- 您現(xiàn)在的位置：買(mǎi)賣(mài)IC網(wǎng) > PDF目錄383617 > MICRF008 (Micrel Semiconductor,Inc.) QwikRadio⑩ Sweep-Mode Receiver PDF資料下載
參數(shù)資料
| 型號(hào)： | MICRF008 |
| 廠商： | Micrel Semiconductor,Inc. |
| 英文描述： | QwikRadio⑩ Sweep-Mode Receiver |
| 中文描述： | QwikRadio系列⑩掃描模式接收機(jī) |
| 文件頁(yè)數(shù)： | 11/12頁(yè) |
| 文件大?。?/td> | 115K |
| 代理商： | MICRF008 |
July 2003
11
MICRF008
MICRF008
Micrel
To determine what is the demodulator bandwidth required for
the application, the absolute minimum pulse width used in the
encoder transmitted signal needs to be found. The data
pattern has several different types of pulse width depending
what data format is being used (NRZ, Manchester, PWM,
etc). The minimum pulsewidth is the shortest pulse in the
output of the encoder being sent to the transmitter input
measured during one bit time when the signal is high. See
Figure 9 below for clarification.
Shortest
pulsewidth
Data 50%
Manchester
Dead Time
Preamble
bit period = 1/data rate
Figure 9. Data Pattern
Then, the demodulator bandwidth required is calculated by,
Demod BW =
0.65
shortest pulseHz
]
Data Squelching
Data squelching can be achieved by software or hardware.
The software squelch is preferred over hardware squelch for
it is more flexible, reliable, lower cost over manufacturing, etc.
However, it takes time and resources to develop any soft-
ware. If one needs a squelch function, a resistor can be used
in the C
TH
pin. R1 and R2 are in the test circuit for this
purpose. Either one of them can be used or both. If only one
resistor is used, the value of the resistor should be chosen
according to the amount of squelch needed and if the DO pin
needs to be sitting high or low without an RF income signal.
Values from 10M
and below can be used. When both
resistors are used, a more accurate control can be achieved
for the squelch function.
The drawbacks using these resistors are: loss in receiver
sensitivity, reduced demodulator bandwidth, and the C
TH
capacitor equation will not work. As a result, C
TH
capacitor
will have to be determined empirically. Another way to imple-
ment a hardware squelch is to make R1 equal to 10M
to
6.8M
, and use a low-pass filter after the DO pin and a
comparator circuit. The low-pass filter can be a capacitor,
which is C6 in the Test Circuit. The reference voltage in the
comparator can be set close to VDD/2 and the other input
connected to the DO pin.
Power Supply Filter
A decoupling capacitor right at the V
DD
pin is strongly
recommended as it is in the test circuit, which has 0.1
μ
F. Not
shown in the Test Circuit Schematic is an EMI Inductor, L1 in
the silkscreen layer. It has the purpose to further filter an
income noise on the V
DD
line, generally present in switching
power supplies. It is good practice to separate RF ground
from digital ground and also V
DD
RF from other V
DD
lines.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| MICRF008BM | QwikRadio⑩ Sweep-Mode Receiver |
| MICRF011 | QwikRadiotm Receiver/Data Demodulator Preliminary Information |
| MICRF011BM | QwikRadiotm Receiver/Data Demodulator Preliminary Information |
| MICRF011BN | QwikRadiotm Receiver/Data Demodulator Preliminary Information |
| MICRF102 | QwikRadio UHF ASK Transmitter |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| MICRF008_11 | 制造商:MICREL 制造商全稱(chēng):Micrel Semiconductor 功能描述:QwikRadio Sweep-Mode Receiver |
| MICRF008BM | 功能描述:IC RECEIVER 300-440MHZ 8-SOIC RoHS:否 類(lèi)別:RF/IF 和 RFID >> RF 接收器 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS 產(chǎn)品變化通告:Product Discontinuation 09/Jan/2012 標(biāo)準(zhǔn)包裝:50 系列:* 頻率:850MHz ~ 2.175GHz 靈敏度:- 數(shù)據(jù)傳輸率 - 最大:- 調(diào)制或協(xié)議:- 應(yīng)用:* 電流 - 接收:* 數(shù)據(jù)接口:PCB，表面貼裝 存儲(chǔ)容量:- 天線連接器:PCB，表面貼裝 特點(diǎn):- 電源電壓:4.75 V ~ 5.25 V 工作溫度:0°C ~ 85°C 封裝/外殼:40-WFQFN 裸露焊盤(pán) 供應(yīng)商設(shè)備封裝:40-TQFN-EP（6x6） 包裝:托盤(pán) |
| MICRF008BM TR | 功能描述:IC RECEIVER 300-440MHZ 8-SOIC RoHS:否 類(lèi)別:RF/IF 和 RFID >> RF 接收器 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS 產(chǎn)品變化通告:Product Discontinuation 09/Jan/2012 標(biāo)準(zhǔn)包裝:50 系列:* 頻率:850MHz ~ 2.175GHz 靈敏度:- 數(shù)據(jù)傳輸率 - 最大:- 調(diào)制或協(xié)議:- 應(yīng)用:* 電流 - 接收:* 數(shù)據(jù)接口:PCB，表面貼裝 存儲(chǔ)容量:- 天線連接器:PCB，表面貼裝 特點(diǎn):- 電源電壓:4.75 V ~ 5.25 V 工作溫度:0°C ~ 85°C 封裝/外殼:40-WFQFN 裸露焊盤(pán) 供應(yīng)商設(shè)備封裝:40-TQFN-EP（6x6） 包裝:托盤(pán) |
| MICRF008YM | 功能描述:射頻接收器 300-440MHz Low-Cost Receiver, Sweep-Mode( Lead Free) RoHS:否 制造商:Skyworks Solutions, Inc. 類(lèi)型:GPS Receiver 封裝 / 箱體:QFN-24 工作頻率:4.092 MHz 工作電源電壓:3.3 V 封裝:Reel |
| MICRF008YM TR | 功能描述:射頻接收器 300-440MHz Low-Cost Receiver, Sweep-Mode( Lead Free) RoHS:否 制造商:Skyworks Solutions, Inc. 類(lèi)型:GPS Receiver 封裝 / 箱體:QFN-24 工作頻率:4.092 MHz 工作電源電壓:3.3 V 封裝:Reel |
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。