参数资料
型号: MC9S12DG256MFU
厂商: FREESCALE SEMICONDUCTOR INC
元件分类: 微控制器/微处理器
英文描述: 16-BIT, FLASH, 25 MHz, MICROCONTROLLER, PQFP80
封装: QFP-80
文件页数: 18/132页
文件大小: 782K
代理商: MC9S12DG256MFU
MC9S12DT256 Device User Guide — V03.07
114
The loop bandwidth fC should be chosen to fulfill the Gardner’s stability criteria by at least a factor of 10,
typical values are 50.
ζ = 0.9 ensures a good transient response.
And finally the frequency relationship is defined as
With the above values the resistance can be calculated. The example is shown for a loop bandwidth
fC=10kHz:
The capacitance Cs can now be calculated as:
The capacitance Cp should be chosen in the range of:
A.5.3.2 Jitter Information
The basic functionality of the PLL is shown in
Figure A-3. With each transition of the clock f
cmp, the
deviation from the reference clock fref is measured and input voltage to the VCO is adjusted
accordingly.The adjustment is done continuously with no abrupt changes in the clock output frequency.
Noise, voltage, temperature and other factors cause slight variations in the control loop resulting in a clock
jitter. This jitter affects the real minimum and maximum clock periods as illustrated in
fC
2
ζ fref
πζ
1
ζ
2
+
------------------------------------------ 1
10
------
fC
fref
410
--------------
ζ 0.9
=
()
;
<
<
fC < 25kHz
n
fVCO
fref
-------------
2 synr 1
+
()
==
= 50
R
2
π nfC
KΦ
-----------------------------
=
=2*
π*50*10kHz/(316.7Hz/)=9.9k=~10k
Cs
2
ζ
2
π fC R
----------------------
0.516
fC R
---------------
ζ 0.9
=
()
;
=
= 5.19nF =~ 4.7nF
Cs 20
Cp Cs 10
≤≤
Cp = 470pF
相关PDF资料
PDF描述
MC68331CFC20B1 32-BIT, 20 MHz, MICROCONTROLLER, PQFP132
MC68332ACPV20 32-BIT, 20 MHz, MICROCONTROLLER, PQFP144
MC68340CFT25E 32-BIT, 25.16 MHz, MICROCONTROLLER, PQFP144
MC68360ZP25L 4 CHANNEL(S), 10M bps, LOCAL AREA NETWORK CONTROLLER, PBGA357
MC68EN360RC33L 4 CHANNEL(S), 10M bps, LOCAL AREA NETWORK CONTROLLER, CPGA241
相关代理商/技术参数
参数描述
MC9S12DG256MFUE 功能描述:16位微控制器 - MCU BARRACUDA4 MOS13 L01Y RoHS:否 制造商:Texas Instruments 核心:RISC 处理器系列:MSP430FR572x 数据总线宽度:16 bit 最大时钟频率:24 MHz 程序存储器大小:8 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:2 V to 3.6 V 工作温度范围:- 40 C to + 85 C 封装 / 箱体:VQFN-40 安装风格:SMD/SMT
MC9S12DG256MPV 制造商:Freescale Semiconductor 功能描述: 制造商:FREESCALE-SEMI 功能描述:
MC9S12DG256MPVE 功能描述:16位微控制器 - MCU 256K FLASH HCS12 MCU EPP RoHS:否 制造商:Texas Instruments 核心:RISC 处理器系列:MSP430FR572x 数据总线宽度:16 bit 最大时钟频率:24 MHz 程序存储器大小:8 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:2 V to 3.6 V 工作温度范围:- 40 C to + 85 C 封装 / 箱体:VQFN-40 安装风格:SMD/SMT
MC9S12DG256VFUE 功能描述:16位微控制器 - MCU BARRACUDA4 MOS13 L01Y RoHS:否 制造商:Texas Instruments 核心:RISC 处理器系列:MSP430FR572x 数据总线宽度:16 bit 最大时钟频率:24 MHz 程序存储器大小:8 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:2 V to 3.6 V 工作温度范围:- 40 C to + 85 C 封装 / 箱体:VQFN-40 安装风格:SMD/SMT
MC9S12DG256VPV 制造商:Freescale Semiconductor 功能描述: 制造商:Freescale Semiconductor 功能描述:MicroController, 16-Bit, 112 Pin, Plastic, QFP