DS18S20Z Maxim Integrated Products, DS18S20Z Datasheet - Page 12

• Manufacturer Part Number: DS18S20Z
• Description: IC THERM MICROLAN HI-PREC 8-SOIC
• Manufacturer: Maxim Integrated Products

Specifications of DS18S20Z

• Sensing Temperature: -55°C ~ 125°C
• Output Type: Digital
• Voltage - Supply: 3 V ~ 5.5 V
• Accuracy: ±0.5°C
• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• Full Temp Accuracy: +/- 2 C
• Digital Output - Bus Interface: Serial (1-Wire)
• Digital Output - Number Of Bits: 9 bit
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 55 C
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

COPY SCRATCHPAD [48h]
This command copies the contents of the scratchpad T
the device is being used in parasite power mode, within 10µs (max) after this command is issued the
master must enable a strong pullup on the 1-Wire bus for at least 10ms as described in the Powering the
DS18S20 section.
RECALL E
This command recalls the alarm trigger values (T
and 3, respectively, in the scratchpad memory. The master device can issue read-time slots following the
Recall E
recall is in progress and 1 when the recall is done. The recall operation happens automatically at power-
up, so valid data is available in the scratchpad as soon as power is applied to the device.
READ POWER SUPPLY [B4h]
The master device issues this command followed by a read-time slot to determine if any DS18S20s on the
bus are using parasite power. During the read-time slot, parasite powered DS18S20s will pull the bus low,
and externally powered DS18S20s will let the bus remain high. See the Powering the DS18S20 section
for usage information for this command.
Table 2. DS18S20 Function Command Set
Note 1:
Note 2:
Note 3:
Convert T
Read
Scratchpad
Write
Scratchpad
Copy
Scratchpad
Recall E
Read Power
Supply
COMMAND
2
2
For parasite-powered DS18S20s, 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.
The master can interrupt the transmission of data at any time by issuing a reset.
Both bytes must be written before a reset is issued.
command and the DS18S20 will indicate the status of the recall by transmitting 0 while the
2
[B8h]
Initiates temperature
conversion.
Reads the entire
scratchpad including the
CRC byte.
Writes data into
scratchpad bytes 2 and 3
(T
Copies T
from the scratchpad to
EEPROM.
Recalls T
from EEPROM to the
scratchpad.
Signals DS18S20 power
supply mode to the
master.
H
and T
DESCRIPTION
TEMPERATURE CONVERSION COMMANDS
H
H
L
).
and T
and T
L
L
data
data
MEMORY COMMANDS
PROTOCOL
12 of 23
H
and T
BEh
4Eh
B8h
B4h
44h
48h
H
and T
L
) from EEPROM and places the data in bytes 2
L
DS18S20 transmits conversion
status to master (not applicable
for parasite-powered
DS18S20s).
DS18S20 transmits up to 9
data bytes to master.
Master transmits 2 data bytes
to DS18S20.
None
DS18S20 transmits recall
status to master.
DS18S20 transmits supply
status to master.
registers (bytes 2 and 3) to EEPROM. If
1-Wire BUS ACTIVITY
AFTER COMMAND IS
ISSUED
NOTES
DS18S20
1
2
3
1