DS1822+ Maxim Integrated Products, DS1822+ Datasheet - Page 12

• Manufacturer Part Number: DS1822+
• Description: Board Mount Temperature Sensors IC THERMOMETER ECONO DIG
• Manufacturer: Maxim Integrated Products

Specifications of DS1822+

• Temperature Threshold: Programmable
• Full Temp Accuracy: +/- 2 C
• Package / Case: TO-92
• Digital Output - Bus Interface: 1-Wire
• Digital Output - Number Of Bits: 9 bit to 12 bit
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 3 V
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 55 C
• Output Type: Digital
• Supply Current: 1.5 mA
• Ic Output Type: Digital
• Sensing Accuracy Range: ± 2°C
• Supply Voltage Range: 3V To 5.5V
• Resolution (bits): 12bit
• Sensor Case Style: TO-92
• No. Of Pins: 3
• Accuracy %: 2°C
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

issued the master must enable a strong pullup on the 1-Wire bus for at least 10ms as described in the
POWERING THE DS1822 section.
RECALL E
This command recalls the alarm trigger values (T
places the data in bytes 2, 3, and 4, respectively, in the scratchpad memory. The master device can issue
read time slots following the Recall E
transmitting 0 while the 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 DS1822s on the
bus are using parasite power. During the read time slot, parasite powered DS1822s will pull the bus low,
and externally powered DS1822s will let the bus remain high. Refer to the POWERING THE DS1822
section for usage information for this command.
DS1822 FUNCTION COMMAND SET Table 4
NOTES:
1. For parasite-powered DS1822s, the master must enable a strong pullup on the 1-Wire bus during
2.
3.
Convert T
Read Scratchpad
Write Scratchpad Writes data into scratchpad
Copy Scratchpad Copies T
Recall E
Read Power
Supply
temperature conversions and copies from the scratchpad to EEPROM. No other bus activity may take
place during this time.
Command
The master can interrupt the transmission of data at any time by issuing a reset.
All three bytes must be written before a reset is issued.
2
2
[B8h]
Initiates temperature
conversion.
Reads the entire scratchpad
including the CRC byte.
bytes 2, 3, and 4 (T
and configuration registers).
configuration register data
from the scratchpad to
EEPROM.
Recalls T
configuration register data
from EEPROM to the
scratchpad.
Signals DS1822 power
supply mode to the master.
TEMPERATURE CONVERSION COMMANDS
Description
H
H
, T
, T
L
L
, and
, and
2
MEMORY COMMANDS
command and the DS1822 will indicate the status of the recall by
H
, T
L
,
12 of 21
H
Protocol
and T
BEh
B8h
B4h
4Eh
44h
48h
L
) and configuration data from EEPROM and
DS1822 transmits conversion
status to master (not applicable
for parasite-powered DS1822s).
DS1822 transmits up to 9 data
bytes to master.
Master transmits 3 data bytes to
DS1822.
None
DS1822 transmits recall status to
master.
DS1822 transmits supply status
to master.
After Command is Issued
1-Wire Bus Activity
DS1822
Notes
1
2
3
1