DS1825U+ Maxim Integrated Products, DS1825U+ Datasheet - Page 12

• Manufacturer Part Number: DS1825U+
• Description: IC THERMOMETER DIGITAL 8-USOP
• Manufacturer: Maxim Integrated Products

Specifications of DS1825U+

• Function: Thermometer, Thermostat
• Topology: Register Bank, Scratchpad
• Sensor Type: Internal
• Sensing Temperature: -55°C ~ 125°C
• Output Type: Digital
• Output Alarm: Yes
• Output Fan: No
• Voltage - Supply: 3 V ~ 3.7 V
• Operating Temperature: -55°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 8-MSOP, Micro8™, 8-uMAX, 8-uSOP,
• Temperature Threshold: Programmable
• Full Temp Accuracy: +/- 0.5 C
• Digital Output - Bus Interface: 1-Wire
• Digital Output - Number Of Bits: 9 bit to 12 bit
• Supply Voltage (max): 3.7 V
• Supply Voltage (min): 3 V
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 55 C
• Supply Current: 1.5 mA
• Ic Output Type: Digital
• Sensing Accuracy Range: ± 0.5°C
• Supply Voltage Range: 3V To 3.7V
• Resolution (bits): 12bit
• Sensor Case Style: µSOP
• No. Of Pins: 8
• Accuracy %: 0.5°C
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

READ SCRATCHPAD [BEh]
This command allows the master to read the contents of the scratchpad. The data transfer starts with the least
significant bit of byte 0 and continues through the scratchpad until the 9
may issue a reset to terminate reading at any time if only part of the scratchpad data is needed.
COPY SCRATCHPAD [48h]
This command copies the contents of the scratchpad T
EEPROM. If the device is being used in parasite power mode, within 10ms (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
DS1825 section.
RECALL E
This command recalls the alarm trigger values (T
data in bytes 2, 3, and 4, 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 DS1825s on the bus are
using parasite power. During the read time slot, parasite powered DS1825s will pull the bus low, and externally
powered DS1825s will let the bus remain high. Refer to the POWERING THE DS1825 section for usage
information for this command.
Table 5. DS1825 FUNCTION COMMAND SET
NOTES:
1. For parasite-powered DS1825s, the master must enable a strong pullup on the 1-Wire bus during temperature
2. The master can interrupt the transmission of data at any time by issuing a reset.
3. All three bytes must be written before a reset is issued.
Convert T
Read Scratchpad
Write Scratchpad
Copy Scratchpad
Recall E
Read Power
Supply
conversions and copies from the scratchpad to EEPROM. No other bus activity may take place during this
time.
Command
2
2
[B8h]
2
Initiates temperature
conversion.
Reads the entire scratchpad
including the CRC byte.
Writes data into scratchpad
bytes 2, 3, and 4 (T
configuration registers).
Copies T
configuration register data
from the scratchpad to
EEPROM.
Recalls T
configuration register data
from EEPROM to the
scratchpad.
Signals DS1825 power supply
mode to the master.
command and the DS1825 will indicate the status of the recall by transmitting 0 while the
H
Description
H
, T
, T
TEMPERATURE CONVERSION COMMANDS
L
L
, and
, and
H
, T
MEMORY COMMANDS
L
, and
H
and T
12 of 21
Protocol
H
L
) and configuration data from EEPROM and places the
, T
BEh
4Eh
B8h
B4h
44h
48h
L
and configuration registers (bytes 2, 3, and 4) to
DS1825 transmits conversion status
to master (not applicable for
parasite-powered DS1825s).
DS1825 transmits up to 9 data
bytes to master.
Master transmits 3 data bytes to
DS1825.
None
DS1825 transmits recall status to
master.
DS1825 transmits supply status to
master.
th
After Command is Issued
byte (byte 8: CRC) is read. The master
1-Wire Bus Activity
Notes
1
2
3
1