Analog Devices Inc./Maxim Integrated MAX16038LLA46+

Overview

MAX16038LLA46+ from Maxim Integrated is an 8-pin μDFN battery-backup supervisory IC with watchdog timer, active-low push-pull reset output, and 4.63V factory-set reset threshold. It monitors VCC (1.2V–5.5V), asserts reset during brownout or manual trigger, switches OUT to BATT when VCC drops below VTH, and provides power-fail warning via PFO. Used in POS terminals and portable equipment for SRAM backup and microprocessor reliability.

For engineers reviewing the MAX16038LLA46+ datasheet, MAX16038LLA46+ pinout, MAX16038LLA46+ application, or MAX16038LLA46+ equivalent, key selection criteria include its 1.6s watchdog timeout, 13µA quiescent current, 140ms minimum reset timeout, push-pull RESET structure, and 2mm × 2mm 8-pin μDFN package - all critical for low-power, space-constrained embedded systems requiring deterministic reset behavior and battery switchover.

Technical Context

The MAX16038LLA46+ integrates a precision reset generator with 4.63V ±0.13V threshold, a 1.6s watchdog timer with edge-triggered clear, and a dedicated WDI input that detects µP activity failure. Its internal MOSFET enables seamless VCC-to-BATT switchover at 40mV hysteresis, maintaining OUT voltage during brownout without external components.

It features an active-low push-pull RESET output (VOL ≤ 0.3V @ 1.6mA), a power-fail comparator with 1.235V reference and 1% hysteresis, and operates across –40°C to +85°C. All logic inputs (WDI, PFI) are TTL/CMOS-compatible with defined VIH/VIL thresholds and <100ns glitch immunity.

Key Specifications

Pinout & Package

MAX16038LLA46+ uses an 8-pin, 2mm × 2mm, 0.5mm pitch μDFN package with exposed thermal pad (pin 8). The device belongs to the MAX16037–MAX16040 8-pin variant group and includes watchdog functionality but excludes MR, CEIN/CEOUT, and BATTON.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX16034LLA46+, MAX16038LLA46+ saves board area and cost by omitting unused MR and CE functions, while retaining identical reset accuracy, watchdog timing, and battery switchover performance - making it optimal for compact, cost-sensitive designs where those features are unnecessary.

Availability

MAX16038LLA46+ is available at Aetrix Electronics and suitable for POS terminals, industrial controllers, set-top boxes, and portable medical devices requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX16038LLA46+ 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, mixed-signal, and power-management ICs for industrial, computing, and communications markets.

The MAX16033–MAX16040 family delivers integrated battery-backup supervision for µP systems, targeting applications demanding ultra-low quiescent current, small footprint, and guaranteed reset timing - especially where SRAM data retention and watchdog reliability are critical.

FAQ

What is the exact reset threshold voltage of MAX16038LLA46+ and how is it trimmed?

The MAX16038LLA46+ has a factory-trimmed reset threshold of 4.63V, with a guaranteed range of 4.50V to 4.75V over –40°C to +85°C. This value is laser-trimmed during production and specified in the Electrical Characteristics table under "MAX160_ _ _L_46" row. No external components are needed to set or adjust this threshold, and it remains stable over temperature and time without drift compensation circuitry.

Does MAX16038LLA46+ support battery switchover for voltages below 2.5V?

Yes, MAX16038LLA46+ supports battery switchover down to 1.2V VCC operation and can accept BATT inputs as low as 2.1V. When VCC falls below the 4.63V threshold and VBATT exceeds VCC by ≥40mV, the internal MOSFET connects BATT to OUT. Data sheet Figure toc03 confirms BATT-to-OUT on-resistance remains ≤8Ω at VBATT = 2V and –40°C, enabling reliable SRAM backup even with partially discharged lithium or alkaline cells.

Can MAX16038LLA46+ drive a standard microprocessor reset pin directly?

Yes, MAX16038LLA46+ features an active-low push-pull RESET output capable of sinking 1.6mA with VOL ≤ 0.3V at VCC ≥ 2.1V, meeting the input requirements of most µPs (e.g., ARM Cortex-M, Intel x86, Renesas RX). No external pull-up resistor is required. The 140ms minimum reset timeout ensures compliance with JEDEC JESD78, and the output remains asserted until VCC stabilizes above 4.63V and the timeout expires.

How does the watchdog timer in MAX16038LLA46+ respond to software stalls?

The MAX16038LLA46+ watchdog timer triggers a reset pulse if the WDI input remains static (high or low) for longer than 1.6s (typical). A rising or falling edge on WDI clears the timer, allowing flexible firmware integration - e.g., toggling WDI at loop entry/exit. Upon timeout, RESET asserts for 140ms (min), forcing µP reboot. This behavior is verified in Figure 2 of the datasheet and applies identically to MAX16038LLA46+ as part of the MAX16034/MAX16038 variant group.

Is MAX16038LLA46+ pin-compatible with other devices in the MAX16033–MAX16040 family?

No, MAX16038LLA46+ is not pin-compatible with 10-pin variants like MAX16034LLA46+. It uses the 8-pin μDFN package (pins 1–8), while 10-pin versions add CEIN and CEOUT on pins 2 and 10. However, among 8-pin devices (MAX16037–MAX16040), MAX16038LLA46+ shares identical pinout and footprint with MAX16037, MAX16039, and MAX16040 - differing only in functional blocks (WDI vs. MR vs. BATTON vs. RESETIN).