ST7 microcontroller measures the battery current, battery voltage and thermistor voltage of

both slots. Using the measurements and the timekeeper values, it updates slot states and

the output configuration. If necessary, it resets the timekeeper.

AN2390 Datasheet(PDF) 17 Page - STMicroelectronics