參數(shù)資料
型號: DS18S20Z/T&R
廠商: MAXIM INTEGRATED PRODUCTS INC
元件分類: Switch/Digital Output Temperature Sensor
英文描述: DIGITAL TEMP SENSOR-SERIAL, 9BIT(s), 0.50Cel, RECTANGULAR, SURFACE MOUNT
封裝: SOP-8
文件頁數(shù): 18/23頁
文件大?。?/td> 252K
代理商: DS18S20Z/T&R
DS18S20
4 of 23
Figure 2. Temperature Register Format
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
LS BYTE
2
6
2
5
2
4
2
3
2
1
2
0
2
-1
BIT 15
BIT 14
BIT 13
BIT 12
BIT 11
BIT 10
BIT 9
BIT 8
MS BYTE
S
S = SIGN
Table 1. Temperature/Data Relationship
TEMPERATURE
(
°C)
DIGITAL OUTPUT
(BINARY)
DIGITAL OUTPUT
(HEX)
+85.0*
0000 0000 1010 1010
00AAh
+25.0
0000 0000 0011 0010
0032h
+0.5
0000 0000 0000 0001
0001h
0
0000 0000 0000 0000
0000h
-0.5
1111 1111 1111 1111
FFFFh
-25.0
1111 1111 1100 1110
FFCEh
-55.0
1111 1111 1001 0010
FF92h
*The power-on reset value of the temperature register is +85°C.
OPERATION—ALARM SIGNALING
After the DS18S20 performs a temperature conversion, the temperature value is compared to the user-
defined two’s complement alarm trigger values stored in the 1-byte TH and TL registers (see Figure 3).
The sign bit (S) indicates if the value is positive or negative: for positive numbers S = 0 and for negative
numbers S = 1. The TH and TL registers are nonvolatile (EEPROM) so they will retain data when the
device is powered down. TH and TL can be accessed through bytes 2 and 3 of the scratchpad as explained
in the Memory section.
Figure 3. TH and TL Register Format
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
S
2
6
2
5
2
5
2
5
2
1
2
0
Only bits 8 through 1 of the temperature register are used in the TH and TL comparison since TH and TL
are 8-bit registers. If the measured temperature is lower than or equal to TL or higher than TH, an alarm
condition exists and an alarm flag is set inside the DS18S20. This flag is updated after every temperature
measurement; therefore, if the alarm condition goes away, the flag will be turned off after the next
temperature conversion.
The master device can check the alarm flag status of all DS18S20s on the bus by issuing an Alarm Search
[ECh] command. Any DS18S20s with a set alarm flag will respond to the command, so the master can
determine exactly which DS18S20s have experienced an alarm condition. If an alarm condition exists and
the TH or TL settings have changed, another temperature conversion should be done to validate the alarm
condition.
相關(guān)PDF資料
PDF描述
DS1963L-F5 SPECIALTY MEMORY CIRCUIT, MEDB2
DS1963S SPECIALTY MEMORY CIRCUIT, MEDB2
DS1985-F3 2K X 8 EEPROM 3V, RDB2
DS1986-F3 64K X 1 OTPROM, MEDB2
DS1986-F5 64K X 1 OTPROM, MADB2
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
DS18VN6LPQ 制造商:Banner Engineering 功能描述:SENSOR, PHOTOELECTRIC, DS18VN6LPQ PICO QP NPN POL RET
DS18VP6FF50Q8 制造商:Banner Engineering 功能描述:DS18VP6FF50Q8 EURO QD PNP 50MM FIXED FIELD
DS18VP6LP-29537 制造商:Banner Engineering 功能描述:DS18 Series: Polarized Retro, Range: 3.5 m, Input: 10-30V dc, Output: Complement
DS18VP6LPQ8 制造商:Banner Engineering 功能描述:SENSOR, PHOTOELECTRIC, DS18VP6LPQ8 EURO QD PNP POL RETRO
DS1904 制造商:MAXIM 制造商全稱:Maxim Integrated Products 功能描述:Real-Time Clock/calendar in binary format RTC iButton Over 10 years of operation