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. •1)Features Echo mixing ratio is adjustable with a DC voltage. 3) Delay time of 131ms. (when fCLK = 357kHz) 4) Internal mute function. 5) Single power supply (5V). 2) A second order LPF can be configured with the internal amplifier and an attached capacitor and resistor. •Block diagram BU9253FS / BU9255FS 15 14 13 VCC OSC 12 11 10 A/D COUNTER 9 +– 16 SRAM MIX +– D/A 1 2 3 4 5 6 7 8 BU9253AS 17 16 15 14 VCC OSC 13 12 11 A/D COUNTER 10 +– 18 SRAM MIX +– D/A 1 2 3 4 5 6 7 8 9 1 Multimedia ICs BU9253AS / BU9253FS / BU9255FS Pin descriptions •BU9253FS / BU9255FS Pin No. BU9253AS Pin name 1 GND 2 ECHO VR 3 BIAS 4 DAINT IN 5 DAINT OUT 6 DALPF IN 7 DALPF OUT 8 MIX OUT 9 MIX IN Function Pin No. Pin name Ground 1 GND Echo level DC control 2 ECHO VR Analog DC bias 3 N.C. Internally DA integrator input 4 BIAS Analog DC bias DA integrator output 5 DAINT IN DA LPF input 6 DAINT OUT DA LPF output 7 DALPF IN Source sound and echo sound mixing output 8 9 Mixing amplifier source sound input Ground Echo level DC control DA integrator input DA integrator output DA LPF input DALPF OUT DA LPF output MIX OUT Source sound and echo sound mixing output Mixing amplifier source sound input 10 ADLPF IN AD LPF input 10 MIX IN 11 ADLPF OUT AD LPF output 11 ADLPF IN 12 ADINT OUT AD integrator output 12 ADLPF OUT AD LPF output 13 ADINT IN AD integrator input 13 ADINT OUT Vcc 14 ADINT IN Mute control 15 VCC Vcc Oscillator output 16 N.C. Internally 17 MUTE 18 CR 14 VCC 15 MUTE 16 CR •Absolute maximum ratings (Ta = 25°C) Parameter Symbol Limits Unit VCC 7 V Applied voltage BU9253FS Power dissipation BU9253AS BU9255FS 500∗1 600∗2 500∗1 – 10 ~ + 70 Pd Operating temperature Topr Storage temperature Topr VIN Input voltage mW °C – 55 ~ + 125 °C – 0.3 ~ VCC + 0.3 V ∗1 Reduced by 5.0mW for each increase in Ta of 1°C over 25°C. ∗2 Reduced by 6.0mW for each increase in Ta of 1°C over 25°C. •Recommended operating conditions (Ta = 25°C) Parameter Power supply voltage 2 Function Symbol Min. Typ. Max. Unit VCC 4.0 5.0 5.5 V AD LPF input AD integrator output AD integrator input Mute control Oscillator output Multimedia ICs BU9253AS / BU9253FS / BU9255FS = 25°C, V = 5.0V, f = 375kHz, f = 1kHz, V = - 10dBV, pin 2 = V •Electrical characteristics (Ta distortion = 400Hz ~ 30kHz filter, output noise voltage : DIN-AUDIO) CC CLK CC, I pin 15 = VCC, *Pin No. are for BU9253FS , BU9255FS and BU9253AS Parameter Symbol Min. Typ. Max. Unit Current consumption ICC — 6 12 mA No signal Voltage gain 1 GV1 – 5.6 – 1.4 dB Delay total gain IN1→OUT Voltage gain 2 GV2 –1 Output distortion 1 THD1 Output distortion 2 — – 3.5 Conditions 0 1 dB Through total gain IN2→OUT, pin2 = ground 1.5 3 % Delay side THD2 — Output noise voltage 1 VNO1 — – 80 – 60 dBV Delay, Rg = 1kΩ Output noise voltage 2 VNO2 — – 90 – 80 dBV Through side Rg = 1kΩ, pin2 = ground Max. output voltage 1 VOM1 1.4 1.7 — Vrms Delay, THD = 10% Through side, THD = 1% Pin 2 = ground Max. output voltage 2 Mute control Oscillation frequency 0.02 0.1 % Through, pin2 = ground VOM2 1.4 1.7 — Vrms VH 3.8 — 5.0 V H mode hold voltage, pin 15 DC VM 1.6 — 2.8 V M mode hold voltage, pin 15 DC L mode hold voltage, pin 15 DC VL 0 — 0.7 V fC — 375 — kHz 3 Multimedia ICs BU9253AS / BU9253FS / BU9255FS •Measurement circuit (for BU9253FS / BU9255FS) VCC 100µ 0.012µ IN1 0.1µ 20k 10k VCC 2.2µ 1k 8.2k 100p IN2 0.01µ 4700p 39k 16 15 13 14 OSC 12 10 11 1k 9 – + A/D COUNTER 2.2µ SRAM MIX – + D/A 2 1 3 5 4 6 22µ 7 8 3300p OUT 4.7k 0.01µ 2.2µ 0.47µ 10k 15k 22k 0.01µ VCC Unit RESISTOR : [Ω] CAPACITOR: [F] Fig. 1 4 Multimedia ICs BU9253AS / BU9253FS / BU9255FS •Application example (for BU9253FS / BU9255FS) VCC 100µ + 20k 0.012µ 10k 0.1µ VCC 2.2µ 8.2k 0.01µ 100p 39k IN 20k MUTE 4700p 16 15 14 13 OSC 12 11 9 – + A/D COUNTER 10 SRAM MIX + – D/A 1 2 3 4 5 6 7 8 3300p + OUT 22µ 0.01µ 0.47µ 10k 4.7k + 2.2µ 15k 0.01µ ECHO LEVEL Unit RESISTOR : [Ω] CAPACITOR: [F] Fig. 2 (1) Mute control functions Pin 15 voltage (pin 17) Mode H Unmuted (operating state) M Muted L Clock stop and muted • When switching between the muted and unmuted state (pin 15 (pin 17) L→M→H), the pin 15 (pin 17) M time should be longer than one SRAM cycle. This is to assure stability by initializing the SRAM 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 Multimedia ICs BU9253AS / BU9253FS / BU9255FS (3) Setting the echo loop gain VIN VIN + 9 8 VO OUT OdB LPF R VDLY + AD DA SRAM 7 R 2 Recommendable gain + 3dB Recommendable gain – 6dB R: R = 1: 1 mix VR Echo loop ATT VIN ~ VDLY···A = ∗ With Pin NO. BU9253FS VDLY (A < 1) VIN 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): ∞ 1 VOMax. = (1 + A + A2 + ···) VIN = Σ VIN AK · VIN = 1-A K=0 Thus, maximum allowable input is the value of VOMax provided the specifications (1 = A). Assuming a feedback ratio (A) of 0.7 and a maximum VOUT of 4.0 VP-P, VIN must be less than 1.2 VP-P. •External dimensions (Units: mm) BU9253FS / BU9255FS BU9253AS 6.6 ± 0.2 19.4 ± 0.3 9 0.3Min. 0.15 SSOP-A16 6 18 10 1 9 6.5 ± 0.3 0.36 ± 0.1 0.51Min. 8 3.4 ± 0.2 3.95 ± 0.3 4.4 ± 0.2 0.8 0.15 ± 0.1 1.5 ± 0.1 1 0.11 6.2 ± 0.3 16 7.62 0.3 ± 0.1 1.778 0.5 ± 0.1 SDIP18 0° ~ 15°