ba7725s ROHM Co. Ltd., ba7725s Datasheet
ba7725s
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ba7725s Summary of contents
Page 1
... BA7725S / BA7725FS The BA7725S and BA7725FS are analog companders designed for KARAOKE echo systems, and logarithmically compress the signal level and then logarithmically expand factor of 2. These ICs can be used in com- bination with the BU9252S or BU9252F to create a digital echo system. These ICs have an internal line mixer ampli- fier for mixing line input and echo signals ...
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... LOOP GAIN CTRL 17 CMP DET EXP DET 16 CMP DET CT EXP DET CT 15 CMP OUT EXP BF OUT 14 CMP BF IN EXP CMP BF OUT DLY BF OUT 12 DLY BF IN BA7725S / BA7725FS 1 20 MIC AMP MIC AMP OUT RIPPLE FILTER 5 16 ...
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... LPF BF input (expansion) Echo signal input BF output Echo signal input BF input LPF BF output (compression) LPF BF input (compression) Compression output Setting the compression attack / recovery time Attack (R) = 5.6k , recovery (R) = 85.6k Compression detection Attached ripple rejection capacitor V CC — Microphone amplifier output Microphone amplifier input BA7725S / BA7725FS 3 ...
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... ECHO LEVEL 4 CTRL LOOP GAIN 6 CTRL Note: The BA7725FS is mounted on a 20-pin SSOP-A package with a different pin number than the BA7725S. On the BA7725FS, the ECHO LEVEL CTRL pin is pin 3, and the LOOP GAIN CTRL pin is pin 5. 4 BA7725S / BA7725FS Equivalent circuit 4 ...
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... V – 7.5 – 5.5 — dBV ODC1 V — – 42 – 32 dBV ODC2 V 0.0 — 1.0 V 4OFF V 2.0 — 9.0 V 4ON BA7725S / BA7725FS Conditions No input V = – 26.0dBV – 26.0dBV, MIC OFF THD = 1%, 2 MIC OFF 600 , V = – 52dBV – 52dBV, IN Input shorted – 44dBV, MIC OFF, ...
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... MIC AMP IN / LINE OUT gain Microphone amplifier gain (determined by R9 and R10) + line amplifier gain (+12dB) The audio signal is input via pin 22 (BA7725S) or pin 20 (BA7725FS) and amplified by the internal microphone amplifi- er, whose gain can be set with (attached) R9 and R10. Note: Microphone amplifier gain must be set above +15dB. ...
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... BF and attached capacitor and resistor. (3) Echo level control The DC voltage supplied to pin 4 (BA7725S) or pin 3 (BA7725FS) determines when the microphone switch is turned on and off and controls the echo level. Microphone switch control ...
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... Echo signal frequency characteristicis The figure below shows the attenuation of signals out- put from pin 1 when the audio signal is input to pin 22 (BA7725S) or pin 20 (BA7725FS). (This is the attenua- tion when the input signal is output without being passed through the BU9252S / F, and when the prima- ...