Analog Devices Inc./Maxim Integrated MAX8840ELT25+

Overview

MAX8840ELT25+ from Maxim Integrated is a 2.5V fixed-output, ultra-low-noise, high-PSRR, low-dropout linear regulator delivering up to 150mA output current with 120mV dropout at 120mA load, 11µV_RMS output noise (100Hz–100kHz), and 78dB PSRR at 1kHz - designed for powering noise-sensitive analog circuitry in portable RF systems.

For engineers reviewing the MAX8840ELT25+ datasheet, MAX8840ELT25+ pinout, MAX8840ELT25+ application, or MAX8840ELT25+ equivalent, key selection criteria include its µDFN-6 (1.5mm × 1.0mm) package, BP pin-enabled noise suppression, guaranteed ±3% output voltage accuracy over load/temperature, and sub-1µA shutdown current - critical for battery-powered audio, RF front-end, and precision sensor power rails.

Technical Context

The MAX8840ELT25+ employs a p-channel MOSFET pass transistor (typ. R_DS(ON) = 1Ω) enabling low quiescent current (40µA typical) and stable operation without base-drive losses. Its bandgap reference (1.225V) feeds an error amplifier that controls the pass gate via internal feedback, ensuring tight regulation across input (2V–6V) and load (0–150mA) variations.

Noise reduction is achieved through a dedicated BP pin connected to a 10nF capacitor between BP and OUT, which shunts high-frequency noise from the bandgap core. During shutdown, the reference, error amp, and gate driver are disabled, placing OUT in high-impedance state while drawing <1µA total supply current.

Key Specifications

Pinout & Package

MAX8840ELT25+ is housed in a lead-free, RoHS-compliant 6-pin µDFN package measuring 1.5mm × 1.0mm × 0.8mm, with exposed thermal pad (GND-connected) for enhanced thermal performance in compact layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6219B252MR-G and ADP125ARHZ-2.5-R7, the MAX8840ELT25+ delivers the lowest noise (11µV_RMS) in the smallest footprint (1.5mm × 1.0mm), making it optimal for space-constrained, noise-critical portable RF and precision analog applications where 150mA capacity suffices.

Availability

MAX8840ELT25+ is available at Aetrix Electronics and suitable for cellular handsets, Bluetooth accessories, digital cameras, and portable medical devices requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for MAX8840ELT25+ 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 markets.

The MAX8840 series belongs to Maxim's ultra-low-noise LDO product line, engineered specifically for powering sensitive RF, audio, and precision analog circuits in battery-operated portable equipment where PSRR, noise, and size are critical.

FAQ

What is the maximum input voltage rating for the MAX8840ELT25+?

The MAX8840ELT25+ has an absolute maximum input voltage of +7V relative to GND. However, its operational input range is specified from 2V to 6V. Exceeding 6V may cause excessive power dissipation or violate safe operating area limits, especially at elevated temperatures. Always maintain VIN ≤ 6V in normal operation to ensure reliability and parametric compliance per the datasheet.

Does the MAX8840ELT25+ require an external feedback resistor network?

No, the MAX8840ELT25+ does not require an external feedback resistor network. It is a factory-preset 2.5V output LDO with internal resistor divider; the FB pin is absent in this variant (only present on MAX8842). The MAX8840ELT25+ uses pins IN, GND, SHDN, BP, N.C., and OUT - eliminating design complexity and component count for fixed-voltage applications.

How does the BP pin function in the MAX8840ELT25+?

The BP pin in the MAX8840ELT25+ connects to an internal noise-bypass node tied to the bandgap reference. When a 10nF capacitor is placed between BP and OUT, it shunts high-frequency noise away from the error amplifier, reducing output voltage noise to 11µV_RMS. During shutdown, the BP pin is internally shorted to OUT, preventing leakage paths and ensuring fast, predictable turn-off behavior.

What is the thermal shutdown behavior of the MAX8840ELT25+?

The MAX8840ELT25+ activates thermal shutdown when junction temperature exceeds +160°C, disabling the pass transistor and placing OUT in high-impedance state. After cooling by 10°C (to ~150°C), the device automatically recovers and resumes regulation. This hysteresis prevents oscillation during sustained overload and protects the MAX8840ELT25+ from permanent damage under fault conditions like output short-circuit.

Can the MAX8840ELT25+ be used with X5R or Y5V ceramic capacitors?

The MAX8840ELT25+ is guaranteed stable with 1µF X7R or X5R ceramic capacitors across its full operating temperature range (-40°C to +85°C). Y5V dielectrics are not recommended due to large capacitance and ESR variation with temperature; using Y5V may compromise stability below -10°C and require ≥2.2µF to meet phase margin requirements. Always verify capacitor DCR and temperature coefficient per application environment.