TAA4100

TAA4100 TRIPATH | Alldatasheet

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Tripath Technology, Inc. - Technical Information 1 TAA4100 – KL/ Rev. 0.97/04.05 TAA4100 FOUR CHANNEL CLASS-T DIGITAL AUDIO AMPLIFIER USING DIGITAL POWER PROCESSING (DPP TM ) TECHNOLOGY Preliminary Information Revision 0.97 – April 2005 GENERAL DESCRIPTION The TAA4100 is a four-channel Audio Amplifier that uses Tripath’s proprietary Digital Power Processing (DPPTM) technology. Class-T amplifiers offer both the audio fidelity of Class-AB and the power efficiency of Class-D amplifiers. The TAA 4100 has been designed specifically for automotive head unit applications and is configured with fo ur bridged outputs operating on a single 10-26V supply.

APPLICATIONS

¾ Automotive Head Units ¾ Automotive Amplifiers ¾ DVD Receivers ¾ Multimedia Speaker Systems BENEFITS ¾ 4-channel (400W) solution – with integrated FETs - in a single 32-pin SSIP package ¾ High fidelity, high efficiency Class-T ¾ Low external component count ¾ Single-supply operation

FEATURES

¾ Class-T architecture ¾ Four H-Bridge outputs ¾ “Audiophile” Sound Quality ¾ High Efficiency ¾ High Power @25.0V ¾ 100Wsat. sq. wave @ 4Ω ¾ 80W @ 4Ω, 10% THD+N ¾ “Audiophile” Quality Sound ¾ 0.01% THD+N @ 40W 4Ω ¾ 0.01% IHF-IM @ 1W 4Ω ¾ High Efficiency ¾ 88% @ 100W 4Ω ¾ AM “Low EMI” mode ¾ Pop-Free startup and shutdown ¾ High Dynamic Range ¾ Mute and Stand-By function ¾ Automatic DC Offset Trim ¾ Clip Detection Output ¾ Protection Modes: Output Short to VPP and Ground Output Short across Load Load Dump Protection Over-/Under-Voltage Protection Over-current Protection Over-temperature Protection Fortuitous Open Ground

Tripath Technology, Inc. - Technical Information 2 TAA4100 – KL/ Rev. 0.97/04.05 Absolute Maximum Ratings (Note 1) SYMBOL PARAMETER Value UNITS VPP Supply Voltage 33 V VPPMAX Peak Supply Voltage (t< 50ms) 60 V VPPAM Supply Voltage in AM Mode (Note 2) 18 V VINRANGE Voltage Range for Input Section Pins (Note 3) Inputs (Pins 1-4, 6-9) -0.5 to 5.5 V TSTORE Storage Temperature Range -55 to +150 ºC IR Repetitive Peak Output Current 10 A Tj Maximum Junction Temperature 150 ºC PD Total Power Dissipation (Tcase = 70ºC) 80 W ESD ESD Susceptibility - Human Body Model (Note 4) 2k V ESD ESD Susceptibility – Machine Model (Note 5) 200 V Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. See the table below for Operating Conditions. Note 2: Supply voltage is limited in AM Mode due to additional power dissipation of output stage when operating in Class B mode. Please note that t he TAA4100 is still fully protected fr om load dump transients in AM Mode. Note 3: The in put section pins (pins 1-9, 11,12) should not be co nnected to voltages over 5.5V with respect to pin 10 (AGND). Please note that pins 5, 11, and 12 are outputs and can be damaged if a voltage is forced externally. Note 4: Human body model, 100pF discharged through a 1.5KΩ resistor. Note 5: Machine model, 220pF – 240pF discharged through all pins. Operating Conditions (Note 6) SYMBOL PARAMETER MIN. TYP. MAX. UNITS VPP Supply Voltage (Note 6) 10 14.4 26 V VPPAM Supply Voltage for AM Mode (Note 7) 10 14.4 16 V TA Operating Free Air Temperature Range -40 25 85 ºC Note 6: Recommended Operating Conditions indicate conditions for which the device is functional. See Electrical Characteristics for guaranteed specific performance limits. Note 7: Supply voltage is limited in AM Mode due to additional power dissipation of output stage when operating in Class B mode, as opposed to Switching Mode. Thermal Characteristics SYMBOL PARAMETER Value UNITS θJC Junction-to-case Thermal Resistance 1.0° C/W θJA Junction-to-ambient Thermal Resistance (still air) 20° C/W

Tripath Technology, Inc. - Technical Information 3 TAA4100 – KL/ Rev. 0.97/04.05 Electrical Characteristics (Note 8) TA = 25°C. Unless otherwise noted, the supply voltage is VPP = 14.4V. See Application/Test Circuit. Note 8: Minimum and maximum limits are guaranteed but may not be 100% tested. Performance Characteristics (Note 8) TA = 25°C. Unless otherwise noted, the supply voltage is VPP = 14.4V, RL = 4Ω. Measurement Bandwidth = 20kHz. See Application/Test Circuit. SYMBOL PARAMETER Conditions MIN. TYP. MAX. UNITS RIN Input Impedance 43 50 57 kΩ IQ Quiescent Current No load 220 250 mA ISTBY Stand-By Current V SLEEPB < 0.15V 100 200 uA VIL Stand-By On Threshold Voltage SL EEPB Low (amp off) 0.5 V VIH Stand-By Off Threshold Voltage SL EEPB High (amp on) 2.3 V VIL Mute-On Threshold Voltage MUTEB pin Low 1 V VIH Mute-Off Threshold Voltage MUTEB pin High 2.3 V VOS Output Offset Voltage (Mute Off) DC trim active + 3 + 25 mV VOH Fault Reporting Logic Output High Vo ltage Open Drain Output 3.5 V VOL Fault Reporting Logic Output Low Voltage RFAULT = 51KΩ 1 V VIH AM Mode On Threshold Voltage AM pin High 2.3 V VIL AM Mode Off Threshold Voltage AM pin Low 1 V IAM AM Mode Pin Input Current 1 µA SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNITS POUT Output Power (Continuous power/ channel) VPP=25V sat. sq. wave VPP=25V THD+N=10% VPP=25V THD+N=1% VPP=14.4V sat. sq. wave, R L = 2Ω VPP=14.4V THD+N=10%, RL = 2Ω VPP=14.4V THD+N=1%, RL = 2Ω VPP=14.4V sat. sq. wave VPP=14.4V THD+N=10% VPP=14.4V THD+N=1% 100 W W W W W W W W W AV Voltage Gain VOUT/VIN, RIN = 0Ω 28.7 29.7 30.7 dB THD + N Total Harmonic Distortion Plus Noise POUT = 10W/Channel, RL = 4Ω BW = 22Hz-20kHz(AES17) 0.01 % IHF-IM IHF Intermodulation Distortion 19kHz, 20kHz, 1:1 (IHF) POUT = 1W/Channel 0.01 % SNR Signal-to-Noise Ratio A-Weighted, P OUT = 100W/Channel, VPP=25V 97 dB PSRR Power Supply Rejecti on Ratio VPP= 14.4V, Ripple=200mV, f= 1kHz 60 dB η Power Efficiency Vs=25.0V, 4 x 100W sat sq wave 88 % CS Channel Separation Po=1W, f = 1kHz Po=1W, f = 10kHz dB dB enOUT Output Noise Voltage A-Weighted 200 µV

Tripath Technology, Inc. - Technical Information 4 TAA4100 – KL/ Rev. 0.97/04.05 AM Mode (Note 9) TA = 25°C. Unless otherwise noted, the supply voltage is VPP = 14.4V, RL = 4Ω. Measurement Bandwidth = 20kHz. See Application/Test Circuit. Note 9: The TAA4100 heat sinking in AM Mode must be increased (as compared to Class T mode) to sustain the typical output numbers. This is due to the lower efficiency of Class B output stage operation. Please note that the AM Mode operating supply range, due to this increased power dissipation, is 10V-16V. Protection Circuits (Note 8) TA = 25°C. Unless otherwise noted, the supply voltage is VPP = 14.4V. SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNITS IOCD Over-current detect 5.5 A THD+N Total Harmonic Dist plus Noise Po=0.5-5W per channel 0.04 % SNR Signal to Noise ratio A-Weighted, Po=15W 92.5 dB Pout Output Power (Note 7) VPP=16V, THD+N=10% VPP=14.4V, THD+N=10% W W CS Channel Separation Po=1W, f=1kHz 80 dB en Output Noise Voltage A-Weighted 185 µV SYMBOL PARAMETER CONDITIONS MIN. TYP. MAX. UNITS OVON Over-voltage Threshold Over-voltage turn on (amp muted) 27.0 30 32.5 V OVOFF Over-voltage Reset Over-voltage turn off (mute off) 26.0 28.0 V UVOFF Under-voltage Reset Under-voltage turn off (mute off) 9.5 10.0 V UVON Under-voltage Threshold Under-voltage turn on (amp muted) 7.8 8.1 8.6 V OTON Over-Temperature Threshold Over-temperature turn on (amp muted) 150 160 170 °C OTOFF Over-Temperature Reset Over-temperature turn off (mute off) 120 130 140 °C IOC Over-Current Detect 1kHz ramp, VPP = 25V 8.0 9.5 A VPMAX Load Dump Voltage Withstand Test conditions, t r > 2.5ms, tpulse<50mS 60 V

Tripath Technology, Inc. - Technical Information 5 TAA4100 – KL/ Rev. 0.97/04.05 TAA4100 Pinout Note: The heat slug of the TAA4100 is connected to PGND. OUT1P CPUMP PGND OUT4N OUT3N VPP3 OUT3P FAULT OUT2P VPP2 OUT2N IN1 OUT1N PGND VPP1 DCAP OUT4P AGND2 VPPA HMUTEB 5VGEN AGND1 MUTEB OVRLDB AM SLEEPB IN4 IN3 IN2 PGND 32-pin SSIP Package (Top View) VPP4 BIASCAP

Tripath Technology, Inc. - Technical Information 6 TAA4100 – KL/ Rev. 0.97/04.05 Pin Description PIN NAME/FUNCTION TYPE DESCRIPTION

1 IN1 INPUT Channel 1 Input

2 IN2 INPUT Channel 2 Input

3 IN3 INPUT Channel 3 Input

4 IN4 INPUT Channel 4 Input

5 BIASCAP Internal reference bypass capacitor connection

6 SLEEPB INPUT (L) Logic input, ACTIVE LOW. Setting SLEEP to low puts the TAA4100 in sleep mode. This pin must be driven high via an external power supply or microcontroller for the TAA4100 to begin operation. Input range is 0 to 5V with 3.3V compliant inputs. 7 AM INPUT (L) Logic input, ACTIVE HIGH. Enables Analog Mode operation. Typically driven by an external power supply of microcontroller. Input range is 0 to 5V with 3.3V compliant inputs. 8 OVRLDB OUTPUT (L) Logic output, ACTIVE LOW. OVRLDB low indicates the input has overloaded the amplifier 9 MUTEB INPUT (L) Logic Input, ACTIVE LOW. Setting MUTE to low puts the device in mute mode. Typically driven by external power supply or microcontroller. Input range is 0 to 5V with 3.3V compliant inputs.

10 AGND1 GND Analog ground

11 5VGEN On chip 5V regulator bypass capacitor connection 12 HMUTEB OUTPUT (L) Logic output, ACTIVE LOW. HMUTEB low indicates TAA4100 is in mute mode

13 VPPA POWER Positive power supply voltage connection

14 AGND2 GND Analog ground

15 CPUMP OUTPUT Charge pump output capacitor

16 OUT4P OUTPUT Positive Output Channel 4

17 VPP4 POWER Positive Supply Voltage Channel 4

18 PGND GND Power Ground

19 OUT4N OUTPUT Negative Output Channel 4

20 OUT3N OUTPUT Negative Output Channel 3

21 VPP3 POWER Positive Supply Voltage Channel 3

22 OUT3P OUTPUT Positive Output Channel 3

23 FAULT OUTPUT (L) Open Drain Logic Output, ACTIVE HIGH. FAULT high indicates fault condition.

24 OUT2P OUTPUT Positive Output Channel 2

25 VPP2 POWER Positive Supply Voltage Channel 2

26 OUT2N OUTPUT Negative Output Channel 2

27 OUT1N OUTPUT Negative Output Channel 1

28 PGND GND Power Ground

29 VPP1 POWER Positive Supply Voltage Channel 1

30 OUT1P OUTPUT Positive Output Channel 1

31 DCAP OUTPUT External Charge Pump Circuit Output. DCAP is a free running 400kHz square wave between VDDA (pin 13) and AGND (pin 14) with a 14.4Vpp nominal amplitude.

32 PGND GND Power Ground

Tripath Technology, Inc. - Technical Information 7 TAA4100 – KL/ Rev. 0.97/04.05 TAA4100 Functional Block Diagram Processing Modulation VREF VPP PGND Processing Modulation VREF Processing Modulation VREF Processing Modulation VREF MODE CONTROL Mute Standby AM Mode Clipping/Signal Overload Detection PROTECTION Over-Current Over/Under-Voltage Over-Temperature VPP PGND VPP PGND VPP PGND VPP PGND VPP PGND VPP PGND VPP PGND Charge Pump Supply Internal 5V Regulator

Tripath Technology, Inc. - Technical Information 8 TAA4100 – KL/ Rev. 0.97/04.05 Application/Test Circuit TAA4100 CB 0.1uF MUTEB Processing Modulation PGND12 VPP1 CZ 0.22uF RZ 10Ω, 2W OUT1P30 OUT1N27 LO 10uH PGND12 VPP1 DO DO LO 10uH DO DO PGND (PIN 28) VPP (PIN 29) PGND (PIN 28) VPP(PIN 29) CO 0.47uF IN1 1 AGND 50KΩ CI 0.47uF CO 0.47uF Processing Modulation PGND12 VPP2 CZ 0.22uF RZ 10Ω, 2W OUT2P24 OUT2N26 LO 10uH PGND12 VPP2 DO DO LO 10uH DO DO PGND (PIN 28) VPP (PIN 25) PGND (PIN 28) VPP(PIN 25) CO 0.47uF IN2 2 AGND 50KΩ CI 0.47uF CO 0.47uF Processing Modulation PGND34 VPP3 CZ 0.22uF RZ 10Ω, 2W OUT3P22 OUT3N20 LO 10uH PGND34 VPP3 DO DO LO 10uH DO DO PGND (PIN 18) VPP (PIN 21) PGND (PIN 18) VPP(PIN 21) CO 0.47uF IN3 3 AGND 50KΩ CI 0.47uF CO 0.47uF Processing Modulation PGND34 VPP4 CZ 0.22uF RZ 10Ω, 2W OUT4P16 OUT4N19 LO 10uH PGND34 VPP4 DO DO LO 10uH DO DO PGND (PIN 18) VPP (PIN 17) PGND (PIN 18) VPP(PIN 17) CO 0.47uF IN4 4 AGND 50KΩ CI 0.47uF CO 0.47uF 2.5V AGND 5BIASCAP 7AM 8OVRLDB

12 HMUTEB

31 DCAP

29 VPP1

25 VPP2

0.1uF28 PGND CBR 0.1uF + CBR 1000uF VPP PGND

23 FAULT

51KΩ

21 VPP3

17 VPP4

0.1uF18 PGND CBR 0.1uF + CBR 1000uF VPP PGND 115VGEN 10AGND CS 0.1uF +CS 3.3uF 15CPUMP 13VPPA CCP 0.1uF +CCP 3.3uFVPP 14AGND CS 0.1uF VREGEXT SLEEPB 6 AGND VREGEXT CCP 0.1uF DCP DCP CCP 0.1uF VPPCPUMP

32 PGND

0.01uF RL CDO 0.01uF RL CDO 0.01uF RL CDO 0.01uF

Tripath Technology, Inc. - Technical Information 9 TAA4100 – KL/ Rev. 0.97/04.05 External Components Description (Refer to the Application/Test Circuit) Components Description CI AC input coupling capacitor which, in conjunction with R IN, forms a highpass filter at )2(1 INIC CRf π= where RIN is typically 50kΩ. CS Supply decoupling for the power supply pins. For optimum performance, these components should be located close to the TAA4100 and returned to their respective “ground” as shown in the Application/Test Circuit. CBR Supply decoupling for the high current fu ll-bridge supply pins. These components must be located as close to the power supply pins as possible to minimize output ringing which causes power supply overshoot. By reducing overshoot, these capacitors maximize the TAA4100 reliability. These capacitors should have good high frequency performance including low ESR and low ESL. CCP Supply decoupling for the charge pump (h igh side gate drive supply) circuitry. These components must be located as close to the TAA4100 as possible. DO Output diode, which is used to mini mize output overshoots/undershoots on the output nodes These devices clamp the output to the low impedance node formed by the close connection of CBR. Note the connection shown in the Application/Test Circuit. The “high side” diode protects the bottom side device from excessive BVDSS due to overshoots on the output node. The “bottom side” diode protects the top side device from excessive BVDSS due to undershoots on the output node. This device must be an ultra fast rectifier capable of sustaining the entire supply range and high peak currents. CZ Zobel capacitor, which in conjunction with R Z, terminates the output filter at high frequencies. Use a high quality film capacitor capable of sustaining the ripple current caused by the switching outputs. RZ Zobel resistor, which in conjunction with C Z, terminates the output filter at high frequencies. The combination of RZ and CZ minimizes peaking of the output filter under both no load conditions or with real world loads, including loudspeakers, which usually exhibit a rising impedance with increasing frequency. Depending on the program material, the power rating of R Z may need to be adjusted. If the system requires full power operation at 20kHz then the power rating for RZ will likely need to be increased. LO Output inductor, which in conjunction with C O and CDO, demodulates (filters) the switching waveform into an audio signal. Forms a second order filter with a cutoff frequency of )CL2(1 O TOTCf π= and a quality factor of TOTTOTL CRQ CL2 O= where CTOT = CO || 2 * CDO. CO Output capacitor, which, in conjunction with LO, demodulates (filters) the switching waveform into an audio signal. Use a high quality film capacitor capable of sustaining the ripple current caused by the switching outputs. CDO Differential Output Capacitor. Differe ntial noise decoupling for reduction of conducted emissions. Must be located near chassis exit point for maximum effectiveness. RFAULT Pull-up resistor for the open drain FAULT pin output. Recommended resistor value is 51kΩ. DCP Charge pump diodes. Used to generate floating supply for driving high side circuitry. Small signal diodes such as 1N4148 are recommended for these components.

Tripath Technology, Inc. - Technical Information 10 TAA4100 – KL/ Rev. 0.97/04.05 Typical Performance VPP = 14.4V f = 1Khz BW = 22Hz - 20kHz(AES17) THD+N versus Output Power RL = 4Ω RL = 2Ω 0.001 100 0.002 0.005 0.01 0.02 0.05 0.1 0.2 0.5 1 2 5 10 20 50 100 W 0.001 100 0.002 0.005 0.01 0.02 0.05 0.1 0.2 0.5 1 2002 5 10 20 50 100 W VPP = 25V RL = 4Ω f = 1Khz BW = 22Hz - 20kHz(AES17) THD+N versus Output Power -130 -120 -110 -100 -90 -80 -70 -60 -50 -40 -30 -20 -10 d B r A 60 30k100 200 500 1k 2k 5k 10k 20k 19kHz, 20kHz 1:1 PO = 1W VPP = 25V RL = 4Ω 32k FFT FS = 65kHz BW = <10Hz - 80kHz Intermodulation Distortion 0.01 0.02 0.05 0.1 0.2 0.5 20 20k50 100 200 500 1k 2k 5k 10k Hz PO = 1W VPP = 25V RL = 4Ω BW = 30kHz BW = 22kHz THD+N versus Frequency 0 20 40 60 80 100 120 Total Output Power (W) 140 160 100Eff (%) Pdiss (W) Efficiency and Power Dissipation versus Total output Power VPP = 14.4V RL = 4Ω f= 1kHz BW = 22Hz - 20kHz(AES17) Power Dissipation Efficiency 100Eff (%) 0 50 100 150 200 250 300 Total Output Power (W) 350 400 450 Pdiss (W) Efficiency and Power Dissipation versus Total output Power VPP = 25V RL = 4Ω f= 1kHz BW = 22Hz - 20kHz(AES17) Power Dissipation Efficiency 100

Tripath Technology, Inc. - Technical Information 11 TAA4100 – KL/ Rev. 0.97/04.05 Typical Performance (continued) Eff (%) 0 25 50 75 100 125 150 Total Output Power (W) 175 200 225 Pdiss (W) Efficiency and Power Dissipation versus Total output Power VPP = 14.4V RL = 2Ω f = 1kHz BW = 22Hz - 20kHz(AES17) Power Dissipation Efficiency 250 T 0.001 100 0.002 0.005 0.01 0.02 0.05 0.1 0.2 0.5 1 2 5 10 20 50 100 W RL = 8Ω f = 1Khz BW = 22Hz - 20kHz(AES17) THD+N versus Output Power VPP = 14.4V VPP = 25V -120 -110 -100 -90 -80 -70 -60 -50 -40 -30 -20 -10 d B V 20 20k50 100 200 500 1k 2k 5k 10k Hz VPP = 25V RL = 4Ω 32k FFT F S = 65kHz BW = 22Hz - 20kHz(AES17) Noise Floor T T T T T T T -100 -90 -80 -70 -60 -50 -40 -30 -20 -10 20 20k50 100 200 500 1k 2k 5k 10k Hz d B r A VPP = 25V RL = 4Ω PO = 1W BW = 22Hz - 20kHz Channel Separation 10 12 14 2616 2418 22 20 Output Power versus Supply Voltage Supply Voltage (V) Output Power (W) THD+N = SSW THD+N = 10% THD+N = 1% RL = 4Ω f = 1kHz BW= 22Hz - 20kHz(AES17) 100 110 120 10 11 12 13 14 16 15 Output Power versus Supply Voltage Supply Voltage (V) Output Power (W) THD+N = SSW THD+N = 10% THD+N = 1% RL = 2Ω f = 1kHz BW= 22Hz - 20kHz(AES17)

Tripath Technology, Inc. - Technical Information 12 TAA4100 – KL/ Rev. 0.97/04.05 Typical Performance AM Mode 100 0.01 0.02 0.05 0.1 0.2 0.5 1 2 5 10 20 50 100 W AM MODE RL = 4Ω f = 1Khz BW = 22Hz - 20kHz(AES17) THD+N versus Output Power VPP = 14.4V VPP = 16V 01 02 0 3 0 4 05 0 60 Total Output Power (W) 70 80 Eff (%) Pdiss (W) Efficiency and Power Dissipation versus Total output Power AM MODE V DD = 14.4V RL = 4Ω f = 1kHz BW = 22Hz - 20kHz(AES17) Power Dissipation Efficiency

Tripath Technology, Inc. - Technical Information 13 TAA4100 – KL/ Rev. 0.97/04.05

Application Information

The TAA4100 is a 4-channel BTL (Bridge Tied Load) output audio amplifier that operates on a single supply voltage ranging from 10-26V. The device is targeted specifically to meet the demands of OEM and aftermarket automobile in-dash head units. With a single supply voltage of 25V, the device delivers four 100 Watt (saturated square wave) channels into 4 ohm. Since the TAA4100 is a switching amplifier, the average dissipation at low to medium output power is far superior to best in class AB amplifiers specifically designed for in-dash head units. TAA4100 BASIC AMPL IFIER OPERATION The TAA4100 has three major operational blocks: the signal processor, the MOSFET driver and the power MOSFETs. The signal processor is a 5V CMOS block that amplifies the audio input signal and converts the signal to a high frequency switching pattern. This switching pattern is spread spectrum in nature and has a typical idle switching frequency of about 650kHz. The MOSFET driver level shifts the processor’s 5V switching pattern to the VPP power supply voltage and drives the power MOSFETs. The MOSFETs are N-channel devices configured as a full bridge to supply audio power to the load. The outputs of the power MOSFETs must be low pass filtered to remove the high frequency switching pattern leaving only the amplified audio signal. CIRCUIT BOARD LAYOUT The TAA4100 is a power (high current) amplifier that operates at relatively high switching frequencies. Therefore, amplifier outputs switch between the s upply voltage and ground at high speeds while driving high currents. This high-frequency di gital signal is passed through an LC low-pass filter to recover the amplified audio signal. Since the amplifier must drive the inductive LC output filter and speaker loads, the amplifier outputs can be pulled above the supply vo ltage and below ground by t he energy in the output inductance. To avoid subjecting the TAA4100 to potentially damaging voltage stress, it is critical to have a good printed circuit board layout. It is recommended that Tripath’s layout and application circuit be used for all applications and only be deviated from after care ful analysis of the effects of any changes. Please refer to the TAA4100 evaluation board document, EB- TAA4100, available on the Tripath website, at www.tripath.com. The following components are important to place near either their associated TAA4100 pins. The recommendations are ranked in order of layout importance, either for proper device operation or performance considerations. - The capacitors, C BR, provide high frequency bypassing of the amplifier power supplies and will serve to reduce spikes and modulation of the power supply rails. Please note that bypassing requires a combination of capacitors for adequate stabilization. - The output diodes, D O, are used to minimize overshoot s/undershoots on the output node. Improper routing of these diodes will render t hem useless due to PCB trace inductance. Thus, these components must be located very close to the output pins with the “other side of the diode” routed directly to the appropriate VPP or PGND pin. - The capacitors, C S, provide high frequency bypassing of t he amplifier power supplies. Please note that bypassing requires a combination of capacitors for adequate stabilization. TAA4100 GROUNDING Proper grounding techniques are required to maximize TAA4100 functionality and performance. Parametric parameters such as THD+N, Noise Floor and Crosstalk can be adversely affected if proper

Tripath Technology, Inc. - Technical Information 14 TAA4100 – KL/ Rev. 0.97/04.05 grounding techniques are not implemented on the PCB layout. The following discussion highlights some recommendations about grounding both with respect to the TAA4100 as well as general “audio system” design rules. The TAA4100 is divided into two sections: the input section, which spans pins 1-11 and the output (high voltage) section, which spans pins 12 through pin 32. On the TAA4100 evaluation board, the ground is also divided into distinct sections, one for the input and one for the output. To minimize ground loops and keep the audio noise floor as low as possible, the input and output ground should be externally connected at a single point as close to the TAA4100 as possible. Additionally, any external input circuitry such as preamps, or active filters, should be referenced to pin 10. INPUT STAGE DESIGN The TAA4100 input stage is configured as an inverting amplifier that allows the system designer flexibility in setting the low frequency response. The gain is internally set at approximately 30dB with a typical input impedance of 50kohm. Please note that the input stage of the TAA4100 runs off of an internally regulated 5V supply. Thus, the input signal should not exceed 5Vpp (absolute maximum is 6Vpp). Due to the gain structure of the TAA4100, it will likely be necessary to drive the input stage with more than 5Vpp to achieve the saturated sine wave output numbers shown in the typical characteristics. If this requirement is needed for a specific application, then the input pins (pins 1-4) should be schottky diode clamped between AGND (pin 10) and 5VGEN (pin 11). Suitable schottky diode arrays are available in small package footprints from multiple semiconductor companies. INPUT CAPACITOR SELECTION CI and RIN (typically 50kΩ) determine the input low-frequency pole. Typically this pole is set at 10Hz. C I is calculated according to: C I = 1 / (2π x FP x RI) where: RI = 50kΩ FP = Input low frequency pole (typically less than 10Hz) AUTOMATIC OUTPUT OFFSET VOLTAGE CORRECTION The TAA4100 contains an automatic DC calibration routine that reduces the output offset voltage to a maximum of 25mV when the device is active (mute off). Please note that the DC calibration is done on the transition of MUTEB from low to high. The entire calibration sequence takes approximately 6mS after the MUTEB pin is pulled high. POWER SUPPLY REQUIREMENTS The device is configured to operate from a single supply voltage of 10-26V. This allows the device to operate from an automobile battery under various conditions including: battery voltage with the engine off, alternator voltage with engine running and boosted voltage operation up to 26V using a DC-DC converter or voltage booster. The sleep pin must be driven from a microcontroller or external 3.3V or 5.0V power supply. AM MODE The TAA4100 is typically configured as a high power, high efficiency, four channel switching amplifier. The TAA4100 also has an additional amplifier mode named “AM Mode.” By pulling the AM pin to a logic high level, the TAA4100 is configured as a Class B amplifier as opposed to the normal, Class-T amplifier.

Tripath Technology, Inc. - Technical Information 15 TAA4100 – KL/ Rev. 0.97/04.05 AM mode significantly reduces EMI generation since the output amplifiers are now operated in linear mode. Operating in Class B mode also reduces the TAA4100 efficiency especially at low to medium output powers. Due to this increased power dissipation, it is recommended that the AM mode is used for applications such as AM radio playback where the average output level is minimal and a switching amplifier would most effect radio reception. The operating supply range is also limited to 10V-16V due to the increased power dissipation. A DC to DC converter that is used to step up the battery voltage for Class T operation (for instance 14.4V Æ 20V or above) should be disabled before entering AM Mode. This will ensure that the supply voltage in AM Mode is limited to the battery voltage thereby minimizing the device power dissipation. To avoid possible damage to the output stage, appropriate sequencing must be adhered to when activating or disabling AM Mode. The TAA4100 MUST be muted (MUTEB = high) during logic changes of the AM pin. To change from Class-T mode to AM Mode, the following procedure must be followed. With AM = Low and MUTEB = High Æ MUTEB = Low Æ AM = High Æ MUTEB = High To change from AM Mode to Class-T mode, the following procedure must be followed. With AM = High, MUTEB = High Æ MUTEB = Low Æ AM = Low Æ MUTEB = High Thus, MUTEB is low during any transition of the AM pin. PROTECTION CIRCUITS The TAA4100 is guarded against over-current, over/under voltage, and over-temperature conditions. If the device goes into one of the various protection states, the FAULT pin goes to a logic HIGH state indicating a fault condition. When this occurs, all amplifier outputs are TRI-STATED and will float to VDD. OVER-CURRENT PROTECTION An over-current fault occurs if more than approximately 9.5 amps (typical) of current flows from any of the amplifier output pins. This can occur if the speaker wires are shorted together, if one side of the speaker is shorted to ground, or if an output is connected to VPP. An over-current fault sets an internal latch that automatically clears after a 600mS second delay. OVER AND UNDER VOLTAGE PROTECTION The over-voltage protection of theTAA4100 will be activated if the supply voltage is increased above 30.0 volts (typical) and 27.0 volts (minimum). This fault puts the amplifier into mute and resets automatically once the supply voltage is reduced below the hysteresis band (26.0 volts). The TAA4100 also has built-in load dump protection. This circuit puts the amplifier into sleep mode if the supply voltage is increased above 30V. The TAA4100 is able to survive power supply spikes to 60V if the duration is less than 50mS. The TAA4100 is also equipped with under voltage protection. This circuit is activated if the supply voltage goes below 8.1 volts (typical) and causes the output to mute. Increasing the supply voltage above the hysteresis band (typically 9.5V) will bring the amplifier out of mute mode.

Tripath Technology, Inc. - Technical Information 16 TAA4100 – KL/ Rev. 0.97/04.05 OVER-TEMPERATURE PROTECTION An over-temperature FAULT occurs if the junction temperature of the part exceeds 160°C (typical). The thermal hysteresis is approximately 30°C, therefore the fault will automatically clear when the junction temperature drops below 130°C. SLEEP PIN (Active LOW) The SLEEPB (SLEEP) pin is a logic input that when pulled low puts the TAA4100 into a low quiescent current mode. This pin must be pulled up to an external 3.3V or 5V supply to activate (disable sleep mode) the TAA4100. The sleep pin cannot be pulled up to VPP due to internal circuitry limitations. The amplifier takes approximately 500mS to come out of sleep. This period of time allows the input capacitor to charge fully assuming a value of 0.47uF. If the input capacitor size is increased, then additional time will be required to allow for the input capacitor to fully charge. To ensure that turn on is pop-free, the input capacitor must be fully charged before MUTEB is pulled high. MUTEB PIN The MUTEB pin is a logic input that mutes the TAA4100. Pulling this pin low activates the mute circuitry. Pulling the pin high enables output switching and amplification. Please note that the input stage is still biased at approximately 2.5V, even when MUTEB pin is low. This keeps the BIASCAP, CB and input coupling capacitors, CI, completely charged. This allows for a clean transition from mute to on, and vice- versa, which eliminates turn-on/off pops. Please note that DC calibration is done every time MUTEB transitions from low to high. The DC calibration takes approximately 6mS. FAULT PIN The FAULT pin is a logic output that indicates various fault conditions within the device. These conditions include: over-voltage, under-voltage, over-current at any output, low charge pump voltage, low 5V regulator voltage, and over-temperature (junction temperature greater than approximately 160°C). The FAULT pin is an open drain output. The recommended pull-up to an external 3.3V or 5V supply is 51kΩ. Alternatively, this pin can be pulled up to VPP through a 51kΩ resistor. A logic high on this pin indicates a fault condition. This pin has a 1mA maximum sink current capability. HMUTEB PIN The HMUTEB pin is a logic output that indicates if the TAA4100 is muted. This mute state can be simply caused a low state on the MUTEB pin or by various fault conditions within the TAA4100. A logic low on the HMUTEB pin indicates the TAA4100 is muted. TURN-ON AND TURN-OFF NOISE If turn-on or turn-off noise is present in a TAA4100 amplifier, the cause is frequently due to other circuitry external to the TAA4100. The TAA4100 has extremely sophisticated turn on and off pop suppression circuitry that will eliminate “pops’ in nearly all configurations. It is recommended that the MUTEB pin is pulled low during power-up and power-down of the VPP supply. In addition, MUTEB must be held low until the input capacitor is fully charged. Thus, a power on sequence as follows is recommended. First, power up the TAA4100 with SLEEPB and MUTEB low. Pull SLEEPB high and let input capacitor charge (minimum sleep time is about 500mS). Then, pull MUTEB high. On power off, MUTEB should be pulled low and then the power supply voltage removed. It is not necessary to activate SLEEPB on power down.

Tripath Technology, Inc. - Technical Information 17 TAA4100 – KL/ Rev. 0.97/04.05 OUTPUT FILTER DESIGN One advantage of Tripath amplifiers over PWM solutions is the ability to use higher-cutoff-frequency filters. This means any load-dependent peaking/droop in the 20kHz audio band potentially caused by the filter can be made negligible. This is especially important for applications where the user may select a 4Ω or 8Ω speaker. Furthermore, speakers are not purely resistive loads and the impedance they present changes over frequency and from speaker model to speaker model. The core material of the output filter inductor has an effect on the distortion levels produced by a TAA4100 amplifier. Tripath recommends an output inductor capable of at least 9A before saturation. Recently, there have been a number of dual inductors designed specifically for bridged output switching amplifiers such as the TAA4100. These dual inductors are two inductors shielded by a common ferrite shield. They may be manufactured as common mode chokes with the windings wound in the same direction or as differential mode chokes with the windings wound in opposite directions. Since the ferrite reduces the energy storage capability of the inductor, it is important to ensure that the shielded dual inductor does not saturate at the maximum currents attainable by the TAA4100. Dual inductors wound as common mode inductors may aid in reducing common mode noise to the load. They also may result in lower than initial inductances due to electric field cancellation effects. Tripath also recommends that an RC damper be used after the LC low-pass filter. No-load operation of a TAA4100 amplifier can create significant peaking in the LC filter, which produces strong resonant currents that can overheat the integrated MOSFETs and/or other components. The RC dampens the peaking and prevents problems. It is highly recommended that the design process for a TAA4100 amplifier include an analysis of the interaction of intended speaker(s) with the LC filter and RC damper to ensure the desired frequency response is attained. Component values for the LC filter and RC damper may need to be altered from the Tripath suggestions to achieve the required response. PARALLELING THE OUTPUTS The outputs of the TAA4100 can be paralleled to increase the current capability as compared to a single output. Each output must still have its own inductor. Thus, the device output pins cannot be directly connected. All 4 channels can be paralleled (after the inductors) or a pair of channels could be paralleled, for example CH1 and CH2 while using CH3 and CH4 a single bridged channels. To parallel, simply connect OUTxP to OUTyP of an adjacent channel, and OUTxN to OUTyN of an adjacent channel. Again, this connection needs to be after the output inductors (10uH in most cases). Paralleling 2 channels will allow 2 ohm operation across the entire supply range of 10-26V. Paralleling all 4 channels will allow 1 ohm operation across the entire supply range. Please note that the same input signal must be driven into each channel that is being paralleled. Also, individual input capacitors should still be used for each channel. PERFORMANCE MEASUREMENTS OF A TAA4100 AMPLIFIER Tripath amplifiers operate by modulating the input signal with a high-frequency switching pattern. This signal is sent through a low-pass filter (external to the TAA4100) that demodulates it to recover an amplified version of the audio input. The frequency of the switching pattern is spread spectrum and typically varies between 200kHz and 1.5MHz, which is well above the 20Hz – 22kHz audio band. The pattern itself does not alter or distort the audio input signal but it does introduce some inaudible noise components. The measurements of certain performance parameters, particularly those that have anything to do with noise, like THD+N, are significantly affected by the design of the low-pass filter used on the output of the

Tripath Technology, Inc. - Technical Information 18 TAA4100 – KL/ Rev. 0.97/04.05 TAA4100 and also the bandwidth setting of the measurement instrument used. Unless the filter has a very sharp roll-off just past the audio band or the bandwidth of the measurement instrument ends there, some of the inaudible noise components introduced by the Tripath amplifier switching pattern will get integrated into the measurement, degrading it. Tripath amplifiers do not require large multi-pole filters to achieve excellent performance in listening tests, usually a more critical factor than performance me asurements. Though using a multi-pole filter may remove high-frequency noise and improve THD+N ty pe measurements (when they are made with wide- bandwidth measuring equipment), these same filters can increase distortion due to inductor non-linearity. Multi-pole filters require relatively large inductors, and inductor non-linearity increases with inductor value.

Tripath Technology, Inc. - Technical Information 19 TAA4100 – KL/ Rev. 0.97/04.05

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Tripath Technology, Inc. - Technical Information 20 TAA4100 – KL/ Rev. 0.97/04.05 PRELIMINARY INFORMATION – This product is still in development. Specifications are subject to change based on future product analysis and characterization. Please contact Tripath Technology for additional information not included or covered in this advanced document. Tripath Technology Inc. reserves the right to make changes without further notice to any products herein to improve reliability, function or design. Tripath does not assume any liability arising out of the application or use of any product or circuit described herein; neither does it convey any license un der its patent rights, nor the rights of others. Tripath and Digital Power Processing are trademarks of Tripath Technology Inc. Other trademarks referenced in this document are owned by their respective companies TRIPATH’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN CONSENT OF THE PRESIDENT OF TRIPATH TECHNOLOGY INC. As used herein: 1. Life support devices or system s are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose fa ilure to perform, when properly used in accordance with instructions for use provided in this labeling, can be reasonably expected to result in significant injury to the user. 2. A critical component is any component of a life su pport device or system whose failure to perform can be reasonably expected to cause the failure of the life s upport device or system, or to affect its safety or effectiveness. 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

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FOUR CHANNEL CLASS-T DIGITAL AUDIO AMPLIFIER USING DIGITAL POWER PROCESSING (DPPTM ) TECHNOLOGY

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