ba3880as / ba3880afs audio ics high-definition sound processor ba3880as / ba3880afs the ba3880as and ba3880afs are sound processor ics that perform phase and harmonic compensation on audio signals to accurately reproduce the "rise" section of audio signals that determine the characteristics of the sound, and thus reproduce the original recording as naturally as possible. ! ! ! ! applications component stereo systems, radio cassette players, car stereo systems, televisions, vcrs, and active speakers. ! ! ! ! features 1) corrects distortion in the rising section of audio signals that results from miss-matched speakers and amplifiers, and reproduces the original sound faithfully. 2) to allow application with all types of speakers and sources, the clarity can be adjusted using dc control. 3) dc control provided for selection of either processor mode or bypass mode. 4) bass boost fixed internally to 4db. ! ! ! ! absolute maximum ratings (ta = 25 c) parameter power supply voltage power dissipation operating temperature storage temperature v cc pd topr tstg 11 1000 ? ? 40~ + 85 ? 55~ + 125 v symbol limits unit mw c c ? reduced by 10mw for each increase in ta of 1 c over 25 c. ! ! ! ! recommended operating conditions parameter power supply voltage v cc 5.4~10.8 v symbol limits unit
ba3880as / ba3880afs audio ics ! ! ! ! block diagrams ba3880as 1 2 3 4 5 6 7 8 9 10 11 mixl vcal v cc defl detl gnd detr defr ctl vcar mixr 22 21 20 19 18 17 16 15 14 13 12 outl inl apfl hpfl lpfl biasc lpfr hpfr apfr inr outr + + ctl + + vca ? + + + hi mid lo + lpf hpf + + ctl + + ? + + + + lpf hpf hi mid lo vca ba3880afs 1 2 3 4 5 6 7 8 9 10 11 mixl vcal v cc defr detl gnd detr defr ctl vcar mixr 22 21 20 19 18 17 16 15 14 13 12 outl inl apfl hpfl lpfl biasc lpfr hpfr apfr inr outr + + ? + + + + + hi mid lo 24 23 lpf ctl vca + ctl vca + + + ? + + + hi mid lo + + hpf lpf hpf ! ! ! ! electrical characteristics (unless otherwise noted, ta = 25 c, v cc = 9v, f in = 1khz, v in = 200mvrms, r g = 600 ? , r l = 100k ? and v ctl = 4.5v) parameter circuit current voltage gain 1 voltage gain 2 voltage gain 3 voltage gain 4 voltage gain 5 channel balance maximum output voltage output noise voltage 1 output noise voltage 2 total harmonic distortion 1 total harmonic distortion 2 channel separation ripple rejection ratio i cc g v1 g v2 g v3 g v4 g v5 ma symbol 3.9 ? 2.0 ? 2.5 ? 1.0 9.0 ? min. 5.9 0 ? 0.5 1.0 11.0 4.0 typ. 11.8 2.0 1.5 4.0 13.0 ? db db max. unit conditions db db db cb ? 2.0 0 2.0 db f in = 10khz, v ctl = 0v v om 2.0 2.3 ? vrms thd = 1% v no1 ? 210 vrms r g = 0 ? , din audio, v ctl = 9v v no2 ? 16 70 vrms r g = 0 ? , din audio thd 1 ? 0.005 0.05 % 400hz~30khz bpf, v ctl = 9v thd 2 ? 0.04 0.4 % 400hz~30khz bpf cs ?? 67 ? 60 db v in = 1vrms rr 60 68 ? db r g = 0 ? , f r = 100hz, v r = 100mvrms f in = 10khz, v ctl = 0v f in = 50hz v ctl = 9v v in = 0vrms f in = 10khz ? note : when v ctl = 9v, the ic is in bypass mode (through operations). when v ctl = 4.5v, the ic is in processor mode (enhance operations) with minimum definition level. when v ctl = 0v, the ic is in processor mode (enhance operations) with maximum definition level.
ba3880as / ba3880afs audio ics ! ! ! ! measurement circuits ba3880as 0.1 0.01 1 47 470p 6800p 9v 100k 1 22 2 21 3 20 4 19 5 18 6 17 7 16 8 15 9 14 10 13 11 12 470p 6800p 0.01 0.068 0.068 4.7 4.7 1 9v 4.5v v v thd 47 4.7 100k v v thd 4.7 600 4.7 600 4.7 mixl vcal v cc defl detl gnd detr defr ctl vcar mixr (units) r : ? c : f outl inl apfl hpfl lpfl biasc lpfr hpfr apfr inr outr ba3880as a fig.1
ba3880as / ba3880afs audio ics ba3880afs 0.1 1 47 470p 6800p 9v 1 24 2 23 3 22 4 21 5 20 6 19 7 18 8 17 9 16 10 15 11 14 0.01 6800p 470p 4.7 1 9v 4.5v 4.7 100k v v thd 4.7 600 mixl vcal v cc defl detl gnd detr defr ctl vcar mixr outl inl apfl hpfl lpfl biasc lpfr hpfr apfr inr outr ba3880afs a fig.2 0.01 100k v v thd 4.7 600 4.7 12 0.068 13 47 0.068 (units) r : ? c : f
ba3880as / ba3880afs audio ics ! ! ! ! circuit operations the ba3880as and ba3880afs high-definition sound processor system ics treat the amplifiers and speakers as a total audio systems, and perform signal processing at the amplifier input stage to accurately reproduce the rise sections of audio signals that determine the characteristics of sound, and ensure that the replayed audio is as close to the original sound and as natural sounding as possible. problems relating to playback of sound on audio systems. with naturally-generated sound, high-frequency harmonic components generally occur first, followed by the fundamental frequency components. this also applies to the attack section of the sound that characterizes many musical instruments. it is the amplitude component that gives form to the frequency component and envelope at the rising point of sound, and this expresses the characteristics of the sound. therefore, when replaying audio on audio playback systems, it is extremely important that the rise section of the signal be expressed accurately with respect to the original sound. however, there is inevitable mismatching between the speakers and amplifiers in current audio systems. solid-state power amplifiers use negative feedback techniques and operate off a fixed voltage supply, but as speakers are a current element, mismatching in the system inevitably occurs. in addition, the speaker impedance characteristics are strongly influenced by the electrical reactance of the voice coil, and the mechanical reactance of the cone assembly. as a result of this, distortion is generated in the rising sections of audio signals, causing phase shift in the reproduced sound. in addition , impedance increases in the treble region which reduces the speaker amplitude and reduces the harmonic component, and as a result there is a tendency to masking of large mid-frequency signal components that follow, and this makes it difficult to reproduce the rising sections of the sound. ! ! ! ! operating principles to solve the problems described above, the ba3880as and ba3880afs perform the audio signal processing described below. phase shift compensation bass middle treble 20 150 2.4k 20k f (hz) the input signal is separated into three regions: bass (20hz to 150hz), middle (150hz to 2.4khz) and treble (2.4khz to 20khz). these regions are then joined again with the middle and treble regions phase shifted ? 180 and ? 360 respectively with respect to the bass signal. this phase shift adjusts the delay time characteristic for each band and minimizes the distortion of the rising section of the audio signal. amplitude compensation (harmonic compensation) to maintain appropriate auditory balance for the treble region that is made up of harmonic components, a high-speed detector and high-performance vca circuit are used for amplitude control of the treble component. the amount of compensation is determined from a calculation performed based on the dc level input to the ctl pin, and the dc level detected from the input signal. the internal control signal obtained from this calculation compensates the amplitude of the treble component input to the vca. this amplitude compensation recovers the harmonic component, and improves the reproduction clarity (definition level) of instruments and vocals.
ba3880as / ba3880afs audio ics bass boost to maintain good balance with the dynamically changing treble component, the bass component is boosted. the bass boost is fixed at 4db (typ.) internally, and cannot be adjusted. mode switch the dc voltage on the ctl pin can be used to switch the ic between processing mode and bypass mode. when processing mode is selected, the audio signal is enhanced using the compensation circuits described above before being output. when bypass mode is selected, the signal bypasses all of the compensation circuits, and only passes through a buffer amplifier before output. external components the frequency characteristic in processing mode with maximum definition level is given below. c1 large gain bass boost frequency small c2 large small definition level c1: external capacitor connected between the vca and mix pins (0.015 f in the application circuit). c2: external capacitor connected between the out and mix pins (470pf in the application circuit). as indicated in the diagram, capacitors c1 and c2 determine the treble component cutoff frequency. by varying the values of these components, the frequency characteristic can be changed as indicated by the dotted line in the diagram. this varies the balance of the harmonic component, and is an important factor in determining the tone quality. control table recommended setting range for bypass mode undifined range recommended setting range for processor mode v ctl 0.64 v cc 0.57 v cc 0.75 v cc 0.5 v cc v cc min. (1db typ.) max. (11db typ.) 0v (gnd) item threshold level mode setting definition level
ba3880as / ba3880afs audio ics ! ! ! ! application examples ba3880as 0.056 0.056 0.01 47 4.7 1 47 0.1 (units) r : ? c : f 1 2 5 6 7 8 9 10 11 mixl vcal v cc v cc v ctl defl detl gnd gnd detr defr ctl vcar mixr 22 21 20 19 18 17 16 15 14 13 12 outl l ? ch output inl apfl hpfl lpfl biasc lpfr hpfr apfr inr outr + + ctl + + vca ? + + + hi mid lo + lpf hpf + + ctl + + vca ? + + + + lpf hpf hi mid lo 4.7 4.7 1 4.7 l ? ch input 0.01 0.015 470p 0.015 470p 4.7 r ? ch output 4.7 r ? ch input 4 3 fig.3 each fixed number was recommended from the bbe company.
ba3880as / ba3880afs audio ics ba3880afs 0.015 470p 1 47 0.1 v cc v ctl gnd 0.01 0.015 470p 1 2 3 4 5 6 7 8 9 10 11 mixl vcal v cc defr detl gnd detr defr ctl vcar mixr 22 21 20 19 18 17 16 15 14 13 12 outl inl apfl hpfl lpfl biasc lpfr hpfr apfr inr outr + + ? + + + + + hi mid lo 24 23 lpf ctl vca + ctl vca + + + ? + + + hi mid lo + + hpf lpf hpf 4.7 1 4.7 r ? ch output 4.7 r ? ch input 0.01 0.056 47 0.056 4.7 l ? ch output 4.7 l ? ch input 4.7 (units) r : ? c : f fig.4 each fixed number was recommended from the bbe company.
ba3880as / ba3880afs audio ics ! ! ! ! operation notes (1) control pin (ctl) the level of the dc voltage applied to the control pin should be in the range 0v to v cc . appropriate switching may not be possible in the region of the threshold voltage. allow sufficient margin when setting this voltage. (2) recommended operating range provided the ic is operated within the operating temperature range and within the recommended operating conditions, the general circuit functions are guaranteed to operate correctly, and there will not be significant changes in the electrical characteristics. (3) application example provided the circuit constants in the application example are used, the application circuit should function correctly. however, we recommend that you confirm the characteristics of the circuit in actual use, and take note of the cautionary items described above. if you change the circuit constants, check both the static and transient characteristics of the circuit, and allow sufficient margin to accommodate variations in both the ic and the external components. (4) license the ics are manufactured under license from bbb sound inc. (u.s.a.). a license agreement with bbb sound inc. is required to use this component. ! ! ! ! electrical characteristic curves 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 2 4 6 8 10 12 definition level : (db) control voltage : v ctl (v) v cc = 9v f = 10khz v in = 200mvrms fig. 3 definition level vs. control voltage definition level : (db) input voltage : v in (dbv) fig. 4 definition level vs. input voltage 0 ? 10 ? 20 ? 30 ? 40 ? 50 ? 60 2 4 6 8 10 12 v cc = 9v f = 10khz v ctl = 0v ? 70 ? 80 14 16 ! ! ! ! external dimensions (units : mm) ba3880as 0.15 0.3min. 7.8 0.3 5.4 0.2 1.8 0.1 0.11 1 24 0.36 0.1 10.0 0.2 12 13 0.8 0.15 0.1 ba3880afs ssop-a24 sdip22 3.95 0.3 0.51min. 19.4 0.3 3.4 0.2 0.5 0.1 6.5 0.3 1 11 12 22 0.3 0.1 0 ~15 1.778 7.62
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