- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄376961 > DS1821 Programmable Digital Thermostat PDF資料下載
參數(shù)資料
| 型號(hào)： | DS1821 |
| 元件分類： | 溫度傳感器 |
| 英文描述： | Programmable Digital Thermostat |
| 文件頁數(shù)： | 4/16頁 |
| 文件大?。?/td> | 570K |
| 代理商： | DS1821 |
DS1821
4 of 16
Thermostat Controls
In its thermostat mode, the DS1821 functions as a thermostat with programmable hysteresis, as shown in
Figure 2. Temperature conversions begin as soon as V
DD
is applied to the device, and are continually
made, so that the thermostat output updates as soon as a temperature conversion is complete. This is
approximately once every second.
When the DS1821’s temperature meets or exceeds the value stored in the high temperature trip register
(TH), the output becomes active, and will stay active until the temperature falls below the temperature
stored in the low temperature trigger register (TL). In this way, any amount of hysteresis may be
obtained.
The active state for the output is programmable by the user, so that an active state may either be a logic 1
(+5V, output transistor off) or a logic 0 (0V, output transistor on).
THERMOSTAT OUTPUT OPERATION
Figure 2
DQ (Thermostat output, Active=High) V
DD
=5 volts
PROGRAMMING THE DS1821
To program the DS1821, it must be placed in 1-Wire mode. This mode is active when the device arrives
from the factory. Once the part has been programmed, and if the user has set the power-up state to
thermostat mode, 1-Wire mode may only be achieved by bringing the V
DD
pin low while holding the DQ
line high, then clocking the DQ line 16 times.
The DS1821 has four internal registers that may be accessed through the DQ pin when the device is in 1-
Wire mode. These registers are the high temperature trigger (TH), low temperature trigger (TL), the
actual measured temperature result, and the status register. The TH,TL, and status registers are all
nonvolatile.
The DS1821 must have temperature settings resident in the TH and TL registers for thermostatic
operation. The temperature result register and the thermostat limit registers (TH and TL) hold an 8-bit
number in the two’s complement format described in Table 1.
TL
TH
T (°C)
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| DS1830 | Reset Sequence Pushbutton |
| DS1830A | Reset Sequence Pushbutton |
| DS1830AS | Reset Sequence Pushbutton |
| DS1830AU | Reset Sequence Pushbutton |
| DS1830U | Reset Sequence Pushbutton |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| DS1821_07 | 制造商:DALLAS 制造商全稱:Dallas Semiconductor 功能描述:Programmable Digital Thermostat and Thermometer |
| DS1821+ | 功能描述:板上安裝溫度傳感器 Programmable Digital Thermostat/Thrmmtr RoHS:否 制造商:Omron Electronics 輸出類型:Digital 配置: 準(zhǔn)確性:+/- 1.5 C, +/- 3 C 溫度閾值: 數(shù)字輸出 - 總線接口:2-Wire, I2C, SMBus 電源電壓-最大:5.5 V 電源電壓-最小:4.5 V 最大工作溫度:+ 50 C 最小工作溫度:0 C 關(guān)閉: 安裝風(fēng)格: 封裝 / 箱體: 設(shè)備功能:Temperature and Humidity Sensor |
| DS1821C+ | 功能描述:恒溫器 Programmable Digital Thermo-stat/monitor RoHS:否 制造商:Maxim Integrated 功能: 開路溫度: 閉合溫度: 準(zhǔn)確性:+/- 1 C 溫度范圍:- 55 C to + 125 C 電流額定值:500 uA 電壓額定值:2.7 V to 5.5 V 產(chǎn)品:Thermostats |
| DS1821-C02 | 功能描述:板上安裝溫度傳感器 RoHS:否 制造商:Omron Electronics 輸出類型:Digital 配置: 準(zhǔn)確性:+/- 1.5 C, +/- 3 C 溫度閾值: 數(shù)字輸出 - 總線接口:2-Wire, I2C, SMBus 電源電壓-最大:5.5 V 電源電壓-最小:4.5 V 最大工作溫度:+ 50 C 最小工作溫度:0 C 關(guān)閉: 安裝風(fēng)格: 封裝 / 箱體: 設(shè)備功能:Temperature and Humidity Sensor |
| DS1821-C04 | 制造商:DSC 功能描述: |
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。