Document Outline

• PIN ASSIGNMENT
• PIN DESCRIPTION
• D
• DESCRIPTION
  • • SYMBOL
• OVERVIEW
• DS1822 BLOCK DIAGRAM Figure 1
• OPERATION – MEASURING TEMPERATURE
• TEMPERATURE REGISTER FORMAT Figure 2
• TEMPERATURE/DATA RELATIONSHIP Table 2
• OPERATION – ALARM SIGNALING
• TH AND TL REGISTER FORMAT Figure 3
• POWERING THE DS1822
• SUPPLYING THE PARASITE-POWERED DS1822 DURING TEMPERATURE CONVERSIONS Figure 4
• POWERING THE DS1822 WITH AN EXTERNAL SUPPLY Figure 5
• 64-BIT LASERED ROM CODE
• 64-BIT LASERED ROM CODE Figure 6
• MEMORY
• DS1822 MEMORY MAP Figure 7
  • • • • • SCRATCHPAD (Power-up State)
• CONFIGURATION REGISTER
• Byte 4 of the scratchpad memory contains the configuration register, which is organized as illustrated in Figure 8. The user can set the conversion resolution of the DS1822 using the R0 and R1 bits in this register as shown in Table 3. The power-up de
• CONFIGURATION REGISTER Figure 8
• THERMOMETER RESOLUTION CONFIGURATION Table 3
  • • • • • • Resolution
• CRC GENERATION
• CRC GENERATOR Figure 9
• 1-WIRE BUS SYSTEM
• HARDWARE CONFIGURATION
• HARDWARE CONFIGURATION Figure 10
• TRANSACTION SEQUENCE
• INITIALIZATION
• ROM COMMANDS
• SEARCH ROM [F0h]
• READ ROM [33h]
• MATCH ROM [55h]
• SKIP ROM [CCh]
• ALARM SEARCH [ECh]
• DS1822 FUNCTION COMMANDS
• CONVERT T [44h]
• WRITE SCRATCHPAD [4Eh]
• READ SCRATCHPAD [BEh]
• COPY SCRATCHPAD [48h]
• RECALL E2 [B8h]
• READ POWER SUPPLY [B4h]
• DS1822 FUNCTION COMMAND SET Table 4
  • • • • • • • MEMORY COMMANDS
• NOTES:
• ROM COMMANDS FLOW CHART Figure 11
• DS1822 FUNCTION COMMANDS FLOW CHART Figure 12
• 1-WIRE SIGNALING
• INITIALIZATION PROCEDURE: RESET AND PRESENCE PULSES
• INITIALIZATION TIMING Figure 13
• READ/WRITE TIME SLOTS
• WRITE TIME SLOTS
• READ/WRITE TIME SLOT TIMING DIAGRAM Figure 14
• READ TIME SLOTS
• DETAILED MASTER READ 1 TIMING Figure 15
• RECOMMENDED MASTER READ 1 TIMING Figure 16
• RELATED APPLICATION NOTES
• DS1822 OPERATION EXAMPLE 1
• DS1822 OPERATION EXAMPLE 2
• ABSOLUTE MAXIMUM RATINGS*
• DC ELECTRICAL CHARACTERISTICS (-55˚C to +125˚C; VDD=3.0V to 5.5V)
  • • PARAMETER
      • • • • SYMBOL
          • Local Power
          • Local Power
          • Local Power
          • Parasite Power
• NOTES:
• AC ELECTRICAL CHARACTERISTICS: NV MEMORY
• (-55˚C to +100˚C; VDD=3.0V to 5.5V)
  • • • • • • SYMBOL
          • -55˚C to +55˚C
          • -55˚C to +55˚C
• AC ELECTRICAL CHARACTERISTICS (-55˚C to +125˚C; VDD=3.0V to 5.5V)
  • • PARAMETER
      • • • • SYMBOL
• TYPICAL PERFORMANCE CURVE Figure 17
  • • • TBA
• TIMING DIAGRAMS Figure 18