SI4705-D-EVB【PDF 19/34 页】BOARD EVAL MOBILE SI4704/05-D50

您好，
买卖IC网欢迎您。
请登录
免费注册

15页 16页 17页 18页 [19页]20页 21页 22页 23页

Si4704/05-D50

4.5. De-emphasis

Pre-emphasis and de-emphasis is a technique used by

FM broadcasters to improve the signal-to-noise ratio of

FM receivers by reducing the effects of high-frequency

interference and noise. When the FM signal is

transmitted, a pre-emphasis filter is applied to

accentuate the high audio frequencies. The Si4704/05

incorporates a de-emphasis filter that attenuates high

frequencies to restore a flat frequency response. Two

time constants are used in various regions. The de-

emphasis time constant is programmable to 50 or 75 μs

and is set by the FM_DEEMPHASIS property.

4.6. Volume Control

4.10. Tuning

The frequency synthesizer uses Silicon Laboratories’

proven technology, including a completely integrated

VCO. The frequency synthesizer generates the

quadrature local oscillator signal used to downconvert

the RF input to a low intermediate frequency. The VCO

frequency is locked to the reference clock and adjusted

with an automatic frequency control (AFC) servo loop

during reception. The tuning frequency can be directly

programmed using the FM_TUNE_FREQ. The

Si4704/05 supports channel spacing of 50, 100, or

200 kHz in FM mode.

4.11. Seek

The audio output may be muted. Volume is adjusted

The Si4704/05 seek functionality

is performed

digitally by the RX_VOLUME property.

4.7. Stereo DAC

High-fidelity stereo digital-to-analog converters (DACs)

drive analog audio signals onto the LOUT and ROUT

pins. The audio output may be muted. Volume is

adjusted digitally with the RX_VOLUME property.

4.8. Soft Mute

The soft mute feature is available to attenuate the audio

outputs and minimize audible noise in very weak signal

conditions. The soft mute feature is triggered by the

completely on-chip and will search up or down the

selected frequency band for a valid channel. A valid

channel is qualified according to a series of

programmable signal indicators and thresholds. The

seek function can be made to stop at the band edge and

provide an interrupt, or wrap the band and continue

seeking until arriving at the original departure frequency.

The device sets interrupts with found valid stations or, if

the seek results in zero found valid stations, the device

indicates failure and again sets an interrupt.(Refer to

“AN332: Si47xx Programming Guide”.

The Si4704/05-D50 uses RSSI, SNR, and AFC to

SNR metric. The SNR threshold for activating soft mute

qualify stations. Most

of these variables have

is programmable, as are soft mute attenuation levels

and attack and release rates.

4.9. FM Hi-Cut Control

Hi-cut control is employed on audio outputs with

degradation of the signal due to low SNR and/or

multipath interference. Two metrics, SNR and multipath

interference, are monitored concurrently in forcing hi-cut

of the audio outputs. Programmable minimum and

maximum thresholds are available for both metrics. The

transition frequency for hi-cut is also programmable with

up to seven hi-cut filter settings. A single set of attack

and release rates for hi-cut are programmable for both

metrics from a range of 2 ms to 64 s. The level of hi-cut

applied can be monitored with the FM_RSQ_STATUS

command. Hi-cut can be disabled by setting the hi-cut

filter to audio bandwidth of 15 kHz.

programmable thresholds for modifying the seek

function according to customer needs.

RSSI is employed first to screen all possible candidate

stations. SNR and AFC are subsequently used in

screening the RSSI qualified stations. The more

thresholds the system engages, the higher the

confidence that any found stations will indeed be valid

broadcast stations. The Si4704/05-D50 defaults set

RSSI to a mid-level threshold and add an SNR

threshold set to a level delivering acceptable audio

performance. This trade-off will eliminate very low RSSI

stations while keeping the seek time to acceptable

levels. Generally, the time to auto-scan and store valid

channels for an entire FM band with all thresholds

engaged is very short depending on the band content.

Seek is initiated using the FM_SEEK_START

command. The RSSI, SNR, and AFC threshold settings

are adjustable using properties.

Rev. 1.0

19

发布紧急采购，3分钟左右您将得到回复。

采购需求

(若只采购一条型号，填写一行即可)

*型号	*数量	厂商	批号	封装

添加更多采购

我的联系方式

*

*

*

相关PDF资料

SI4706-B20-GM IC FM RADIO TUNER 20-QFN

SI4712DY-T1-GE3 MOSFET N-CH/SCHOTTKY 30V 8SOIC

SI4731-D50-EVB BOARD EVAL SI4730/SI4731-D50

SI4731-D50-GM IC RADIO RECEIVER AM/FM 20-QFN

SI4737-C-EVB BOARD EVAL SI4737 VERSION C

SI4743-C-EVB BOARD EVALUATION FOR SI4743-C

SI4770-A-EVB BOARD EVAL FOR CE AM/FM SI4770

SI4777-A20-GM IC RCVR AM/FM CE HD-RADIO TUNER

相关代理商/技术参数

SI4706-B10-GM 制造商:Silicon Laboratories Inc 功能描述:

SI4706-B20-GM 功能描述:IC FM RADIO TUNER 20-QFN RoHS:是类别:RF/IF 和 RFID >> RF 接收器系列:- 产品培训模块:Lead (SnPb) Finish for COTS 产品变化通告:Product Discontinuation 09/Jan/2012 标准包装:50 系列:* 频率:850MHz ~ 2.175GHz 灵敏度:- 数据传输率 - 最大:- 调制或协议:- 应用:* 电流 - 接收:* 数据接口:PCB，表面贴装存储容量:- 天线连接器:PCB，表面贴装特点:- 电源电压:4.75 V ~ 5.25 V 工作温度:0°C ~ 85°C 封装/外壳:40-WFQFN 裸露焊盘供应商设备封装:40-TQFN-EP（6x6）包装:托盘

SI4706-B-EVB 功能描述:BOARD EVALUATION FOR SI4706-B RoHS:是类别:RF/IF 和 RFID >> RF 评估和开发套件，板系列:- 标准包装:1 系列:- 类型:GPS 接收器频率:1575MHz 适用于相关产品:- 已供物品:模块其它名称:SER3796

SI4706-C30-GM 功能描述:IC FM RADIO TUNER 20-QFN RoHS:是类别:RF/IF 和 RFID >> RF 接收器系列:- 产品培训模块:Lead (SnPb) Finish for COTS 产品变化通告:Product Discontinuation 09/Jan/2012 标准包装:50 系列:* 频率:850MHz ~ 2.175GHz 灵敏度:- 数据传输率 - 最大:- 调制或协议:- 应用:* 电流 - 接收:* 数据接口:PCB，表面贴装存储容量:- 天线连接器:PCB，表面贴装特点:- 电源电压:4.75 V ~ 5.25 V 工作温度:0°C ~ 85°C 封装/外壳:40-WFQFN 裸露焊盘供应商设备封装:40-TQFN-EP（6x6）包装:托盘

SI4706-C-EVB 功能描述:BOARD EVALUATION FOR SI4706-C RoHS:是类别:RF/IF 和 RFID >> RF 评估和开发套件，板系列:- 标准包装:1 系列:- 类型:GPS 接收器频率:1575MHz 适用于相关产品:- 已供物品:模块其它名称:SER3796

SI4706-D50-EVB 功能描述:BOARD EVAL SI4706-D50 20-QFN RoHS:是类别:RF/IF 和 RFID >> RF 评估和开发套件，板系列:- 标准包装:1 系列:- 类型:GPS 接收器频率:1575MHz 适用于相关产品:- 已供物品:模块其它名称:SER3796

Si4706-D50-GM 功能描述:射频接收器 Adv Hi-perf FM RDS TMC Rcvr Mobile Dev RoHS:否制造商:Skyworks Solutions, Inc. 类型:GPS Receiver 封装 / 箱体:QFN-24 工作频率:4.092 MHz 工作电源电压:3.3 V 封装:Reel

Si4706-D50-GMR 功能描述:射频接收器 Adv Hi-perf FM RDS TMC Rcvr Mobile Dev RoHS:否制造商:Skyworks Solutions, Inc. 类型:GPS Receiver 封装 / 箱体:QFN-24 工作频率:4.092 MHz 工作电源电压:3.3 V 封装:Reel