NJU8711 -1- ver.2004-06-02 3v operation switching driver for class d amplifier general description the NJU8711 is a switching driver for class d amplifier including beep and bpz (bipolar zero) output circuits. it converts 1bit digital signal input, such as pwm or pdm signal, to analog signal output with simple external lc low-pass filter. the NJU8711 realizes very high power-efficiency by class d operation. therefore, it is suitable for portable audio set and others. features 2-channel 1bit audio signal input standby(hi-z), bpz control internal bpz charger beep function operating voltage : 2.0v to 3.6v cmos technology package outline : ssop10 block diagram NJU8711v en 1 en 2 beep in 2 in 1 mck out 1 out 2 bpz output bpz output output control v ss v dd package outline pin configuration en 1 mc k v dd beep en 2 out 2 in 2 v ss in 1 out 1 1 2 3 4 5 10 9 8 7 6
NJU8711 - 2 - ver.2004-06-02 terminal description no. symbol i/o function 3 v dd - power supply, v dd =3v 8 v ss - power gnd, v ss =0v 2 mck i master clock input terminal the condition of the data input terminal is fetched with the rising edge of this signal. 1 5 en 1 en 2 i output control terminal output circuit is selected by the condition of this terminal. 7 9 in 1 in 2 i audio signal input terminal 1-bit audio signal inputs into this terminal. 4 beep i beep signal input terminal beep signal inputs into this terminal. 6 10 out 1 out 2 o output terminal ? when output terminal selects audio signal, in 1 terminal input data outputs from out 1 terminal and in 2 terminal input data outputs from out 2 terminal. ? when output terminal selects beep signal, beep terminal input data outputs from out 1 and out 2 terminals. input terminal structure v dd v ss input terminal inside circuit
nju3555 NJU8711 -3- ver.2004-06-02 functional description (1) signal output pwm signals of l channel and r output from out 1 and out 2 terminals respectively. these signals are converted to analog signal by external 2nd-order or over lc filter. the output driver power supplied from v dd and v ss are required high response power supply against voltage fluctuation like as switching regulator because output t.h.d is effected by power supply stability. (2) master clock master clock (mck) synchronizes the audio signal inputs (in 1 and in 2 ). the setup time and the hold time should be kept in the ac characteristics because in 1 and in 2 are fetched with the rising edge of mck. mck requires jitter-free or jitter as small as possible because the jitter downs s/n ratio. out 1 and out 2 occur the pop noise when mck is stopped in operation without standby mode. therefore, the standby mode should be set before mck stop. (3) output control output circuit is selected by the conditions of en 1 and en 2 terminals. en 2 en 1 output state of out 1 & out 2 0 0 standby(high impedance) 0 1 audio signal output 1 0 bpz output 1 1 beep signal output (4) beep function the beep signal must be input before the rising edge of en 2 signal and must be stopped after the falling edge of en 2 signal. en 1 en 2 mc k beep bee p si g nal out p ut audio signal output audio signal output
NJU8711 - 4 - ver.2004-06-02 absolute maximum ratings (ta=25 c) parameter symbol rating unit supply voltage v dd -0.3 to +4.0 v input voltage vin -0.3 to v dd +0.3 v operating temperature topr -40 to +85 c storage temperature tstg -40 to +125 c power dissipation ssop10 p d 280 mw note 1) all voltage values are specified as v ss =0v. note 2) if the lsi is used on condition beyond the absolute maximum rating, the lsi may be destroyed. using lsi within electrical characteristics is strongly recommended for normal operation. use bey ond the electrical characteristics conditions will cause malfunction and poor reliability. note 3) decoupling capacitors should be connected between v dd -v ss due to the stabilized operation. electrical characteristics (ta=25 c, v dd =3.0v, v ss =0.0v, load impedance=16 ? , f s =44.1khz, unless otherwise noted) parameter symbol conditions min. typ. max. unit v dd supply voltage v dd 2.0 3.0 3.6 v bpz driving voltage v bpz v dd /2-0.2 v dd /2 v dd /2+0.2 v output driver high side resistance r h v out =v dd -0.1v - 1.5 2 ? output driver low side resistance r l v out =0.1v - 1.5 2 ? beep high side current i bh v out =v dd -1v 100 250 600 ua beep low side current i bl v out =1v 100 250 600 ua operating current at standby i st stopping mck, in 1 , in 2 , beep - - 1 ua operating current at no input signal i dd no-load operating in 1 , in 2 =32f s mck=256f s - 1 2 ma v ih 0.7v dd - v dd v input voltage v il 0 - 0.3 v dd v input leakage current i lk - - 1 ua note 4) when v dd supply voltage is lower than typical voltage, a pop noise may occur in output change between bpz and audio signal. therefore, please consider and check the circuit carefully against pop noise.
nju3555 NJU8711 -5- ver.2004-06-02 timing characteristics ? audio signal input (ta=25 c, v dd =3.0v, v ss =0.0v, unless otherwise noted) parameter symbol conditions min. typ. max. unit mck frequency f mcki 8 - 25 mhz mck pulse width (h) t mckh 12 - - ns mck pulse width (l) t mckl 12 - - ns in 1 ,in 2 setup time t ds 20 - - ns in 1 ,in 2 hold time t dh 20 - - ns note 5) t mcki shows the cycle of the mck signal. ? output control signal input (ta=25 c, v dd =3.0v, v ss =0.0v, unless otherwise noted) parameter symbol conditions min. typ. max. unit rise time t up - - 100 ns fall time t dn - - 100 ns note 6) all timings are based on 30% and 70% voltage level of v dd . t mckh t ds t dh mc k in 1 , in 2 t mckl t mcki t dn t up en 1 ,en 2
NJU8711 - 6 - ver.2004-06-02 application circuit ? stereo otl application example ? 1 channel btl application example note 7) de-coupling capacitors must be connected between each power supply pin and gnd pin. note 8) the power supply for v dd requires fast driving response performance such as a switching regulator for thd. note 9) the bigger capacitor value of external ac-coupling capacitors realize better low frequency response characteristics. in addition, esr(equivalent series resistance) should be low. note 10) the above circuit shows only application example and does not guarantee the any electrical characteristics. therefore, please consider and check the circuit carefully to fit your application. NJU8711 in 1 out 1 output control en 1 v dd switching regulator 100uf 2.2uf out 2 audio signal master cloc k mck beep signal in 2 beep en 2 v ss headphon e 16 ? 0.22uf 100uh 220uf 1k ? 0.22uf 100uh 220uf 1k ? 7 9 4 1 5 2 6 10 3 8 NJU8711 in 1 out 1 output control en 1 v dd out 2 audio signal master cloc k mck beep signal in 2 beep en 2 v ss speaker 8 ? 1.5uf 22uh 1.5uf 22uh switching regulator 100uf 2.2uf 6 10 3 8 7 9 4 1 5 2 a915by-101m ? a915by-220m is manufactured by toko, inc. for further information, please refer to its technical papers. a915by-101m a915by-220m ? a915by-220m is manufactured by toko, inc. for further information, please refer to its technical papers. a915by-220m
nju3555 NJU8711 -7- ver.2004-06-02 [caution] the specifications on this databook are only given for information , without any guarantee as regards either mistakes or omissions. the application circuits in this databook are described only to show representative usages of the product and not intended for the guarantee or permission of any right including the industrial rights.
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