NJU8710 -1- ver.2004-06-02 2v operation clock-less switching driver for class d amplifier general description the NJU8710 is a 2v operation clock-less switching driver for a class d amplifier with separated power supply between input and output. the NJU8710 provides powerful drivability in both of sink and source without flow-through current. therefore, it can be used to the buffer or the switch as a driver ic. furthermore it converts 1bit digital signal input, such as pwm or pdm signal, to analog signal output of the hi-fi audio level through a simple external lc low-pass filter. the NJU8710 realizes very high power-efficiency because of the class d operation and low voltage operation. therefore, it is suitable for battery powered applications and others. features 2-channel 1bit digital signal input standby(hi-z) control function operating voltage : 1.7v to 2.7v driving voltage : 1.7v to v dd cmos technology package outline : vsp10 block diagram pin configuration package outline preliminary NJU8710r stbyb in 1 v ss v dd in 2 v ss 1 2 3 4 5 10 9 8 7 6 outx 1 v ddo outx 2 v ddo stby in 2 in 1 outx 1 outx 2 v dd v ss v ddo v ss v ddo dead time generator
NJU8710 - 2 - - 2 - ver.2004-06-02 terminal description no. symbol i/o function 10 v dd ? power supply: v dd =2v 5 6 v ddo ? output power supply: v ddo =2v 3 8 v ss ? power gnd and output gnd terminal: v ss =0v 2 9 in 1 in 2 i 1-bit data input terminal 4 7 outx 1 outx 2 o output terminal outx 1 terminal outputs the inverted signal of in 1 terminal, outx 2 terminal outputs the inverted signal of in 2 terminal. 1 stbyb i standby control terminal (l:standby) *v ss (terminal no.3,8) should be connected at a nearest point to the ic. *v ddo (terminal no.5,6) should be connected at a nearest point to the ic. *stbyb(terminal no.1) must be connected to v dd , when this function is not used. input terminal structure functional description (1) signal output (outx 1 , outx 2 terminal) output signal becomes a inverted input signal. a flow-through current at the signal polarity transition doesn't generate by optimized dead time control circuit. output signal is converted to analog signal via external 2nd-order or higher lc filter. a switching regulator with a high response against a voltage fluctuation is the best selection for the v ddo, which is the power supply for output drivers. to obtain better t.h.d. performance, the stabilization of the power is required. (2) standby control function by setting the stbyb terminal to ?l?, the NJU8710 becomes standby condition. during standby condition, outx 1 and outx 2 are in hi-z. v dd v ss input terminal ic circuit
nju3555 NJU8710 -3- ver.2004-06-02 absolute maximum ratings (ta=25 c) parameter symbol rating unit v dd -0.3 to +4.0 v supply voltage v ddo -0.3 to +2.7 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 vsp10 p d 450* mw power supply voltage condition - v dd v ddo v * : mounted on two-layer board of based on the jedec. 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 beyond the electrical characteristics conditions will cause malfunction and poor reliability. note 3) de-coupling capacitors should be connected between v dd -v ss and v ddo -v ss due to the stabilized operation. electrical characteristics (ta=25 c, v dd =v ddo =2.0v, v ss =0.0v, unless otherwise noted) parameter symbol conditions min. typ. max. unit v dd supply voltage v dd 1.7 2.0 2.7 v v ddo supply voltage v ddo 1.7 2.0 v dd v output driver high side resistance r h v out =v ddo -0.1v - 1.5 2 ? output driver low side resistance r l v out =0.1v - 1.5 2 ? operating current at hi-z output i st in 1 , in 2 , stbyb=?l? - - 1 a i dd - 0.05 t.b.d operating current at no input signal i ddo no-load operating, in 1 =in 2 =1.4mhz - 0.6 t.b.d 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 a
NJU8710 - 4 - - 4 - ver.2004-06-02 timing characteristics ? signal spread characteristics (ta=25 c, v dd =v ddo =2.0v, v ss =0.0v unless otherwise noted) parameter symbol conditions min. typ. max. unit maximum operating frequency f max - - 25 mhz signal spread time (h l) t pdl - - 20 ns signal spread time (l h) t pdh - - 20 ns ? output control signal input (stbyb) (ta=25 c, v dd =v ddo =2.0v, v ss =0.0v unless otherwise noted) parameter symbol conditions min. typ. max. unit rise time t up - - 50 ns fall time t dn - - 50 ns outx 1 , outx 2 t pdl in 1 , in 2 t pdh 0.7v dd 0.3v dd 0.7v dd 0.3v dd t dn t up stbyb 0.7v dd 0.7v dd 0.3v dd 0.3v dd
nju3555 NJU8710 -5- ver.2004-06-02 application circuit (analog signal output) ? stereo otl application example ? monaural btl application example note 4) de-coupling capacitors must be connected between each power supply terminal and gnd terminal. note 5) the power supply for v ddo requires fast driving response performance such as a switching regulator for t.h.d.. note 6) 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 7) 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. a914by-101m ? a914by-101m is manufactured by toko, inc. for further information, please refer to its technical papers. a914by-101m NJU8710 in 1 outx 1 standby control outx 2 audio signal in 2 stbyb headphone 32 ? 0.22 f 100 ? 0.22 f 100 ? 2 9 1 4 7 v ddo 0.1 f switching regulato r 0.1 f a914by-101m in 1 audio signal in 2 speaker 32 ? 0.22 f 100 f 100 f switching regulato r 0.1 f a914by-101m outx 1 outx 2 stbyb 2 9 1 4 7 v ddo v ss 5 3 v ddo v ss 6 8 10 v dd NJU8710 ? a914by-101m is manufactured by toko, inc. for further information, please refer to its technical papers.
NJU8710 - 6 - - 6 - 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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