Analog Devices Inc./Maxim Integrated MAX8891EXK15+T

Overview

The MAX8891EXK15+T from Maxim Integrated is a fixed-output, low-dropout linear regulator delivering 1.5V at up to 150mA with 120mV dropout at 120mA load, 40µA ground current, and 65dB PSRR at 10kHz - optimized for battery-powered portable electronics requiring minimal PCB area and stable low-voltage biasing.

For engineers reviewing the MAX8891EXK15+T datasheet, MAX8891EXK15+T pinout, MAX8891EXK15+T application, or MAX8891EXK15+T equivalent, this device serves as a space-constrained, high-PSRR LDO for voltage-sensitive subsystems in handheld radios, digital cameras, and PDA logic rails where input-to-output headroom and quiescent power are critical selection criteria.

Technical Context

The MAX8891EXK15+T uses an internal p-channel MOSFET pass transistor (R_DS(ON) ≈ 1Ω) to achieve low dropout and eliminate base-drive current loss, enabling stable operation down to 2V input while maintaining 1.5V output. Its bandgap reference (1.225V) and error amplifier regulate against load and line variations without external feedback components.

It operates with only 1µF ceramic input and output capacitors, supports shutdown with <1µA supply current, and integrates overcurrent and thermal protection (trip at +160°C, 10°C hysteresis). The SC70-5 package places GND as both electrical return and primary thermal path.

Key Specifications

Pinout & Package

Package: 5-pin SC70 (2.0mm × 1.25mm × 0.9mm), RoHS-compliant, lead-free, thermally enhanced with exposed pad not present - GND pin serves dual role as electrical reference and primary heat conduction path to PCB copper.

Key Features

Applications

Equivalent & Alternatives

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

Compared with the MAX8891EXK15+T, the XC6206P152MR trades dropout performance for lower IQ in ultra-low-power roles, while the AP2112K-1.5TRG1 offers higher current headroom at the cost of PCB area and dropout efficiency - making the MAX8891EXK15+T optimal for size- and noise-sensitive 150mA portable LDO applications.

Availability

MAX8891EXK15+T is available at Aetrix Electronics and suitable for Bluetooth portable radios, digital cameras, and PDA logic rails requiring stable component supply, long-lifecycle availability, and guaranteed RoHS compliance.

Supply support for MAX8891EXK15+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) designs precision analog, mixed-signal, and power management ICs for demanding industrial, automotive, and portable applications.

The MAX8891/MAX8892 product line delivers high-PSRR, low-I_Q LDOs optimized for battery-powered consumer electronics where minimal board area, extended runtime, and noise immunity are critical design constraints.

FAQ

What is the maximum input voltage rating for the MAX8891EXK15+T?

The MAX8891EXK15+T has an absolute maximum input voltage of +7V referenced to GND, but its specified operating input range is 2V to 6V. Operation above 6V risks exceeding safe power dissipation limits and may trigger thermal shutdown. For reliable 1.5V output regulation, VIN must remain ≥1.62V (1.5V + 120mV dropout) under full 120mA load - the MAX8891EXK15+T is not rated for input voltages beyond 6V in normal operation.

Does the MAX8891EXK15+T require an external feedback resistor network?

No, the MAX8891EXK15+T does not require an external feedback resistor network. It is a factory-preset, fixed-output LDO delivering 1.5V with internal resistive division. Unlike the adjustable MAX8892 variant, the MAX8891EXK15+T uses pin 4 as a no-connect (N.C.) terminal - external resistors on that pin have no functional effect and must remain unconnected to ensure proper operation and stability.

Can the MAX8891EXK15+T be used with X5R ceramic capacitors?

Yes, the MAX8891EXK15+T is fully compatible with X5R ceramic capacitors for both input and output bypassing. The datasheet explicitly confirms that 1µF X5R or X7R dielectrics provide stable operation across the full -40°C to +85°C temperature range. X5R capacitors maintain sufficient capacitance and low ESR under bias and temperature variation, satisfying the regulator's stability requirements without needing larger values or alternative dielectrics.

What is the thermal shutdown behavior of the MAX8891EXK15+T?

The MAX8891EXK15+T activates thermal shutdown at +160°C junction temperature and exhibits 10°C hysteresis - it re-enables only after cooling to +150°C. During sustained overload, this results in pulsed output rather than latch-off, allowing self-recovery once ambient conditions improve. The SC70-5 package relies on PCB copper for heat spreading, so adequate GND pad area and thermal vias are essential to delay trip onset and maintain continuous operation under 150mA load at elevated ambient temperatures.

How does the MAX8891EXK15+T compare to the MAX8892 in terms of pin compatibility?

The MAX8891EXK15+T and MAX8892 share identical SC70-5 packaging and pinout numbering, but differ functionally at pin 4: MAX8891EXK15+T uses it as N.C., while MAX8892 uses it as FB. Though physically interchangeable, they are not functionally pin-compatible - populating a MAX8892-design board with MAX8891EXK15+T will leave FB floating (non-fatal but unused), while substituting MAX8892 into a MAX8891EXK15+T layout creates an unintended feedback path that disrupts regulation. Board-level replacement requires schematic and layout verification.