參數(shù)資料
型號(hào): TPA2000D2PWRG4
廠商: TEXAS INSTRUMENTS INC
元件分類: 音頻/視頻放大
英文描述: 2 W, 2 CHANNEL, AUDIO AMPLIFIER, PDSO24
封裝: GREEN, PLASTIC, TSSOP-24
文件頁數(shù): 2/22頁
文件大?。?/td> 679K
代理商: TPA2000D2PWRG4
www.ti.com
0 V
–5 V
+5 V
Current
OUT+
OUT–
Differential
Voltage
Across
Load
0 V
–5 V
+5 V
Current
OUT+
OUT–
Differential
Voltage
Across
Load
Output = 0 V
Output > 0 V
EFFICIENCY: WHY YOU MUST USE A FILTER WITH THE TRADITIONAL CLASS-D
EFFECTS OF APPLYING A SQUARE WAVE INTO A SPEAKER
SLOS291F – MARCH 2000 – REVISED MARCH 2007
APPLICATION INFORMATION (continued)
Figure 13. The TPA2000D2 Output Voltage and Current Waveforms Into an Inductive Load
MODULATION SCHEME
The main reason that the traditional class-D amplifier needs an output filter is that the switching waveform
results in maximum current flow. This causes more loss in the load, which causes lower efficiency. The ripple
current is large for the traditional modulation scheme because the ripple current is proportional to voltage
multiplied by the time at that voltage. The differential voltage swing is 2 × VDD and the time at each voltage is
half the period for the traditional modulation scheme. An ideal LC filter is needed to store the ripple current from
each half cycle for the next half cycle, while any resistance causes power dissipation. The speaker is both
resistive and reactive, whereas an LC filter is almost purely reactive.
The TPA2000D2 modulation scheme has very little loss in the load without a filter because the pulses are very
short and the change in voltage is VDD instead of 2 × VDD. As the output power increases, the pulses widen
making the ripple current larger. Ripple current could be filtered with an LC filter for increased efficiency, but for
most applications the filter is not needed.
An LC filter with a cutoff frequency less than the class-D switching frequency allows the switching current to flow
through the filter instead of the load. The filter has less resistance than the speaker, which results in less power
dissipated and increased efficiency.
Audio specialists have said for years not to apply a square wave to speakers. If the amplitude of the waveform is
high enough and the frequency of the square wave is within the bandwidth of the speaker, the square wave
could cause the voice coil to jump out of the air gap and/or scar the voice coil. A 250-kHz switching frequency,
however, is not significant because the speaker cone movement is proportional to 1/f2 for frequencies beyond
the audio band. Therefore, the amount of cone movement at the switching frequency is very small. However,
10
相關(guān)PDF資料
PDF描述
TPA2000D2PWG4 2 W, 2 CHANNEL, AUDIO AMPLIFIER, PDSO24
TPA2000D4DAPRG4 2 W, 2 CHANNEL, AUDIO AMPLIFIER, PDSO32
TPA2000D4DAPR 2 W, 2 CHANNEL, AUDIO AMPLIFIER, PDSO32
TPA2000D4DAP 2 W, 2 CHANNEL, AUDIO AMPLIFIER, PDSO32
TPA2000D4DAPG4 2 W, 2 CHANNEL, AUDIO AMPLIFIER, PDSO32
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
TPA2000D4 制造商:TI 制造商全稱:Texas Instruments 功能描述:STEREO 2-W CLASS-D AUDIO POWER AMPLIFIER WITH STEREO HP AMPLIFIER
TPA2000D4_07 制造商:TI 制造商全稱:Texas Instruments 功能描述:STEREO 2-W CLASS-D AUDIO POWER AMPLIFIER WITH STEREO HP AMPLIFIER
TPA2000D4DAP 功能描述:音頻放大器 Stereo Filter-Free Class-D RoHS:否 制造商:STMicroelectronics 產(chǎn)品:General Purpose Audio Amplifiers 輸出類型:Digital 輸出功率: THD + 噪聲: 工作電源電壓:3.3 V 電源電流: 最大功率耗散: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TQFP-64 封裝:Reel
TPA2000D4DAPG4 功能描述:音頻放大器 Stereo Filter-Free Class-D RoHS:否 制造商:STMicroelectronics 產(chǎn)品:General Purpose Audio Amplifiers 輸出類型:Digital 輸出功率: THD + 噪聲: 工作電源電壓:3.3 V 電源電流: 最大功率耗散: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TQFP-64 封裝:Reel
TPA2000D4DAPR 功能描述:音頻放大器 Stereo Filter-Free Class-D RoHS:否 制造商:STMicroelectronics 產(chǎn)品:General Purpose Audio Amplifiers 輸出類型:Digital 輸出功率: THD + 噪聲: 工作電源電壓:3.3 V 電源電流: 最大功率耗散: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TQFP-64 封裝:Reel