INTRODUCTION
The DS1631 was designed to be software compatible with the DS1621 in most applications, which makes
it a simple matter to switch from the DS1621 to the DS1631. This application note describes the
differences and similarities between the two parts including DS1631 functions that allow compatibility
with the DS1621 but which are not documented in the DS1631 data sheet. All subjects not covered in this
application note (e.g., 2-wire communication) are the same for both devices.
This application note is aimed at users interested in transitioning from the DS1621 to the DS1631. For
new designs incorporating the DS1631, please refer to the DS1631 data sheet for usage instructions, as
information in this application note will not be pertinent. Users switching from the DS1621 to the
DS1631 will also need to reference the DS1631 data sheet for device specifications and other information
not covered in this application note.