- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄382996 > GJRF400 (Electronic Theatre Controls, Inc.) SINGLE CHIP RF TRANSCEIVER PDF資料下載
參數(shù)資料
| 型號： | GJRF400 |
| 廠商： | Electronic Theatre Controls, Inc. |
| 英文描述： | SINGLE CHIP RF TRANSCEIVER |
| 中文描述： | 單芯片射頻收發(fā)器 |
| 文件頁數(shù)： | 3/8頁 |
| 文件大?。?/td> | 117K |
| 代理商： | GJRF400 |
Gran-Jansen AS Oslo Norway
98-05
3
Detailed Description
The transmitter consists of a PLL frequency synthesiser
and a power amplifier. The frequency synthesiser
consists of a voltage controlled oscillator (VCO), a
crystal oscillator, prescaler, programmable frequency
dividers and a phase-detector. The loop-filter is external
for flexibility The VCO is a Colpitts oscillator and needs
an external resonator and varicap. FSK modulation can
be applied externally to the VCO or to the crystal
oscillator. The synthesiser has two different, N and M,
frequency dividers. For low bitrate applications
(approximate 100 bps) FSK modulation can be
implemented by switching between these dividers. The
lengths of the N and M registers are 12 and 10 bits
respectively. For all types of FSK modulation, data is
entered at the Data IXO pin (see application circuit,
Figure 7).
In receive mode the PLL synthesiser generates the local
oscillator (LO) signal. The N and M values that give the
LO frequency are stored in the N0 and M0 registers.
The receiver is a zero intermediate frequency (IF) type
in order to make channel filtering possible with low-
power integrated low-pass filters. The receiver consists
of a low noise amplifier (LNA) that drives a quadrature
mixer pair. The mixer outputs feed two identical signal
channels in phase quadrature.
Each channel includes a variable gain amplifier, a second
order passive RC lowpass filter (to protect the gyrator
filter from strong adjacent channel signals), a gyrator
filter and finally a limiter. The main channel filter is a
gyrator-capacitor implementation of a five-pole elliptic
lowpass filter. The elliptic filter minimises the total
capacitance required for a given selectivity and dynamic
range. The lowpass cut-off frequency can be adjusted by
an external resistor.
The demodulator demodulates the I and Q channel
outputs and produces a digital data output. It detects the
relative phase difference of the I and the Q channel
signals. If the I channel signal lags the Q channel, the
FSK tone frequency lies above the LO frequency (data
‘1’). If the I channel leads the Q channel, the FSK tone
lies below the LO frequency (data ‘0’). The output of the
receiver is available on the Data IXO pin.
A three pin serial interface is used to program the circuit.
External components are necessary for RF input and
output impedance matching and decoupling of power.
Other external components are VCO resonator and
varicap, crystal, feedback capacitors and components for
FSK modulation in VCO/crystal oscillator, loop filter,
bias resistors for power amplifier and gyrator filters.
Circuit blocks
VCO
Figure 2: VCO
The VCO is basically a Colpitts oscillator. The oscillator
has an external resonator and varicap. The control
voltage for the varicap is derived from the phase detector
via a passive loop filter.
The VCO’s external components should be screened to
avoid undue pick-up of external unwanted signals.
Crystal-oscillator
Figure 3: Crystal oscillator
As the crystal oscillator is a reference for the RF output
frequency and also for the LO frequency in the receiver,
very good phase and frequency stability is required. The
crystal oscillator is tuned by varying a trimming capacitor.
Passive components in parallel with the internal
MOSFET are necessary if FSK modulation is applied to
the crystal oscillator. The drift in the RF frequency is the
same as the drift in crystal frequency when measured in
PPM.
The circuit has been tested with a 10MHz crystal, but
other crystal frequencies can be used as well.
相關PDF資料 |
PDF描述 |
|---|---|
| GL2EG6 | Convex Type, Colored Diffusion LED Lamps for Indicator |
| GL2PR6 | ┆2mm, Convex Type, Colored Diffusion LED Lamps for Indicator |
| GL2HD6 | Convex Type, Colored Diffusion LED Lamps for Indicator |
| GL2HS6 | Convex Type, Colored Diffusion LED Lamps for Indicator |
| GL2HY6 | Convex Type, Colored Diffusion LED Lamps for Indicator |
相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| GJS6120U | 制造商:Panduit Corp 功能描述:TELECOM EQUIPMENT BONDING CONDUCTOR (TEB - Bag 制造商:Panduit Corp 功能描述:CABLE JUMPER KIT |
| GJS6180U | 制造商:Panduit Corp 功能描述:Cable Assembly Jumper 4.57m 6AWG Lug Terminal to Lug Terminal 制造商:Panduit Corp 功能描述:TELECOM EQUIPMENT BONDING CONDUCTOR (TEB - Bag |
| GJS660U | 功能描述:光纖線纜 GJ Grounding Jumper #6 AWG RoHS:否 制造商:Avago Technologies 類型:Plastic Optical Fiber (POF) 纖維類型: 外殼顏色:Black 長度:500 meters 外殼材料:Polyethylene |
| GJS696U | 制造商:Panduit Corp 功能描述:JUMPER KITS, EQUIPMENT GROUNDING, #6 AWG - Bulk 制造商:Panduit Corp 功能描述:JUMPER KITS, EQUIPMENT #6 AWG GROUNDING, 制造商:Panduit Corp 功能描述:Jumper Kits, Equipment Grounding, #6 AWG |
| GJSBL1030CT | 制造商:GTM 制造商全稱:GTM 功能描述:SCHOTTKY BARRIER RECTIFIERS |
發(fā)布緊急采購，3分鐘左右您將得到回復。