DS1820 Digital Thermometer

Architecture: The DS18S20 uses a bandgap temperature sensing architecture rather than the dual-oscillator
architecture used by the DS1820. This architectural difference is invisible to the user.

Specification Differences: The primary specification difference between the two parts is the
temperature conversion time: DS1820 = 500ms (max) and DS18S20 = 750ms (max).

Software Compatibility: The DS18S20 is software compatible with the DS1820 in most applications.

Hardware Compatibility: The DS18S20 is available in TO-92 (DS18S20) and 8-pin SOIC (DS18S20Z) packages.
The DS18S20 (TO-92 package) replaces the DS1820 (PR35 package) since both packages are 3-pin packages with the same lead pitch.
There is no replacement package for the DS1820S (16-pin SSOP); however, the DS18S20Z (8-pin SOIC) provides a smaller surface mount package option.