數(shù)字溫度傳感器外文翻譯6-免費(fèi)閱讀
【正文】 溫度傳感器的寄生電源是在 DQ管腳為高電壓的時(shí)候存儲(chǔ)電量來為以后 DQ 為低的時(shí)候供電。如果 DS18B20 是寄生供電的話，由于在傳感器轉(zhuǎn)換期間需要比較大量的電能，所以就不能夠支持上訴的功能了。而當(dāng) DQ為低電平時(shí)，傳 感器就不工作了？當(dāng)然不是了，在溫度傳感器的內(nèi)部有一個(gè)電容，當(dāng) DQ 為高電平時(shí)充電，當(dāng) DQ 為低電平時(shí)放電，放出來的電給傳感器供電。此外，暫時(shí)寄存器還和一個(gè)字節(jié)的上限、下限寄存器相連，同時(shí)也和一個(gè)字節(jié)的配置字相連。 C。 thus, it is simple to use one microprocessor to control many DS18B20s distributed over a large area. Applications that can benefit from this feature include HVAC environmental controls, temperature monitoring systems inside buildings, equipment or machinery, and process monitoring and control systems. OVERVIEW The 64bit ROM stores the device’s unique serial code. The scratchpad memory contains the 2byte temperature register that stores the digital output from the temperature sensor. In addition, the scratchpad provides access to the 1byte upper and lower alarm trigger registers (T and T ), and the 1byte configuration H L register. The configuration register allows the user to set the resolution of the temperaturetodigital conversion to 9, 10, 11, or 12 bits. The T, T and configuration registers are nonvolatile (EEPROM), so H L they will retain data when the device is powered down. The DS18B20 uses Dallas’ exclusive 1Wire bus protocol that implements bus munication using one control signal. The control line requires a weak pull up resistor since all devices are linked to the bus via a 3state or opendrain port (the DQ pin in the case of the DS18B20). In this bus system, the microprocessor (the master device) identifies and addresses devices on the bus using each device’s unique 64bit code. Because each device has a unique code, th
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