DS1821 Maxim Integrated Products, DS1821 Datasheet - Page 2
![IC THERMOMETER/STAT PROG 3-PR35](/photos/7/26/72615/406-3-pr35_sml.jpg)
DS1821
Manufacturer Part Number
DS1821
Description
IC THERMOMETER/STAT PROG 3-PR35
Manufacturer
Maxim Integrated Products
Datasheet
1.DS1821.pdf
(18 pages)
Specifications of DS1821
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
Through Hole
Package / Case
TO-92-3 (Long Body), TO-226
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
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
DS1821C+
Manufacturer:
EPCOS
Quantity:
1 000
Company:
Part Number:
DS1821S
Manufacturer:
DALLAS
Quantity:
8 680
Part Number:
DS1821S
Manufacturer:
DALLAS
Quantity:
20 000
Company:
Part Number:
DS1821S+
Manufacturer:
MAXIM
Quantity:
202
Part Number:
DS1821S+TR
Manufacturer:
MAXIM/美信
Quantity:
20 000
ORDER INFORMATION
ORDERING
NUMBER
DS1821
DS1821+
DS1821S
DS1821S/T&R
DS1821S+
DS1821S+T&R
Note: A “+” symbol will also be marked on the package.
+ Denotes lead-free package.
DETAILED PIN DESCRIPTIONS Table 1
*All pins not specified in this table are “No Connect” pins.
OVERVIEW
Figure 1 shows a block diagram of the DS1821 and pin descriptions are given in Table 1. The DS1821
can operate as a standalone thermostat with user-programmable trip-points or as 8-bit temperature sensor
with a 1-Wire digital interface. The open-drain DQ pin functions as the thermostat output for thermostat
operation and as the data I/O pin for 1-Wire communications. The 1-Wire interface provides user access
to the nonvolatile (EEPROM) thermostat trip-point registers (T
and the temperature register.
When configured as standalone thermostat, temperature conversions start immediately at power-up. In
this mode, the DQ pin becomes active when the temperature of the DS1821 exceeds the limit
programmed into the T
programmed into the T
The DS1821 uses Dallas’ exclusive 1-Wire bus protocol that implements bus communication with one
control signal. This system is explained in detail in the 1-Wire BUS SYSTEM section of this datasheet.
PR35
1
2
3
8-PIN
SO*
2
1
8
SYMBOL
DS1821
DS1821 (See Note)
DS1821S
DS1821S
DS1821S (See Note)
DS1821S (See Note)
L
GND
V
DQ
register.
H
DD
register, and remains active until the temperature drops below the limit
PACKAGE
MARKING
Ground pin.
Open drain data input/output pin – 1-Wire operation; Open drain
thermostat output pin –thermostat operation.
Power supply pin.
DS1821 in 3-pin PR35
DS1821 in 3-pin PR35
DS1821 in 208 mil 8-pin SO
DS1821 in 208 mil 8-pin SO, 2000 Piece Tape-and-Reel
DS1821 in 208 mil 8-pin SO
DS1821 in 208 mil 8-pin SO, 2000 Piece Tape-and-Reel
2 of 18
DESCRIPTION
H
and T
DESCRIPTION
L
), the status/configuration register,