參數(shù)資料
型號： MC33690
廠商： Motorola, Inc.
英文描述： Standalone Tag Reader Circuit
中文描述： 獨(dú)立標(biāo)簽讀寫器電路
文件頁數(shù)： 6/24頁
文件大小： 442K
代理商： MC33690
Go to: www.freescale.com
revision 4.8, 5 February 2002
Motorola, Inc., 2002.
Read function
When answering to the base station, a
transponder generates an absorption modulation
of the magnetic field. It results in an amplitude/
phase modulation of the current across the
antenna. This information is picked up at the
antenna tap point between the coil and the
capacitor. An external resistive ladder down
scales this voltage to a level compatible with the
demodulator input voltage range (see parameter
V
INRD
page 16).
The demodulator (see figure 2) consists of :
- an input stage (emitter follower),
- a sample & hold circuit,
- a voltage follower,
- a low offset voltage comparator.
The sampling time is automatically set to take
into account a phase shift due to the tolerances
of the antenna components (L and C) and of the
oscillator. The allowed phase shift measured at
the input RD ranges from -45
°
to +45
°
. Assuming
that the phase reference is the falling edge of the
driving signal TD1, this leads to a sampling time
phase ranging from -78.75
°
to 90
°
with discrete
steps of 11.25
°
. After reset condition, the
sampling time phase is +11.25
°
.
The antenna phase shift evaluation is only
done :
- after each wake-up command
(see pages
10 to 12),
- or after reset (see page 7).
This is necessary to obtain the best demodulator
performances.
In order to ensure a fast demodulator settling
time after wake up, reset or a write sequence, the
external capacitor C
EXT
is preloaded at its
working voltage.
This preset occurs 256μs after switching the
antenna drivers on and its duration is 128μs.
After wake up or reset, the preset has the same
duration but begins 518μs after clock settling.
After power on reset, VSUP must meet the
minimum specified value, enabling the nominal
operation of VDD, before the start of the preset.
Otherwise the preset must be done by the user
through a standby/wake-up sequence.
Write function
Whatever the selected configuration (see
page 9), the write function is achieved by
switching on/off the output drivers TD1/2.
Once the drivers have been set in high
impedance, the load current flows alternatively
Figure 3 : Current flow when the buffers are switched off
C
A
L
A
R
1
R
A
TD1
VDD
TD2
VDD
I
LOAD
F
Freescale Semiconductor, Inc.
For More Information On This Product,
n
.
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MC33690DWE 功能描述:數(shù)字信號處理器和控制器 - DSP, DSC STAND ALONE TAG READER RoHS:否 制造商:Microchip Technology 核心:dsPIC 數(shù)據(jù)總線寬度:16 bit 程序存儲器大小:16 KB 數(shù)據(jù) RAM 大小:2 KB 最大時鐘頻率:40 MHz 可編程輸入/輸出端數(shù)量:35 定時器數(shù)量:3 設(shè)備每秒兆指令數(shù):50 MIPs 工作電源電壓:3.3 V 最大工作溫度:+ 85 C 封裝 / 箱體:TQFP-44 安裝風(fēng)格:SMD/SMT
MC33690DWER2 功能描述:數(shù)字信號處理器和控制器 - DSP, DSC STAND ALONE TAG READER RoHS:否 制造商:Microchip Technology 核心:dsPIC 數(shù)據(jù)總線寬度:16 bit 程序存儲器大小:16 KB 數(shù)據(jù) RAM 大小:2 KB 最大時鐘頻率:40 MHz 可編程輸入/輸出端數(shù)量:35 定時器數(shù)量:3 設(shè)備每秒兆指令數(shù):50 MIPs 工作電源電壓:3.3 V 最大工作溫度:+ 85 C 封裝 / 箱體:TQFP-44 安裝風(fēng)格:SMD/SMT
MC33696FCAE 功能描述:射頻收發(fā)器 UHF TRANSCEIVER RoHS:否 制造商:Atmel 頻率范圍:2322 MHz to 2527 MHz 最大數(shù)據(jù)速率:2000 Kbps 調(diào)制格式:OQPSK 輸出功率:4 dBm 類型: 工作電源電壓:1.8 V to 3.6 V 最大工作溫度:+ 85 C 接口類型:SPI 封裝 / 箱體:QFN-32 封裝:Tray
MC33696FCAER2 功能描述:射頻收發(fā)器 UHF TRANSCEIVER ECHO RoHS:否 制造商:Atmel 頻率范圍:2322 MHz to 2527 MHz 最大數(shù)據(jù)速率:2000 Kbps 調(diào)制格式:OQPSK 輸出功率:4 dBm 類型: 工作電源電壓:1.8 V to 3.6 V 最大工作溫度:+ 85 C 接口類型:SPI 封裝 / 箱體:QFN-32 封裝:Tray
MC33696FCE 功能描述:射頻收發(fā)器 PLL Tuned UHF Recvr RoHS:否 制造商:Atmel 頻率范圍:2322 MHz to 2527 MHz 最大數(shù)據(jù)速率:2000 Kbps 調(diào)制格式:OQPSK 輸出功率:4 dBm 類型: 工作電源電壓:1.8 V to 3.6 V 最大工作溫度:+ 85 C 接口類型:SPI 封裝 / 箱體:QFN-32 封裝:Tray
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