參數(shù)資料
型號: TPA6135A2RTET
廠商: TEXAS INSTRUMENTS INC
元件分類: 音頻/視頻放大
英文描述: 0.025 W, 2 CHANNEL, AUDIO AMPLIFIER, PQCC16
封裝: 3 X 3 MM, PLASTIC, QFN-16
文件頁數(shù): 7/23頁
文件大?。?/td> 948K
代理商: TPA6135A2RTET
RF AND POWER SUPPLY NOISE IMMUNITY
CONSTANT MAXIMUM OUTPUT POWER AND ACOUSTIC SHOCK PREVENTION
INPUT COUPLING CAPACITORS
C
IN
1
=
2
R
C
f
p
(3)
IN
C
IN
1
C
=
2
R
p
(4)
CHARGE PUMP FLYING CAPACITOR AND HPVSS CAPACITOR
www.ti.com .................................................................................................................................................. SLOS623A – FEBRUARY 2009 – REVISED APRIL 2009
The TPA6135A2 employs a new differential amplifier architecture to achieve high power supply noise rejection
and RF noise rejection. RF and power supply noise are common in modern electronics. Although RF frequencies
are much higher than the 20 kHz audio band, signal modulation often falls in-band. This, in turn, modulates the
supply voltage, allowing a coupling path into the audio amplifier. A common example is the 217 Hz GSM
frame-rate buzz often heard from an active speaker when a cell phone is placed nearby during a phone call.
The TPA6135A2 has excellent rejection of power supply and RF noise, preventing audio signal degradation.
Typically the output power increases with increasing supply voltage on an unregulated headphone amplifier. The
TPA6135A2 maintains a constant output power independent of the supply voltage. Thus the design for
prevention of acoustic shock (hearing damage due to exposure to a loud sound) is simplified since the output
power will remain constant, independent of the supply voltage. This feature allows maximizing the audio signal at
the lowest supply voltage.
Input coupling capacitors block any dc bias from the audio source and ensure maximum dynamic range. Input
coupling capacitors also minimize TPA6135A2 turn-on pop to an inaudible level.
The input capacitors are in series with TPA6135A2 internal input resistors, creating a high-pass filter. Equation 3
calculates the high-pass filter corner frequency. The input impedance, RIN, is dependent on device gain. Larger
input capacitors decrease the corner frequency. See the Operating Characteristics table for input impedance
values.
For a given high-pass cutoff frequency, the minimum input coupling capacitor is found as:
Example: Design for a 20 Hz corner frequency with a TPA6135A2 gain of +6 dB. The Operating Characteristics
table gives RIN as 13.2 k
. Equation 4 shows the input coupling capacitors must be at least 0.6
F to achieve a
20 Hz high-pass corner frequency. Choose a 0.68
F standard value capacitor for each TPA6135A2 input (X5R
material or better is required for best performance).
Input capacitors can be removed provided the TPA6135A2 inputs are driven differentially with less than ±1 VRMS
and the common-mode voltage is within the input common-mode range of the amplifier. Without input capacitors
turn-on pop performance may be degraded and should be evaluated in the system.
The TPA6135A2 uses a built-in charge pump to generate a negative voltage supply for the headphone
amplifiers. The charge pump flying capacitor connects between CPP and CPN. It transfers charge to generate
the negative supply voltage. The HPVSS capacitor must be at least equal in value to the flying capacitor to allow
maximum charge transfer. Use low equivalent-series-resistance (ESR) ceramic capacitors (X5R material or
better is required for best performance) to maximize charge pump efficiency. Typical values are 1
F to 2.2 F
for the HPVSS and flying capacitors. Although values down to 0.47
F can be used, total harmonic distortion
(THD) will increase.
Copyright 2009, Texas Instruments Incorporated
15
Product Folder Link(s) :TPA6135A2
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相關代理商/技術(shù)參數(shù)
參數(shù)描述
TPA6135A2RTET 制造商:Texas Instruments 功能描述:Audio Power Amplifiers TI
TPA6136A2 制造商:TI 制造商全稱:Texas Instruments 功能描述:25-mW DIRECTPATH STEREO HEADPHONE AMPLIFIER WITH POP SUPPRESSION
TPA6136A2YFFEVM 功能描述:音頻 IC 開發(fā)工具 TPA6136A2YFF Eval Mod RoHS:否 制造商:Texas Instruments 產(chǎn)品:Evaluation Kits 類型:Audio Amplifiers 工具用于評估:TAS5614L 工作電源電壓:12 V to 38 V
TPA6136A2YFFR 功能描述:音頻放大器 25mW DirectPath St Headphone Amp 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: 安裝風格:SMD/SMT 封裝 / 箱體:TQFP-64 封裝:Reel
TPA6136A2YFFT 功能描述:音頻放大器 25mW DirectPath St Headphone Amp 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: 安裝風格:SMD/SMT 封裝 / 箱體:TQFP-64 封裝:Reel