Analog Devices Inc./Maxim Integrated MAX8875EUK27+

Overview

MAX8875EUK27+ from Maxim Integrated is a 2.7V fixed-output, 150mA low-dropout linear regulator with P-channel MOSFET pass element, 85µA no-load quiescent current, and active-low open-drain Power-OK (POK) output. It operates from +2.5V to +6.5V input and delivers stable voltage for battery-powered portable electronics including cellular phones, modems, and palmtop computers.

For engineers reviewing the MAX8875EUK27+ datasheet, MAX8875EUK27+ pinout, MAX8875EUK27+ application, or MAX8875EUK27+ equivalent, key selection criteria include dropout voltage at 150mA (165mV), ±1% output accuracy, thermal shutdown (170°C), reverse-battery protection, and compatibility with 1µF ceramic output capacitors.

Technical Context

The MAX8875EUK27+ uses an internal 1.25V bandgap reference and error amplifier to regulate output via a 1.1Ω (typ) P-channel MOSFET pass transistor - eliminating base-drive current and enabling load-independent 85µA quiescent supply current. Its POK output is an open-drain N-channel MOSFET activated when VOUT falls >1% below nominal due to dropout, overcurrent, or thermal shutdown.

Shutdown is controlled by an active-low SHDN pin with 0.4V logic threshold and <1µA max shutdown current. The device integrates reverse-battery protection limiting reverse current to 1mA, thermal overload protection with 20°C hysteresis, and short-circuit protection with 160mA min / 600mA max current limit.

Key Specifications

Pinout & Package

The MAX8875EUK27+ is housed in a 5-pin SOT23-5 package with exposed pad for thermal enhancement. GND serves dual role as electrical ground and heatsink - requires connection to large copper area for optimal thermal performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-dropout regulator applications.

Compared with MAX8885EUK27+, the MAX8875EUK27+ delivers lower quiescent current and better noise/PSRR but requires strict 1µF ceramic capacitor implementation; versus MCP1700T-2702E/MB, it trades ultra-low IQ for integrated power monitoring and enable control essential in battery-critical systems.

Availability

MAX8875EUK27+ is available at Aetrix Electronics and suitable for cellular telephones, modems, and palmtop computers requiring stable component supply, long-term lifecycle support, and guaranteed parametric compliance across −40°C to +85°C.

Supply support for MAX8875EUK27+ 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, communications, computing, and consumer applications.

The MAX8875 series was developed specifically for battery-powered portable equipment demanding ultra-low quiescent current, small footprint, and integrated power-monitoring - targeting PCS phones, cordless handsets, and PCMCIA peripherals.

FAQ

What is the maximum input voltage rating for the MAX8875EUK27+?

The MAX8875EUK27+ has an absolute maximum input voltage of +7V referenced to GND, but its specified operating range is +2.5V to +6.5V. Exceeding +6.5V may cause functional instability or accelerated aging, even if within absolute ratings. For reliable operation in 6V battery systems, ensure VIN remains ≤6.5V under all conditions including charging transients.

Does the MAX8875EUK27+ require an external pull-up resistor on the POK pin?

Yes, the MAX8875EUK27+ POK pin is an open-drain N-channel MOSFET output and requires an external pull-up resistor to generate a logic-high signal when regulation is valid. A 100kΩ resistor to OUT is recommended per the datasheet; using a larger value reduces current consumption but increases susceptibility to noise, while smaller values increase static power draw without improving response time.

Can the MAX8875EUK27+ operate with a 10µF output capacitor instead of the recommended 1µF?

Yes, the MAX8875EUK27+ remains stable with a 10µF ceramic or tantalum output capacitor, and doing so improves PSRR, load-transient response, and output noise performance. However, the 1µF minimum is specified for guaranteed stability across temperature and process variation - larger capacitors are acceptable and beneficial, provided ESR stays within 0.2Ω for ceramics or ≤5Ω for tantalum types.

What happens to the POK output during shutdown of the MAX8875EUK27+?

The POK function is disabled during shutdown of the MAX8875EUK27+. When SHDN is pulled low, the internal regulator core powers down, and POK enters high-impedance state - it neither asserts nor de-asserts. This behavior prevents false reset signals during intentional power-down sequences and requires external logic to manage system reset coordination if both shutdown and power-good monitoring are needed.

Is reverse-battery protection active on both IN and SHDN pins of the MAX8875EUK27+?

Yes, reverse-battery protection in the MAX8875EUK27+ monitors polarity on both IN and SHDN pins independently. If either pin falls below GND potential, internal circuitry disconnects parasitic paths and limits reverse current to ≤1mA - protecting the device from damage during accidental battery reversal in handheld products where user-replaceable batteries are common.