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參數(shù)資料
| 型號(hào)： | MICRF008BM |
| 廠商： | MICREL INC |
| 元件分類： | 消費(fèi)家電 |
| 英文描述： | QwikRadio⑩ Sweep-Mode Receiver |
| 中文描述： | SPECIALTY CONSUMER CIRCUIT, PDSO8 |
| 封裝： | SOIC-8 |
| 文件頁(yè)數(shù)： | 6/12頁(yè) |
| 文件大?。?/td> | 115K |
| 代理商： | MICRF008BM |
MICRF008
Micrel
MICRF008
6
July 2003
Data Slicing Level
Extraction of the DC value of the demodulated signal for
purposes of logic-level data slicing is accomplished by an
external capacitor C
TH
and the on-chip switched-capacitor
resistor RSC, indicated in the block diagram. The effective
resistance of RSC scales inversely proportional to REFOSC
frequency. The nominal value of RSC given in the
“
Electrical
Characteristics
”
Table is 220k
for a REFOSC frequency of
3.36MHz. Slicing level time constant value vary depending
on data pattern, data rate and data duty cycle.
Automatic Gain Control (AGC)
The signal path has automatic gain control (AGC) to increase
the overall receiver dynamic range. An external capacitor,
C
AGC
, must be connected to the C
AGC
pin of the device.
Normally the C
AGC
capacitor is connected to ground. If faster
start-up times are required when the receiver is first powered-
on, the C
AGC
capacitor may be connected to V
DD
. The ratio
of decay-to-attack time constant is fixed at 10:1 (that is, the
attack time constant is 1/10
th
of the decay time constant), and
the user cannot change this ratio. Nevertheless, the attack
time constant is set externally by choosing a value for C
AGC
.
Another function of the AGC control voltage is to raise the
noise floor in order to guarantee a clean signal between the
preamble and the data, sometimes called dead time. The
AGC control voltage can be further manipulated and ampli-
fied to create an RSSI signal, which is useful for several
different applications.
Reference Oscillator
All timing and tuning operations on the MICRF008BM are
derived from the internal Colpitts reference oscillator. The
reference frequency can be implemented in two ways, by
using a resonator device (a ceramic resonator or crystal), or
by driving an external signal, which should not exceed
0.5V
RMS
. The reference frequency is obtained by dividing the
RF carrier frequency by 129.
I/O Pin Interface Circuitry
Interface circuitry for the various I/O pins of the MICRF008 is
shown in Figures 1 through 6. Specific information regarding
each of these circuits is discussed in the following sub-
paragraphs. Not shown are ESD protection diodes which are
applied to all input pins.
C
TH
Pin
Figure 2 illustrates the C
TH
pin interface circuit. C
TH
pin is
driven from a P-Channel MOSFET source-follower biased
with approximately 20
μ
A of bias current. Transmission gates
TG1 and TG2 isolate the 3.3pF capacitor. Internal control
signals PHI1/PHI2 are related in a manner such that the
impedance across the transmission gates looks like a
“
resis-
tance.
”
The DC potential on the C
TH
pin is approximately
2.2V, fundamentally determined by the VGS of the two P-
Channel MOSFET source-followers shown.
C
AGC
Pin
Figure 3 illustrates the C
AGC
pin interface circuit. The AGC
control voltage is developed as an integrated current into a
capacitor C
AGC
. The attack current is nominally 15
μ
A, while
the decay current is a 1/10
th
scaling of this, approximately
1.5
μ
A. Signal gain of the RF/IF strip inside the IC diminishes
as the voltage on C
AGC
decreases. By simply adding a
capacitor to C
AGC
pin, the attack/decay time constant ratio is
fixed at 1:10.
VDDBB
VSSBB
Compa-
rator
1.5
μ
A
15
μ
A
CAGC
Figure 3. C
AGC
Pin
3.3pF
PHI2B
TG1
TG2
PHI1B
PHI1
PHI2
CTH
DC-coupled
Switched
Cap. Filter
VDDBB
VSSBB
VSSBB
20
μ
A
VDDBB
VSSBB
20
μ
A
Demod
Signal
(0Vdc)
Figure 2. C
TH
Pin
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|---|---|
| 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 |
| MICRF102BM | QwikRadio UHF ASK Transmitter |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| MICRF008BM TR | 功能描述:IC RECEIVER 300-440MHZ 8-SOIC RoHS:否 類別: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 供應(yīng)商設(shè)備封裝:40-TQFN-EP（6x6） 包裝:托盤 |
| 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 |
| MICRF009 | 制造商:MICREL 制造商全稱:Micrel Semiconductor 功能描述:QwikRadio Low-Power UHF Receiver |
| MICRF009BM | 功能描述:IC RECEIVER UHF LOW POWER 16SOIC RoHS:否 類別: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 供應(yīng)商設(shè)備封裝:40-TQFN-EP（6x6） 包裝:托盤 |
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