Analog Devices Inc./Maxim Integrated MAX4166EUA

Overview

MAX4166EUA from Maxim Integrated is a single-channel, rail-to-rail input/output operational amplifier with shutdown control, designed for high-output-drive precision analog signal conditioning in low-voltage battery-powered systems. It delivers ±80mA output current, operates from +2.7V to +6.5V single supply, features 5MHz gain-bandwidth product, 250µV typical offset voltage, and consumes only 1.2mA quiescent current - enabling direct headphone/speaker driver applications without external boost stages.

For engineers reviewing the MAX4166EUA datasheet, MAX4166EUA pinout, MAX4166EUA application, or MAX4166EUA equivalent, this page provides verified technical context, package-specific pin mapping for the 8-pin µMAX package, real-world application cards for portable audio and signal buffering, and two validated alternative op amps with documented functional trade-offs.

Technical Context

The MAX4166EUA employs a dual-input-stage architecture (NPN/PNP) enabling rail-to-rail common-mode input range extending 0.25V beyond VEE and VCC, with seamless transition near mid-supply to minimize CMRR degradation. Its output stage supports rail-to-rail swing - guaranteed within 430mV of VCC at 25Ω load (VCC = 5V) and within 25mV of VEE under light loads.

It integrates an active-low SHDN pin that reduces supply current to 38µA per amplifier (VCC = 3V) while placing the output in high-impedance state, with 1µs enable time and 5µs power-up settling. The device is unity-gain stable driving capacitive loads up to 250pF and exhibits no phase reversal when overdriven.

Key Specifications

Pinout & Package

The MAX4166EUA is housed in an 8-pin µMAX package (3.0mm × 3.0mm × 1.1mm, 0.65mm pitch), optimized for space-constrained portable designs. Pin 1 is marked by a dot; pin numbering follows standard counter-clockwise orientation from top-left corner.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-output-drive, rail-to-rail op amp applications.

Compared with OPA2340UA and AD8676ARMZ, the MAX4166EUA uniquely combines shutdown capability, 80mA drive, and µMAX packaging - making it the only option among the three suitable for space-constrained, battery-powered audio drivers requiring low-quiescent-power sleep states.

Availability

MAX4166EUA is available at Aetrix Electronics and suitable for portable audio systems, battery-powered instrumentation, and low-voltage industrial sensor interfaces requiring stable component supply and long-term manufacturability.

Supply support for MAX4166EUA 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) is a semiconductor company specializing in high-performance analog and mixed-signal ICs for power, interface, sensing, and timing applications.

The MAX4165–MAX4169 family was engineered specifically for portable, low-voltage systems needing precision amplification with high output current - targeting audio, sensor signal chains, and compact industrial controls where space and battery life are critical.

FAQ

What is the maximum capacitive load the MAX4166EUA can drive stably?

The MAX4166EUA is unity-gain stable driving capacitive loads up to 250pF without external compensation. This is confirmed in the datasheet's AC Electrical Characteristics table and Typical Operating Characteristics (Figure 8). Exceeding 250pF may cause peaking or oscillation unless an isolation resistor (e.g., 39Ω) is added in series with the output, as demonstrated in Figure 10. For loads >250pF, verify stability under actual operating conditions including temperature and supply voltage.

Does the MAX4166EUA support true rail-to-rail output swing at full load?

The MAX4166EUA guarantees rail-to-rail output swing only under light loads (e.g., RL ≥ 100kΩ). At full load (25Ω), the output is specified to swing within 430mV of VCC and 160mV of VEE when VCC = 5V - meaning it reaches ~4.57V high and ~0.16V low. This is sufficient for most portable audio applications but does not achieve true 0–5V swing at 25Ω. Load-dependent headroom is explicitly characterized in the DC Electrical Characteristics table.

What is the recommended power supply bypassing for the MAX4166EUA in µMAX package?

Per the Applications Information section, the MAX4166EUA requires local bypassing at the VCC pin: a 0.1µF ceramic capacitor in parallel with at least 1µF bulk capacitance (e.g., tantalum or aluminum electrolytic). Place both capacitors as close as possible to pins 3 (VEE) and 6 (VCC), with short, low-inductance traces. This minimizes supply impedance and prevents instability, especially during high-current transient output events like audio peaks.

Can the MAX4166EUA be used with dual supplies?

Yes, the MAX4166EUA operates from dual supplies ranging from ±1.35V to ±3.25V. Its rail-to-rail input and output stages function symmetrically around ground, and all specifications (e.g., offset voltage, PSRR, GBW) are validated across this dual-supply range. However, the shutdown feature remains referenced to VEE (not ground), so SHDN must be pulled below VEE + 0.8V to activate shutdown - requiring appropriate level translation in split-rail systems.

How does the input stage architecture affect common-mode rejection in the MAX4166EUA?

The MAX4166EUA uses complementary NPN/PNP input pairs that switch near VCC/2 to extend rail-to-rail common-mode range. This architecture causes a measurable reduction in CMRR (56dB min over temperature) within the transition region, as documented in the DC Electrical Characteristics table. Designers should avoid biasing the input near mid-supply in high-precision applications; instead, use input networks that shift common-mode voltage away from VCC/2 to maintain optimal CMRR performance.