Tr i path Technol ogy, I nc. - Techni cal I nfor m ati on EB-TA1101B Class-T Digital Audio Amplifier Evaluation Board using Digital Power Processing T M Technology Technical Information Revision E – February 2001 GENERAL DESCRIPTION The EB-TA1101B evaluation board is based on the TA1101B, digital audio power amplifier from Tripath Technology. The board is designed to provide a simple and straightforward environment for the evaluation of the Tripath TA1101B. The board can be connected to a +12V supply using cables with banana connectors. Audio inputs are standard RCA jacks. The TA1101B provides amplification for two channels of audio. Signal outputs are on four banana connectors to which any 4Ω or 8Ω passive speaker may be connected. Features Class-T architecture Proprietary Digital Power Processing TM Technology Requires single +12V power source Output Power (per channel @ VS = 12V): 15W - 4Ω @ 10% THD+N 10W - 4Ω @ 0.1% THD+N Easy engineering evaluation platform for Tripath Technology’s TA1101B product “Audiophile performance” typically: 0.04% THD+N, 9Wrms @ 4Ω 0.18% IHF-IM, 1Wrms @ 4Ω 1 Efficiency - >85% @ full power (RL = 8Ω) No heat sink required up to 10W per channel Mute input Turn-on & turn-off pop suppression Intelligent short-circuit protection Intelligent over-temperature protection Connects to any passive 4/8Ω speakers Takes standard audio line output from any sound system 2-layer low cost board 30-pin Power SOP package EB-TA1101B, 02.01 Tr i path Technol ogy, I nc. - Techni cal I nfor m ati on Introduction The EB-TA1101B was designed to provide the designer with a simple means of evaluating the performance and functionality of the TA1101B 2x10W amplifier IC from Tripath Technology. The EB-TA1101B is very simple to operate and requires only a few things to get up and running: Stereo signal source 12V power supply (not to exceed 13.2V) Two loads (4-Ohm minimum) For more information on the TA1101B, please refer to the TA1101B datasheet (www.tripath.com). Power In +12V(red), Gnd(blk) In1 Output 1 Out1+(wht), Out1-(blu) Inputs Outputs In2 Sleep Mute Output 2 Out2+(wht), Out2-(blu) EB-TA1101B Board Connection and Operation Figure 1 shows the connections required for proper operation of the EB-TA1101B. Input Connection Audio input to the board is provided via two RCA female connectors. Connector Name IN1 IN2 Channel Channel 1 Input Channel 2 Input Power Connection The TA1101B requires a +12V power supply (13.2V max) to operate. Power to the board is provided via the red and black female banana connectors. The positive 12V from the power supply connects to the red banana connector labeled 12V+. The ground connection of power supply attaches to the black banana connector labeled GND. 2 EB-TA1101B, 02.01 Tr i path Technol ogy, I nc. - Techni cal I nfor m ati on +12V - + TA1101B Gnd In2 Mute Audio Source R Gnd Out1+ Out1Out2- Sleep Out2+ + + Speaker Right 12V+ Speaker Left In1 L Figure 1 Connector Label 12V+ GND Description Positive of the 12V Power supply Negative (GND) of 12V Power Supply Color Red Black Warning: Do not exceed Maximum Operating Supply Voltage of 13.2V Output Connection There are four female banana connectors on the evaluation board for speaker output. The TA1101B has differential outputs (bridged) so it requires two wires per channel to connect to each speaker. Connector Label Out1+ Out1Out2+ Out2- Description Positive output of Channel 1 Negative output of Channel 1 Positive output of Channel 2 Negative output of Channel 2 Color White Blue White Blue Jumper Settings There are two jumpers on the EB-TA1101B board, which should both be connected (shorted) for normal operation. Jumper, J1 connects the FAULT output to the MUTE pin, allowing the part to Mute itself when a Fault condition (over-current, etc.) is detected. Jumper, J2 connects the SLEEP pin to GND, effectively disabling SLEEP for normal operation. If J2 is removed, the part will go into SLEEP mode. Jumper Purpose J1 Connects FAULT to MUTE J2 Connects SLEEP to GND 3 EB-TA1101B, 02.01 Tr i path Technol ogy, I nc. - Techni cal I nfor m ati on Gain Settings The TA1101B amplifier gain can be adjusted by modifying external resister values. R2 and R5 are used to set the gain for Channel 1, while R4 and R6 set the gain for Channel 2. The equation for the gain setting is: R A V = 12 ⋅ f Ri Where, R371 For channel 1: A V _ Ch1 = 12 ⋅ R370 R372 For channel 2: A V _ Ch2 = 12 ⋅ R373 For a more detailed description, please refer to the TA1101B data sheet. Performing Measurements on the EB-TA1101B The TA1101B operates by generating a high frequency 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 – 20kHz 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 parameters, particularly noise related specifications such as THD+N, are significantly affected by the 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 the bandwidth of the measurement instrument is limited, some of the inaudible noise components introduced by the TA1101B amplifier switching pattern will degrade the measurement. One feature of the TA1101B is that it does not require large multi-pole filters to achieve excellent performance in listening tests, usually a more critical 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 EBTA1101B 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 with Tripath Class-T amplifiers) EMI and Shielding The TA1101B evaluation board has perforated holes around the amplifier and associated circuitry so that an EMI shield can be soldered directly to the board. Due to the spread-spectrum nature of the Class-T amplifier (the energy is spread across a wider spectrum, instead of being concentrated at a single frequency), we have found that specific EMI shielding is typically not necessary for most applications where the amplifier board is mounted inside a chassis. However, a shield perimeter is still provided for use in more sensitive applications. (See Application Note 11 for more information on EMI) 4 EB-TA1101B, 02.01 Tr i path Technol ogy, I nc. - Techni cal I nfor m ati on CONTACT INFORMATION World Wide Sales Offices United States & Europe SE Asia & China Japan & Korea Jim Hauer Eugene Hsu Osamu Ito [email protected] [email protected] [email protected] 408.567.3089 886.2.2653.7428 81.42.334.2433 TRIPATH TECHNOLOGY, INC 3900 Freedom Circle Santa Clara CA 95054 408.567.3000 www.tripath.com 5 EB-TA1101B, 02.01 Tr i path Technol ogy, I nc. - Techni cal I nfor m ati on 6 EB-TA1101B, 02.01 Tr i path Technol ogy, I nc. - Techni cal I nfor m ati on 7 EB-TA1101B, 02.01 1 VDD L5 FBM2125 12V+ +12V_PLANE BN1 C21 1000pF GND BN2 L8 0.1uF C17 1uF OVERLOADB 20k C14 2.2uF 20k A R5 1 2 V5D 4 AGND1 5 REF 6 OVERLOADB 7 AGND2 8 V5A 9 VP1 10 IN1 11 MUTE 12 VP2 20k FBM2125 R6 13 IN2 14 BIASCAP 15 AGND3 + IN2 L2 20k J4 C24 100pF C15 2.2uF R4 C26 TA1101B DCAP1 3 + R2 DCAP2 COPPER AREA* C16 C23 100pF R7 8.2K, 1% RCA GND 10uH, 2A U1 FBM2125 * J3 L1 HEATSLUG* IN1 CPUMP 29 PGND1 28 VDDA 27 NC 26 OUTP1 25 VDD1 24 OUTM1 23 OUTM2 22 VDD2 21 OUTP2 20 DGND 19 PGND2 18 FAULT 17 SLEEP 16 C27 0.47uF VDD 30 C5 1uF D5 MBRS130T3 VDD C7 0.1uF C12 0.47uF C29 0.1uF R9 10, 1/4W 10uH, 2A C10 1000pF VDD D6 MBRS130T3 D7 MBRS130T3 A + C6 0.1uF C19 180uF,25V D8 MBRS130T3 L7 FAULT 10uH, 2A C9 C25 0.47uF R1 1Meg SLEEP JUMPER J2 GND JUMPER OUT1- C28 0.47uF VDD NOTES: OUT1+ BN3 BN4 180uF,25V VDD J1 MUTE L6 C8 1000pF C18 31 0.1uF +5GEN + RCA 12V+ 1. TA1101B inputs have a DC bias of 2.5V. If input preamp circuitry is NOT biased at 0V, C14 and C15 may need to be reversed. C20 0.1uF L9 C13 0.47uF C30 0.1uF R10 10, 1/4W 10uH, 2A OUT2- BN5 1000pF C11 1000pF OUT2+ BN6 C22 0.47uF 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. * 3 sq. in. of 1oz. copper directly under TA1101B on solder side of PC board with a 5 x 16 array of 14mil vias. Tripath Technology, Inc. Title http://www.tripath.com Size B Date: 1 TA1101B Evaluation Board Document Number Monday, February 12, 2001 Rev E Sheet 1 of 1 EB-TA1101B Revision: E Bill Of Materials Quantity Reference Value Description Mfgr/Part# COMMENT 2 R10,R9 10, 1/4W Resistor 1 R7 8.2K, 1% Resistor 4 R2, R4, R5, R6 20k Resistor 1 R1 1Meg Resistor 7 C6,C7,C16,C20,C26, C29, C30 0.1uF Capacitor 6 C12, C13, C22,C25,C27,C28 0.47uF Capacitor 5 C8,C9,C10,C11,C21 1000pF Capacitor 2 C23,C24 100pF Capacitor 2 C18,C19 180uF,25V Capacitor 2 C17,C5 1uF Capacitor 2 C15,C14 2.2uF Capacitor 4 L6,L7,L8,L9 10uH, 2A Inductor 3 L1,L2,L5 FBM2125 Ferrite bead 4 D5,D6,D7,D8 MBRS130T3 Diode 1 U1 TA1101B IC 6 BN1, BN2, BN3, BN4, BN5, BN6 Connector 2 J3, J4 Connector RCA input jack 2 J1, J2 Header Header, 2-pin 0.1" Zobel resistor Feedback resistor main output filter cap Panasonic HFQ Low ESR, high temp aluminum elect. Input coupling cap ISI RL622 Taiyo-yuden On Semi Tripath Johnson Components or TOKO 8RDY Output series inductor. FBMJ2125 HM330-T Ferrite bead, 33ohms (100MHz) MBRS130T3 Output protection diode TA1101B 101-09XX-001 PCB mount female banana