EB-TA2022 CLASS-T DIGITAL AUDIO AMPLIFIER 2 CHANNEL TA2022 EVALUATION BOARD

Transcription

1 Tripath Technology, Inc. - Technical Information EB-TA0 CLASS-T DIGITAL AUDIO AMPLIFIER CHANNEL TA0 EVALUATION BOARD Technical Information Revision.0 March 00 GENERAL DESCRIPTION The EB-TA0 Version.0 is a stereo 00W per channel audio amplifier designed to provide a simple and straightforward environment for the evaluation of the TA0 amplifier. This evaluation board includes a circuit that will automatically trim any DC offset at the output and a relay. For additional documentation on the TA0, see the TA0 Data Sheet. APPLICATIONS Mini/Micro Component Systems Home Theater Receivers Car stereo head units & trunk amplifiers Powered DVD Systems BENEFITS More power per cubic inch for 00W per channel design Simplifies thermal management Signal Quality comparable to linear amplifiers Simple building block for multi-channel design FEATURES High Power: Ω,.0% THD+N Low Noise Floor: 0uV A-weighted Low Distortion:.0% 7W, Ω High Efficiency: 9% for 8Ω loads 87% for Ω loads Dynamic Range = 0dB Over-Current Protection Over and Under Voltage Protection Over Temperature Protection Single Ended Outputs EB-TA0 Rev..0/0.0

2 Tripath Technology, Inc. - Technical Information OPERATING INSTRUCTIONS BOARD CONNECTION DIAGRAM J TA0 V+ Pgnd V- Vo GND GND Vo AGND V IN AGND IN AWAKE MUTE J J Audio Source OUT AGND OUT + - V VPP Pgnd VNN Speaker Right Speaker Left Three external power supplies are required to operate the EB-TA0: VPP, VNN (referenced to Pgnd), and V (referenced to Agnd). The VPP and VNN form a split rail supply referenced to Pgnd. The V ground (Agnd) must be kept separate from the VPP and VNN ground (Pgnd). Agnd and Pgnd are joined at a common point on the EB-TA0 near headers J and J. Minimum and Maximum supply voltages are +/-0V and +/-6V, respectively, depending on the load impedance. It is not recommended that the EB-TA0 be operated above +/-V when driving Ω loads, single ended, as the internal current limit circuit may activate, causing the amplifier to mute. The VPP and VNN power supply connection, J, is through a 7-Pin 0.6 spaced header. The female terminal housing for this header is Molex Please see TABLE for header connections. The V power supply connection, J, is through a -Pin 0.00 spaced header. The female terminal housing for this header is Molex Please see TABLE for header connections. EB-TA0 Rev..0/0.0

3 Tripath Technology, Inc. - Technical Information TABLE TABLE J Connector Pin# Connection J Connector Pin# Connection Pin Agnd Pin Vo Pin V Pin GND Pin IN Pin GND Pin Agnd Pin Vo Pin IN Pin VNN Pin6 Pgnd Pin7 VPP OUTPUT The output connection for each channel of the EB-TA0 is made at pins of header J. The output of the TA0 is single-ended, therefore each output has a positive output (Vo and Vo) and a ground (GND and GND). INPUT The input connection for each channel of the EB-TA0 is made at pins of header J. The left and right inputs should be connected to IN (pin) and IN (pin). These inputs share a common ground referenced to Agnd (pin). JUMPER SETTINGS There is a -pin header for the MUTE control of the TA0. With the jumper placed in the AWAKE position the part is un-muted by grounding (AGND) the mute pin. When the jumper is placed in the MUTE position the mute pin is pulled high (V) and the amplifier is muted. OUTPUT OFFSET NULL AND RELAY There is an automatic offset trim circuit for each channel using an LM8 op-amp. Once the LM8 trims any DC to 0Vdc a comparator allows a relay to close. GAIN SETTING The gain of the EB_TA0 Version.0 is set to 8V/V. The gain of the TA0 is the product of the input stage and the modulator stage. The input stage gain is set to unity. Before changing the gain of the TA0, please refer to the TA0 Amplifier Gain section of the TA0 Data Sheet. EB-TA0 Rev..0/0.0

4 Tripath Technology, Inc. - Technical Information Performing Measurements on the EB-TA0 Version.0 The TA0 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 00kHz and MHz, which is well above the 0Hz 0kHz 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 TA0 amplifier switching pattern will degrade the measurement by including out of band (audio) energy. One feature of the TA0 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 EB-TA0 has a simple two-pole output filter with excellent performance in listening tests. (See Application Note for additional information on bench testing) Contact Information TRIPATH TECHNOLOGY, INC 60 Orchard Parkway, San Jose, CA P F For more Sales Information, please visit For more Technical Information, please visit EB-TA0 Rev..0/0.0

5 EB-TA0 Revised: /8/00 JR. Revision: Ver.0 Bill Of Materials Item Quantity Reference Part Digikey Part # Manufacturers Part# (Package) 0 C,C,C,C,C8, 0.uF;0V PCC86CT-ND Panasonic ECJ-VFH0Z (SMT 080) C9,C,C8,C9,C0 C,C 0.uF;00V AVX-06C0KATA (SMT 06) C7 90pF;0V PCC9CGCT-ND PANASONIC ECJ-VCH9J(SMT 080) C6 0pF;0V PCCCGCT-ND PANASONIC ECJ-VCHJ(SMT 080) C,C6,C,C6.uF;V P666-ND Panasonic ECE-AZR(Thru-Hole) 6 C7,C8,C9,C0 0.uF;0V P667-ND Panasonic ECQ-VHJL(Thru-Hole) 7 C9,C 0uF;0V P06-ND Panasonic EEU-FCHS(Thru-Hole) 8 C 00uF;V P6-ND Panasonic ECA-VM0(Thru-Hole) 9 C7,C8 7uF;6V P80-ND Panasonic ECE-ACKA70(Thru-Hole) 0 C uf, 0V P960-ND Panasonic ECE-AAKS0(Thru-Hole) D,D8,D9 B00/B B00DICT-ND Diodes Inccorporated (SMA) D,D,D,D MURS0T MURS0T (SMT SMB) D N NBDICT-ND V, 00mW, DO- D N NBDICT-ND 6.8V, 00mW, DO- D N8 N8DICT-ND DO- 6 D6 LED 7 J 7-pin,0.6" header WM60-ND Molex J -pin,0.00" header WM0-ND Molex J -pin,0.00" header WM00-ND Molex J9,J0 Screw Terminal 890K-ND Keystone 890 L 00uH TK00-ND JWMiller k or Toko 87LY-0J L,L6 uh American Cores AW T--V*see note R7,R8 9Ω (SMT 080) R6 00Ω (SMT 080) R0,R,R,R,R0 KΩ (SMT 080) 6 R6,R8,R9,R0.KΩ (SMT 080) 7 R,R7 KΩ (SMT 080) 8 R 8.KΩ,% (SMT 080) 9 R,R7,R,R 9.KΩ,% (SMT 080) 0 R8,R9 0KΩ (SMT 080) R8 KΩ (SMT 080) R,R,R,R 0KΩ, % (SMT 080) R7 KΩ (SMT 080) R9 KΩ (SMT 080) R,R0,R,R,R 0KΩ (SMT 080) 6 R 80KΩ (SMT 080) 7 R,R,R 00KΩ (SMT 080) 8 R 00KΩ (SMT 080) 9 R,R6,R6 9KΩ,% (SMT 080)

6 0 R6,7 6Ω;W P6.W-BK-ND (W Thru-hole) U TA0 Tripath Technology U LM8 LM8N-ND 8-Dip U LM9 LM9N-ND -Dip Q,Q,Q N7000 N7000FS-ND TO-9 Q N906 N906-ND TO-9 6 K DPDT RELAY 8A,V PB97-ND RTE0F 7 CON,CON,CON,CON /8"STANDOFF 80K-ND 8 STANDOFF NUT HEX -0 H66-ND 9 screw terminal(horiz.) J9,J0 890k-nd Keystone screw terminal screw /" -0 H-ND TA0 washer NO. FLAT H7-ND TA0 screw /8" -0 H78-ND Note : Inductor selection is critical for optimal operation of the TA0 as well as being an important component in over current protection and EMI containment. Tripath recommends the customer use a toroidal inductor for all applications with the TA0. For typical applications we recommend the Micrometals T68- core or the American Cores (Amidon) T This core has a high peak current capability due to its low-m Carbonyl-E metal powder. A distributed air gap increases its' energy storage capability, Which allows for a small footprint and high current capability. The T68- and T cores have a 7.mm outer diameter. Forty-four turns of AWG wire makes a complete single layer winding around the toroid with six to eight layers overlapping yielding an ideal value of uh. This widing pattern, which covers the core completely, aids in shielding the electric field. It should be noted that when multiple layers are used there may be an increase in winding capacitance, which can cause ringing and increased radiated emmisions. Winding techniques, such as bank winding, can minimize this effect. It is important that the innitial windings not be crossed over by the last few windings. If a few windings more than the single layer are required it is best to wind the core with a full single layer, back off a number of turns,and rewind over the last few windings. A larger diameter Carbonyl-E core may be used if a single layer wound core is required. If a smaller core is required, a.mm outer diameter Carbonyl-E core may be substituted, though thermal requirements must be considered. Please contact Tripath Applications if there are questions pertaining to this subject. Substitution Notes: - ITEM#- This component must be.uf, 00V with X7R material characteristic and placed close to pins,8 and 9,0 of TA0 with less than /8" lead length to the part. - ITEM#7- This component should be a high frequency,low ESR capacitor. We recommend.ω, or less and a ripple current rating of at least A. - ITEM#- This component should be a 0A inductor with very high linearity. Please see Data Sheet for substitution details. - ITEM#- This component should be an ultra-fast PN junction rectifier diode with a maximum Vf of V at 0A. - ITEM#- The Bootstrap Diodes(D8,D9)should be Schottky diodes rated at least 00mA,00V,0nS. The VN0 Diode (D) should be a Fast Recovery, switching, or Shottky diode rated at least 00mA,0V,0nS.

7 tornado_p_zip_6 TA0-00 U L 00uH;JWMiller k or Toko 87LY-0J VBOOT VN0 VPP VN0SW HOCOM OUT VNN VNN OUT HOCOM VPP VBOOT VN0FBK AGND V REF VNSENSE VPSENSE AGND V OAOUT INV MUTE OAOUT INV BIASCAP FBKGND FBKOUT FBKGND FBKOUT HMUTE D D C VN0 VN0FDBK V- R0 k C 0.uF;0v C7 7uF;6v D B00/B C 00uF;v R8 0 C.uF;6V C 0.uF;v D8 B00/B C9 D MURS0 C 0uF;0V 0uF;0V PGnd D9 B00/B D D MURS0 MURS0 V+ 0.uF;00V C V- D MURS0 C 0.uF;00V VN0FDBK R7 0 C.uF;6V V R 8.k Vnsense Vpsense C8 7uF;6v R 9.k R 9.k R 0k C9 0.uF;6v MUTE R0 k R 0k C8 0.uF;6v R k R k R k R k AGnd D6 LED R 0K R 0K V C.uF, V C6.uF, V HMUTE AGnd IN IN Vpsense Vnsense R 9k V+ C B Voa Voa R6 6;W C7 0.uF;0V R7 6;W L uh T68- Core(AWG) L6 uh T68- Core(AWG) R7 9.k FBKGND FBKGND R 9.k C6 0pF;0V R6.k R8.k R9.k C7 90pF;0V R0.k AGnd R6 9k V- B A PGnd C8 0.uF;0V Vob Vob V- V+ C9 0.uF;0V PGnd PGnd PGnd C0 0.uF;0V J 6 7 CON7 IN IN V J CON AGnd V MUTE J HEADER AGnd PGnd STA J0 STANDOFF STA STANDOFF J9 SCREW TERMINAL STA STANDOFF STA STANDOFF A Title EB-TA0 Ver..0 Size Document Number Rev B Schematic.0 Date: Friday, March 0, 00 Sheet of

8 C.uF D C Voa HMUTE Voa R 0k R 0k C8 0.uF UA LM8 R 00K C7 0.uF R9 0k R 80k R7 k R8 k R9 k Q N7000 V+ R7 k UA LM9 UB LM9 UC LM9 C0 0.uF D N R6 0k Q N7000 R 0K D N C uf, 0V R 00k Q N906 R 00k V+ Q N7000 D n8 R6 00 Vob Vob FBKGND K DPDT RELAY Voa Voa D C B R 0k C9 0.uF R0 0k R 00K C6.uF UB LM R8 0k UD LM9 FBKGND B A A Title OFFSET CORRECTION & RELAY CIRCUIT Size Document Number Rev B SCHEMATIC.0 Date: Friday, March 0, 00 Sheet of

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