Optical disc ICs Headphone amplifier with internal LPF and EVR for CD-ROM BA3530FS The BA3530FS is an H / P amplifier with internal secondary LPF and EVR circuits. When multibit output from a D / A converter is input, the secondary LPF outputs an audio signal. The amplifier circuit allows for line output and headphone output. The output level for headphones can be changed with the EVR circuit. This IC also has independent internal mute circuits for the left and right channels. FApplications CD-ROM drives and other products (with line and headphone output pins) that process digital audio signals FFeatures 1) Internal LPF, line amplifier and EVR. 2) Internal mute function. 3) Internal thermal shutdown circuit. FAbsolute maximum ratings (Ta = 25_C) FRecommended operating conditions 140 4) No attached components are needed for oscillation prevention, even at a load of 8Ω. 5) Mute function reduces the popping noises that can occur when the power is turned on and off. Optical disc ICs BA3530FS Block diagram 141 Optical disc ICs BA3530FS FElectrical characteristics (unless otherwise noted, Ta = 25_C, VCC = 5.0V, line RL1 = 50kΩ, H / P RL2 = 32Ω, VIN = 0.8Vrms, f = 1kHz, EVR Max.) 142 Optical disc ICs BA3530FS Measurement circuit 143 Optical disc ICs Application example 144 BA3530FS Optical disc ICs Operation notes (1) Preventing popping noises The BA3530FS has a mute function that reduces the popping noises that can occur when the power is turned on or off. The popping noises that occur when the muting function turns on and off can be reduced by attaching a capacitor and resistor to the mute pins (pins 3 and 14). BA3530FS (2) Recommended time chart Electrical characteristic curves External dimensions (Units: mm) 145