DS1621
ORDERING INFORMATION
ORDERING
NUMBER
DS1621
DS1621+
DS1621S
DS1621S+
DS1621S/T&R
DS1621S+T&R
DS1621V
DS1621V+
DS1621V/T&R
DS1621V+T&R
PACKAGE
MARKING
DS1621
DS1621 (See Note)
DS1621
DS1621 (See Note)
DS1621
DS1621 (See Note)
DS1621V
DS1621V (See Note)
DS1621V
DS1621V (See Note)
DESCRIPTION
DS1621 in 300 mil DIP
DS1621 in Lead-Free 300 mil DIP
DS1621 in 150 mil SOIC
DS1621 in Lead-Free 150 mil SOIC
DS1621 in 150 mil SO, 2500 Piece Tape-and-Reel
DS1621 in Lead-Free 150 mil SO, 2500 Piece Tape-and-Reel
DS1621 in 208 mil SOIC
DS1621 in Lead-Free 208 mil SOIC
DS1621 in 208 mil SO, 2500 Piece Tape-and-Reel
DS1621 in Lead-Free 208 mil SO, 2500 Piece Tape-and-Reel
Note: A “+” symbol will also be marked on the package near the Pin 1 indicator.
Table 1. DETAILED PIN DESCRIPTION
PIN
1
2
3
4
5
6
7
8
SYMBOL
SDA
SCL
T
OUT
GND
A2
A1
A0
V
DD
DESCRIPTION
Data input/output pin for 2-wire serial communication port.
Clock input/output pin for 2-wire serial communication port.
Thermostat output. Active when temperature exceeds TH; will reset when
temperature falls below TL.
Ground pin.
Address input pin.
Address input pin.
Address input pin.
Supply voltage input power pin. (2.7V to 5.5V)
OPERATION
Measuring Temperature
A block diagram of the DS1621 is shown in Figure 1.
The DS1621 measures temperature using a bandgap-based temperature sensor. A delta-sigma analog-to-
digital converter (ADC) converts the measured temperature to a digital value that is calibrated in °C; for
°F applications, a lookup table or conversion routine must be used.
The temperature reading is provided in a 9-bit, two’s complement reading by issuing the READ
TEMPERATURE command. Table 2 describes the exact relationship of output data to measured
temperature. The data is transmitted through the 2-wire serial interface, MSB first. The DS1621 can
measure temperature over the range of -55°C to +125°C in 0.5°C increments.
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MAXIM [ MAXIM INTEGRATED PRODUCTS ]
