Analog Devices Inc./Maxim Integrated MAX8875EUK25+T

Overview

MAX8875EUK25+T from Maxim Integrated is a 2.5V fixed-output, 150mA low-dropout linear regulator with P-channel MOSFET pass device, 85µA no-load quiescent current, and active-low open-drain Power-OK (POK) output. It operates from +2.5V to +6.5V input, delivers ±1% output accuracy over temperature, and is optimized for battery-powered portable electronics requiring stable low-voltage rail generation.

For engineers reviewing the MAX8875EUK25+T datasheet, MAX8875EUK25+T pinout, MAX8875EUK25+T application, or MAX8875EUK25+T equivalent, key selection criteria include dropout voltage at 150mA (165mV), reverse-battery protection, thermal shutdown (170°C), 1µF ceramic output capacitor support, and SOT23-5 package compatibility in space-constrained designs.

Technical Context

The MAX8875EUK25+T integrates a 1.25V bandgap reference, error amplifier, internal resistor divider, and P-channel MOSFET pass transistor (R_DS(ON) ≈ 1.1Ω) to regulate 2.5V output with load-independent quiescent current. Its POK comparator monitors V_OUT against a hysteresis threshold (−5.3% to −8.5% depending on load condition) and asserts low when out-of-regulation.

Shutdown logic disables regulation when SHDN is pulled low, reducing supply current to ≤1µA. Thermal protection activates at 170°C junction temperature with 20°C hysteresis, enabling pulsed operation under sustained overload. Reverse-battery protection limits reverse current to ≤1mA when VIN or SHDN falls below GND.

Key Specifications

Pinout & Package

MAX8875EUK25+T is housed in a 5-pin SOT23-5 package with exposed pad for thermal dissipation. The GND pin serves dual electrical and thermal functions and must be soldered to a large PCB copper area.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX8875EUK25+T, MAX8885EUK25+T trades minimal quiescent current increase for broader capacitor compatibility, while MCP1700-2502E/TO sacrifices POK and package size for lower IQ - neither offers drop-in replacement without layout or firmware changes.

Availability

MAX8875EUK25+T is available at Aetrix Electronics and suitable for cellular telephones, palmtop computers, and electronic planners requiring stable component supply, long-term lifecycle support, and guaranteed parametric performance across industrial temperature ranges.

Supply support for MAX8875EUK25+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 semiconductor company specializing in high-performance analog, mixed-signal, and power-management ICs for industrial, communications, and consumer applications.

The MAX8875 series was designed specifically for battery-powered portable equipment needing ultra-low quiescent current, small footprint, and integrated power-monitoring - targeting PCS phones, modems, and handheld instrumentation.

FAQ

What is the minimum input voltage required for MAX8875EUK25+T to maintain regulation?

The MAX8875EUK25+T requires VIN ≥ VOUT + dropout voltage. At 150mA load, dropout is 165mV, so minimum VIN = 2.5V + 0.165V = 2.665V. Below this, the output drops proportionally. The device remains functional down to VIN = 2.5V but enters dropout, where regulation is no longer guaranteed. This value is confirmed in the Electrical Characteristics table under "Dropout Voltage" for IOUT = 150mA.

Does MAX8875EUK25+T require an external pull-up resistor on the POK pin?

Yes, MAX8875EUK25+T's POK pin is an open-drain N-channel MOSFET output and requires an external pull-up resistor to generate a valid logic-high level. A 100kΩ resistor to OUT is recommended per the Typical Operating Circuit and Pin Description. Without it, POK cannot drive high and will remain floating or weakly pulled low through leakage, making power-fail detection unreliable.

Can MAX8875EUK25+T be used with a 10µF output capacitor instead of the specified 1µF?

Yes, MAX8875EUK25+T supports 10µF ceramic output capacitors - doing so improves PSRR, reduces output noise, and enhances load-transient response. The datasheet explicitly recommends larger values "to reduce noise and improve load-transient response, stability, and power-supply rejection." No stability issues arise; the 1µF minimum is for worst-case ESR and temperature conditions, not an upper limit.

What protection features does MAX8875EUK25+T include beyond thermal shutdown?

MAX8875EUK25+T includes short-circuit protection (indeterminate duration), reverse-battery protection (limits reverse current to ≤1mA), and current limiting (typical 390mA). These operate independently: reverse-battery protection engages when VIN or SHDN falls below GND; current limit activates before thermal shutdown under overload; and short-circuit protection sustains indefinite grounding of OUT without damage - all verified in Absolute Maximum Ratings and Detailed Description sections.

Is the 2.5V output voltage of MAX8875EUK25+T adjustable via external resistors?

No, MAX8875EUK25+T has a factory-trimmed, fixed 2.5V output achieved through internal resistor feedback. The device lacks FB or ADJ pins, and the datasheet confirms preset voltages are "factory-set" with no provision for external adjustment. For adjustable versions, Maxim offers other families (e.g., MAX8860), but MAX8875EUK25+T is strictly fixed-output and not configurable.