Analog Devices Inc./Maxim Integrated MAX492CPA+

Overview

MAX492CPA+ from Maxim Integrated is a dual, micropower, single-supply rail-to-rail operational amplifier with 500kHz gain-bandwidth product, 150µA per amplifier quiescent current, and ±200µV input offset voltage. It operates from +2.7V to +6V (or ±1.35V to ±3V), delivers rail-to-rail output swing within 50mV of supplies into 100kΩ, and supports precision signal conditioning in battery-powered instrumentation and portable data acquisition systems.

For engineers reviewing the MAX492CPA+ datasheet, MAX492CPA+ pinout, MAX492CPA+ application, or MAX492CPA+ equivalent, this page provides verified technical context, package-specific pin functions, real-world design value of rail-to-rail I/O and low-noise operation, and two validated alternative op amps for low-voltage, micropower analog front-ends.

Technical Context

The MAX492CPA+ uses complementary NPN/PNP input stages to achieve rail-to-rail common-mode input range (VEE − 0.25V to VCC + 0.25V at +25°C), with no phase reversal beyond that range. Its folded-cascode architecture enables high DC accuracy (108dB large-signal voltage gain, 90dB CMRR) while maintaining unity-gain stability and driving ≥1nF capacitive loads.

Each amplifier features internal protection diodes (±0.7V differential limit) and offset-null capability only on the MAX495 variant - the MAX492CPA+ lacks external null pins. Its 25nV/√Hz input voltage noise and 0.2V/µs slew rate support precision low-frequency amplification without bandwidth compromise.

Key Specifications

Pinout & Package

MAX492CPA+ is housed in an 8-pin plastic DIP (dual in-line package) with 0.3-inch body width and through-hole mounting. Pin spacing is 0.1 inch (2.54mm), compatible with standard prototyping and PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV2462IDR and OPA2333AIDR, MAX492CPA+ uniquely balances ultra-low quiescent current (150µA), rail-to-rail I/O, and guaranteed no-phase-reversal behavior - making it optimal for cost-sensitive, battery-constrained analog front-ends where DC accuracy and fault resilience are co-prioritized.

Availability

MAX492CPA+ is available at Aetrix Electronics and suitable for portable ECG monitors, battery-powered pH meters, and wireless sensor node signal chains requiring stable component supply and long-lifecycle support.

Supply support for MAX492CPA+ 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, medical, and communications applications.

The MAX492/MAX494/MAX495 family was engineered specifically for micropower, single-supply rail-to-rail operation in battery-constrained instrumentation - prioritizing DC accuracy, low noise, and robustness over speed.

FAQ

What is the operating temperature range for MAX492CPA+?

The MAX492CPA+ is rated for 0°C to +70°C ambient operation, matching the 'C' grade designation in Maxim's ordering nomenclature. This range covers commercial-grade portable instrumentation and consumer medical devices. The device maintains specified DC performance - including ±200µV offset voltage and 150µA supply current - across this full range, with derated AC parameters above +25°C per the datasheet's -40°C to +85°C characterization tables.

Does MAX492CPA+ support rail-to-rail input and output simultaneously?

Yes, MAX492CPA+ supports true rail-to-rail input common-mode voltage (VEE − 0.25V to VCC + 0.25V at +25°C) and rail-to-rail output swing (within 50mV of VEE/VCC into 100kΩ). This simultaneous capability enables full dynamic range utilization in single-supply systems - for example, a 3V-powered MAX492CPA+ can accept and reproduce signals from 0V to 3V without clipping or level-shifting circuitry.

Can MAX492CPA+ drive capacitive loads without oscillation?

Yes, MAX492CPA+ is designed to drive capacitive loads ≥1nF stably. It remains unconditionally stable with up to 1000pF pure capacitance (RL = ∞) and supports >400pF even when sourcing ~100µA. For heavier loads (e.g., 10,000pF), adding a 47Ω series isolation resistor at the output restores phase margin without degrading DC accuracy - a key advantage over many competing CMOS rail-to-rail op amps.

Is external offset nulling possible on MAX492CPA+?

No, external offset nulling is not supported on MAX492CPA+. Unlike the single MAX495 (which has dedicated NULL1 and NULL2 pins), the dual MAX492CPA+ does not include offset-null terminals. Its ±200µV input offset voltage is factory-trimmed and fixed; system-level calibration must be performed digitally or via external potentiometer in the feedback network if tighter DC accuracy is required.

What is the maximum capacitive load MAX492CPA+ can drive while maintaining 0.1% settling?

MAX492CPA+ achieves 0.1% settling in <12µs with a 500pF load and 20kΩ resistive termination (Figure 7b), and in ~20µs with 1000pF and no resistive load (Figure 6). For 0.1% precision in buffered ADC applications, loads ≤500pF are recommended without added isolation; beyond that, a 47Ω series resistor restores full stability and sub-µs settling consistency.