MAX8821

19-1014; Rev 0; 10/07 White LED Charge Pump with Mono Class D Audio Amp and Dual LDO www.datasheet4u.com General Description Features ♦ White LED Inverting Charge Pump Independent Adaptive Current Regulators for Each LED 6 Low-Dropout Current Regulators Flexible I2C Dimming Control for Each LED Ramp-Up/Down, Current Control for Each LED Low 70µA (typ) Quiescent Current TA Derating Function Protects LEDs ♦ Mono 2W Class D Loudspeaker Amplifier 85% Efficiency (RL = 8Ω, POUT = 600mW) Low 0.05% THD+N at 1kHz High 65dB PSRR at 1kHz Fully Differential Inputs -3dB to +24dB Gain Settings in 3dB Steps Integrated Click-and-Pop Suppression Low Quiescent Current ♦ Dual Low-Noise LDO 45µVRMS Output Noise, 70dB PSRR Flexible I2C-Controlled Output Voltages 200mA and 300mA Output Current Drive MAX8821 The MAX8821 integrates a charge pump for white LEDs, an audio loudspeaker amplifier, and two lownoise LDOs controlled by an I2C control interface. The high-efficiency, adaptive-mode inverting charge pump drives up to six LEDs with constant current for uniform brightness. The LED current is controlled by an I2C interface and adjusts from 0.1mA to 25.6mA per LED into 32 pseudo-logarithmic steps. Independent voltages for each LED maximize efficiency even with large LED forward voltage (VF) mismatch. An internal temperature derating function reduces the current above +40°C to protect the LEDs. The high-efficiency mono Class D audio amplifier delivers up to 2W into a 4Ω speaker from a 5V input ...