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參數(shù)資料
| 型號： | TK5552 |
| 廠商： | Atmel Corp. |
| 英文描述： | Read/Write Transponder |
| 中文描述： | 讀/寫轉(zhuǎn)發(fā) |
| 文件頁數(shù)： | 7/22頁 |
| 文件大小： | 326K |
| 代理商： | TK5552 |
7
TK5552
4698A–RFID–04/03
Downlink Data Decoding
The time between two detected gaps is used to encode the information. As soon as a
gap is detected, a counter starts counting the number of field clock cycles until the next
gap is detected. Depending on how many field clocks elapse, the data is regarded as 0
or 1. The required number of field clocks is shown in Figure 10. A valid 0 is assumed if
the number of counted clock periods is between 16 and 32, for a valid 1 it is 48 or 64,
respectively. If the data transmission was correct, programming is started and the writ-
ten block is cycling its data back to the base station until POR.
Figure 10.
Downlink Data Decoding Scheme
Behavior of the Real
Device
The TK5552 detects a gap if the voltage across the coils decreases below the threshold
value of an internal MOS transistor. Until then, the clock pulses are counted. The num-
ber given for a valid '0' or '1' (see Figure 10) refers to the actual clock pulses counted by
the device. There are, however, always more clock pulses being counted than applied
by the base station. The reason for this is that an RF field cannot be switched off imme-
diately. The coil voltage decreases exponentially. Even if the RF field coming from the
base station is switched off, it takes some time until the voltage across the coils reaches
the threshold value of an internal MOS transistor and the device detects the gap.
Referring to Figure 11, the device uses t
0 internal
and t
1 internal
. The exact values for t
0
and
t
1
are depend on the application (e.g., field strength, etc.)
Typical time frames are:
t
0
= 70 μs to 150 μs
t
1
= 300 μs to 400 μs
t
gap
= 180 μs to 400 μs
Antennas with a high Q-factor require longer times for t
gap
and shorter time values for t
0
and t
1
.
Figure 11.
Ideal and Real Behavior of Signals
1
16
32
Field clock cycles
48
64
Fail
0
Fail
1
Downlink done
Downlink data decoder
1
0
1
t
1
t
gap
t
0
Gap detect
1
t
1
Gap detect
Ideal behavior
RF level decreases to zero immediately
Real behavior
RF level decreases exponentially
Coil
voltage
Coil
voltage
1
0
t
gap
t
0
t
1 internal
t
0 internal
相關PDF資料 |
PDF描述 |
|---|---|
| TK5552A-PP | Read/Write Transponder |
| TK5561A-PP | READ/WRITE CRYPTO TRANSPONDER FOR SHORT CYCLE TIME |
| TL061AMN | LOW POWER J-FET SINGLE OPERATIONAL AMPLIFIER |
| TL061B | LOW POWER J-FET SINGLE OPERATIONAL AMPLIFIER |
| TL061BC | LOW POWER J-FET SINGLE OPERATIONAL AMPLIFIER |
相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| TK5552A-PP | 制造商:ATMEL 制造商全稱:ATMEL Corporation 功能描述:Read/Write Transponder |
| TK5561A-PP | 功能描述:射頻無線雜項 Crypto-Transp. Prog f.all appl. RoHS:否 制造商:Texas Instruments 工作頻率:112 kHz to 205 kHz 電源電壓-最大:3.6 V 電源電壓-最小:3 V 電源電流:8 mA 最大功率耗散: 工作溫度范圍:- 40 C to + 110 C 封裝 / 箱體:VQFN-48 封裝:Reel |
| TK55A10J1(Q) | 制造商:Toshiba America Electronic Components 功能描述: 制造商:Toshiba America Electronic Components 功能描述:Trans MOSFET N-CH 100V 55A 3-Pin(3+Tab) TO-220SIS |
| TK55D10J1 | 制造商:TOSHIBA 制造商全稱:Toshiba Semiconductor 功能描述:Switching Regulator Applications |
| TK55D10J1(Q) | 功能描述:MOSFET MOSFET N-Ch RoHS:否 制造商:STMicroelectronics 晶體管極性:N-Channel 汲極/源極擊穿電壓:650 V 閘/源擊穿電壓:25 V 漏極連續(xù)電流:130 A 電阻汲極/源極 RDS（導通）:0.014 Ohms 配置:Single 最大工作溫度: 安裝風格:Through Hole 封裝 / 箱體:Max247 封裝:Tube |
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