DS1822Z Maxim Integrated Products, DS1822Z Datasheet
DS1822Z
Specifications of DS1822Z
Available stocks
Related parts for DS1822Z
DS1822Z Summary of contents
Page 1
... Dallas Semiconductor. PIN ASSIGNMENT DALLAS 1822 (NV) alarm (BOTTOM VIEW) identifies and TO-92 (DS1822) PIN DESCRIPTION GND - Ground products Data In/Out V - Power Supply Voltage Connect DS1822 Econo 1-Wire Digital Thermometer GND 4 5 8-Pin 150mil SO (DS1822Z) 101107 ...
Page 2
... DS1822/T&R 1822 DS1822+ 1822 (See Note) DS1822+T&R 1822 (See Note) DS1822Z DS1822 DS1822Z/T&R DS1822 DS1822Z+ DS1822 (See Note) DS1822Z+T&R DS1822 (See Note) Note: A “+” symbol will also be marked on the package. DETAILED PIN DESCRIPTIONS Table 1 8-PIN SO* TO-92 SYMBOL DESCRIPTION 5 1 GND *All pins not specified in this table are “ ...
Page 3
... DS1822 BLOCK DIAGRAM Figure PARASITE POWER 4.7K CIRCUIT DQ INTERNAL V GND 64-BIT ROM DD AND 1-wire PORT POWER SUPPLY SENSE DS1822 MEMORY CONTROL LOGIC TEMPERATURE SENSOR ALARM HIGH TRIGGER (T REGISTER (EEPROM) SCRATCHPAD ALARM LOW TRIGGER (T REGISTER (EEPROM) CONFIGURATION REGISTER (EEPROM) 8-BIT CRC GENERATOR DS1822 ) ...
Page 4
... 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 and for negative numbers 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 ...
Page 5
... If the measured temperature is lower than or equal alarm condition exists and an alarm flag is set inside the DS1822. 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. ...
Page 6
... The use of parasite power is not recommended for temperatures above 100°C since the DS1822 may not be able to sustain communications due to the higher leakage currents that can exist at these temperatures. For applications in which such temperatures are likely strongly recommended that the DS1822 be powered by an external power supply ...
Page 7
... All memory commands are described in detail in the DS1822 FUNCTION COMMANDS section. Byte 0 and byte 1 of the scratchpad contain the LSB and the MSB of the temperature register, respectively. These bytes are read-only. Bytes 2 and 3 provide access to T contains the configuration register data, which is explained in detail in the CONFIGURATION REGISTER section of this data sheet ...
Page 8
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 ...
Page 9
Application Note 27 entitled Understanding and Using Cyclic Redundancy Checks with Dallas Semiconductor Touch Memory Products. CRC GENERATOR Figure 9 (MSB) 1-WIRE BUS SYSTEM The 1-Wire bus system uses a single bus master to control one or ...
Page 10
TRANSACTION SEQUENCE The transaction sequence for accessing the DS1822 is as follows: Step 1. Initialization Step 2. ROM Command (followed by any required data exchange) Step 3. DS1822 Function Command (followed by any required data exchange very important ...
Page 11
... This command initiates a single temperature conversion. 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 low-power idle state. If the device is being used in parasite power mode, within 10μs (max) after this ...
Page 12
... NOTES: 1. For parasite-powered DS1822s, the master must enable a strong pullup on the 1-Wire bus during temperature conversions and copies from the scratchpad to EEPROM. No other bus activity may take place during this time. 2. The master can interrupt the transmission of data at any time by issuing a reset. ...
Page 13
ROM COMMANDS FLOW CHART Figure 11 Initialization Sequence 33h N READ ROM COMMAND Y DS1822 T X FAMILY CODE 1 BYTE DS1822 T X SERIAL NUMBER 6 BYTES DS1822 T X CRC BYTE MASTER T X RESET PULSE DS1822 T ...
Page 14
... B4h N READ POWER SUPPLY ? PARASITE POWERED ? MASTER MASTER R “1s” R “0s” MASTER ENABLES STRONG PULLUP ON DQ DS1822 CONVERTS TEMPERATURE COPY IN PROGRESS Y MASTER DISABLES STRONG PULLUP MASTER N B8h 2 RECALL MASTER BEGINS DATA 2 RECALL FROM E PROM DEVICE N BUSY RECALLING DATA ? Y MASTER MASTER R “ ...
Page 15
SIGNALING The DS1822 uses a strict 1-Wire communication protocol to insure data integrity. Several signal types are defined by this protocol: reset pulse, presence pulse, write 0, write 1, read 0, and read 1. All of these signals, with ...
Page 16
The DS1822 samples the 1-Wire bus during a window that lasts from 15μs to 60μs after the master initiates the write time slot. If the bus is high during the sampling window written to the DS1822. If ...
Page 17
... Application Note 104: Minimalist Temperature Control Demo Application Note 106: Complex MicroLANs Application Note 108: MicroLAN—In the Long Run Application Note 162: Interfacing the DS18X20/DS1822 1-Wire Temperature Sensor in a Microcontroller Environment Sample 1-Wire subroutines that can be used in conjunction with AN74 can be downloaded from the Dallas website or anonymous FTP Site ...
Page 18
... DS1822 OPERATION EXAMPLE 1 In this example there are multiple DS1822s on the bus and they are using parasite power. The bus master initiates a temperature conversion in a specific DS1822 and then reads its scratchpad and recalculates the CRC to verify the data. MASTER MODE ...
Page 19
... To minimize I DDS 0.3V ≤ DQ ≤ Active current refers to supply current during active temperature conversions or EEPROM writes. 10. DQ line is high (high-Z state). 11. Drift data is based on a 1000 hour stress test at +125°C with V -0.5V to +6.0V -55°C to +125°C -55°C to +125°C See IPC/JEDEC J-STD-020A Specification +220° ...
Page 20
... RDV t RSTH t RSTL t PDHIGH t PDLOW C IN/OUT > 960μs, a power on reset may occur. RSTL DS1822 Typical Performance Curve +3s Error Mean Error -3s Error Temperature (° 3.0V to 5.5V) DD MIN TYP MAX 2 10 50k 10 = 3.0V to 5.5V) DD MIN TYP MAX UNITS 93.75 ms 187.5 ms 375 ms 750 ms 10 µ ...
Page 21
TIMING DIAGRAMS Figure DS1822 ...