参数资料
型号: SM1211E915TOPIC
厂商: Semtech
文件页数: 15/92页
文件大小: 0K
描述: KIT PICTAIL EXT FOR SX1211
特色产品: SM1211E915toPIC Development Kit
标准包装: 1
类型: 收发器,UHF
频率: 915MHz
适用于相关产品: SX1211
已供物品: 板,模块,天线
产品目录页面: 584 (CN2011-ZH PDF)
SX1211
WIRELESS & SENSING
With the recommended Bill Of Materials (BOM) of the reference design of section 7.5.3, the PLL prototype is the
following:
64 ≤ R ≤ 169
S < P+1
PLLBW = 15 kHz nominal
Startup times and reference frequency spurs as specified.
3.2.5. Voltage Controlled Oscillator
The integrated VCO requires only two external tank circuit inductors. As the input is differential, the two inductors
should have the same nominal value. The performance of these components is important for both the phase noise
and the power consumption of the PLL. It is recommended that a pair of high Q factor inductors is selected. These
should be mounted orthogonally to other inductors (in particular the PA choke) to reduce spurious coupling
between the PA and VCO. In addition, such measures may reduce radiated pulling effects and undesirable
transient behavior, thus minimizing spectral occupancy. Note that ensuring a symmetrical layout of the VCO
inductors will further improve PLL spectral purity.
For best performance wound type inductors, with tight tolerance, should be used as described in section 7.5.3.
3.2.5.1. SW Settings of the VCO
To guarantee the optimum operation of the VCO over the SX1211’s frequency and temperature ranges, the
following settings should be programmed into the SX1211:
Target channel
(MHz)
Freq_band
863-
870
10
902-
915
00
915-
928
01
950-
960
10
Table 10: MCParam_Freq_band Setting
3.2.5.2. Trimming the VCO Tank by Hardware and Software
To ensure that the frequency band of operation may be accurately addressed by the R, P and S dividers of the
synthesizer, it is necessary to ensure that the VCO is correctly centered. Note that for the reference design (see
section 7.5) no centering is necessary. However, any deviation from the reference design may require the
optimization procedure, outlined below, to be implemented. This procedure is simplified thanks to the built-in VCO
trimming feature which is controlled over the SPI interface. This tuning does not require any RF test equipment,
and can be achieved by simply measuring Vtune, the voltage between pins 6 (LFM) and 7 (LFP).
The VCO is centered if the voltage is within the range:
50 ≤ Vtune ( mV ) ≤ 150
Note that this measurement should be conducted when in transmit mode at the center frequency of the desired
band (for example ~867 MHz in the 863-870 MHz band), with the appropriate MCParam_Freq_band setting.
If this inequality is not satisfied then adjust the MCParam_VCO_trim bits from 00 whilst monitoring Vtune. This
allows the VCO voltage to be trimmed in + 60 mV increments. Should the desired voltage range be inaccessible,
the voltage may be adjusted further by changing the tank circuit inductance value. Note that an increase in
inductance will result in an increase Vtune.
Rev 8 – February 2013
Page 15 of 92
www.semtech.com
相关PDF资料
PDF描述
GLDC01B SWTCH TOP PLNGR SNAP SPDT
TC25N3A32K7680 OSCILLATOR 32.7680 KHZ 2.5V SMD
CGH40035F-TB BOARD DEMO AMP CIRCUIT CGH40035
CGH55030F-TB RF EVAL HEMT AMPLIFIER
TC25L3A32K7680 OSCILLATOR 32.7680 KHZ 3.3V SMD
相关代理商/技术参数
参数描述
SM-1212 制造商:COOPER INDUSTRIES 功能描述:SCKT 1/4 FMALE SQ DRV 3/8 FMA
SM1212E433 功能描述:RF EVAL FOR SX1212 433MHZ ISM RoHS:是 类别:RF/IF 和 RFID >> RF 评估和开发套件,板 系列:- 标准包装:1 系列:- 类型:GPS 接收器 频率:1575MHz 适用于相关产品:- 已供物品:模块 其它名称:SER3796
SM-1220M 制造商: 功能描述: 制造商:undefined 功能描述:
SM12-3/16-BLK-200FT 制造商:SUMITOMO 功能描述:177-10101 SM12 3/16 BLK SPL
SM12-3/4-WHT-200FT 制造商:SUMITOMO 功能描述:SM12-3/4-WHT-200FT 制造商:SUMITOMO 功能描述:177-10189 SM12 3/4 WHT SPL