Analog Devices Inc./Maxim Integrated MAX16999AUA15+T

Overview

MAX16999AUA15+T from Maxim Integrated is a low-quiescent-current linear regulator delivering 100mA at preset 1.5V output, operating from 2.5V–5.5V input, with 13μA typical quiescent current and active-low open-drain reset. It features logic-controlled enable, adjustable POR delay via external CRES capacitor, thermal and short-circuit protection, and is designed for high-temperature automotive and industrial microcontroller keep-alive power rails.

For engineers reviewing the MAX16999AUA15+T datasheet, MAX16999AUA15+T pinout, MAX16999AUA15+T application, or MAX16999AUA15+T equivalent, key selection criteria include guaranteed 100mA load capability at +125°C, ±2.5% output voltage accuracy, 8-pin μMAX-EP package with exposed thermal pad, and integrated reset timeout programmability - all critical for always-on subsystems in telematics and motor control ECUs.

Technical Context

The MAX16999AUA15+T implements a p-channel MOSFET pass transistor with internal feedback divider and precision 0.825×VREF error amplifier to regulate fixed 1.5V output. Its POR circuit uses a 10μA CRES pullup current charging an external capacitor to generate a programmable reset timeout, with fault timer fallback ensuring startup even if CRES shorts.

Enable logic latches EN state via 120kΩ internal resistor; shutdown reduces ground current to ≤1μA. Thermal protection activates at +165°C junction temperature with 15°C hysteresis, while undervoltage lockout (UVLO) disables regulation below 2.2V input with 45mV hysteresis - enabling robust operation in noisy automotive battery environments.

Key Specifications

Pinout & Package

The MAX16999AUA15+T is housed in an 8-pin μMAX-EP package (outline 21-0107) with exposed thermal pad (EP) that must be soldered to a large PCB ground plane for optimal thermal performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-quiescent linear regulator applications.

Compared with TPS7A0515PDBVR and NCP1117ST15T3G, the MAX16999AUA15+T uniquely integrates programmable reset timeout, 13μA quiescent current, and high-temperature operation in a thermally enhanced 8-pin μMAX package - making it the sole option for automotive-grade, sequenced, ultra-low-power auxiliary regulation.

Availability

MAX16999AUA15+T is available at Aetrix Electronics and suitable for automotive telematics, industrial microcontroller keep-alive circuits, and portable device backup power systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX16999AUA15+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, mixed-signal, and power management ICs for automotive, industrial, and communications markets.

The MAX16999 belongs to Maxim's high-temperature linear regulator product line, engineered specifically for always-on auxiliary power in automotive ECUs and industrial controllers where reliability at +125°C ambient is mandatory.

FAQ

What is the exact output voltage of MAX16999AUA15+T and how is it trimmed?

The MAX16999AUA15+T delivers a factory-trimmed fixed 1.5V output voltage, confirmed by the "15" suffix in the part number per Maxim's Selector Guide. Output accuracy is ±2.5% over -40°C to +125°C, achieved via internal laser trimming of the feedback divider. This 1.5V rail is intended for MCU interrupt domains or low-voltage peripherals requiring tight regulation without external resistors.

How does the reset timeout function on MAX16999AUA15+T and what capacitor value sets a 45ms delay?

The MAX16999AUA15+T generates reset timeout by charging the external CRES capacitor with a 10μA internal current source; RESET goes high-impedance when CRES voltage exceeds 600mV. Using the formula t = CCRES × 60 × 10³, a 15nF capacitor yields ~45ms delay. The MAX16999AUA15+T datasheet confirms this relationship and specifies CRES tolerance impact on timing accuracy.

Can MAX16999AUA15+T operate reliably at +125°C ambient temperature?

Yes, the MAX16999AUA15+T is fully specified for continuous operation at TA = +125°C, delivering 100mA output current on multilayer PCBs per Table 1. Its thermal shutdown triggers at +165°C junction temperature with 15°C hysteresis, and θJA is characterized at 77.6°C/W for multilayer boards - enabling reliable use in under-hood automotive and industrial control environments.

What is the shutdown current of MAX16999AUA15+T and how is EN pin behavior latched?

The MAX16999AUA15+T draws ≤1μA supply current in shutdown (EN = low), with typical standby current of 0.3μA. Its EN input incorporates a 120kΩ internal pullup/pulldown resistor that latches the last valid logic state, preventing spurious wake-up if the enable line becomes floating - a key reliability feature confirmed in the MAX16999AUA15+T detailed description section.

Does MAX16999AUA15+T support parallel operation with other regulators, and what design precautions apply?

Yes, the MAX16999AUA15+T is explicitly designed for parallel operation with equal-voltage supplies (e.g., main MCU core rail), as documented in Figure 2 and Applications Information. To prevent current imbalance, output capacitors must be matched and placed close to each regulator; the MAX16999AUA15+T's low dropout and tight output accuracy minimize circulating currents between paralleled devices.