参数资料
型号: MCP3421A2T-E/CH
厂商: Microchip Technology
文件页数: 25/42页
文件大小: 0K
描述: IC ADC 18BIT 3.75SPS 1CH SOT23-6
产品培训模块: MCP3901 Analog Front End
标准包装: 1
位数: 18
采样率(每秒): 3.75
数据接口: I²C,串行
转换器数目: 1
电压电源: 单电源
工作温度: -40°C ~ 125°C
安装类型: 表面贴装
封装/外壳: SOT-23-6
供应商设备封装: SOT-23-6
包装: 标准包装
输入数目和类型: 2 个单端,双极;1 个差分,单极
产品目录页面: 672 (CN2011-ZH PDF)
其它名称: MCP3421A2T-E/CHDKR
2009 Microchip Technology Inc.
DS22003E-page 31
MCP3421
6.2.5
TEMPERATURE MEASUREMENT
shows
an
example
of
temperature
measurement using a thermocouple sensor and the
MCP9800 silicon temperature sensor. The MCP9800 is
a high accuracy temperature sensor that can detect the
temperature in the range of -55°C to 125°C with 1°C
accuracy.
The
type
K
thermocouple
sensor
senses
the
temperature at the hot junction (THJ) with respect to the
cold junction temperature (reference, TCJ). The
temperature difference between the hot and cold
junctions is represented by the voltage V1. This voltage
is then converted to digital codes by the MCP3421.
In the circuit, the MCP9800 is used for cold junction
compensation. The MCU computes the difference of
the hot and cold junction temperatures, which is
proportional to the hot junction temperature (THJ).
With
Type
K
thermocouple,
it
can
measure
temperature from 0°C to 1250°C degrees. The full
scale output range of the
Type K thermocouple is
about
50 mV.
This
provides
40 V/°C
(= 50 mV/1250°C)
of
measurement
resolution.
Equation 6-2 shows the measurement budget for ther-
mocouple sensor signal using the MCP3421 device
with 18 bits and PGA = 8 settings. With this configura-
tion, it can detect the input signal level as low as
approximately 2 V. The internal PGA boosts the input
signal level eight times. The 40 V/°C input from the
thermocouple is amplified internally to 320 V/°C
before the conversion takes place. This results in
20.48 LSB/°C output codes. This means there are
about 20 LSB output codes (or about 4.32 bits) per 1°C
of change in temperature.
EQUATION 6-2:
MEASUREMENT BUDGET
FOR THERMOCOUPLE
SENSOR
FIGURE 6-10:
Example of Temperature
Measurement.
Equation 6-3 shows an example of calculating the
expected number of output code with various PGA gain
settings for
Type K thermocouple output.
EQUATION 6-3:
EXPECTED NUMBER OF
OUTPUT CODE FOR
TYPE K THERMOCOUPLE
Input Signal Level after gain of 8:
Where:
1 LSB
=
15.625 V with 18-bit configuration
Detectable Input Signal Level
15.625
μV/PGA
=
1.953125
μV for PGA
8
=
40
μV/°C
() 8320
μV/°C
=
=
No. of LSB/°C
320
μV/°C
15.625
μV
-------------------------
20.48 Codes/°C
==
~ 40 V°C
Thermocouple Sensor
MCP9800
Isothermal Block
Heat
Cold Junction (TCJ)
Hot Junction
(THJ)
SCL
SDA
V1
VDD
To MCU
(MASTER)
MCP3421
10 k
Ω
10 k
Ω
1
F
10
F
log
2
50 mV
15.625
μV
PGA
------------------------
Expected
Number of Output Code =
Where:
1 LSB
=
15.625 V with 18-bit configuration.
= 11.6 bits for PGA = 1
= 12.6 bits for PGA = 2
= 13.6 bits for PGA = 4
= 14.6 bits for PGA = 8
相关PDF资料
PDF描述
B37937K9561J60 CAP CER 560PF 16V 5% NP0 0603
MCP3421A1T-E/CH IC ADC 18BIT 3.75SPS 1CH SOT23-6
MCP3421A3T-E/CH IC ADC 18BIT 3.75SPS 1CH SOT23-6
ADCMP581BCPZ-WP IC COMPARATOR ECL UFAST 16-LFCSP
ADCMP582BCPZ-WP IC COMPARATOR PECL UFAST 16LFCSP
相关代理商/技术参数
参数描述
MCP3421A3T-E/CH 功能描述:模数转换器 - ADC 18-B delta-sigma ADC Sngl Ch 4sps RoHS:否 制造商:Texas Instruments 通道数量:2 结构:Sigma-Delta 转换速率:125 SPs to 8 KSPs 分辨率:24 bit 输入类型:Differential 信噪比:107 dB 接口类型:SPI 工作电源电压:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-32
MCP3421A3T-E/OT 制造商:MICROCHIP 制造商全称:Microchip Technology 功能描述:18-Bit Analog-to-Digital Converter with I2C Interface and On-Board Reference
MCP3421A4T-E/CH 制造商:Microchip Technology Inc 功能描述:ANALOG-TO-DIGITAL CONVERTER WITH 18-BIT 制造商:Microchip Technology Inc 功能描述:18-BIT DELTA-SIGMA ADC, SINGLE CHANNEL, 4SPS - Tape and Reel 制造商:Microchip Technology Inc 功能描述:IC ADC 18BIT I2C 4SPS SOT23-6 制造商:Microchip Technology Inc 功能描述:18-bit delta-sigma ADC, single channel, 4sps, 6 SOT-23 T/R
MCP3421A4T-E/OT 制造商:MICROCHIP 制造商全称:Microchip Technology 功能描述:18-Bit Analog-to-Digital Converter with I2C Interface and On-Board Reference
MCP3421A5T-E/CH 制造商:Microchip Technology 功能描述:18-BIT DELTA-SIGMA ADC, SINGLE 制造商:Microchip Technology Inc 功能描述:18-BIT DELTA-SIGMA ADC, SINGLE CHANNEL, 4SPS - Tape and Reel 制造商:Microchip Technology Inc 功能描述:IC ADC 18BIT I2C 4SPS SOT23-6