Analog Devices Inc./Maxim Integrated MAX8891EXK33+T

Overview

MAX8891EXK33+T from Maxim Integrated is a fixed-output, low-dropout linear regulator delivering 3.3V at up to 150mA with 120mV dropout at 120mA load, 40µA ground current, and 65dB PSRR at 10kHz-designed for space-constrained battery-powered systems such as Bluetooth radios and digital cameras.

For engineers reviewing the MAX8891EXK33+T datasheet, MAX8891EXK33+T pinout, MAX8891EXK33+T application, or MAX8891EXK33+T equivalent, key selection criteria include guaranteed 150mA output, SC70 package footprint, 1µF ceramic capacitor stability, shutdown current <1µA, and thermal/overcurrent protection.

Technical Context

The MAX8891EXK33+T uses an internal p-channel MOSFET pass transistor (R_DS(ON) ≈ 1Ω) enabling low dropout and minimal ground current across load and temperature. Its bandgap reference (1.225V) feeds an error amplifier that controls gate drive to maintain regulation without base-drive losses typical of PNP-based LDOs.

It operates from 2V to 6V input, delivers ±3% output voltage accuracy over load (100μA–80mA) and temperature (−40°C to +85°C), and features integrated thermal shutdown (160°C trip, 10°C hysteresis) and current limiting (200mA).

Key Specifications

Pinout & Package

Supplied in a 5-pin SC70 package (2.0mm × 1.25mm, 0.65mm pitch), optimized for ultra-compact layouts. Thermal performance relies on GND pin connection to a large copper pour.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LDO regulator applications.

Compared with TPS78233DRVR and MCP1700-3302E/TO, the MAX8891EXK33+T uniquely balances ultra-small SC70 size, robust protection (thermal + current limit), and sub-1µA shutdown-making it optimal for miniaturized, safety-aware portable designs where board space and reliability are prioritized over raw current headroom.

Availability

MAX8891EXK33+T is available at Aetrix Electronics and suitable for Bluetooth portable radios, digital cameras, portable medical sensors, and industrial handheld terminals requiring stable component supply, RoHS-compliant packaging, and guaranteed −40°C to +85°C operation.

Supply support for MAX8891EXK33+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) is a U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and power-management ICs for industrial, communications, and consumer applications.

The MAX8891/MAX8892 product line was designed specifically for space-constrained, battery-powered portable electronics requiring ultra-low quiescent current, small-footprint LDO regulation with robust protection and ceramic-capacitor compatibility.

FAQ

What is the output voltage tolerance of the MAX8891EXK33+T over temperature and load?

The MAX8891EXK33+T guarantees ±3% output voltage accuracy across load current (100μA to 80mA) and full operating temperature range (−40°C to +85°C), as specified in the Electrical Characteristics table. At +25°C, typical deviation is within ±0.5%, and the device maintains tight regulation due to its precision 1.225V bandgap reference and low-drift error amplifier. This accuracy ensures reliable operation for 3.3V I/O interfaces and analog sensor biasing in the MAX8891EXK33+T's target applications.

Does the MAX8891EXK33+T require external feedback resistors?

No, the MAX8891EXK33+T does not require external feedback resistors. It is a fixed-output variant with factory-trimmed 3.3V regulation implemented via internal resistor divider. Unlike the adjustable MAX8892, the MAX8891EXK33+T uses pin 4 as N.C. (not internally connected), eliminating external component count and layout complexity. This simplifies design and improves long-term stability by avoiding resistor drift and parasitic effects associated with external networks in the MAX8891EXK33+T.

What is the minimum input voltage required for regulation at full 150mA load?

The minimum input voltage for regulation at 150mA load is determined by dropout voltage. While the MAX8891EXK33+T specifies 120mV dropout at 120mA, its datasheet shows ~135mV at 150mA for 3.3V output. Thus, VIN(min) = 3.3V + 0.135V = 3.435V. The device remains functional down to 2V input but cannot regulate below this dropout threshold. This value is critical for battery end-of-life planning in systems using the MAX8891EXK33+T with single-cell Li-ion or Li-poly sources.

Can the MAX8891EXK33+T be used with X5R ceramic capacitors?

Yes, the MAX8891EXK33+T is fully compatible with X5R ceramic capacitors for both input and output. The datasheet explicitly confirms stability with 1µF X5R or X7R dielectrics across the full −40°C to +85°C operating range. Unlike Z5U or Y5V types, X5R exhibits minimal capacitance and ESR shift with temperature, ensuring consistent loop stability and transient response. This compatibility directly supports the MAX8891EXK33+T's design goal of low-cost, space-efficient decoupling without ESR tuning.

How does thermal shutdown behave during continuous overload in the MAX8891EXK33+T?

The MAX8891EXK33+T enters thermal shutdown at 160°C junction temperature and recovers when junction cools to 150°C (10°C hysteresis). Under continuous overload, this results in pulsed output-regulation cycles on/off-preventing permanent damage while allowing limited functionality. The GND pin serves as the primary thermal path, so PCB layout with adequate copper area is essential to sustain average power. This behavior is documented in the Thermal-Overload Protection section and applies identically across all MAX8891 variants including the MAX8891EXK33+T.