NJM2770 -1 - high-power & low-voltage audio power amplifier general description package outline the NJM2770 is high-power and low-voltage audio power amplifier with standby function. no external coupling capacitors required because of the differential output type. two external resistors adjust the closed loop gain. the output power is 250mw typical at 3v-supply 8ohm-load, and 400mw typical at 4.5v-supply 16ohm-load. the standby current is only 0.1 a typical. the package of NJM2770 is vsp8, and suitable for pcs, codeless telephone, speaker amplifier for hands free system, and especially cellular phone because of low operating current, low standby current, and high power output. featurs operating voltage +2-+4.5v operating current 2.0ma typ.,at v + =3v low power-down current 0.1 a typ high power otput 250mw typ. at v + =3v,r l =8 ? 400mw typ. v + =4.5v,r l =16 ? gain range at voice band gv=0-43db load impedance r l =4-200 ? thermal shut down function package outline vsp8,tvsp8 bipolar technology pin configuration & block diagram pin function bias 1 2 3 4 8 5 6 7 -v in +v in +v ref v out 1 cd gnd v + v out 2 # a # b tsd 40k ? 40k ? 50k ? 50k ? 145k ? 1.cd 2.+v ref 3.+v in 4.-v in 5.v out 1 6.v + 7.gnd 8.v out 2 NJM2770r NJM2770rb1
NJM2770 - 2 - absolute maximum ratings (ta=25 c) parameter symbol ratings unit supply voltage v + +5 v power dissipation p d (vsp8,tvsp8) 400 mw operating temperature range topr -40 to +85 c storage temperature range tstg -40 to +150 c electrical characteristics (v + =3.0v,r l =8 ? ,f=1khz,1pin=2v,ta=25 c,unless otherwise specified) parameter symbol test condition min. typ. max. unit operating voltage range v + 2.0 - 4.5 v operating current i cc r l = ,no signal - 2.0 4.0 ma power down current i ccd r l = 1pin=0.8v,no signal - 0.1 1.0 a open loop gain a v 1 amp # a, f<100hz 80 85 - db closed loop gain a v 2 amp # b -0.35 0 +0.35 db output power p o 1 thd=10% 110 250 - mw p o 2 v + =4.5v, r l =16 ? , thd=10% 200 400 - mw total harmonic distortion thd1 p o =100mw, g vd =6db - 0.1 0.5 % thd2 v + =4.5v, r l =16 ? , p o =150mw, g vd =6db - 0.1 - % power supply rejection ratio svr1 c1= , c2=0.01 f, d c 50 - - db (v + =3.0v-4.5v) svr2 c1=0.1 f, c 2 = 0 - 35 - db svr3 c1=1.0 f, c2=4.7 f - 70 - db mute attenuation mat f =1khz-20khz, 1pin=0.8v - 80 - db output voltage v o 1 0.95 1.10 1.25 v (r f =20k ? , dc) v o 2 v + =4.5v, r l =16 ? - 1.85 - v output high level v oh i out =-75ma, v + =2.0-4.5v - v + -1.0 - v output low level v ol i out =75ma, v + =2.0-4.5v - 0.21 - v output dc offset ? v o r f =20k ? , 5pin-8pin -30 0 +30 mv input bias current i b 4pin -100 - 100 na equivalent resistance r +in 3pin 100 170 220 k ? r ref 2pin 18 26 40 k ? cd input voltage h v cdh 1pin 2.0 - v + v cd input voltage l v cdl 1pin 0.0 - 0.8 v cd input resistance r cd v + =v cd =4.5v, 1pin 50 85 175 k ? control terminal explanation chip disable control(cd pin) parameter control signal status cd off h(=v cdh ) ic is active. cd on l(=v cdl ) ic is standby. (with mute)
NJM2770 - 3 - application curcuit bias 1 2 3 4 8 5 6 7 ci ri c 2 cd(power down) 10 f v + =+3v # a # b 4.7 f input speaker 8 ? /16 ? rf 20k ? 0.1 f 20k ? c 1 1.0 f tsd 50k ? 50k ? 145k ? note:1.the cd terminal(1pin) should connect high level( > 2.0v), when NJM2770 is active. the standby mode, when the cd terminal is low level( < 0.8v). 2.to add the c1 and c2 capacitor, the power-supply-rejection-ratio will be improved. when c1 is large vaiue, c2 will be unnecessary. 3.the power-up time depend on the c1 and c2 capacitor. 4.the input current of cd terminal is as shown below figure. v + 1pin 72k ? 80k ? gnd 5.no connect oscillation-protect rc required. to connect oscillation-protect rc, if the NJM2770 oscillate with pc board/stray capacitor/long speaker wire and others condition.
NJM2770 - 4 - memo [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.
|
