參數(shù)資料
型號: TPA3002D2PHPR
廠商: TEXAS INSTRUMENTS INC
元件分類: 音頻控制
英文描述: 2 CHANNEL(S), VOLUME CONTROL CIRCUIT, PQFP48
封裝: GREEN, PLASTIC, HTQFP-48
文件頁數(shù): 15/40頁
文件大?。?/td> 735K
代理商: TPA3002D2PHPR
TPA3002D2
SLOS402C DECEMBER 2002 REVISED JANUARY 2004
www.ti.com
22
1 nF
Ferrite
Chip Bead
OUTP
OUTN
Ferrite
Chip Bead
1 nF
Figure 34. Typical Ferrite Chip Bead Filter (Chip bead example: Fair-Rite 2512067007Y3)
VOLUME CONTROL OPERATION
Three pins labeled VOLUME, VARDIFF, and VARMAX control the class-D volume when driving speakers and
the VAROUT volume. All of these pins are controlled with a dc voltage, which should not exceed VREF.
When driving speakers in class-D mode, the VOLUME pin is the only pin that controls the gain. Table 1 lists
the gain in class-D mode as determined by the voltage on the VOLUME pin in reference to the voltage on VREF.
If using a resistor divider to fix the gain of the amplifier, the VREF terminal can be directly connected to
AVDDREF and a resistor divider can be connected across VREF and REFGND. (See Figure 29 in the
Applications Section). For fixed gain, calculate the resistor divider values necessary to center the voltage
between the two percentage points given in the first column of Table 1. For example, if a gain of 10.7 dB is
desired, the resistors in the divider network can both be 10 k
. With these resistor values, a voltage of 50%
× VREF will be present at the VOLUME pin and result in a class-D gain of 10.7 dB.
If using a DAC to control the class-D gain, VREF and REFGND should be connected to the reference voltage
for the DAC and the GND terminal of the DAC, respectively. For the DAC application, AVDDREF would be left
unconnected. The reference voltage of the DAC provides the reference to the internal gain circuitry through the
VREF input and any fluctuations in the DAC output voltage will not affect the TPA3002D2 gain. The percentages
in the first column of Table 1 should be used for setting the voltages of the DAC when the voltage on the
VOLUME terminal is increased. The percentages in the second column should be used for the DAC voltages
when decreasing the voltage on the VOLUME terminal. Two lookup tables should be used in software to control
the gain based on an increase or decrease in the desired system volume. This is explained further in a section
below.
If using an analog potentiometer to control the gain, it should be connected between VREF and REFGND.
VREF can be connected to AVDDREF or an external voltage source, if desired. The first and second column
in Table 1 should be used to determine the point at which the gain changes depending on the direction that the
potentiometer is turned. If the voltage on the center tap of the potentiometer is increasing, the first column in
Table 1 should be referenced to determine the trip points. If the voltage is decreasing, the trip points in the
second column should be referenced.
The trip point, where the gain actually changes, is different depending on whether the voltage on the VOLUME
terminal is increasing or decreasing as a result of hysteresis about each trip point. The hysteresis ensures that
the gain control is monotonic and does not oscillate from one gain step to another. A pictorial representation
of the volume control can be found in Figure 36. The graph focuses on three gain steps with the trip points
defined in the first and second columns of Table 1 for class-D gain. The dotted lines represent the hysteresis
about each gain step.
VARDIFF AND VARMAX OPERATION
The TPA3002D2 allows the user to specify a difference between the class-D gain and VAROUT gain. This is
desirable to avoid any listening discomfort when plugging in headphones. When interfacing with the variable
outputs, the VARDIFF and VARMAX pins control the VAROUT channel gain proportional to the gain set by the
voltage on the VOLUME pin. When VARDIFF = 0 V, the difference between the class-D gain and the VAROUT
gain is 16 dB. As the voltage on the VARDIFF terminal is increased, the VAROUT channel gain decreases.
Internal to the TPA3002D2 device, the voltage on the VARDIFF terminal is subtracted from the voltage on the
VOLUME terminal and this value is used to determine the VAROUT gain.
相關PDF資料
PDF描述
TPA3002D2PHP 2 CHANNEL(S), VOLUME CONTROL CIRCUIT, PQFP48
TPA3002D2PHPRG4 2 CHANNEL(S), VOLUME CONTROL CIRCUIT, PQFP48
TPA3002D2PHPG4 2 CHANNEL(S), VOLUME CONTROL CIRCUIT, PQFP48
TPA3003D2PFBR 2 CHANNEL(S), VOLUME CONTROL CIRCUIT, PQFP48
TPA3003D2PFB 2 CHANNEL(S), VOLUME CONTROL CIRCUIT, PQFP48
相關代理商/技術參數(shù)
參數(shù)描述
TPA3002D2PHPRG4 功能描述:音頻放大器 Stereo Med Pwr Filter-Free Class-D RoHS:否 制造商:STMicroelectronics 產品: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
TPA3003D2 制造商:TI 制造商全稱:Texas Instruments 功能描述:3-Q STEREO CLASS-D AUDIO POWER AMPLIFIER WITH DC VOLUME CONTROL
TPA3003D2_06 制造商:TI 制造商全稱:Texas Instruments 功能描述:3-Q STEREO CLASS-D AUDIO POWER AMPLIFIER WITH DC VOLUME CONTROL
TPA3003D2EVM 功能描述:音頻 IC 開發(fā)工具 TPA3003D2 Eval Mod RoHS:否 制造商:Texas Instruments 產品:Evaluation Kits 類型:Audio Amplifiers 工具用于評估:TAS5614L 工作電源電壓:12 V to 38 V
TPA3003D2PFB 功能描述:音頻放大器 Ster Lo-Pwr Wide Sply Vltg Class-D RoHS:否 制造商:STMicroelectronics 產品: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