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Description

1-3

Introduction

1.2

Description

The TPA005D02 Class D Stereo Audio Power Amplifier Evaluation Module is
a complete, 2-Watt per channel stereo audio power amplifier. It consists of the
TI TPA005D02 Class D Stereo Audio Power Amplifier IC along with a small
number of other parts mounted on a circuit board that measures approximately
2

1/4

 inches by 1

3/4

 inches (Figure 1–1).

Figure 1–1. The TI TPA005D02 Class D Stereo Audio Amplifier Evaluation Module

Texas Instruments

1998

R6

R7

VDD

GND

L1

L2

L3

L4

U1

C21

C19

C15

+

TPA005D02 EVM Board     Rev. A

VDD

GND

C25

Lout+

Lout–

Mute

Rout–

Rout+

C24

D2

D3

C4

C2

C3

C5

GND

RIN+

RIN–

C1

R2

R1

Q1

LIN–

LIN+

GND

Mute

S1

D1

C9

SLOP223

C7

C6

1

R3

+

C22

C23

C12

C10

C14

C13

C17

S2

C20

R4

R5

C8

C1
1

C27

C26

Shutdown

Single in-line header pins extend from the underside of the module circuit
board to allow the EVM to either be plugged into the TI Plug-N-Play Audio Am-
plifier Evaluation Platform, or to be wired directly into existing circuits and
equipment when used stand-alone.

The platform has room for a single TPA005D02 class D evaluation module and
is a convenient vehicle for demonstrating TI’s audio power amplifier and
related evaluation modules. The EVMs simply plug into the platform, which
automatically provides power to the modules, interconnects them correctly,
and connects them to a versatile array of standard audio input and output jacks
and connectors. Easy-to-use configuration controls allow the platform and
EVMs to quickly model many possible end-equipment configurations.

There is nothing to build, nothing to solder, and nothing but the speakers
included with the platform to hook up.

Содержание TPA005D02

Страница 1: ...TPA005D02 Class D Stereo Audio Power Amplifier Evaluation Module October 1998 Mixed Signal Products User s Guide SLOU032A...

Страница 2: ...ONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OF DEATH PERSONAL INJURY OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE CRITICAL APPLICATIONS TI SEMICONDUCTOR PRODUCTS ARE NOT DESIGNED AUTHORIZED OR WARRANT...

Страница 3: ...This equipment is intended for use in a laboratory test environment only It generates uses and can radiate radio frequency energy and has not been tested for compliance with the limits of computing d...

Страница 4: ...iv...

Страница 5: ...verview of Class D Audio Amplifiers 3 5 3 2 3 EVM Design Considerations 3 7 3 2 4 Efficiency of Class D vs Linear Operation 3 15 3 3 Using The TPA005D02 Class D EVM With the Plug N Play Platform 3 22...

Страница 6: ...nal Showing Peak and RMS Power with Music Applied 3 20 3 17 Supply Current vs Peak Output Voltage of TPA005D02 vs TPA0202 with Music Input 3 21 3 18 Platform Signal Routing and Outputs 3 24 3 19 Mute...

Страница 7: ...ss D Stereo Audio Amplifier Evaluation Module SLOP223 It includes a list of EVM features a brief description of the module illustrated with a pictorial diagram and a list of EVM specifications Topic P...

Страница 8: ...luation Platform J Evaluation module is designed to simply plug into the platform automatically making all signal control and power connections J Platform provides flexible power options J Jumpers on...

Страница 9: ...R4 R5 C8 C11 C27 C26 Shutdown Single in line header pins extend from the underside of the module circuit board to allow the EVM to either be plugged into the TI Plug N Play Audio Am plifier Evaluation...

Страница 10: ...4 Introduction 1 3 TPA005D02 Class D EVM Specifications Supply voltage range VDD 4 5 V to 5 5 V Supply current IDD 2 8 A max Continuous output power per channel PO 4 BTL VDD 5 V 2 W Audio input volta...

Страница 11: ...g connections directly to the module pins and it can be wired directly into existing circuits or equipment The platform switch and jumper settings shown in Table 2 1 are typical for the TPA005D02 clas...

Страница 12: ...or both may result Figure 2 1 Quick Start Platform Map 3 Signal Conditioning CAUTION Do not insert or remove EVM boards with power applied ICC JP4 F1 VR1 R1 JP3 JP2 JP1 AC DC J2 VCC J1 D1 D2 D3 D4 J2...

Страница 13: ...S3 P N P Platform Mute X Lo Note 2 U5 Notes 1 X Don t care 2 Set S2 to ON when signal conditioning board is installed in U1 set S2 to OFF when no signal conditioning board is installed Power supply 7...

Страница 14: ...ate right channel and left channel VDD supplies can be connected or a single supply can be used for both Inputs and outputs 3 Ensure that audio signal source level adjustments are set to minimum 4 Con...

Страница 15: ...ule module performance graphs and module PCB layer illustrations Topic Page 3 1 Precautions 3 2 3 2 The TPA005D02 Audio Power Amplifier Evaluation Module 3 3 3 3 Using The TPA005D02 Class D EVM With t...

Страница 16: ...or both may result Figure 3 1 The TI Plug N Play Audio Amplifier Evaluation Platform Signal Conditioning CAUTION Do not insert or remove EVM boards with power applied ICC JP4 F1 VR1 R1 JP3 JP2 JP1 AC...

Страница 17: ...atform Figure 3 1 or wired directly into circuits or equipment The module has single in line header connector pins mounted to the underside of the board These pins allow the module to be plugged into...

Страница 18: ...47 F 0 047 F C20 1 F 1 F 1 F C6 C8 C3 C2 470 pF 470 pF RIN RIN LIN LIN GND MUTE GND VDD VDD R1 20 K R2 1 K C1 1 F VDD D1 3 9 V R3 20 K S1 R4 100 K Q1 2N3906 U1 TPA005D02 R5 100 K S2 C4 0 22 F C27 220...

Страница 19: ...Bridge LPF VCONTROL Load Ramp Generator PWM Control VOUT The audio input signal Vin is applied to a comparator along with a triangle wave created by the ramp generator Vramp When the triangle wave cr...

Страница 20: ...ation which further enhances the amplifier performance 3 2 2 1 BTL Operation In the bridge tied load output mode the two output lines of each channel operate as mirror images of each other for increas...

Страница 21: ...er and C 1 F for the value of capacitors C2 C3 C6 and C7 These values give a 3 dB point of 15 9 Hz close to the desired 3 dB point of 20 Hz Ceramic capacitors are preferred over electrolytic for their...

Страница 22: ...ance The values used in the output filter are 15 H for the inductor and 0 22 F and 1 F capacitors in parallel for an equivalent capacitance of 2 22 F setting the cutoff frequency to 27 5 kHz The main...

Страница 23: ...0 1 radian second which means that the components must be frequency scaled To frequency scale each component is divided by 0 2 fc fc is the desired cut off frequency in Hertz C SE 1 2 R L 0 L SE 2 R L...

Страница 24: ...or loses its functionality and looks like a short circuit to the PWM signal which increases the harmonic distortion considerably A shielded inductor may be required if the class D amplifier is placed...

Страница 25: ...aluminum electrolytic capacitors were chosen Tantalum capacitors provide a higher capacitance value in a smaller package and have lower ESR values than aluminum electrolytic capacitors SMT packages fu...

Страница 26: ...attached If a voltage spike or current spike hits the ground plane the entire plane shifts up or down unlike a split plane which has inductance between the halves that dampens the noise and can cause...

Страница 27: ...er when the amplifier IC is initially placed in shutdown The PNP transistor needs to be biased so that it is operational from at least 4 5 V to 5 5 V Zener diode D1 and resistors R1 R2 and R3 set the...

Страница 28: ...operating the shutdown or mute switch Table 3 1 TPA005D02 Class D EVM Fault Indicator Table LED 1 LED 2 Fault Description OFF OFF No faults device is operating normally OFF ON Under voltage condition...

Страница 29: ...r amplifier is designed to act as a variable resistor network between the power supply and the load The transistors operate in their linear region and voltage that is dropped across the transistors in...

Страница 30: ...Figure 3 9 transitions between the supply voltage and slightly below ground The inductor and capacitor form a low pass filter which makes the output current equal to the average of the inductor curre...

Страница 31: ...ciency h PL PSUP Efficiency h VDD VP2 2RL 2 p V P RL Efficiency h 1 Efficiency h p 4 V P V DD In the ideal efficiency equations assume that VP VDD which is the maximum sine wave magnitude without clip...

Страница 32: ...on above 0 causes conduction loss Figure 3 13 shows an H bridge output circuit simplified for conduction loss analysis and can be used to determine new efficiencies with conduction losses included Fi...

Страница 33: ...SW V DD 2RDS on R L 2RDS on 2 2RDS on Switching losses are constant at all output power levels which means that switching losses can be ignored at high power levels in most cases At low power levels h...

Страница 34: ...ower results in a higher crest factor Crest Factor 10 log PPK Prms Figure 3 15 Audio Signal Showing Peak and RMS Power Time PPK Power PRMS Figure 3 16 is a comparison of a 5 V class D amplifier to a s...

Страница 35: ...rent vs Peak Output Voltage of TPA005D02 vs TPA0202 with Music Input 400 350 250 200 150 0 300 1 1 5 2 2 5 Supply Current mA rms SUPPLY CURRENTS vs PEAK OUTPUT VOLTAGE AND PEAK OUTPUT POWER 4 3 3 5 10...

Страница 36: ...only with the proper orientation Evaluation modules are easily removed from the platform by simply prying them up and lifting them out of their sockets Care must be taken however to prevent bending t...

Страница 37: ...le S1 connects the amplifier IC SHUTDOWN pin to ground forcing it into a low power state This function is not controlled by a control input to the module only by switch S1 The shutdown mode reduces th...

Страница 38: ...t U1 if an EVM is installed there or socket U1 can be bypassed and the audio input signal applied directly to the inputs of the TPA005D02 class D EVM Platform switch S2 selects signal conditioning or...

Страница 39: ...ound R4 and R5 The switch in the headphone jack pulls one line or the other up to VDD through a 240 resistor R3 depending on whether a plug is inserted in J10 or not Figure 3 19 Mute Mode and Polarity...

Страница 40: ...connected to the platform should be capable of providing 5 A of current to avoid clipping of the output signal during peaks Current consumption driving speakers at normal listening levels is typicall...

Страница 41: ...nnectors for stripped speaker wires J8 and optionally through a miniature 1 8 stereo phone jack J10 for headphones The audio output lines from the power amplifiers are separate all the way to the edge...

Страница 42: ...are connected to ground Note that the mute signal applied to the EVM mute pin must be able to supply enough current to overcome the pullup resistor on the module 100 k Do not drive the module inputs...

Страница 43: ...27M010 C24 C25 C26 C27 Capacitor Ceramic 0 22 F 25 V X7R 10 0603 4 muRata GRM39X7R224K10 C22 C23 Capacitor Metal Film 1 F 50 V 5 leaded 0 287 0 315 0 197 2 Panasonic ECQ V1H105JI D2 D3 LED SM Green 25...

Страница 44: ...exhibits slightly less harmonic distortion at high power levels when used in the stand alone mode The EVM has a flat response over the audio frequency band as shown in Figure 3 22 Both channels track...

Страница 45: ...igh power levels 40 mW to 1 9 W is a function of the output filter components particularly the inductors A slight increase in supply voltage over 5 V substantially reduces the harmonic distortion at p...

Страница 46: ...t full output power which is the worst case scenario Crosstalk may be reduced by using shielded inductors in the output filter Figure 3 24 Distortion versus Frequency 10 0 1 20 100 1k THD N Total Harm...

Страница 47: ...ained from any TI Sales Office Figure 3 26 TPA005D02 Class D EVM Silkscreen Texas Instruments 1998 R6 R7 VDD GND L1 L2 L3 L4 U1 C21 C19 C15 TPA005D02 EVM Board Rev A VDD GND C25 Lout Lout Mute Rout Ro...

Страница 48: ...TPA005D02 Class D EVM PCB Layers 3 34 Details Figure 3 28 TPA005D02 Class D EVM 2nd Layer Figure 3 29 TPA005D02 Class D EVM 3rd Layer...

Страница 49: ...TPA005D02 Class D EVM PCB Layers 3 35 Details Figure 3 30 TPA005D02 Class D EVM Bottom Layer...

Страница 50: ...3 36 Details...

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