Analog Devices Inc./Maxim Integrated MAX999AAUK+T

Overview

The MAX999AAUK+T from Maxim Integrated is a single ultra-high-speed comparator with internal hysteresis, optimized for +3V/+5V single-supply operation. It features 4.5ns propagation delay (5mV overdrive), ±3.5mV typical input-referred hysteresis, and operates across –40°C to +125°C. Its Beyond-the-Rails™ input range extends 100mV beyond both supply rails, and it drives TTL/CMOS loads directly in a 5-pin SOT23 package-ideal for GPS receiver front-ends and high-speed zero-crossing detection.

For engineers reviewing the MAX999AAUK+T datasheet, MAX999AAUK+T pinout, MAX999AAUK+T application, or MAX999AAUK+T equivalent, key selection criteria include guaranteed propagation delay over temperature, rail-to-rail input capability without external biasing, output drive strength within 0.55V of VCC/GND at +125°C, and absence of shutdown or latch functionality compared to family members like MAX961.

Technical Context

This comparator uses a current-driven output stage enabling fast slew rates and low static power consumption. Its internal hysteresis (3.5mV) eliminates need for external feedback resistors and suppresses oscillation near trip points, ensuring clean switching even with slow-moving or noisy inputs.

The input stage incorporates dual 200Ω series resistors and back-to-back diode clamps between IN+ and IN−, limiting differential voltage to ~2.1V and protecting against overvoltage while maintaining 3pF input capacitance and 8kΩ differential input impedance.

Key Specifications

Pinout & Package

MAX999AAUK+T is housed in a RoHS-compliant 5-pin SOT23 package (package code U5+2), with 0.95mm pitch, 2.9mm × 1.6mm footprint, and exposed pad not connected internally.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX961EUA+T, MAX999AAUK+T trades latch/shutdown for smaller size and extended temperature range; versus TLV3501IDBVR, it adds rail-exceeding input capability and +125°C qualification - critical for automotive and industrial timing integrity.

Availability

MAX999AAUK+T is available at Aetrix Electronics and suitable for GPS receivers, motor control systems, battery management units, and high-speed test equipment requiring stable component supply across extended temperature ranges.

Supply support for MAX999AAUK+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 high-speed ICs for demanding industrial, automotive, and communications applications.

The MAX961–MAX964/MAX997/MAX999 family delivers ultra-high-speed comparators with integrated hysteresis and rail-exceeding inputs - engineered specifically for timing-critical signal conditioning in portable, automotive, and instrumentation systems.

FAQ

What is the maximum operating temperature specification for the MAX999AAUK+T?

The MAX999AAUK+T is fully specified from –40°C to +125°C, making it suitable for under-hood automotive applications and industrial environments where ambient temperatures exceed +85°C. This extended range is explicitly called out in the datasheet's Operating Temperature Range table and differentiates it from standard E-grade variants like MAX999EUK-T, which are limited to –40°C to +85°C.

Does the MAX999AAUK+T support shutdown mode?

No, the MAX999AAUK+T does not include a shutdown function. Unlike MAX961/MAX963/MAX964/MAX997, this variant omits the SHDN pin and associated circuitry. Its supply current remains at 5–7mA across the full temperature range. If low-power standby is required, consider MAX961EUA+T instead - but note its larger 8-pin μMAX package and different pinout.

What is the input common-mode voltage range of the MAX999AAUK+T?

The MAX999AAUK+T supports an input common-mode voltage range of –0.1V to VCC + 0.1V - a feature branded as Beyond-the-Rails™. This allows either input (IN+ or IN−) to be driven up to 100mV below GND or above VCC without false output inversion, provided the other input remains within that same range. This eliminates level-shifting circuitry in many sensor interface applications.

Can the MAX999AAUK+T drive standard TTL or CMOS logic directly?

Yes, the MAX999AAUK+T provides TTL/CMOS-compatible outputs. At +5V supply and +125°C, it guarantees VOH ≥ VCC – 0.55V (≥4.45V) and VOL ≤ 0.55V - sufficient to meet VIH(min) and VIL(max) thresholds of standard 5V TTL and CMOS families. No external pull-up is required for logic-level compatibility, though one may be used for open-drain flexibility.

Is there a complementary output available on the MAX999AAUK+T?

No, the MAX999AAUK+T provides only a single active-high output (pin 5, Q). It does not include a complementary (Q̅) output, unlike MAX961 or MAX963. The device is a single comparator with unidirectional output logic - intended for applications where only one decision state needs to be asserted, such as threshold alarms or clock regeneration.