tripath technology, inc. - technical information 1 EB-TA2020 ?rev. d/02.01 EB-TA2020 class-t digital audio amplifier evaluation board using digital power processing tm technology technical information revision d ? 02.01 general description the EB-TA2020 evaluation platform is based on the ta2020-020 digital audio power amplifier from tripath technology. this board is designed to provide a simple and straightforward environment fo r the evaluation of the tripath ta2020- 020. the ta2020-020 provides amplification for two channels of audio and drives 4 ? and 8 ? passive loads (loudspeakers). input, output and power connections are via standard connectors . features class-t architecture proprietary digital power processing tm technology requires single 13.5v power source output power (per channel @ v s = 13.5v) 20w - 4 ? @ 10% thd+n 12w - 4 ? @ 0.1% thd+n easy engineering evaluation platform for tripath technology?s ta2020-020 product ?audiophile performance? typically: 0.03% thd+n, 4w @ 4 ? 0.08% ihf-im @ 4 ? efficiency - >85% @ full power (r l = 8 ? ) frequency response: 20 hz ? 20 khz = + 0.5 db mute input turn-on & turn-off pop suppression short-circuit protection intelligent over-temperature protection connects to any passive 4/8 ? speakers takes standard audio line output from any sound system bridged outputs 2-layer low cost board 30-pin power sop package
tripath technology, inc. - technical information 2 EB-TA2020 ?rev. d/02.01 introduction the EB-TA2020 was designed the designer with a si mple means of evaluating the performance and functionality of the ta2020, 2 x 20w amplifie r ic from tripath technology. the EB-TA2020 is simple to operate and requires only a few things to get up and running: ? stereo signal source ? 13.5v power supply (not to exceed 14.6v) ? two loads (4 ohm minimum) for more information on the ta2020, please refer to the ta2020 datasheet ( www.tripath.com ) in1 in2 out2p out2n output 2 out1n out1p output 1 vcc power in gnd mute sleep inputs EB-TA2020 board connection and operation figure 1 shows the connections required for proper operation of the EB-TA2020. input connection audio input to the board is provi ded via two rca female connectors. connector name channel in1 channel 1 input in2 channel 2 input power connection the EB-TA2020 requires a +13.5v power supply (14.3v max) to operate. power to the board is connected via the red and black banana connectors. the positive 13.5v from the power supply is connected to t he red banana connector labeled vcc. the ground connection of power attaches to the black banana connector labeled gnd.
tripath technology, inc. - technical information 3 EB-TA2020 ?rev. d/02.01 audio source + - ta2020 in2 in1 sleep fault gnd mute out2p out2n out1n out1p vcc gnd 13.5v + + - - gnd l r speaker right speaker left figure 1 connector label description color vcc positive of the 13.5v power supply red gnd_p negative (gnd) of 13.5v power supply black warning : do not exceed maximum operating supply voltage (vs) of 14.6v output connection there are four banana connectors on the evaluat ion board for speaker output. the ta2020-020 has differential outputs, and so it requires tw o wires per channel to connect to each speaker. connector label description color out1p positive output of channel 1 white out1n negative output of channel 1 blue out2p positive output of channel 2 white out2n negative output of channel 2 blue jumper setting there are two jumpers on the board that contro l the mute and sleep functions. these jumpers should be in place at all times for normal operati on. the mute jumper connects the fault output
tripath technology, inc. - technical information 4 EB-TA2020 ?rev. d/02.01 pin to the mute input pin. if the jumper is re moved, the part will enter mute mode. with the jumper in place, if the part enters an over-curr ent or over-temperature f ault condition, the output will be muted. with the sleep jumper removed, the ta2020-020 goes into sleep mode when no input signal is present. with the jumper in pl ace, the sleep mode is disabled. gain setting the EB-TA2020 amplifier gain can be adjusted by changing the external resistors r370-r373. r370 and r371 are used to set the gain for channel 1. r372 and r373 are used to set the gain for channel 2. the equation for the gain setting is: ? ? ? ? ? ? ? ? ? = i f v r r 12 a where, for channel 1: ? ? ? ? ? ? ? = 370 r 371 r 12 a 1 ch _ v for channel 2: ? ? ? ? ? ? ? = 373 r 372 r 12 a 2 ch _ v for a more detailed description, please refer to the ta2020 data sheet. performing measurements on the EB-TA2020 the ta2020 operates by generating a high frequenc y switching signal based on the audio input. this signal is sent through a low-pass filter that recovers an amplified version of the audio input . the frequency of the switching pattern is spread spectrum in nature and typically varies between 100khz and 1mhz, which is well above the 20hz ? 20k hz audio band. the pattern itself does not alter or distort the audio input signal, but it does introduce some inaudible components. the measurements of certain performance parameter s, particularly noise related specifications such as thd+n, are significantly affected by t he design of the low-pass filter used on the output as well as the bandwidth setting of the measurement instrument used. unless the filter has a very sharp roll-off just beyond the audio band or t he bandwidth of the measurement instrument is limited, some of the inaudible noise component s introduced by the ta2020 amplifier switching pattern will degrade the measurement. one feature of the ta2020 is that it does not require large multi-pol e filters to achieve excellent performance in listening tests, usually a more cr itical factor than performance measurements. though using a multi-pole filter may remove high-frequency noise and improve thd+n type measurements (when they are made with wide- bandwidth measuring equipment), these same filters degrade frequency response. the EB-TA2020 evaluation board has a simple two-pole output filter with excellent performance in listening tests. (see application note 4 for more information on bench testing)
tripath technology, inc. - technical information 5 EB-TA2020 ?rev. d/02.01 contact information tripath technology, inc 2560 orchard parkway, san jose, ca 95131 408.750.3000 - p 408.750.3001 - f for more sales information, please visit us @ www.tripath.com/cont_s.htm for more technical information, please visit us @ www.tripath.com/data.htm
5 5 4 4 3 3 2 2 1 1 d d c c b b a a tripath technology tripath technology inc. notes: 1. ground plane is split into two. both halves are joined at one point. 2. the mute function can be optionally tied to the fault pin to allow for an automatic reset in the event of an over current fault. * ** connect gnd_power from pin 20 to gnd_a pin 3 with a single trace. * gnd * * gnd_p gnd_a rf ri rf ri rca rca 3. ta2020 inputs have a dc bias of 2.5v. if i nput preamp circuitry is not biased at 0v, c590 and c591 may need to be reversed. d EB-TA2020 evaluation board b 11 thursday, august 31, 2000 title size document number rev date: sheet of vcc vcc vcc vcc vcc vcc out1- 1384 sleep out1+ 1377 out2+ 1385 r668 10 1711 gnd r665 10 out2- 1386 ovrldb d704 1n5817 c674 0.1uf d728 1n5817 c667 0.47uf r374 1meg c666 0.47uf d703 1n5817 c450 0.1uf l390 10uh l398 10uh d702 1n5817 c593 0.1uf c696 0.1uf c673 0.1uf l399 10uh c695 0.1uf + c451b 180uf,25v l389 10uh 1710 vcc r368 8.2k, 1% + c451 180uf,25v j1 in1 c448 0.47uf j2 in2 c447 0.47uf c359 0.1uf c391 0.47uf c694 0.1uf + c432 1uf c439 0.47uf + c361 1uf + c591 2.2uf + c590 2.2uf gnd r372 20k mute r371 20k fault r370 20k u1 ta2020 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 nc v5d agnd1 rref nc overloadb agnd2 v5a vp1 in1 mute / idle vp2 in2 biascap nc agnd3 sleep fault pgnd2 dgnd outp2 vdd2 outm2 outm1 vdd1 outp1 vdda pgnd1 cpump +5gen dcap2 dcap1 r373 20k c362 0.1uf
EB-TA2020 revision: d bill of materials quantity reference value description mfgr / part# comment 1 r368 8.2k, 1% resistor 4 r370,r371,r372,r373 20k resistor input, feedback resistors 1 r374 1meg resistor 2 r668,r665 10, 1/4w resistor ouput zobel resistor 9 c359,c362,c450,c593,c673, 0.1uf capacitor c674,c694,c695,c696 2 c432,c361 1uf capacitor 4 c391,c439,c447,c448 0.47uf capacitor main output filter cap 2 c451b,c451 180uf,25v capacitor panasonic hfq series low esr, high temp electrolytic 2 c591,c590 2.2uf capacitor input coupling cap 2 c667,c666 0.47uf capacitor 4 l389,l390,l398,l399 10uh inductor isi rl622-100k output series inductor 4 d702,d703,d704,d728 1n5817 diode on semi 1n5817 output protection diode 1 u1 ta2020 ic tripath technology ta2020-020 2 j1, j2 connector rca input jack 6 1377, 1384, 1385, 1386, 1710, 1711 connector johnson components 101-09xx-001 pcb mount female banana 1 1736, 1738, 1738 header header, 3-pin 0.1" 1 1459, 1688 header header, 2-pin 0.1"
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