Battery backup supervisor in a 2x2 mm DFN
The MAX16038LLA29+T from Analog Devices is a battery-backup circuit that monitors a single supply rail and automatically switches to a backup battery when the primary voltage drops below the threshold. It integrates a precision voltage reference, a comparator, and a reset generator in an 8-uDFN package measuring 2x2 mm. The reset output is active-low, push-pull, so no external pull-up resistor is needed — it drives the reset input of an MCU, FPGA, or SRAM directly. With a threshold of 2.93 V and a minimum reset timeout of 140 ms, this part monitors a single supply rail and holds the reset output for the timeout period.
Threshold and timeout — what they mean for the BOM
The 2.93 V threshold triggers a reset before the supply falls far enough to cause erratic logic behaviour. The 140 ms minimum reset timeout ensures the processor stays in reset through the worst-case power-up ramp. Because the part monitors only one voltage, it fits designs where a single core rail needs supervision. Multi-rail systems need a companion supervisor or a multi-channel part.
Package and temperature grade
The 8-uDFN (2x2 mm) footprint saves board area but the exposed pad requires a thermal land on the PCB for proper soldering. The -40°C to 85°C range covers industrial, telecom, and outdoor equipment but not full automotive under-hood environments.
Lifecycle and sourcing
The MAX16038LLA29+T is listed as Active on the manufacturer's product status. It is ROHS3 compliant, which covers most global regulatory requirements for lead-free assembly.