Analog Devices Inc./Maxim Integrated MAX40111ANT+

Overview

MAX40111ANT+ from Maxim Integrated is a precision, low-noise, rail-to-rail input/output operational amplifier optimized for high-dynamic-range signal conditioning in space-constrained systems. It delivers 15MHz gain-bandwidth, 12.7nV/√Hz input voltage noise, <140μV max input offset voltage (at +25°C), and operates from 1.8V to 5.5V supply across –40°C to +125°C - making it ideal for SAR ADC driver circuits in portable medical sensors.

For engineers reviewing the MAX40111ANT+ datasheet, MAX40111ANT+ pinout, MAX40111ANT+ application, or MAX40111ANT+ equivalent, key selection considerations include its sub-1ms power-up autocalibration, ultra-low input bias current (<12pA at +85°C), shutdown recovery time (<30μs), and WLP package compatibility with photodiode transimpedance and active filter designs.

Technical Context

The MAX40111ANT+ employs a proprietary CMOS input stage with an integrated ultra-quiet charge pump that generates an internal rail 1V above VDD to power the PMOS differential pair - eliminating crossover distortion without external components. This architecture enables true rail-to-rail input operation extending 100mV beyond supply rails and maintains low THD+N (–105dB) at 10kHz.

Its on-chip power-on auto-calibration reduces input offset voltage to ≤30μV at +25°C and retains trim settings after shutdown exit. The active-low SHDN pin supports logic-level independence (VIH = 1.3V, VIL = 0.5V), enabling direct interfacing with 1.8V/3.3V microcontrollers regardless of VDD.

Key Specifications

Pinout & Package

MAX40111ANT+ is housed in a 6-bump wafer-level package (WLP) with 0.4mm pitch, footprint code N60T1+1, and land pattern per Application Note 1891. Thermal resistance θJA = 95.15°C/W on a four-layer board.

Key Features

Applications

Equivalent & Alternatives

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

Compared with OPA333AIDBVR and ADA4522-1ARMZ, the MAX40111ANT+ uniquely balances 15MHz bandwidth, sub-1ms calibration, 1μA shutdown, and 0.4mm-pitch WLP - making it the only option meeting simultaneous requirements for portable medical ADC drivers and photodiode TIAs.

Availability

MAX40111ANT+ is available at Aetrix Electronics and suitable for wearable devices, home medical diagnostics, and industrial IoT sensor nodes requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX40111ANT+ 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 high-performance analog and mixed-signal ICs for demanding industrial, medical, and communications applications - emphasizing precision, low power, and robustness.

The MAX40111ANT+ belongs to Maxim's precision op-amp family targeting ultra-low-noise, rail-to-rail signal conditioning in battery-powered and thermally challenging environments - specifically engineered for medical sensor front-ends and high-resolution data acquisition.

FAQ

What is the maximum capacitive load the MAX40111ANT+ can drive while remaining stable?

The MAX40111ANT+ is specified to remain stable with capacitive loads up to 300pF without external compensation, as confirmed in the Electrical Characteristics table under "Capacitive Loading Stability." This makes it suitable for driving ADC input filters and long PCB traces in compact layouts. For loads exceeding 300pF, a series resistor (≥50Ω) at the output is recommended to isolate capacitance and preserve phase margin. The device's internal compensation is optimized for this range and does not require external components for standard use cases.

Does the MAX40111ANT+ require external components for its power-on auto-calibration routine?

No, the MAX40111ANT+ performs full input offset voltage autocalibration internally on every power-up event - no external capacitors, resistors, or timing components are needed. The process completes in less than 1ms and places IN+, IN-, and OUT in high-impedance state during calibration. This self-contained feature eliminates manual trimming and ensures consistent ≤30μV VOS at +25°C across units and over time, directly supporting repeatable performance in production medical devices.

Can the MAX40111ANT+ operate from a 1.7V supply as stated in some features lists?

The MAX40111ANT+ is guaranteed to operate from 1.8V to 5.5V across –40°C to +125°C, per Absolute Maximum Ratings and Electrical Characteristics tables. While the Benefits section notes "Supply Voltage Range: 1.7V to 5.5V", this 1.7V value applies only to the 0°C to +70°C commercial temperature range (see Electrical Characteristics footnote). For industrial and automotive applications requiring –40°C operation, the minimum valid supply is 1.8V - using 1.7V may result in undefined behavior or failure to calibrate.

How does the internal charge pump in the MAX40111ANT+ affect power supply noise sensitivity?

The internal charge pump in the MAX40111ANT+ operates at high frequency (>10MHz) and is decoupled from the analog signal path, resulting in negligible contribution to output noise or PSRR degradation. Measured PSRR is 78–95dB across 10Hz–100kHz, confirming effective rejection of supply ripple. The pump draws minimal additional current (included in the 750μA typical IDD spec) and requires no external bypassing - its ultra-quiet design ensures it remains transparent to system-level noise budgets in sensitive biosignal chains.

Is the shutdown mode of the MAX40111ANT+ compatible with 1.2V GPIOs?

No - the MAX40111ANT+ SHDN pin requires VIH ≥ 1.3V and VIL ≤ 0.5V, as specified in the Logic Input DC Characteristics table. A 1.2V GPIO cannot reliably assert logic high (VIH threshold unmet), risking incomplete shutdown activation. For 1.2V systems, a level-shifter or pull-up to ≥1.3V is required. The pin's logic independence from VDD means it works with 1.8V/3.3V controllers even when VDD = 5.5V, but does not extend down to 1.2V logic families.