參數(shù)資料
型號: UCB1200
廠商: NXP Semiconductors N.V.
英文描述: Advanced modem/audio analog front-end
中文描述: 先進(jìn)的調(diào)制解調(diào)器/音頻模擬前端
文件頁數(shù): 8/54頁
文件大?。?/td> 1052K
代理商: UCB1200
1998 Jul 22
8
Philips Semiconductors
Product specification
Advanced modem/audio analog front-end
UCB1200
The audio sample rate (f
sa
) is derived from the SIB interface clock pin (SIBCLK) and is programmable through the SIB
interface using AUD_DIV[n]. The audio sample rate is given by the following equation:
2
f
×
(
)
AUD_DIV[n]
×
)
(8 < AUD_DIV[n] < 128)
For example, a serial clock of 9.216 MHz, with a divisor of 12, results in an audio sample rate of 24.0 kHz. Both the rising
and the falling edges of SIBCLK are used in case AUD_DIV[n] is set to an odd number, which demands a 50% duty cycle
of SIBCLK to obtain time equidistant sampling.
The UCB1200 audio codec input path accepts microphone signals directly, only a DC blocking capacitor is needed since
the MICP input is biased around 1.4V. The ‘ground’ side of the microphone is either connected to the analog ground
(V
ssa1
) or to the MICGND pin. The latter will decrease the current consumption of active microphones, since the MICGND
pin is made Hi-Z when the audio codec input path is disabled.
The full scale input voltage of the audio input path is programmable in 1.5 dB steps by setting the appropriate number in
AUDIO_GAIN[n] in the audio control register A.
A clip detection circuit will inform the user whenever the input voltage exceeds the maximum input voltage, since this will
lead to a high distortion. In that case AUD_CLIP_STAT in the audio control register B is set. When ACLIP_RIS_INT is
set, an interrupt is generated on the IRQOUT pin on the rising edge of the clip detect signal. When ACLIP_FAL_INT is
set, an interrupt is generated on the falling edge of the clip detect signal.
The frequency response of the audio codec depends mainly on the selected sample rate, since the bandwidth is limited
in the down and up sampling filters. These digital filters both contain several FIR and IIR low pass filters and a DC
removal filter (high pass filter). A 3rd order smoothing filter is implemented in the DAC path, between DAC and speaker
driver stage to reduce the spurious frequencies at the speaker outputs.
f
sa
-64
=
Fig.4 Possible microphone connections.
PASSIVE
V
DDA1
1
7
21
MICP
MICGND
20
V
SSA1
18
ACTIVE
V
DDA1
1
7
21
MICP
MICGND
20
V
SSA1
18
UCB1200
UCB1200
相關(guān)PDF資料
PDF描述
UCB1200BE Advanced modem/audio analog front-end
UCB1300 Advanced modem/audio analog front-end
UCB1300BE Advanced modem/audio analog front-end
UCB1400BE Audio codec with touch screen controller and power management monitor
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
UCB1200B 制造商:未知廠家 制造商全稱:未知廠家 功能描述:UCB1200B
UCB1200BE 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Advanced modem/audio analog front-end
UCB1300 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Advanced modem/audio analog front-end
UCB1300BE 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Advanced modem/audio analog front-end
UCB1400 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Audio codec with touch screen controller and power management monitor