Headphone Amplifier (U59) - VESTEL MB120 DS Service Manual

B. HEADPHONE AMPLIFIER (U59)
Description
The AD22657B is a 2-Vrms cap-less stereo line driver. The device is ideal for single supply electronics.
Cap-less design can eliminate output dc-blocking capacitors for better low frequency response and save cost.
The AD22657B is capable of delivering 2-Vrms output into a 10k ohm load with 3.3V supply. The gain
settings can be set by users from 1V/V to 10V/V externally. The AD22657B has under voltage protection to
prevent POP noise. Build-in shutdown control and de-pop control sequence also help AD22657B to be a pop-
less device.
The AD22657B is available in a 10-pin MSOP package.
Features
• Operation Voltage: 3V to 3.6V
• Cap-less Output
− Eliminates Output Capacitors
− Improves Low Frequency Response
− Reduces POP/Clicks
• Low Noise and THD
− Typical SNR 107dB
− Typical Vn 7uVrms
− Typical THD+N < 0.02%
• Maximum Output Voltage Swing into 2.5k Load
− 2Vrms at 3.3V Supply Voltage
• Single-ended Input
• External Gain Setting from 1V/V to 10V/V
• Fast Start-up Time: 0.5ms
• Integrated De-Pop Control
• External Under Voltage Protection
• Thermal Protection
• Less External Components Required
• +/-8kV IEC ESD Protection at line outputs
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Table 5: Recommended Operating Conditions