参数资料
型号: XE8805AMI028LF
厂商: Semtech
文件页数: 11/156页
文件大小: 0K
描述: IC DAS 16BIT FLASH 8K MTP 64LQFP
标准包装: 160
系列: XE880x
应用: 感测机
核心处理器: Coolrisc816?
程序存储器类型: 闪存(22 kB)
控制器系列: XE8000
RAM 容量: 512 x 8
接口: UART,USRT
输入/输出数: 24
电源电压: 2.4 V ~ 5.5 V
工作温度: -40°C ~ 85°C
安装类型: 表面贴装
封装/外壳: 64-LQFP
包装: 托盘
供应商设备封装: 64-LQFP(10x10)
产品目录页面: 585 (CN2011-ZH PDF)
配用: XE8000MP-ND - PROG BOARD AND PROSTART2 CARD
Semtech 2006
www.semtech.com
16-22
XE8805/05A
Figure 16-8. Integral non-linearity of the ADC (PGA disabled, reference voltage of 4.8V)
The different PGA stages have been designed to find the best compromise between the noise performance, the
integral non-linearity and the power consumption. To obtain this, the first stage has the best noise performance and
the third stage the best linearity performance. For large input signals (small PGA gains, i.e. up to about 50), the
noise added by the PGA is very small with respect to the input signal and the second and third stage of the PGA
should be used to get the best linearity. For small input signals (large gains, i.e. above 50), the noise level in the
PGA is important and the first stage of the PGA should be used.
The following figures give the non-linearity for different gain settings of the PGA, selecting the appropriate stage to
get the best noise and linearity performance. Figure 16-9 shows the non-linearity when the third stage is used with
a gain of 1. It is of course not very useful to use the PGA with a gain of 1 unless it is used to compensate offset. By
increasing the gain, the integral non-linearity becomes even smaller since the signal in the amplifiers reduces.
Figure 16-10 shows the non-linearity for a gain of 2. Figure 16-11 shows the non-linearity for a gain of 5. Figure
16-12 shows the non-linearity for a gain of 10. By comparing these figures to Figure 16-8, it can be seen that the
third stage of the PGA does not add significant integral non-linearity.
Figure 16-13 shows the non-linearity for a gain of 20 and Figure 16-14 shows the non-linearity for a gain of 50. In
both cases the PGA2 is used at a gain of 10 and the remaining gain is realized by the third stage. It can be seen
again that the second stage of the PGA does not add significant non-linearity.
For gains above 50, the first stage PGA1 should be selected in stead of PGA2. Although the non-linearity in the first
stage of the PGA is larger than in stage 2 and 3, the gain in stage 3 is now sufficiently high so that the non-linearity
of the first stage does become negligible as is shown in Figure 16-15 for a gain of 100. Therefor, the first stage is
preferred over the second stage since it has less noise.
Increasing the gain further up to 1000 will further increase the linearity since the signal becomes very small in the
first two stages. The signal is full scale at the output of stage 3 and as shown in Figure 16-9 to Figure 16-12, this
stage has very good linearity.
Not
Recommended
for
New
Designs
相关PDF资料
PDF描述
XE8807AMI026TLF IC MCU LOW PWR MTP FLASH 32-TQFP
XIO2200AGGW IC PCI-EXPRESS/BUS BRIDGE 176BGA
XIO2200AZGW IC PCI-EXPRESS/BUS BRIDGE 176BGA
XPC823ZT81B2T IC MPU POWERQUICC 81MHZ 256-PBGA
XPC8240RZU250E MCU HOST PROCESSOR 352-TBGA
相关代理商/技术参数
参数描述
XE8805AMI028TLF 制造商:Semtech Corporation 功能描述:
XE8805MI028 制造商:SEMTECH 制造商全称:Semtech Corporation 功能描述:Data Acquisition MCU
XE8806A 制造商:SEMTECH 制造商全称:Semtech Corporation 功能描述:Ultra Low-Power Low-Voltage
XE8806AMI000 制造商:SEMTECH 制造商全称:Semtech Corporation 功能描述:Ultra Low-Power Low-Voltage
XE8806AMI026LF 制造商:SEMTECH 制造商全称:Semtech Corporation 功能描述:Ultra Low-Power Low-Voltage