參數(shù)資料
型號(hào): TLV320AIC33IRGZR
廠商: TEXAS INSTRUMENTS INC
元件分類: 消費(fèi)家電
英文描述: SPECIALTY CONSUMER CIRCUIT, PQCC48
封裝: 7 X 7 MM, GREEN, PLASTIC, VQFN-48
文件頁(yè)數(shù): 29/93頁(yè)
文件大小: 1427K
代理商: TLV320AIC33IRGZR
DELTA-SIGMA AUDIO DAC
AUDIO DAC DIGITAL VOLUME CONTROL
ANALOG OUTPUT COMMON-MODE ADJUSTMENT
www.ti.com ........................................................................................................................................... SLAS480B – JANUARY 2006 – REVISED DECEMBER 2008
filter is designed to maintain at least 65-dB rejection of images that land below 7.455 Fs. In order to utilize the
programmable interpolation capability, the Fsref should be programmed to a higher rate (restricted to be in the
range of 39 kHz to 53 kHz when the PLL is in use), and the actual Fs is set using the NDAC divider. For
example, if Fs = 8 kHz is required, then Fsref can be set to 48 kHz, and the DAC Fs set to Fsref/6. This ensures
that all images of the 8-kHz data are sufficiently attenuated well beyond a 20-kHz audible frequency range.
The stereo audio DAC incorporates a third order multi-bit delta-sigma modulator followed by an analog
reconstruction filter. The DAC provides high-resolution, low-noise performance, using oversampling and noise
shaping techniques. The analog reconstruction filter design consists of a 6-tap analog FIR filter followed by a
continuous time RC filter. The analog FIR operates at a rate of 128 × Fsref (6.144 MHz when Fsref = 48 kHz,
5.6448 MHz when Fsref = 44.1 kHz). Note that the DAC analog performance may be degraded by excessive
clock jitter on the MCLK input. Therefore, care must be taken to keep jitter on this clock to a minimum.
The audio DAC includes a digital volume control block which implements a programmable digital gain. The
volume level can be varied from 0 dB to –63.5 dB in 0.5-dB steps, in addition to a mute bit, independently for
each channel. The volume level of both channels can also be changed simultaneously by the master volume
control. Gain changes are implemented with a soft-stepping algorithm, which only changes the actual volume by
one step per input sample, either up or down, until the desired volume is reached. The rate of soft-stepping can
be slowed to one step per two input samples through a register bit.
Because of soft-stepping, the host does not know when the DAC has been actually muted. This may be
important if the host wishes to mute the DAC before making a significant change, such as changing sample
rates. In order to help with this situation, the device provides a flag back to the host via a read-only register bit
that alerts the host when the part has completed the soft-stepping and the actual volume has reached the
desired volume level. The soft-stepping feature can be disabled through register programming. If soft-stepping is
enabled, the MCLK signal should be kept applied to the device until the DAC power-down flag is set. When this
flag is set, the internal soft-stepping process and power down sequence is complete, and the MCLK can then be
stopped if desired.
The TLV320AIC33 also includes functionality to detect when the user switches on or off the de-emphasis or
digital audio processing functions, to first (1) soft-mute the DAC volume control, (2) change the operation of the
digital effects processing, and (3) soft-unmute the part. This avoids any possible pop/clicks in the audio output
due to instantaneous changes in the filtering. A similar algorithm is used when first powering up or down the
DAC. The circuit begins operation at power up with the volume control muted, then soft-steps it up to the desired
volume level. At power down, the logic first soft-steps the volume down to a mute level, then powers down the
circuitry.
The output common-mode voltage and output range of the analog output are determined by an internal bandgap
reference, in contrast to other codecs that may use a divided version of the supply. This scheme is used to
reduce the coupling of noise that may be on the supply (such as 217-Hz noise in a GSM cellphone) into the
audio signal path.
However, due to the possible wide variation in analog supply range (2.7 V – 3.6 V), an output common-mode
voltage setting of 1.35 V, which would be used for a 2.7 V supply case, will be overly conservative if the supply is
actually much larger, such as 3.3 V or 3.6 V. In order to optimize device operation, the TLV320AIC33 includes a
programmable output common-mode level, which can be set by register programming to a level most appropriate
to the actual supply range used by a particular customer. The output common-mode level can be varied among
four different values, ranging from 1.35 V (most appropriate for low supply ranges, near 2.7 V) to 1.8 V (most
appropriate for high supply ranges, near 3.6 V). Note that there is also some limitation on the range of DVDD
voltage as well in determining which setting is most appropriate.
Table 3. Appropriate Settings
CM SETTING
RECOMMENDED AVDD, DRVDD
RECOMMENDED DVDD
1.35
2.7 V – 3.6 V
1.65 V – 1.95 V
1.50
3.0 V – 3.6 V
1.65 V – 1.95 V
Copyright 2006–2008, Texas Instruments Incorporated
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Product Folder Link(s): TLV320AIC33
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TLV320AIC33IRGZR 制造商:Texas Instruments 功能描述:AUDIO CODEC IC ((NW)) 制造商:Texas Instruments 功能描述:IC, AUDIO CODEC, 24BIT, 96KHZ, QFN-48
TLV320AIC33IRGZRG4 功能描述:接口—CODEC Lo-Pwr Stereo CODEC RoHS:否 制造商:Texas Instruments 類型: 分辨率: 轉(zhuǎn)換速率:48 kSPs 接口類型:I2C ADC 數(shù)量:2 DAC 數(shù)量:4 工作電源電壓:1.8 V, 2.1 V, 2.3 V to 5.5 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:DSBGA-81 封裝:Reel
TLV320AIC33IRGZT 功能描述:接口—CODEC Lo-Pwr Stereo CODEC RoHS:否 制造商:Texas Instruments 類型: 分辨率: 轉(zhuǎn)換速率:48 kSPs 接口類型:I2C ADC 數(shù)量:2 DAC 數(shù)量:4 工作電源電壓:1.8 V, 2.1 V, 2.3 V to 5.5 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:DSBGA-81 封裝:Reel
TLV320AIC33IRGZT 制造商:Texas Instruments 功能描述:IC STEREO AUDIO CODEC 48-VQFN
TLV320AIC33IRGZT 制造商:Texas Instruments 功能描述:AUDIO CODEC IC 制造商:Texas Instruments 功能描述:IC, AUDIO CODEC, 24BIT, 96KHZ, QFN-48