To minimize EMI and RFI emission, the new device switches to linear mode during CV mode where power dissipation is at a minimum.
“As portable devices integrate increasingly complex features such as GPS, Bluetooth, Wi-Fi, FM, cameras, and high resolution displays, they require higher capacity batteries and longer charge times to support those functions,” says Siamak Bastami, product line director for AnalogicTech. “This unique solution is optimized to serve these portable systems where larger battery capacity and faster charge time is an essential requirement for high performance.”
Low Noise Linear Mode:
The AAT3620 is a dual mode, PWM switching and linear mode charger designed to maximize charge efficiency. Operating across a 4.3V to 6.0V input range, the device performs battery charging using a 1.5 MHz PWM converter. During CC and most of CV mode the device delivers up to 2A. When the current dips below 300mA in CV mode, the device automatically switches to a low noise linear mode minimizing noise, EMI and RFI emission.
The AAT3620 also features programmable end of charge using external resistor, built-in reverse blocking, a 1% constant voltage mode regulation and an integrated programmable charging timer. Over-voltage, over-current and over-temperature protection circuits monitor charge state and battery charge temperature for fault conditions. The charger IC also adds a status monitor output pin to indicate battery charge status and power source status via a display LED.
