DS1821S Maxim Integrated Products, DS1821S Datasheet - Page 8

• Manufacturer Part Number: DS1821S
• Description: IC THERMOMETER/STAT PROG 8-SOIC
• Manufacturer: Maxim Integrated Products

Specifications of DS1821S

• Function: Thermometer, Thermostat
• Topology: Comparator, Register Bank
• Sensor Type: Internal
• Sensing Temperature: -55°C ~ 125°C
• Output Type: Digital
• Output Alarm: No
• Output Fan: No
• Voltage - Supply: 2.7 V ~ 5.5 V
• Operating Temperature: -55°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (5.3mm Width), 8-SOP, 8-SOEIAJ
• Full Temp Accuracy: +/- 1 C
• Digital Output - Bus Interface: Serial (1-Wire)
• Digital Output - Number Of Bits: 8 bit
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 55 C
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

CONFIGURATION REGISTER BIT DESCRIPTIONS Table 3
*
DONE — Temperature Conversion Done
(Read Only)
NVB — Non-volatile Memory Busy
(Read Only)
THF* — Temperature High Flag
(Read/Write)
TLF* — Temperature Low Flag
(Read/Write)
T/R ¯ * — Power-up Operating Mode
(Read/Write)
POL* — Thermostat Output (DQ) Polarity
(Read/Write)
1SHOT* — Conversion Mode
(Read/Write)
Stored in EEPROM
(User Access)
Bit Name
DONE = 0 — Temperature conversion is in progress.
DONE = 1 — Temperature conversion is complete.
NOTE: DONE = 0 at POR.
NVB = 0 — Nonvolatile memory is not busy.
NVB = 1 — A write to EEPROM memory is in progress
THF = 0 — The measured temperature has not exceeded the
value stored in the T
THF = 1 — At some point in time the measured temperature has
been higher than the value stored in the T
remain a 1 until it is over-written with a 0 by the user.
TLF = 0 — The measured temperature has not been lower than
the value stored in the T
TLF = 1 — At some point in time the measured temperature has
been lower than the value stored in the T
remain a 1 until it is over-written with a 0 by the user.
T/R ¯ = 0 — DS1821 powers up in 1- wire mode.
T/R ¯ = 1 — DS1821 powers up in thermostat mode.
POL = 0 — Thermostat output (DQ) is active low.
POL = 1 — Thermostat output (DQ) is active high.
1SHOT = 0 — Continuous conversion mode. The Start Convert
T [EEh] command initiates continuous temperature conversions,
which can be stopped with the Stop Convert T [22h] command.
1SHOT = 1 — One-shot mode. The Start Convert T [EEh]
command initiates a single temperature conversion after which
the DS1821 returns to a low-power standby state.
8 of 18
Functional Description
H
register.
L
register.
H
L
register. THF will
register. TLF will