поискавой системы для электроныых деталей |
|
DS1822 датащи(PDF) 4 Page - Maxim Integrated Products |
|
DS1822 датащи(HTML) 4 Page - Maxim Integrated Products |
4 / 21 page DS1822 4 of 21 OPERATION—MEASURING TEMPERATURE The core functionality of the DS1822 is its direct-to-digital temperature sensor. The resolution of the temperature sensor is user-configurable to 9, 10, 11, or 12 bits, corresponding to increments of 0.5 °C, 0.25 °C, 0.125°C, and 0.0625°C, respectively. The default resolution at power-up is 12 bit. The DS1822 powers-up in a low-power idle state; to initiate a temperature measurement and A-to-D conversion, the master must issue a Convert T [44h] command. Following the conversion, the resulting thermal data is stored in the 2-byte temperature register in the scratchpad memory and the DS1822 returns to its idle state. If the DS1822 is powered by an external supply, the master can issue “read-time slots” (see the 1- WIRE BUS SYSTEM section) after the Convert T command and the DS1822 will respond by transmitting 0 while the temperature conversion is in progress and 1 when the conversion is done. If the DS1822 is powered with parasite power, this notification technique cannot be used since the bus must be pulled high by a strong pullup during the entire temperature conversion. The bus requirements for parasite power are explained in detail in the POWERING THE DS1822 section of this data sheet. The DS1822 output temperature data is calibrated in degrees centigrade; for Fahrenheit applications, a lookup table or conversion routine must be used. The temperature data is stored as a 16-bit sign-extended two’s complement number in the temperature register (see Figure 2). The sign bits (S) indicate if the temperature is positive or negative: for positive numbers S = 0 and for negative numbers S = 1. If the DS1822 is configured for 12-bit resolution, all bits in the temperature register will contain valid data. For 11-bit resolution, bit 0 is undefined. For 10-bit resolution, bits 1 and 0 are undefined, and for 9-bit resolution bits 2, 1 and 0 are undefined. Table 2 gives examples of digital output data and the corresponding temperature reading for 12-bit resolution conversions. TEMPERATURE REGISTER FORMAT Figure 2 bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 LS Byte 2 3 2 2 2 1 2 0 2 -1 2 -2 2 -3 2 -4 bit 15 bit 14 bit 13 bit 12 bit 11 bit 10 bit 9 bit 8 MS Byte S S S S S 2 6 2 5 2 4 TEMPERATURE/DATA RELATIONSHIP Table 2 TEMPERATURE DIGITAL OUTPUT (Binary) DIGITAL OUTPUT (Hex) +125°C 0000 0111 1101 0000 07D0h +85°C* 0000 0101 0101 0000 0550h +25.0625°C 0000 0001 1001 0001 0191h +10.125°C 0000 0000 1010 0010 00A2h +0.5°C 0000 0000 0000 1000 0008h 0°C 0000 0000 0000 0000 0000h -0.5°C 1111 1111 1111 1000 FFF8h -10.125°C 1111 1111 0101 1110 FF5Eh -25.0625°C 1111 1110 0110 1111 FE6Fh -55°C 1111 1100 1001 0000 FC90h *The power on reset value of the temperature register is +85°C |
Аналогичный номер детали - DS1822 |
|
Аналогичное описание - DS1822 |
|
|
ссылки URL |
Конфиденциальность |
ALLDATASHEETRU.COM |
Вашему бизинису помогли Аллдатащит? [ DONATE ] |
Что такое Аллдатащит | реклама | контакт | Конфиденциальность | обмен ссыками | поиск по производителю All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |