AN2390 datasheet(9/42 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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9 / 42 page

AN2390

Evaluation board implementation

9/42

Evaluation board implementation

2.1

Charging circuitry

The evaluation board implements a solution with an external low-voltage DC supply.

To obtain a constant voltage or constant current during various stages, the ST7

microcontroller measures the battery voltage (VBAT) and current (IBAT). Along with this

feedback, it provides the regulated output power to the battery under charge using a non-

inverting buck-boost converter circuit.

The buck boost converter is controlled by 2 PWM signals coming from the microcontroller as

shown in basic circuit diagram (Figure 4). For more details on the buck/boost converter,

please refer to AN2389.

Figure 4.

Basic circuit diagram of MCU-based non-inverting buck-boost converter

PWM1

PWM2

VOUT

P-

P+

AN2390 Datasheet(PDF) 9 Page - STMicroelectronics