- 您现在的位置：买卖IC网 > Datasheet目录503 > RFRXD0920-I/LQ (Microchip Technology)MODULE RCVR 868/915MHZ ASK/FSK Datasheet资料下载
参数资料
| 型号： | RFRXD0920-I/LQ |
| 厂商： | Microchip Technology |
| 文件页数： | 15/32页 |
| 文件大小： | 0K |
| 描述： | MODULE RCVR 868/915MHZ ASK/FSK |
| 产品变化通告： | RFRXD0(4,9)20I/LQ Obsolescence 07/Mar/2012 |
| 标准包装： | 250 |
| 频率： | 800MHz ~ 930MHz |
| 灵敏度： | -106dBm |
| 数据传输率 - 最大： | 80 kbps |
| 调制或协议： | ASK，FM，FSK |
| 应用： | 家庭自动化，遥感，RKE |
| 电流 - 接收： | 9.2mA |
| 数据接口： | PCB，表面贴装 |
| 天线连接器： | PCB，表面贴装 |
| 电源电压： | 2.5 V ~ 5.5 V |
| 工作温度： | -40°C ~ 85°C |
| 封装/外壳： | 32-LQFP |
| 供应商设备封装： | 32-LQFP（7x7） |
| 包装： | 托盘 |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页当前第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页第29页第30页第31页第32页
rfRXD0420/0920
3.2
Amplitude Shift Keying (ASK)
If the bit decision occurs near the end of the signal
Figure 3-9 illustrates an example ASK applications cir-
cuit.
The IF Limiting Amplifier with RSSI is used as an ASK
detector. The RSSI signal is post detector filtered and
then compared to a reference voltage to determine if
the incoming RF signal is a logical one or zero. The
reference voltage can be configured as a dynamic
voltage level determined by the incoming RF signal
strength or by a predetermined fixed level.
period, then the time constant should be set at less
than or equal to the signal period. Figure 3-11
illustrates this method.
Once the signal decision time and time period of the
signal period are known, then capacitor C1 can be
selected. Once C1 is selected, the designer should
observe the RSSI signal with an oscilloscope and
perform operational and/or bit error rate testing to
confirm receiver performance.
3.2.1
RSSI POST DETECTOR FILTERING
FIGURE 3-11: NEAR END OF THE SIGNAL
PERIOD DECISION RSSI LOW-
The RSSI signal is low-passed filtered to remove high
frequency and pulse noise to aid the decision making
process of the comparator and increase the sensitivity
of the receiver. The RSSI signal low-pass filter is a RC
filter created by the RSSI output impedance of 36 k ?
and capacitor C1. Setting the time constant (RC = τ ) of
the RC filter depends on the signal period and when the
signal decision will be made.
OOK Signal
PASS FILTERED
Signal Decision
3.2.1.1
Signal Period
Signal Period
Optimum sensitivity of the receiver with reasonable
pulse distortion occurs when the RC filter time constant
is between 1 and 2 times the signal period. If the time
constant of the RC filter is set too short, there is little
noise filtering benefit. However, if the time constant of
the RC filter is set too long, the data pulses will become
elongated causing inter-symbol interference.
RSSI Signal
1 τ to 2 τ
3.2.1.2
Signal Decision
3.2.2
COMPARATOR
If the bit decision occurs in the center of the signal
period (such as K EE L OQ decoders), then one or two
times the RC filter time constant should be set at less
than or equal to half the signal period. Figure 3-10 illus-
trates this method. The top trace represents the
received on-off keying (OOK) signal. The bottom trace
shows the RSSI signal after the RC low-pass filter.
FIGURE 3-10: CENTER SIGNAL PERIOD
DECISION RSSI LOW-PASS
FILTERED
Signal Decision
OOK Signal
Signal Period
RSSI Signal
The internal operational amplifier is configured as a
comparator. The RSSI signal is applied to OPA+ (Pin
20) and compared with a reference voltage on OPA-
(Pin 19) to determine the logic level of the received
signal. The reference voltage can be dynamic or static.
The choice of dynamic versus static reference voltage
depends in part on the ratio of logical ones versus
zeros of the data (this can also be thought of as the AC
content of the data). Provided the ratio has an even
number of logical ones versus zeros, a dynamic refer-
ence voltage can be generated with a simple low-pass
filter. The advantage of the dynamic reference voltage
is the increased receiver sensitivity compared to a fixed
reference voltage. However, the comparator will output
random data. The decoder (for example, a pro-
grammed PICmicro MCU or K EE L OQ decoder) must
distinguish between random noise and valid data.
The choice of a static reference voltage depends in part
on the DC content of the data. That is, the data has an
uneven number of logical ones versus zeros. The
disadvantage of the static reference voltage is
decreased receiver sensitivity compared to a dynamic
reference voltage. In this case, the comparator will
output data without random noise.
1 τ to 2 τ
? 2003 Microchip Technology Inc.
Preliminary
DS70090A-page 15
相关PDF资料 |
PDF描述 |
|---|---|
| RHK005N03T146 | MOSFET N-CH 30V 500MA SOT-346 |
| RHP020N06T100 | MOSFET N-CH 60V 2A SOT-89 |
| RHP030N03T100 | MOSFET N-CH 30V 3A SOT-89 |
| RI-TRP-WEHP-30 | RFID GLASS TRANSP R/W 80BIT 23MM |
| RJ45-XLRM | CONVERTER LEAD RJ45-XLR MALE |
相关代理商/技术参数 |
参数描述 |
|---|---|
| RFRXD0920T-I/LQ | 功能描述:射频收发器 32 LD 800-930 MHz RF RoHS:否 制造商:Atmel 频率范围:2322 MHz to 2527 MHz 最大数据速率:2000 Kbps 调制格式:OQPSK 输出功率:4 dBm 类型: 工作电源电压:1.8 V to 3.6 V 最大工作温度:+ 85 C 接口类型:SPI 封装 / 箱体:QFN-32 封装:Tray |
| RFS04ZG-M6 | 制造商:Power-One 功能描述: |
| RFS04ZG-M6G | 制造商:Power-One 功能描述:RFS Series 20 W Single Output 5 V DC/DC Converter Power Supply - Surface Mount |
| RFS062PJ150CS | 功能描述:RES ARRAY 2 RES 15 OHM 0603 制造商:samsung electro-mechanics 系列:RFS 包装:剪切带（CT） 零件状态:在售 电路类型:隔离 电阻（欧姆）:15 容差:±5% 电阻器数:2 引脚数:4 每元件功率:31.25mW 温度系数:±200ppm/°C 工作温度:-55°C ~ 125°C 应用:- 安装类型:表面贴装 封装/外壳:0302（0805 公制），长边端子 供应商器件封装:603 大小/尺寸:0.032" 长 x 0.024" 宽（0.80mm x 0.60mm） 高度 - 安装（最大值）:0.013"（0.33mm） 标准包装:1 |
| RFS062PJ220CS | 功能描述:RES ARRAY 2 RES 22 OHM 0603 制造商:samsung electro-mechanics 系列:RFS 包装:剪切带（CT） 零件状态:在售 电路类型:隔离 电阻（欧姆）:22 容差:±5% 电阻器数:2 引脚数:4 每元件功率:31.25mW 温度系数:±200ppm/°C 工作温度:-55°C ~ 125°C 应用:- 安装类型:表面贴装 封装/外壳:0302（0805 公制），长边端子 供应商器件封装:603 大小/尺寸:0.032" 长 x 0.024" 宽（0.80mm x 0.60mm） 高度 - 安装（最大值）:0.013"（0.33mm） 标准包装:1 |
发布紧急采购，3分钟左右您将得到回复。