DS1821
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DS1821 BLOCK DIAGRAM Figure 1
TEMPERATURE SENSOR FUNCTIONALITY
The core functionality of the DS1821 is its proprietary direct-to-digital temperature sensor, which
provides 8-bit (1癈 increment) centigrade temperature readings over the range of -55癈 to +125癈.
A block diagram of the temperature measurement circuitry is shown in Figure 2. This circuit measures
the temperature by counting the number of clock cycles generated by an oscillator with a low temperature
coefficient (temp-co) during a gate period determined by a high temp-co oscillator. The low temp-co
counter is preset with a base count that corresponds to 55癈. If the counter reaches 0 before the gate
period is over, the temperature register, which is preset to 55癈, is incremented by one degree, and the
counter is again preset with a starting value determined by the slope accumulator circuitry. The preset
counter value is unique for every temperature increment and compensates for the parabolic behavior of
the oscillators over temperature.
At this time, the counter is clocked again until it reaches 0. If the gate period is not over when the counter
reaches 0, the temperature register is incremented again. This process of presetting the counter, counting
down to zero, and incrementing the temperature register is repeated until the counter takes less time to
reach zero than the duration of the gate period of the high temp-co oscillator. When this iterative process
is complete, the value in the temperature register will indicate the centigrade temperature of the device.
V
DD
.7K
CONFIGURATION REGISTER
1-WIRE
INTERFACE
AND
I/O CONTROL
POWER
SUPPLY
DIGITAL
COMPARATOR/
LOGIC
DS1821
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相关代理商/技术参数
DS1821-C02
功能描述:板上安装温度传感器
RoHS:否 制造商:Omron Electronics 输出类型:Digital 配置: 准确性:+/- 1.5 C, +/- 3 C 温度阈值: 数字输出 - 总线接口:2-Wire, I2C, SMBus 电源电压-最大:5.5 V 电源电压-最小:4.5 V 最大工作温度:+ 50 C 最小工作温度:0 C 关闭: 安装风格: 封装 / 箱体: 设备功能:Temperature and Humidity Sensor
DS1821-C04
制造商:DSC 功能描述:
DS1821S
功能描述:板上安装温度传感器 RoHS:否 制造商:Omron Electronics 输出类型:Digital 配置: 准确性:+/- 1.5 C, +/- 3 C 温度阈值: 数字输出 - 总线接口:2-Wire, I2C, SMBus 电源电压-最大:5.5 V 电源电压-最小:4.5 V 最大工作温度:+ 50 C 最小工作温度:0 C 关闭: 安装风格: 封装 / 箱体: 设备功能:Temperature and Humidity Sensor
DS1821S/T&R
制造商:Maxim Integrated Products 功能描述:PROGRAM THERMOSTAT 208ML 8-SOIC T&R - Tape and Reel 制造商:Maxim Integrated Products 功能描述:IC THERMOMETER/STAT PROG 8-SOIC
DS1821S/T&R
功能描述:板上安装温度传感器 RoHS:否 制造商:Omron Electronics 输出类型:Digital 配置: 准确性:+/- 1.5 C, +/- 3 C 温度阈值: 数字输出 - 总线接口:2-Wire, I2C, SMBus 电源电压-最大:5.5 V 电源电压-最小:4.5 V 最大工作温度:+ 50 C 最小工作温度:0 C 关闭: 安装风格: 封装 / 箱体: 设备功能:Temperature and Humidity Sensor
DS1821S/TR
制造商:DALLAS 制造商全称:Dallas Semiconductor 功能描述:Programmable Digital Thermostat and Thermometer
DS1821S+
功能描述:板上安装温度传感器 Programmable Digital Thermostat/Thrmmtr RoHS:否 制造商:Omron Electronics 输出类型:Digital 配置: 准确性:+/- 1.5 C, +/- 3 C 温度阈值: 数字输出 - 总线接口:2-Wire, I2C, SMBus 电源电压-最大:5.5 V 电源电压-最小:4.5 V 最大工作温度:+ 50 C 最小工作温度:0 C 关闭: 安装风格: 封装 / 箱体: 设备功能:Temperature and Humidity Sensor
DS1821S+R
制造商:MAXIM 制造商全称:Maxim Integrated Products 功能描述:Programmable Digital Thermostat and Thermometer