參數(shù)資料
型號: T5744-TKQ
廠商: ATMEL CORP
元件分類: 通信及網(wǎng)絡
英文描述: UHF ASK Receiver
中文描述: SPECIALTY TELECOM CIRCUIT, PDSO20
封裝: SSO-20
文件頁數(shù): 4/20頁
文件大?。?/td> 277K
代理商: T5744-TKQ
4
T5744
4521B–RKE–01/03
Figure 4.
PLL Peripherals
The passive loop filter connected to Pin LF is designed for a loop bandwidth of BLoop =
100 kHz. This value for BLoop exhibits the best possible noise performance of the LO.
Figure 4 shows the appropriate loop filter components to achieve the desired loop
bandwidth
f
LO
is determined by the RF input frequency f
RF
and the IF frequency f
IF
using the follow-
ing formula:
f
LO
= f
RF
- f
IF
To determine f
LO
, the construction of the IF filter must be considered at this point. The
nominal IF frequency is f
IF
= 1 MHz. To achieve a good accuracy of the filter's corner fre-
quencies, the filter is tuned by the crystal frequency f
XTO
. This means that there is a
fixed relation between f
IF
and f
LO
that depends on the logic level at pin mode. This is
described by the following formulas:
MODE = 0 USA f
IF
= f
LO
/314
MODE = 1 Europe f
IF
= f
LO
/432.92
The relation is designed to achieve the nominal IF frequency of f
IF
= 1 MHz for most
applications. For applications where f
RF
= 315 MHz, MODE must be set to '0'. In the
case of f
RF
= 433.92 MHz, MODE must be set to '1'. For other RF frequencies, f
IF
is
not equal to 1 MHz. f
IF
is then dependent on the logical level at Pin MODE and on f
RF
.
Table 1 summarizes the different conditions.
The RF input either from an antenna or from a generator must be transformed to the RF
input Pin LNA_IN. The input impedance of that pin is provided in the electrical parame-
ters. The parasitic board inductances and capacitances also influence the input
matching. The RF receiver T5744 exhibits its highest sensitivity at the best signal-to-
noise ratio in the LNA. Hence, noise matching is the best choice for designing the trans-
formation network.
A good practice when designing the network, is to start with power matching. From that
starting point, the values of the components can be varied to some extent to achieve the
best sensitivity.
If a SAW is implemented into the input network a mirror frequency suppression of
P
Ref
= 40 dB can be achieved. There are SAWs available that exhibit a notch at
f = 2 MHz. These SAWs work best for an intermediate frequency of IF = 1 MHz. The
selectivity of the receiver is also improved by using a SAW. In typical automotive appli-
cations, a SAW is used.
DVCC
XTO
LF
LFVCC
LFGND
V
C
C10
R1
C9
S
L
V
S
R1 = 820
C9 = 4.7 nF
C10 = 1 nF
相關(guān)PDF資料
PDF描述
T5744-TKS UHF ASK Receiver
T5750 UHF ASK/FSK TRANSMITTER
T5750-6AQ UHF ASK/FSK TRANSMITTER
T5753 UHF ASK/FSK TRANSMITTER
T5753-6AQ UHF ASK/FSK TRANSMITTER
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
T5744-TKS 功能描述:射頻收發(fā)器 UHF ASK Receiver IC 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
T5746 功能描述:手工工具 SEPARATOR TOOL RoHS:否 制造商:Molex 產(chǎn)品:Extraction Tools 類型: 描述/功能:Extraction tool
T5746F 制造商:Harwin 功能描述:SEPARATOR TOOL 制造商:Harwin 功能描述:SEPARATOR TOOL; SVHC:No SVHC (19-Dec-2012); Series:Datamate L-Tek, J-Tek & Mix-Tek ;RoHS Compliant: NA
T5747 功能描述:折皺器 POSITIONER RoHS:否 制造商:Hirose Connector 類型: 描述/功能:Cable and Shield Crimper