- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄369900 > MC33493 (Motorola, Inc.) PLL tuned UHF Transmitter for Data Transfer Applications PDF資料下載
參數(shù)資料
| 型號(hào)： | MC33493 |
| 廠商： | Motorola, Inc. |
| 英文描述： | PLL tuned UHF Transmitter for Data Transfer Applications |
| 中文描述： | 鎖相環(huán)調(diào)諧數(shù)據(jù)傳輸應(yīng)用超高頻發(fā)射器 |
| 文件頁數(shù)： | 17/20頁 |
| 文件大?。?/td> | 595K |
| 代理商： | MC33493 |
RECOMMENDATIONS FOR FSK MODULATION
MOTOROLA
MC33493 Technical Data
17
Figure 15: Application PCB layout for FSK modulation, serial configuration, 434MHz frequency band
Table 6 gives the measured FSK deviations respective to C3 and C4 capacitor values for three deviations.
Crystal reference is NDK NX8045GB/CSJ S1-40125-8050-12.
Table 6 : Crystal pulling capacitor values versus carrier frequency total deviation -1-
Carrier frequency
(MHz)
total deviation (kHz)
45
70
100
90
140
200
Another crystal reference, NDK NX1255GA (see table 4), enables to reach higher deviation as mentioned on
table 7. These results are due to the higher crystal motional capacitor.
Table 7 : Crystal pulling capacitor values versus carrier frequency total deviation -2-
Carrier frequency
(MHz)
total deviation (kHz)
value (pF)
434
150
868
300
RECOMMENDATIONS FOR FSK MODULATION
FSK deviation is function of total load capacitance presented to the crystal. This load capacitance is constituted
by various contributors:
- the crystal characteristic, especially its static capacitance,
- the external load capacitors (C3, C4 as defined in figure 14 and table 6),
- the device internal capacitance of pins XTAL0, XTAL1, CFSK,
- the PCB track capacitance.
The schematic given in figure 16 shows a typical FSK application using serial capacitor configuration, where
device pads and PCB track capacitances are mentioned.
Device pad capacitance is defined by the package capacitance and by the internal circuitry. Typical capacitance
values for these pads are given in table 8.
Some realistic assumptions and measurements have been made concerning track parasitic capacitances for a
0.8mm FR4 double side application PCB. They are given in table 8 and the corresponding PCB layout is shown
in figure 15.
To achieve large deviations, this total load capacitance need to be lowered. For a given crystal, the PCB must be
very carefully laid out in order to reduce as much as possible the capacitance of the tracks wired to XTAL0,
Carrier frequency
C3 capacitor
(pF)
4.7
2.2
1
4.7
2.2
1
C4 capacitor
(pF)
6.8
10
15
6.8
10
15
Recommended
R_off value (k
)
10
-
22
10
-
22
434
868
Carrier frequency
C3 capacitor
C4 capacitor
value (pF)
27
27
Recommended
R_off value (k
)
-
-
1
1
F
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
n
.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| MC33493DTB | PLL tuned UHF Transmitter for Data Transfer Applications |
| MC3359 | Single Output LDO, 400mA, Fixed(3.3V), Low Noise, Fast Transient Response 5-SOT-23 -40 to 85 |
| MC3359DW | Single Output LDO, 400mA, Fixed(5.0V), Low Noise, Fast Transient Response 8-MSOP -40 to 85 |
| MC3359P | Single Output LDO, 400mA, Fixed(5.0V), Low Noise, Fast Transient Response 8-MSOP -40 to 85 |
| MC3362 | Single Output LDO, 400mA, Fixed(2.5V), Low Noise, Fast Transient Response 8-MSOP -40 to 85 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| MC33493ADTBE | 功能描述:射頻發(fā)射器 UHF TRANSMITTER RoHS:否 制造商:Micrel 類型:ASK Transmitter 封裝 / 箱體:SOT-23-6 工作頻率:300 MHz to 450 MHz 封裝:Reel |
| MC33493ADTBER2 | 功能描述:射頻發(fā)射器 UHF TRANSMITTER RoHS:否 制造商:Micrel 類型:ASK Transmitter 封裝 / 箱體:SOT-23-6 工作頻率:300 MHz to 450 MHz 封裝:Reel |
| MC33493DTB | 功能描述:射頻發(fā)射器 315 434 868 MHz RoHS:否 制造商:Micrel 類型:ASK Transmitter 封裝 / 箱體:SOT-23-6 工作頻率:300 MHz to 450 MHz 封裝:Reel |
| MC33493DTBE | 功能描述:射頻發(fā)射器 PLL TUNED UHF TRANSMITTE RoHS:否 制造商:Micrel 類型:ASK Transmitter 封裝 / 箱體:SOT-23-6 工作頻率:300 MHz to 450 MHz 封裝:Reel |
| MC33493DTBER2 | 功能描述:射頻發(fā)射器 PLL TUNED UHF TRANSMITTE RoHS:否 制造商:Micrel 類型:ASK Transmitter 封裝 / 箱體:SOT-23-6 工作頻率:300 MHz to 450 MHz 封裝:Reel |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。