We do not have a pin for pin direct replacement for the DS1821C+. The DS18B20+ is however our next best option and is a very close replacement for the DS1821C+. It has the same package and most of the same electrical characteristics ( one difference being the minimum input voltage is 3V vs. 2.7V). The main difference between the parts is the DS18B20+ does not have a Thermostat mode like the DS1821. The DS18B20+ does however have high and low thermal limits and an alarm command.
