- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄385521 > MAX1479ATE (MAXIM INTEGRATED PRODUCTS INC) 300MHz to 450MHz Low-Power, Crystal-Based +10dBm ASK/FSK Transmitter PDF資料下載
參數(shù)資料
| 型號(hào)： | MAX1479ATE |
| 廠商： | MAXIM INTEGRATED PRODUCTS INC |
| 元件分類： | 通信及網(wǎng)絡(luò) |
| 英文描述： | 300MHz to 450MHz Low-Power, Crystal-Based +10dBm ASK/FSK Transmitter |
| 中文描述： | SPECIALTY TELECOM CIRCUIT, QCC16 |
| 封裝： | 3 X 3 MM, 0.80 MM HEIGHT, TQFN-16 |
| 文件頁(yè)數(shù)： | 8/11頁(yè) |
| 文件大?。?/td> | 635K |
| 代理商： | MAX1479ATE |
M
300MHz to 450MHz Low-Power,
Crystal-Based +10dBm ASK/FSK Transmitter
8
_______________________________________________________________________________________
Output Matching to
PC Board Loop Antenna
In most applications, the MAX1479 power-amplifier out-
put has to be impedance matched to a small-loop
antenna. The antenna is usually fabricated out of a cop-
per trace on a PC board in a rectangular, circular, or
square pattern. The antenna has an impedance that
consists of a lossy component and a radiative compo-
nent. To achieve high radiating efficiency, the radiative
component should be as high as possible, while mini-
mizing the lossy component. In addition, the loop
antenna has an inherent loop inductance associated
with it (assuming the antenna is terminated to ground).
For example, in a typical application, the radiative
impedance is less than 0.5
, the lossy impedance is
less than 0.7
, and the inductance is approximately
50nH to 100nH.
The objective of the matching network is to match the
power-amplifier output to the impedance of the small-
loop antenna. The matching components thus tune out
the loop inductance and transform the low radiative
and resistive parts of the antenna into the much higher
value of the PA output. This gives higher efficiency. The
low radiative and lossy components of the small-loop
antenna result in a higher Q matching network than the
50
network; thus, the harmonics are lower.
Layout Considerations
A properly designed PC board is an essential part of
any RF/microwave circuit. On the power-amplifier out-
put, use controlled-impedance lines and keep them as
short as possible to minimize losses and radiation.
Keeping the traces short reduces parasitic inductance.
Generally, 1in of PC board trace adds about 20nH of
parasitic inductance. Parasitic inductance can have a
dramatic effect on the effective inductance. For exam-
ple, a 0.5in trace connecting a 100nH inductor adds an
extra 10nH of inductance, or 10%.
To reduce the parasitic inductance, use wider traces
and a solid ground or power plane below the signal
traces. Using a solid ground plane can reduce the par-
asitic inductance from approximately 20nH/in to 7nH/in.
Also, use low-inductance connections to ground on all
GND pins and place decoupling capacitors close to all
V
DD
connections.
Chip Information
TRANSISTOR COUNT: 2369
PROCESS: CMOS
COMPONENT
VALUE FOR
f
RF
= 433MHz
22nH
18nH
6.8pF
10pF
10nF
680pF
6.8pF
220pF
10nF
220pF
220pF
100pF
100pF
VALUE FOR
f
RF
= 315MHz
27nH
22nH
15pF
22pF
10nF
680pF
15pF
220pF
10nF
220pF
220pF
100pF
100pF
L1
L3
C1
C2
C3
C4
C6
C8
C10
C11
C12
C14
C15
Table 3. Component Values for Typical
Application Circuit
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| MAX1480A | Complete, Isolated RS-485/RS-422 Data Interface(半雙工，完全隔離的RS-485/422收發(fā)器) |
| MAX1480B | Complete, Isolated RS-485/RS-422 Data Interface(半雙工，完全隔離的RS-485/422收發(fā)器) |
| MAX1480C | Complete, Isolated RS-485/RS-422 Data Interface(半雙工，完全隔離的RS-485/422收發(fā)器) |
| MAX1490A | Complete, Isolated RS-485/RS-422 Data Interface(2.5Mbps，全雙工，完全隔離的RS-485/422收發(fā)器) |
| MAX1490B | Complete, Isolated RS-485/RS-422 Data Interface(2.5Mbps，全雙工，完全隔離的RS-485/422收發(fā)器) |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| MAX1479ATE+ | 功能描述:射頻發(fā)射器 300MHz - 450MHz ASK/FSK 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 |
| MAX1479ATE+T | 功能描述:射頻發(fā)射器 300MHz - 450MHz ASK/FSK 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 |
| MAX1479ATE-T | 功能描述:射頻發(fā)射器 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 |
| MAX1479EVKIT-315 | 功能描述:射頻開(kāi)發(fā)工具 MAX1479 Eval Kit RoHS:否 制造商:Taiyo Yuden 產(chǎn)品:Wireless Modules 類型:Wireless Audio 工具用于評(píng)估:WYSAAVDX7 頻率: 工作電源電壓:3.4 V to 5.5 V |
| MAX1479EVKIT-433 | 功能描述:射頻開(kāi)發(fā)工具 MAX1479 Eval Kit RoHS:否 制造商:Taiyo Yuden 產(chǎn)品:Wireless Modules 類型:Wireless Audio 工具用于評(píng)估:WYSAAVDX7 頻率: 工作電源電壓:3.4 V to 5.5 V |
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。
