Microchip MCP3424 ADC应用方案 – 工业控制,传感器信号调理

microchip公司的MCP3424是四路低噪音高精度delta-sigma 18位ADC,具有差分输入,采用两线I2C兼容的串行接口,单电源2.7V-5.5V工作, 取样速率有3.75,15,60或240/秒.MCP3424的典型应用包括手提仪器和消费类电子产品,温度传感测量,压力和应力测量,称重仪器,工厂自动化设备以及电池燃料测量等.本文介绍了MCP3422,MCP3423和MCP3424方框图以及典型应用连接图, 四路热电偶应用电路图,压力和温度测量电路图,MCP3424评估板电路图与评估板材料清单(BOM).

The MCP3424 is a four channel low-noise, high accuracy delta-sigma A/D converter with differential inputs and up to 18 bits of resolution. The on-board precision 2.048V reference voltage enables an input range of ±2.048V differentially. The device uses a two-wire I2C™ compatible serial interface and operates from a single power supply ranging from 2.7V to 5.5V. The MCP3424 device performs conversions at rates of 3.75, 15, 60 or 240 samples per second depending on user controllable configuration bit settings using the two-wire I2C™ compatible serial interface. The I2C™ address is user configurable with two address selection pins. This device has an onboard programmable gain amplifier (PGA). User can select the PGA gain of x1, x2, x4, or x8 before the analog-to-digital conversion takes place. This allows the MCP3424 device to convert a smaller input signal with high resolution. The device has two conversion modes: (a) Continuous mode and (b) One-Shot mode. In One-Shot mode, the device enters a low current standby mode automatically after one conversion. This reduces current consumption greatly during idle periods. The MCP3424 device can be used for various high accuracy analog-to-digital data conversion applications where ease of use, low power consumption and small footprint are major considerations.

MCP3424主要特性:

18-bit resolution
4-channel differential input operation
On-board voltage reference with 15 ppm/°C drift
On-board PGA, gains of 1, 2, 4, 8
Programmable data rate options
3.75 SPS (18 bits)
15 SPS (16 bits)
60 SPS (14 bits)
240 SPS (12 bits)
INL 10 ppm of FSR max
Low current consumption, 135 µA at 3V
One-shot or continuous conversion options
Supports I2C interface with user configurable addresses
Extended temperature range -40°C to +125°C

MCP3424典型应用:

Portable Instrumentation and Consumer Goods
Temperature Sensing with RTD, Thermistor, and Thermocouple
Bridge Sensing for Pressure, Strain, and Force
Weigh Scales
Battery Fuel Gauges
Factory Automation Equipment

Microchip MCP3424 ADC应用方案 - 工业控制,传感器信号调理

图1. MCP3422方框图

Microchip MCP3424 ADC应用方案 - 工业控制,传感器信号调理

图2.MCP3423方框图

Microchip MCP3424 ADC应用方案 - 工业控制,传感器信号调理

图3. MCP3424方框图

Microchip MCP3424 ADC应用方案 - 工业控制,传感器信号调理

图4.MCP3424电型应用连接图

Microchip MCP3424 ADC应用方案 - 工业控制,传感器信号调理

图5.MCP3424四路热电偶应用电路图

Microchip MCP3424 ADC应用方案 - 工业控制,传感器信号调理

图6.MCP3424压力和温度测量电路图

MCP3424评估板(P/N MCP3424EV)

The MCP3424 Evaluation Board (P/N MCP3424EV) contains an MCP3424 18-bit
Delta-Sigma Analog-to-Digital Converter (ADC). The MCP3424 is a 4-channel ADC
device with various configuration options. The board has analog input connection pads
and various test pads. The user can connect inputs and test the conversion results
using the PICkit Serial Analyzer and its PC graphic user interface (GUI). The MCP3424
Evaluation Board has the following interfaces:

PICkit Serial Analyzer (P/N: DV164122) for writing configuration register bits and
reading the conversion data.
The board has test points for SDL, SDA, and analog inputs. By connecting an oscilloscope to these test points, the user can examine the data communications through the I2C bus line and observe the resulting conversion output.

Microchip MCP3424 ADC应用方案 - 工业控制,传感器信号调理

图7.MCP3424评估板电路图

MCP3424评估板材料清单(BOM):

Microchip MCP3424 ADC应用方案 - 工业控制,传感器信号调理

详情请见:

http://ww1.microchip.com/downloads/en/DeviceDoc/22088b.pdf

http://ww1.microchip.com/downloads/en/DeviceDoc/51737a.pdf

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发布日期:2019年03月07日  所属分类:工业控制