Analog Devices Inc./Maxim Integrated MAX9109EXT+T

Overview

The MAX9109EXT+T from Maxim Integrated is a single, high-speed, low-power TTL-compatible voltage comparator with internal latch and 25ns propagation delay at 10mV overdrive, operating from a +4.5V to +5.5V supply. It features 500µV typical input offset voltage, 2mV internal hysteresis, and wide input common-mode range (–0.2V to V_CC – 1.5V), enabling use in battery-powered threshold detection and zero-crossing circuits.

For engineers reviewing the MAX9109EXT+T datasheet, MAX9109EXT+T pinout, MAX9109EXT+T application, or MAX9109EXT+T equivalent, this device is selected for precision timing-critical analog-to-digital interface stages, infrared data receivers requiring sub-microamp quiescent current, and space-constrained latched comparator functions where SC70-6 footprint and TTL-level output drive are mandatory.

Technical Context

The MAX9109EXT+T implements a bipolar comparator core with fixed 2mV input-referred hysteresis to suppress oscillation during slow input transitions, eliminating external feedback components. Its latch-enable (LE) input controls transparent vs. stored operation, with 2ns setup/hold times and TTL-compatible VIH/VIL thresholds (2.0V/0.8V).

Designed for single-supply systems, it accepts inputs down to –0.2V relative to GND and up to V_CC – 1.5V, while delivering VOH ≥ 3.0V at 100µA and VOL ≤ 0.6V at 3.2mA - ensuring robust interfacing with 5V TTL logic without pull-ups.

Key Specifications

Pinout & Package

The MAX9109EXT+T is packaged in a 6-pin SC70 (X6S-1) surface-mount package measuring 2.0mm × 1.25mm × 0.9mm, optimized for ultra-dense PCB layouts in portable electronics.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM393DR2G and TLV3501CDR, the MAX9109EXT+T uniquely combines latch functionality, 25ns speed, built-in 2mV hysteresis, and TTL output drive in a 6-pin SC70 package-making it irreplaceable for space-constrained, synchronized threshold detection where deterministic timing and noise immunity are co-required.

Availability

The MAX9109EXT+T is available at Aetrix Electronics and suitable for battery-powered infrared receivers, A/D converter interface circuits, and zero-crossing detectors requiring stable component supply and RoHS-compliant packaging.

Supply support for MAX9109EXT+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 industrial, communications, and consumer applications.

The MAX9107/MAX9108/MAX9109 family delivers high-speed, low-power, latch-capable comparators targeting compact, battery-sensitive systems needing TTL compatibility and noise-immune decision-making.

FAQ

What is the maximum operating temperature range for the MAX9109EXT+T?

The MAX9109EXT+T is fully specified and guaranteed over the industrial temperature range of –40°C to +85°C. All electrical parameters-including propagation delay, offset voltage, and hysteresis-are tested and validated across this full range. The device uses a bipolar process and is rated for continuous operation at +85°C ambient without derating, making it suitable for enclosed industrial enclosures and automotive under-hood auxiliary modules where thermal management is constrained.

Does the MAX9109EXT+T require external pull-up resistors on its output?

No, the MAX9109EXT+T does not require external pull-up resistors. Its output is TTL-compatible and actively drives high to ≥3.0V (at 100µA load) and low to ≤0.6V (at 3.2mA load), matching standard 5V TTL logic voltage levels. This eliminates the need for external components, reduces BOM count, and avoids timing delays introduced by RC time constants-critical for maintaining the device's 25ns propagation delay specification in high-speed applications like infrared data links.

How does the internal latch in the MAX9109EXT+T function during operation?

The internal latch in the MAX9109EXT+T is controlled by the LE (Latch Enable) pin. When LE is low, the comparator operates transparently-the output follows input changes with 25ns delay. When LE transitions high, the instantaneous output state is captured and held, regardless of subsequent input movement. Setup and hold times are both 2ns, enabling synchronization to system clocks as fast as 250MHz. This behavior is confirmed in the MAX9109EXT+T datasheet Figure 2 and is exclusive to the MAX9109 variant-not present in MAX9107/MAX9108.

Can the MAX9109EXT+T accept input voltages below ground?

Yes, the MAX9109EXT+T supports input common-mode voltages as low as –0.2V relative to GND, verified per the Electrical Characteristics table (VCMR min = –0.2V). This allows direct interfacing with sensors or signal sources that swing slightly negative-such as transformer-coupled AC signals or op-amp outputs with minor phase inversion artifacts-without clamping diodes or level-shifting circuitry. However, absolute minimum input voltage is –0.3V (per Absolute Maximum Ratings), so sustained operation below –0.2V is not guaranteed.

What is the purpose of the 2mV internal hysteresis in the MAX9109EXT+T?

The 2mV internal hysteresis in the MAX9109EXT+T prevents output oscillation when input signals transition slowly through the decision threshold-common in noisy environments or with high-impedance sources. It creates two distinct trip points (VTRIP+ and VTRIP–), separated by 2mV, ensuring clean, bounce-free switching without external feedback resistors. This hysteresis is factory-trimmed and stable over temperature, directly contributing to the MAX9109EXT+T's reliability in threshold detectors, zero-crossing circuits, and line receivers where EMI immunity is essential.