Audio ICs Low power consumption headphone driver for digital audio BA3577FS The BA3577FS is a headphone driver developed for portable digital audio equipment that supports a voltage of 1.5V. Applications Portable MD players and others Features 1) 1.5V supported. 2) Low current consumption (At PO = 0.5mW / ch, VCC inflow current = 3.3mA, and B inflow current = 6.8mA (Typ.)). 3) Output coupling capacitor of 100µF produces fC = 45Hz (RL = 16Ω). Absolute maximum ratings (Ta = 25C) Recommended operating conditions (Ta = 25C) 818 4) Internal muting switch. 5) Internal ripple filter. 6) Internal BEEP circuit. Audio ICs BA3577FS Block diagram 819 Audio ICs Pin descriptions 820 BA3577FS Audio ICs BA3577FS 821 Audio ICs BA3577FS Electrical characteristics (unless otherwise noted, Ta = 25C, VCC = 2.8V, B = 1.2V, PWSTB = 2.8V, MUTE = 0V, RL = 16Ω, f = 1kHz, DIN AUDIO) 822 Audio ICs BA3577FS Measurement circuit 823 Audio ICs Measurement conditions 824 BA3577FS Audio ICs BA3577FS Circuit operation (1) The BA3577FS operates at the timing chart shown below, which prevents popping noises in the headphone output. (2) The ripple filters (pins 1 and 2) and bias amplifiers (pins 3 and 4) of the BA3577FS cannot be used as external power supplies or reference voltages. (3) The BA3577FS outputs a BEEP signal only when the PWSTB pin (pin 7) and the MUTE pin (pin 9) are HIGH. Also, input a rectangular waveform of 500Hz to 5kHz with an amplitude from the GND to VCC to the BEEP IN pin (pin 11). 825 Audio ICs Application example Electrical characteristic curves 826 BA3577FS Audio ICs BA3577FS External dimensions (Units: mm) 827