参数资料
型号: JN5139/001,531
厂商: NXP Semiconductors
文件页数: 75/82页
文件大小: 0K
描述: MCU 802.15.4 32BIT 2.4G 56-QFN
标准包装: 500
系列: JN5139-001Rx
频率: 2.4GHz
调制或协议: 802.15.4 Zigbee
应用: 通用
功率 - 输出: 3dBm
灵敏度: -96dBm
电源电压: 2.7 V ~ 3.6 V
电流 - 接收: 37mA
电流 - 传输: 37mA
数据接口: PCB,表面贴装
存储容量: 96kB RAM,192kB ROM
天线连接器: PCB,表面贴装
工作温度: -40°C ~ 85°C
封装/外壳: 56-VFQFN
包装: 带卷 (TR)
B.1.2 Crystal Load Capacitance
The crystal load capacitance is the total capacitance seen at the crystal pins, from all sources. As the load
capacitance (CL) affects the oscillation frequency by a process known as ‘pulling’, crystal manufacturers specify the
frequency for a given load capacitance only. A typical pulling coefficient is 15ppm/pF, to put this into context the
maximum frequency error in the IEEE802.15.4 specification is +/-40ppm for the transmitted signal. Therefore, it is
important for resonance at 16MHz exactly, that the specified load capacitance is provided.
The load capacitance can be calculated using:
CL
=
C T 1 × C T 2
C T 1 + C T 2
Total capacitance
C T 1 = C 1 + C 1 P + C 1 in
Where
C 1 is the capacitor component
C 1 P is the PCB parasitic capacitance. With the recommended layout this is about 1.6pF
C 1 in is the on-chip parasitic capacitance and is about 1.4pF typically.
Similarly for C T 2
Hence for a 9pF load capacitance, and a tight layout the external capacitors should be 15pF
B.1.3 Crystal ESR and Required Transconductance
The resistor in the crystal equivalent circuit represents the energy lost. To maintain oscillation, power must be
supplied by the amplifier, but how much? Firstly, the Pi connected capacitors C 1 and C 2 with C S from the crystal,
apply an impedance transformation to Rm, when viewed from the amplifier. This new value is given by:
R ? m = R m ? ? C S + C L ? ?
? ?
? C L ?
2
The amplifier is a transconductance amplifier, which takes a voltage and produces an output current. The amplifier
together with the capacitors C1 and C2, form a circuit, which provides a negative resistance, when viewed from the
crystal. The value of which is given by:
R NEG =
g m
C T 1 × C T 2 × ω 2
Where
g m is the transconductance
ω is the frequency in rad/s
Derivations of these formulas can be easily found in textbooks.
In order to give quick and reliable oscillator start-up, a common rule of thumb is to set the amplifier negative
resistance to be a minimum of 4 times the effective crystal resistance. This gives
m ? ?
≥ 4 R
g m
C T 1 × C T 2 × ω 2
?
?
C S + C L ? ?
C L ? ?
2
? NXP Laboratories UK 2010
JN-DS-JN5139 1v9
75
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JN5139-001-M/01R1V 功能描述:Zigbee/802.15.4模块 WIRELESS MCU IEEE802.15.4 TRNSCVR RoHS:否 制造商:Digi International 频带:902 MHz to 928 MHz 视线范围: 数据速率: 灵敏度: 工作电源电压:2.4 V to 3.6 V 传输供电电流:215 mA 接收供电电流:26 mA 输出功率:250 mW 天线连接器类型:Wire 最大工作温度:+ 85 C 尺寸:32.94 mm x 22 mm x 2.03 mm
JN5139-001-M/02R1V 功能描述:Zigbee/802.15.4模块 WIRELESS MCU IEEE802.15.4 TRNSCVR RoHS:否 制造商:Digi International 频带:902 MHz to 928 MHz 视线范围: 数据速率: 灵敏度: 工作电源电压:2.4 V to 3.6 V 传输供电电流:215 mA 接收供电电流:26 mA 输出功率:250 mW 天线连接器类型:Wire 最大工作温度:+ 85 C 尺寸:32.94 mm x 22 mm x 2.03 mm
JN5139-001-M/03R1T 功能描述:Zigbee/802.15.4模块 WIRELESS MCU IEEE802.15.4 TRNSCVR RoHS:否 制造商:Digi International 频带:902 MHz to 928 MHz 视线范围: 数据速率: 灵敏度: 工作电源电压:2.4 V to 3.6 V 传输供电电流:215 mA 接收供电电流:26 mA 输出功率:250 mW 天线连接器类型:Wire 最大工作温度:+ 85 C 尺寸:32.94 mm x 22 mm x 2.03 mm
JN5139-001-M/04R1T 功能描述:Zigbee/802.15.4模块 WIRELESS MCU IEEE802.15.4 TRNSCVR RoHS:否 制造商:Digi International 频带:902 MHz to 928 MHz 视线范围: 数据速率: 灵敏度: 工作电源电压:2.4 V to 3.6 V 传输供电电流:215 mA 接收供电电流:26 mA 输出功率:250 mW 天线连接器类型:Wire 最大工作温度:+ 85 C 尺寸:32.94 mm x 22 mm x 2.03 mm