KARAOKE echo IC BU9253AS / BU9253FS / BU9255FS. Multimedia ICs

Transcription

1 KARAOKE echo IC The BU9253AS, BU9253FS and BU9255FS are single-chip ICs that contain all the components needed to configure a KARAOKE echo system: an and converter,, 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 ) 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. Block diagram BU9253FS / BU9255FS 3) Delay time of 3ms. (when fclk = 357kHz) 4) Internal mute function. 5) Single power supply (5V) BU9253AS

2 Pin descriptions BU9253FS / BU9255FS Pin No. Pin name Function GND 2 ECHO VR 3 BIAS 4 DAINT IN 5 DAINT OUT 6 DALPF IN 7 DALPF OUT 8 OUT 9 IN 0 ADLPF IN ADLPF OUT 2 ADINT OUT 3 ADINT IN 4 5 MUTE 6 CR Ground Echo level DC control Analog DC bias DA integrator input DA integrator output DA LPF input DA LPF output Source sound and echo sound mixing output Mixing amplifier source sound input AD LPF input AD LPF output AD integrator output AD integrator input Vcc Mute control Oscillator output BU9253AS Pin No. Pin name Function GND Ground 2 ECHO VR Echo level DC control 3 N.C. Internally 4 BIAS Analog DC bias 5 DAINT IN DA integrator input 6 DAINT OUT DA integrator output 7 DALPF IN DA LPF input 8 DALPF OUT DA LPF output 9 OUT Source sound and echo sound mixing output 0 IN Mixing amplifier source sound input ADLPF IN AD LPF input 2 ADLPF OUT AD LPF output 3 ADINT OUT AD integrator output 4 ADINT IN AD integrator input 5 Vcc N.C. MUTE CR Internally Mute control Oscillator output Absolute maximum ratings (Ta = 25 C) Parameter Symbol Limits Unit Applied voltage 7 V Power dissipation BU9253FS BU9253AS Pd mw BU9255FS 500 Operating temperature Topr 0 ~ 70 C Storage temperature Topr 55 ~ 25 C Input voltage 0.3 ~ 0.3 V Reduced by 5.0mW for each increase in Ta of C over 25 C. 2 Reduced by 6.0mW for each increase in Ta of C over 25 C. Recommended operating conditions (Ta = 25 C) Parameter Symbol Min. Typ. Max. Unit Power supply voltage V 2

3 Electrical characteristics (Ta = 25 C, = 5.0V, fclk = 375kHz, f = khz, VI = - 0dBV, pin 2 =, pin 5 =, distortion = 400Hz ~ 30kHz filter, output noise voltage : DIN-AUDIO) *Pin No. are for BU9253FS, BU9255FS and BU9253AS Parameter Symbol Min. Typ. Max. Unit Conditions Current consumption Voltage gain Voltage gain 2 Output distortion Output distortion 2 Output noise voltage Output noise voltage 2 Max. output voltage Max. output voltage 2 Mute control Oscillation frequency ICC 6 2 ma GV db GV2 0 db THD.5 3 % THD % VNO dbv VNO dbv VOM.4.7 Vrms VOM2.4.7 Vrms VH V VM V VL V fc 375 khz No signal Delay total gain IN OUT Through total gain IN2 OUT, pin2 = ground Delay side Through, pin2 = ground Delay, Rg = kω Through side Rg = kω, pin2 = ground Delay, THD = 0% Through side, THD = % Pin 2 = ground H mode hold voltage, pin 5 DC M mode hold voltage, pin 5 DC L mode hold voltage, pin 5 DC 3

4 Measurement circuit (for BU9253FS / BU9255FS) 00µ 0.02µ IN 00p 0.µ 0k 20k 8.2k k 39k 4700p k IN µ 4.7k 3300p OUT 0.47µ 0k 5k 22k Unit RESISTOR : [Ω] CAPACITOR: [F] Fig. 4

5 Application example (for BU9253FS / BU9255FS) 00µ 0.02µ 20k 0.µ 0k 20k IN 00p 39k MUTE 4700p 8.2k µ 0.47µ 0k ECHO LEVEL Fig p 4.7k 5k OUT Unit RESISTOR : [Ω] CAPACITOR: [F] () Mute control functions Pin 5 voltage (pin 7) H M L Mode Unmuted (operating state) Muted Clock stop and muted When switching between the muted and unmuted state (pin 5 (pin 7) L M H), the pin 5 (pin 7) M time should be longer than one cycle. This is to assure stability by initializing the before mode switching. Note: Figures in parentheses ( ) are for BU9253AS. (2) Differences between BU9253AS / FS and BU9255FS There is a difference regarding the signal stopping for muting. With BU9253AS / FS, the output from pin 8 (pin 9) is stopped during muting. With BU9255FS, the output from pin 5 is stopped during muting. 5

6 (3) Setting the echo loop gain 9 8 VO OUT OdB LPF R AD DA 7 VDLY R R: R = : mix Recommendable gain 6dB 2 VR Recommendable gain 3dB VDLY Echo loop ATT ~ VDLY A = (A < ) With Pin NO. BU9253FS Fig. 3 With VOMax being the maximum amplitude of VO at this time (when the phases, including that of the DLY circuit, are in alignment): VOMax. = ( A A2 ) = Σ K = 0 External dimensions (Units: mm) A K = Thus, maximum allowable input is the value of VOMax provided the specifications ( = A). Assuming a feedback ratio (A) of 0.7 and a maximum VOUT of 4.0 VP-P, must be less than.2 VP-P. -A BU9253FS / BU9255FS BU9253AS ± ± ± ± ± ± Min. 0.5 ± ± ± Min ± ± ~ ± 0. SSOP-A6 SDIP8 6