Analog Devices Inc./Maxim Integrated MAX16999AUA18+T

Overview

MAX16999AUA18+T from Maxim Integrated is a low-quiescent-current linear regulator delivering 100mA at up to +125°C, with preset 1.8V output, 13μA quiescent current, and active-low open-drain reset with capacitor-programmable timeout. It powers microcontroller core/interrupt sections during sleep mode and supports keep-alive timers in high-temperature automotive and industrial systems.

For engineers reviewing the MAX16999AUA18+T datasheet, MAX16999AUA18+T pinout, MAX16999AUA18+T application, or MAX16999AUA18+T equivalent, key selection criteria include ultra-low IQ (13μA typ), factory-trimmed 1.8V output, thermal shutdown at +165°C, logic-controlled enable, and adjustable POR delay via CRES capacitor.

Technical Context

The MAX16999AUA18+T integrates a p-channel MOSFET pass transistor, precision error amplifier, and internal voltage reference to regulate output with ±2.5% accuracy over load (1mA–100mA) and temperature (−40°C to +125°C). Its POR timer uses a 10μA pullup current on CRES to generate reset timeout, while a 100ms fault timer ensures fail-safe startup even with CRES faults.

It features undervoltage lockout (UVLO) with 2.2V threshold and 45mV hysteresis, short-circuit protection with continuous current limiting (105–150mA), and thermal-overload protection with 15°C hysteresis. The EN input is latched via 120kΩ internal resistors, maintaining state during signal loss.

Key Specifications

Pinout & Package

MAX16999AUA18+T is housed in an 8-pin μMAX® package with exposed pad (U8E+2 outline), optimized for thermal dissipation in compact high-temp layouts. The exposed paddle must be soldered to a large ground plane for θJA = 77.6°C/W (multilayer PCB).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS7A0518PDBVR and NCP1117ST18T3G, the MAX16999AUA18+T uniquely combines ultra-low 13μA IQ, integrated capacitor-programmable reset, and AEC-Q100-aligned temperature range - making it the sole option for automotive-grade always-on 1.8V domains requiring coordinated power sequencing.

Availability

MAX16999AUA18+T is available at Aetrix Electronics and suitable for automotive telematics, industrial motor control, and battery-backed SDRAM retention applications requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX16999AUA18+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 high-performance analog and mixed-signal ICs for automotive, industrial, and communications markets, with emphasis on reliability under extreme conditions.

The MAX16999 series targets high-temperature power management in automotive and industrial control systems, specifically addressing the need for ultra-low-IQ, reset-integrated LDOs that maintain functionality at +125°C ambient.

FAQ

What is the exact output voltage of MAX16999AUA18+T and how is it set?

The MAX16999AUA18+T has a factory-trimmed fixed output voltage of 1.8V, indicated by the "18" suffix in the part number per the Selector Guide. This voltage is internally trimmed during wafer test and does not require external feedback resistors. Output accuracy is guaranteed at ±2.5% over load (1mA–100mA) and temperature (−40°C to +125°C), as confirmed in the DC Electrical Characteristics table.

Does MAX16999AUA18+T support parallel operation with another regulator?

Yes, the MAX16999AUA18+T is explicitly designed for parallel operation with another regulator of equal output voltage, as stated in the Applications and Detailed Description sections. Its low dropout and matched output voltage enable current sharing in hybrid power architectures-such as pairing with a high-current 1.8V supply to reduce overall system IQ while maintaining peak load capability.

How is the reset timeout programmed on MAX16999AUA18+T?

The reset timeout on MAX16999AUA18+T is programmed using an external capacitor connected to the CRES pin. A 10μA internal current charges this capacitor; when its voltage reaches 600mV (typ), the RESET pin transitions to high impedance. For example, a 15nF capacitor yields ~60ms timeout. The datasheet provides the formula tPOR_DELAY = CCRES × 60 × 10³ seconds, and Figure 18 confirms timing vs. capacitance.

What thermal derating applies to MAX16999AUA18+T at +125°C ambient?

At TA = +125°C, the MAX16999AUA18+T supports up to 100mA output on multilayer PCBs (Table 1), limited by thermal shutdown at +165°C junction. With θJA = 77.6°C/W (multilayer), power dissipation must stay below ~460mW. Derating is implicit in Table 1's current limits - e.g., at VOUT = 1.8V and VIN = 5V, max continuous current is 100mA, yielding ~320mW dissipation, well within safe margin.

Is MAX16999AUA18+T RoHS-compliant and what does the "+T" suffix indicate?

Yes, MAX16999AUA18+T is RoHS-compliant and lead(Pb)-free, as confirmed by the "+" in the part number per the Ordering Information section. The "T" denotes tape-and-reel packaging per standard Maxim ordering conventions. The μMAX-EP package (U8E+2) meets JEDEC standards and is compatible with automated SMT assembly processes.