Компания Maxim Integrated Products объявила о выпуске единственного в отрасли драйвера белых светодиодов (WLED), содержащего высокоэффективную схему накачки заряда, полностью дифференциальный мостовой аудиоусилитель и два низкошумящих LDO стабилизатора тока [англ.].
To maximize efficiency, the MAX8821 LED driver features a negative architecture that completely eliminates high-side, in-line switch resistance loss in 1x mode, delaying 1x to 1.5x mode transitions during battery discharge.
The MAX8821 uses independent adaptive-mode switching for each LED to further extend battery life, even with large LED forward-voltage (VF) mismatching. The audio amplifier accepts differential input signals, which is said to provide excellent noise immunity to improve audio reproduction. The combination of high performance and integration make the MAX8821 suitable for use in cell phones, smartphones, PDAs, and portable media players.
This device drives six WLEDs with 1% accurate current matching. To maximize flexibility, the MAX8821 supports I2C dimming control with 32 pseudo-logarithmic dimming levels. The WLED driver also offers a 70 microamp quiescent current, and features an on-chip TA derating function that reduces the current above +40°C to prevent the LEDs from burning out. The integrated, dual LDO regulators deliver over 200 mA of current output with 45 microvolt noise and 60 dB PSRR for sensitive circuitry.
The MAX8821’s Class D audio amplifier delivers 2 W to the speaker differentially by the use of a bridge-tied load (BTL) output stage. This provides up to four times more output power than a conventional single-ended output stage and eliminates the need for an output-coupling capacitor. In addition, at 1 kHz, this device achieves a 65 dB PSRR gain, which the flexible -3 dB to +24 dB gain settings realize in 3 dB steps. Integrated click-and-pop suppression circuitry ensures a clean sound quality.
The MAX8821 is available in a 4 x 4 x 0.8-mm, 28-pin TQFN package and is fully specified over the -40°C to +85°C extended temperature range.
Pricing: Starts at $2.55 (1000-up, FOB USA).
Дополнительная информация здесь.