ds18b20英汉翻译.doc

ds18b20英汉翻译 附录五：中英文翻译 DS18B20 Programmable Resolution 1-Wire Digital Thermometer FEATURES . Unique 1-Wire interface require only one port pin for communications . Multidrop capability simplifies distributed temperature sensing application . Requires not external components . Can be powered from data line . Zero standby power required . Measures temperatures from -55 ℃ to +125 ℃. Fahrenheit equivalent is -67o F to 257o F . Thermometer resolution is programmable from 9to 12 bits . Converts 12-bit temperature to digital word in 750ms (max) . User-definable, nonvolatile temperature alarm settings . Alarm search command identifies and addresses whose temperature is outside of programmed limits (temperature alarm condition) . Applications include temperature control, industrial systems, consumer products, thermometers or any thermal system DS18B20 working principle DS18B20 literacy timing and temperature measuring principle and DS1820 the same, just get the digits for resolution temperature different and different, and the temperature conversion by the delay time reduced to 750ms 2s. DS18B20 temperature measuring principle fig.03 shows. Graph of low temperature coefficient crystals have little impact by temperature oscillation frequency, used to produce fixed frequency pulse signal to counter 1. High temperature coefficient crystals changing with temperature significantly alter the oscillation rate, the resulting signal input pulses of 2 as counter. Counter 1 and temperature registers were presets in - 55 ℃ corresponds to a base value. Counter 1 to low temperature coefficient of the pulse signal generated crystals for subtraction count, the preset value when the counter 1 reduced to 0, the temperature of the register values will add 1, counter 1 will resume, loaded into preset counter 1 heavy new start crystals of low temperature coefficient of the pulse signal generated count, so circulation until counter 2 count to 0 to stop when the t