Analog Devices Inc./Maxim Integrated MAX16033LLB31+T

Overview

The MAX16033LLB31+T from Maxim Integrated is a low-power microprocessor supervisory circuit with integrated battery switchover, active-low push-pull reset output, 3.08V factory-set reset threshold, 140ms minimum reset timeout, and manual-reset input. It monitors VCC (1.2V–5.5V), asserts RESET during brownout or power failure, and powers SRAM from backup battery when VCC drops below threshold - used in portable POS terminals and industrial controllers requiring reliable nonvolatile memory retention.

For engineers reviewing the MAX16033LLB31+T datasheet, MAX16033LLB31+T pinout, MAX16033LLB31+T application, or MAX16033LLB31+T equivalent, key selection criteria include reset threshold accuracy (±0.07V), battery switchover hysteresis (40mV), quiescent current (13µA at 2.8V), and 10-pin µDFN package compatibility with space-constrained embedded designs.

Technical Context

The MAX16033LLB31+T implements a precision bandgap-based reset generator with 3.08V threshold (±0.07V over -40°C to +85°C), independent power-fail comparator referenced to 1.235V, and debounced manual-reset input with internal 20kΩ pullup. Its chip-enable gating path provides sub-7ns propagation delay (50Ω/50pF) and <100Ω on-resistance between CEIN and CEOUT.

Battery switchover uses dual MOSFET control: VCC-to-OUT resistance is 3.1Ω at 4.75V/150mA, while BATT-to-OUT resistance is 4.6Ω at 2.5V/5mA. The device remains functional down to 1.2V VCC and delivers active-low push-pull RESET with VOL ≤0.3V at 1.6mA sink current.

Key Specifications

Pinout & Package

Package: 10-pin µDFN (2mm × 2mm, 0.5mm pitch), exposed pad, RoHS-compliant, rated for -40°C to +85°C operation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microprocessor supervisory applications.

Compared with MAX16033PLB31+T, the MAX16033LLB31+T eliminates external pull-ups and simplifies layout; versus TPS3808G33DBVR, it adds critical battery backup, CE gating, and MR functionality essential for data-retentive systems.

Availability

MAX16033LLB31+T is available at Aetrix Electronics and suitable for portable POS terminals, industrial controllers, set-top box RTC holdover, and portable medical devices requiring stable component supply and long-term lifecycle support.

Supply support for MAX16033LLB31+T includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Maxim Integrated, now part of Analog Devices, designs precision analog and mixed-signal ICs for power management, sensing, and connectivity in industrial, automotive, and computing applications.

The MAX16033–MAX16040 product line delivers ultra-low-power supervisory circuits with integrated battery switchover and chip-enable gating for systems requiring guaranteed memory retention during power loss.

FAQ

What is the exact reset threshold voltage of the MAX16033LLB31+T?

The MAX16033LLB31+T has a factory-set reset threshold of 3.08V, with guaranteed minimum 3.00V and maximum 3.15V across -40°C to +85°C. This L31 suffix denotes the 3.08V variant within the MAX16033 family, optimized for 3.3V supply monitoring where precise brownout detection is critical. The MAX16033LLB31+T achieves this accuracy using laser-trimmed on-die resistors and a stable bandgap reference.

Does the MAX16033LLB31+T support battery switchover without external components?

Yes, the MAX16033LLB31+T integrates bidirectional MOSFET control for automatic battery switchover between VCC and BATT inputs. When VCC falls below the 3.08V threshold and drops 40mV below VBATT, the device seamlessly connects BATT to OUT with no external diodes, FETs, or controllers required. The MAX16033LLB31+T maintains this function down to 1.2V VCC and supports backup voltages from 2.1V to 5.5V.

How does the chip-enable gating feature work in the MAX16033LLB31+T?

The MAX16033LLB31+T provides a transmission gate between CEIN and CEOUT that disables during reset assertion to prevent erroneous writes to CMOS RAM. When RESET is deasserted, CEIN passes through with ≤7ns propagation delay (50Ω source, 50pF load) and <100Ω on-resistance. If CEIN is low when RESET asserts, CEOUT holds low for 1µs then goes high; if CEIN is high, CEOUT remains high immediately. This behavior is intrinsic to the MAX16033LLB31+T's internal logic and requires no configuration.

What is the quiescent current of the MAX16033LLB31+T in battery backup mode?

In battery backup mode (VCC = 0V, VBATT = 2.8V), the MAX16033LLB31+T draws just 1µA typical supply current at +25°C, rising to 2µA across -40°C to +85°C. This ultra-low current enables multi-year operation from standard coin cells and is achieved through proprietary low-leakage process design and dynamic biasing. The MAX16033LLB31+T specifies this value excluding IOUT, ensuring accurate estimation of battery lifetime in memory-retention applications.

Can the MAX16033LLB31+T monitor a secondary power supply?

Yes, the MAX16033LLB31+T includes a dedicated RESETIN input referenced to an internal 1.235V comparator, allowing monitoring of secondary supplies via external resistor dividers. When RESETIN falls below 1.235V, the MAX16033LLB31+T asserts RESET with 1.5µs propagation delay. This function is independent of the main VCC reset path and supports adjustable thresholds - for example, setting VRTH = 5.0V requires R1/R2 = 3.05 using the formula VRTH = 1.235V × (R1/R2 + 1). The MAX16033LLB31+T's 25nA RESETIN input current enables use of high-value resistors without accuracy loss.