Analog Devices Inc./Maxim Integrated MAX8891EXK28+T

Overview

MAX8891EXK28+T from Maxim Integrated is a fixed-output, low-dropout linear regulator delivering 2.8V at up to 150mA with 120mV dropout at 120mA load, 40µA ground current, and 65dB PSRR at 10kHz-designed for space-constrained battery-powered devices such as Bluetooth radios and digital cameras.

For engineers reviewing the MAX8891EXK28+T datasheet, MAX8891EXK28+T pinout, MAX8891EXK28+T application, or MAX8891EXK28+T equivalent, key selection criteria include guaranteed 150mA output, SC70-5 package footprint, 1µF ceramic capacitor stability, thermal/overcurrent protection, and shutdown current <1µA.

Technical Context

The MAX8891EXK28+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 output regulation without external feedback components.

It operates from 2V to 6V input, supports stable operation with only 1µF input and output ceramic capacitors (X7R/X5R), and integrates shutdown logic, thermal shutdown at +160°C with 10°C hysteresis, and current limiting at 200mA-enabling robust operation in portable equipment with variable load transients.

Key Specifications

Pinout & Package

Supplied in a 5-pin SC70 package (2.0mm × 1.25mm × 0.95mm height), optimized for minimal PCB area and thermal performance via GND pad conduction.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700T-2802E/TT and XC6206P282MR-G, the MAX8891EXK28+T uniquely balances 120mV dropout, 40µA ground current, and 65dB PSRR in a 5-pin SC70-making it optimal for RF and imaging subsystems where both efficiency and noise rejection are critical.

Availability

MAX8891EXK28+T is available at Aetrix Electronics and suitable for Bluetooth radios, digital cameras, cellular handsets, and portable audio devices requiring stable component supply, consistent parametric performance, and RoHS-compliant packaging.

Supply support for MAX8891EXK28+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 markets.

The MAX8891/MAX8892 product line delivers high-PSRR, low-dropout LDOs optimized for battery-powered portable electronics-emphasizing small footprint, low quiescent current, and ceramic-capacitor compatibility.

FAQ

What is the output voltage tolerance of the MAX8891EXK28+T?

The MAX8891EXK28+T has a guaranteed output voltage accuracy of ±3% over load (100μA to 80mA) and temperature (-40°C to +85°C), with typical deviation under ±0.4% at room temperature. This tolerance is factory-trimmed and does not require external calibration. The MAX8891EXK28+T maintains this specification using its internal 1.225V bandgap reference and precision error amplifier-ensuring reliable 2.8V regulation for sensitive analog circuits.

Does the MAX8891EXK28+T require external feedback resistors?

No, the MAX8891EXK28+T does not require external feedback resistors-it is a fixed-output variant with the 2.8V setting internally trimmed and verified during production. Unlike the adjustable MAX8892, the MAX8891EXK28+T uses an integrated resistor divider, eliminating component count and layout complexity. This simplifies design validation and improves long-term stability, as the MAX8891EXK28+T's output voltage remains unaffected by resistor drift or parasitic leakage.

What is the maximum input voltage rating for the MAX8891EXK28+T?

The MAX8891EXK28+T has an absolute maximum input voltage rating of +7V, but its recommended operating input voltage range is 2V to 6V. Operation above 6V risks exceeding safe power dissipation limits, especially at high ambient temperatures or heavy loads. For example, at 150mA output and 6V input, power dissipation reaches 480mW-requiring careful thermal design. The MAX8891EXK28+T's internal thermal shutdown activates at +160°C junction temperature to prevent damage under overvoltage or overload conditions.

Can the MAX8891EXK28+T be used with X5R or Y5V ceramic capacitors?

The MAX8891EXK28+T is stable with X5R and X7R ceramic capacitors (1µF typical), but Y5V dielectrics are not recommended due to large capacitance and ESR variation over temperature. At temperatures below -10°C, Y5V capacitors may fall below the stable ESR region shown in the MAX8891EXK28+T's Typical Operating Characteristics graph, risking oscillation. For full-temperature-range reliability, use 1µF X5R/X7R capacitors-verified in the MAX8891EXK28+T's characterization-and avoid Y5V unless derated to ≥2.2µF with thorough board-level testing.

How does the shutdown function operate on the MAX8891EXK28+T?

The MAX8891EXK28+T features an active-low SHDN pin (Pin 3) that disables the internal voltage reference, error amplifier, gate driver, and pass transistor when pulled ≤0.4V, placing the OUT pin in high-impedance state and reducing supply current to <1µA. The SHDN input bias current is only 0.006µA at +25°C, minimizing loading on control logic. To enable normal operation, tie SHDN to IN or drive it >1.5V. The MAX8891EXK28+T's fast startup time (~10µs) ensures rapid reactivation after wake-up signals.