进坛一段时间，模电菜鸟也有DIY5.5位电压电阻表的发烧想法。哪款ADC更合适，性价比更高呢？求推荐。
ADS1245行吗？下面摘录DATASHEET部分参数。
FEATURES
20-Bit Effective Resolution
High-Impedance Buffered Input
±2.5V Differential Input Range
Pin-Compatible with ADS1244
0.0006% INL (typ), 0.0015% INL (max)
Simple Two-Wire Serial Interface
Simultaneous 50Hz and 60Hz Rejection
Single Conversions with Sleep Mode
Single-Cycle Settling
Self-Calibration
Well Suited for Multi-Channel Systems
Easily Connects to the MSP430
Current Consumption: 158μA
Analog Supply: 2.5V to 5.25V
Digital Supply: 1.8V to 3.6V
ELECTRICAL CHARACTERISTICS
All specifications at TA = −40°C to +85°C, AVDD = +5V, DVDD = +3V, fCLK = 2.4576MHz, and VREF = +1.25V, unless otherwise noted.
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
Analog Input
Full-scale input voltage range AINP − AINN ±2VREF V
Absolute input range AINP, AINN with respect to GND GND + 0.1 AVDD − 1.25 V
Differential input impedance fCLK = 2.4576MHz 3 GΩ
System Performance
Resolution No missing codes 24 Bits
Data rate fCLK = 2.4576MHz 15 SPS(1)
Integral nonlinearity (INL) Differential input signal, end point fit ±0.0006 ±0.0015 %FSR(2)
Offset error 1 14 ppm of FSR
Offset error drift(3) 0.01 ppm of FSR/°C
Gain error(4) 0.005 0.1 %
Gain error drift(3) 0.5 ppm/°C
At DC 90 100 dB
Common-mode rejection fCM(5) = 50 ± 1Hz, fCLK = 2.4576MHz 100 dB
fCM = 60 ± 1Hz, fCLK = 2.4576MHz 100 dB
Normal-mode rejection
fSIG(6) = 50 ± 1Hz, fCLK = 2.4576MHz 60 dB
fSIG = 60 ± 1Hz, fCLK = 2.4576MHz 70 dB
Input referred noise 2 ppm of FSR,RMS
Analog power-supply rejection At DC, ΔAVDD = 5% 100 dB
Digital power-supply rejection At DC, ΔAVDD = 5% 100 dB |
发表于 2013-11-17 17:06:22
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