Analog Devices Inc./Maxim Integrated MAX4105ESA

Overview

MAX4105ESA from Maxim Integrated is a unity-gain-unstable, high-speed voltage-feedback operational amplifier compensated for minimum closed-loop gain of +5V/V, delivering 410MHz -3dB bandwidth, 1400V/µs slew rate, and 2.1nV/√Hz input voltage noise density. It operates on ±3.5V to ±5.5V dual supplies, draws 27mA quiescent current, and drives ±70mA into loads - ideal for video ADC preamplification and high-fidelity cable driver applications.

For engineers reviewing the MAX4105ESA datasheet, MAX4105ESA pinout, MAX4105ESA application, or MAX4105ESA equivalent, key selection criteria include minimum stable gain (+5V/V), bandwidth vs. gain trade-off, output drive capability under capacitive load, differential gain/phase error (0.02%/0.02°), and SOT23-5 layout constraints for RF/video signal integrity.

Technical Context

The MAX4105ESA uses a voltage-feedback architecture optimized for fixed-gain +5V/V configurations, with internal compensation limiting stability to gains ≥+5V/V. Its 410MHz bandwidth and 100MHz 0.1dB gain flatness support wideband video and pulse-amplification tasks requiring minimal amplitude distortion across NTSC/PAL baseband spectra.

It features rail-to-rail output swing (±3.7V into 100kΩ) and maintains low distortion (–88dBc SFDR at 5MHz, RL = 100Ω) while delivering ±70mA peak output current - enabling direct driving of 75Ω coaxial lines with back-termination and active filter stages in high-speed data acquisition systems.

Key Specifications

Pinout & Package

MAX4105ESA is housed in a 5-pin SOT23-5 package with exposed pad (not electrically connected), rated for –40°C to +85°C operation. The package footprint measures 2.9mm × 1.6mm × 1.1mm (L × W × H), compatible with standard reflow profiles and high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed op amp applications.

Compared with MAX4304ESA and THS3201DGN, the MAX4105ESA offers superior slew rate per unit bandwidth and optimal noise-performance balance at +5V/V gain, making it the preferred choice for high-fidelity, fixed-gain video and pulse amplification where SOT23-5 size is critical.

Availability

MAX4105ESA is available at Aetrix Electronics and suitable for video ADC preamplification, high-speed pulse conditioning, and 75Ω coaxial cable driving requiring stable component supply across industrial, broadcast, and medical imaging programs.

Supply support for MAX4105ESA 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 performance applications in communications, computing, and industrial systems.

The MAX4104/MAX4105/MAX4304/MAX4305 product line targets high-fidelity, wideband signal conditioning in video, telecom, and instrumentation - emphasizing low noise, low distortion, and compact packaging for space-constrained RF/analog front-ends.

FAQ

What is the minimum stable gain for MAX4105ESA, and why does it matter?

The MAX4105ESA is compensated for a minimum stable closed-loop gain of +5V/V. This means it will oscillate if configured for unity or lower gains. This design trades gain flexibility for higher bandwidth and slew rate at +5V/V - critical for video line drivers and fixed-gain ADC buffers where predictable high-frequency response is prioritized over configurability. Using MAX4105ESA below +5V/V violates stability specifications and risks oscillation.

Can MAX4105ESA drive a 75Ω coaxial cable directly?

Yes, MAX4105ESA can directly drive a 75Ω coaxial cable when used in a back-terminated configuration: place a 75Ω resistor from OUT to ground at the amplifier side and match the far-end termination. Its ±70mA output current and low output impedance (<1Ω at DC, rising to ~5Ω at 100MHz) ensure proper signal integrity and minimal reflections. Layout must follow high-speed guidelines including microstrip routing and tight bypassing.

What is the maximum capacitive load MAX4105ESA can drive without oscillation?

MAX4105ESA remains stable driving up to 10pF of capacitive load without external compensation. Beyond that, peaking and potential oscillation occur due to phase margin degradation. For loads >10pF (e.g., long PCB traces or ADC input capacitance), an isolation resistor (RISO) of 10–25Ω must be placed in series with the output - value depends on gain and load capacitance per Figure 5 in the datasheet. RISO mitigates resonance but reduces delivered voltage.

How does MAX4105ESA's noise performance compare to MAX4104ESA?

Both MAX4105ESA and MAX4104ESA share identical 2.1nV/√Hz input voltage noise density and 3.1pA/√Hz current noise density. However, MAX4105ESA's higher minimum gain (+5V/V vs. +1V/V) results in higher total output-referred noise in low-gain applications. At +5V/V, MAX4105ESA delivers better signal-to-noise ratio for medium-gain stages where its 410MHz bandwidth suppresses out-of-band noise more effectively than MAX4104ESA's 625MHz response at +1V/V.

Is MAX4105ESA pin-compatible with other devices in the MAX4104/MAX4105/MAX4304/MAX4305 family?

Yes, all four devices - MAX4104ESA, MAX4105ESA, MAX4304ESA, and MAX4305ESA - share identical 5-pin SOT23-5 pinouts (VEE, IN–, IN+, OUT, VCC) and SO-8 footprints. This allows drop-in replacement during prototyping or qualification when gain, bandwidth, and slew rate requirements shift - provided the new device's minimum gain matches the circuit topology. No PCB changes are needed for package-level substitution.