- 您现在的位置：买卖IC网 > PDF目录98196 > TDA7461N (STMICROELECTRONICS) SPECIALTY CONSUMER CIRCUIT, PDIP28 PDF资料下载
参数资料
| 型号： | TDA7461N |
| 厂商： | STMICROELECTRONICS |
| 元件分类： | 消费家电 |
| 英文描述： | SPECIALTY CONSUMER CIRCUIT, PDIP28 |
| 封装： | DIP-28 |
| 文件页数： | 13/35页 |
| 文件大小： | 576K |
| 代理商： | TDA7461N |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页当前第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页第29页第30页第31页第32页第33页第34页第35页
Automatic Threshold Control
Besides the noise controlled threshold adjust-
ment there is an additional possibility for influenc-
ing the trigger threshold. It is depending on the
stereoblend control.
The point where the MPX signal starts to become
noisy is fixed by the RF part. Therefore also the
starting point of the normal noise-controlled trig-
ger adjustment is fixed (fig. 16). In some cases
the behaviour of the noiseblanker can be im-
proved by increasing the threshold even in a re-
gion of higher fieldstrength. Sometimes a wrong
triggering occures for the MPX signal often shows
distortion in this range which can be avoided
even if using a low threshold.
Because of the overlap of this range and the
range of the stereo/mono transition it can be con-
trolled by stereoblend. This threshold increase is
programmable in 3 steps or switched off with bits
D0 and D1 of the fieldstrength control byte.
Over Deviation Detector
If the system is tuned to stations with a high de-
viation the noiseblanker can trigger on the higher
frequencies of the modulation. To avoid this
wrong behaviour, which causes noise in the out-
put signal, the noiseblanker offers a deviation de-
pendent threshold adjustment.
By rectifying the MPX signal a further signal rep-
resenting the actual deviation is obtained. It is
used to increase the PEAK voltage. Offset and
gain of this circuit are programmable in 3 steps
with the bits D6 and D7 of the stereodecoder byte
(the first step turns off the detector, see fig. 15).
FUNCTIONAL DESCRIPTION OF THE MULTI-
PATH DETECTOR
Using the internal detector the audible effects of a
multipath condition can be minimized. A multipath
condition is detected by rectifying the 19kHz
spectrum in the fieldstrength signal.
Selecting the "internal influence" in the configura-
tion byte, the channel separation is automatically
reduced during a multipath condition according to
the voltage appearing at the MPOUT pin.
To obtain a optimal performance an adaptation is
necessary. Therefore the gain of the 19kHz band-
pass is programmable in four steps as well as the
rectifier gain. The attack and decay times can be
set by the external capacitor value.
TEST MODE
During the test mode which can be activated by
setting bit D0 of the testing byte and bit D5 of the
subaddress byte to "1" several internal signals
are available at the CASSR pin.
During this
mode the input resistance of 100kOhm is discon-
nected from the pin. The internal signals available
are shown in the software specification.
RECTIFIER
BANDPASS
19KHz
-
to SB
D97AU880
MPIN
GAIN
2 BITS
GAIN
2 BITS
DC=1
A
VDD
MPOUT
LEVEL
int. INFLUENCE
220nF
Figure 23. Block diagram of the Multipath Detector
TDA7461N
20/32
相关PDF资料 |
PDF描述 |
|---|---|
| TDA7462D | SPECIALTY CONSUMER CIRCUIT, PDSO28 |
| TDA7463AD | 2 CHANNEL(S), TONE CONTROL CIRCUIT, PDSO20 |
| TDA7463A | 2 CHANNEL(S), TONE CONTROL CIRCUIT, PDSO20 |
| TDA7463 | 2 CHANNEL(S), TONE CONTROL CIRCUIT, PDIP16 |
| TDA7465 | 2 CHANNEL(S), TONE CONTROL CIRCUIT, PDIP42 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| TDA7461N_03 | 制造商:STMICROELECTRONICS 制造商全称:STMicroelectronics 功能描述:CAR RADIO SIGNAL PROCESSOR |
| TDA7461ND | 功能描述:音频 DSP Car Radio Signal RoHS:否 制造商:Texas Instruments 工作电源电压: 电源电流: 工作温度范围: 安装风格: 封装 / 箱体: 封装:Tube |
| TDA7461NDTR | 功能描述:音频 DSP CAR RADIO SIGNAL RoHS:否 制造商:Texas Instruments 工作电源电压: 电源电流: 工作温度范围: 安装风格: 封装 / 箱体: 封装:Tube |
| TDA7462 | 制造商:STMICROELECTRONICS 制造商全称:STMicroelectronics 功能描述:DUAL AUDIOPROCESSOR WITH COMPANDER AND SUBWOOFER OUTPUT |
| TDA7462D | 功能描述:音频 DSP Dual Audioprocessor RoHS:否 制造商:Texas Instruments 工作电源电压: 电源电流: 工作温度范围: 安装风格: 封装 / 箱体: 封装:Tube |
发布紧急采购，3分钟左右您将得到回复。