The external sensor channel reads a remote diode up to 100°C, so the controller can track a hot CPU or power-stage temperature while the chip itself sits on a cooler section of the board. The commercial temperature grade means it should not be specified for automotive under-hood, outdoor base stations, or industrial enclosures without active cooling.
Housed in a 24-lead SSOP (3.90 mm width) — also referred to as a 24-QSOP in the supplier device package field. Surface-mount, standard pitch, no thermal pad required. The bulk shipping form (tube or tray) is fine for prototype and low-volume builds; for production reels, the ADM1029ARQ-REEL7 variant uses the same die and layout.
RoHS status — plan for it
The ADM1029ARQ is marked RoHS non-compliant. If your BOM requires RoHS exemption (e.g., lead in solder joints for high-reliability applications), this part may still be acceptable under certain exemptions. For standard EU or China RoHS compliance, you will need to source a lead-free alternate or confirm an exemption applies.