BU9253

Multimedia ICs KARAOKE echo IC BU9253AS / BU9253FS / BU9255FS The BU9253AS, BU9253FS and BU9255FS are single-chip ICs that contain all the components needed to configure a KARAOKE echo system: an A / D and D / A converter, SRAM, LPF, and mixer for mixing source signals. With these ICs, an echo function can be configured easily and with minimum external components. Applications KARAOKE functions for portable stereo sets, mini component stereo sets, video CDs and DVDs, etc. Features 1) Echo mixing ratio is adjustable with a DC voltage. 2) A second order LPF can be configured with the internal amplifier and an attached capacitor and resistor. 3) Delay time of 131ms. (when fCLK = 357kHz) 4) Internal mute function. 5) Single power supply (5V). Block diagram BU9253FS / BU9255FS 16 15 14 13 12 11 10 9 OSC VCC A/D COUNTER SRAM MIX D/A 1 2 3 4 5 6 +– +– 7 8 13 12 BU9253AS 18 17 16 15 14 11 10 OSC VCC A/D COUNTER SRAM MIX D/A 1 2 3 4 5 6 7 +– +– 8 9 1 Multimedia ICs Pin descriptions BU9253FS / BU9255FS Pin No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 BU9253AS / BU9253FS / BU9255FS BU9253AS Function Pin No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Pin name GND ECHO VR N.C. BIAS DAINT IN DAINT OUT DALPF IN Ground Echo level DC control Internally Analog DC bias DA integrator input DA integrator output DA LPF input Source sound and echo sound mixing output Mixing amplifier source sound input AD LPF input Function Pin name GND ECHO VR BIAS DAINT IN ...