参数资料
型号: 71M6521FE-IGT/F
厂商: MAXIM INTEGRATED PRODUCTS INC
元件分类: 模拟信号调理
英文描述: SPECIALTY ANALOG CIRCUIT, QFP64
封装: LEAD FREE, LQFP-64
文件页数: 63/103页
文件大小: 1691K
代理商: 71M6521FE-IGT/F
71M6521DE/71M6521FE
Energy Meter IC
DATA SHEET
OCTOBER 2010
Page: 62 of 103
2005-2010 Teridian Semiconductor Corporation
v1.1
A Maxim Integrated Products Brand
19-5370; 10/10
Example: Let us assume a crystal characterized by the measurements shown in Table 61:
Deviation from
Nominal
Temperature [°C]
Measured
Frequency [Hz]
Deviation from
Nominal
Frequency [PPM]
+50
32767.98
-0.61
+25
32768.28
8.545
0
32768.38
11.597
-25
32768.08
2.441
-50
32767.58
-12.817
Table 61: Frequency over Temperature
The values show that even at nominal temperature (the temperature at which the chip was calibrated for energy), the deviation
from the ideal crystal frequency is 11.6 PPM, resulting in about one second inaccuracy per day, i.e. more than some standards
allow. As Figure 30 shows, even a constant compensation would not bring much improvement, since the temperature
characteristics of the crystal are a mix of constant, linear, and quadratic effects.
32767.5
32767.6
32767.7
32767.8
32767.9
32768
32768.1
32768.2
32768.3
32768.4
32768.5
-50
-25
0
25
50
Figure 30: Crystal Frequency over Temperature
One method to correct the temperature characteristics of the crystal is to obtain coefficients from the curve in Figure 30 by
curve-fitting the PPM deviations. A fairly close curve fit is achieved with the coefficients a = 10.89, b = 0.122, and c = –0.00714
+
=
6
2
6
10
1
c
T
b
T
a
f
nom
When applying the inverted coefficients, a curve (see Figure 31) will result that effectively neutralizes the original crystal
characteristics.
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相关代理商/技术参数
参数描述
71M6521FE-IGTR 制造商:Maxim Integrated Products 功能描述:Metering Systems on a Chip - SoC Residential Energy Meter IC
71M6521FE-IGTR/F 功能描述:计量片上系统 - SoC Residential Energy Meter IC RoHS:否 制造商:Maxim Integrated 核心:80515 MPU 处理器系列:71M6511 类型:Metering SoC 最大时钟频率:70 Hz 程序存储器大小:64 KB 数据 RAM 大小:7 KB 接口类型:UART 可编程输入/输出端数量:12 片上 ADC: 安装风格:SMD/SMT 封装 / 箱体:LQFP-64 封装:Reel
71M6521FE-IGTR/F1 功能描述:计量片上系统 - SoC RoHS:否 制造商:Maxim Integrated 核心:80515 MPU 处理器系列:71M6511 类型:Metering SoC 最大时钟频率:70 Hz 程序存储器大小:64 KB 数据 RAM 大小:7 KB 接口类型:UART 可编程输入/输出端数量:12 片上 ADC: 安装风格:SMD/SMT 封装 / 箱体:LQFP-64 封装:Reel
71M6521FE-IM 制造商:Maxim Integrated Products 功能描述:Metering Systems on a Chip - SoC Residential Energy Meter IC
71M6521FE-IM/F 功能描述:计量片上系统 - SoC Residential Energy Meter IC RoHS:否 制造商:Maxim Integrated 核心:80515 MPU 处理器系列:71M6511 类型:Metering SoC 最大时钟频率:70 Hz 程序存储器大小:64 KB 数据 RAM 大小:7 KB 接口类型:UART 可编程输入/输出端数量:12 片上 ADC: 安装风格:SMD/SMT 封装 / 箱体:LQFP-64 封装:Reel