Analog Devices Inc./Maxim Integrated MAX8840ELT26+

Overview

MAX8840ELT26+ from Maxim Integrated is a 2.6V 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 MAX8840ELT26+ datasheet, MAX8840ELT26+ pinout, MAX8840ELT26+ application, or MAX8840ELT26+ equivalent, key selection criteria include its 2.6V preset output, µDFN-6 (1.5mm × 1.0mm) package, BP pin for noise bypass, 40µA ground current, and guaranteed stability with 1µF ceramic output capacitance.

Technical Context

The MAX8840ELT26+ employs a p-channel MOSFET series pass transistor with 1Ω typical R_DS(ON), enabling low dropout and eliminating base-drive current loss. Its bandgap reference (1.225V) feeds an error amplifier that controls the pass gate via internal feedback, achieving ±3% output voltage accuracy over load and temperature.

Noise suppression is implemented through a dedicated BP pin connected to a 10nF capacitor between BP and OUT, which shunts high-frequency noise from the bandgap core. Shutdown logic disables the reference, error amplifier, and gate driver, reducing supply current to <1µA while placing OUT in high-impedance state.

Key Specifications

Pinout & Package

MAX8840ELT26+ is housed in a 1.5mm × 1.0mm × 0.8mm, 6-pin µDFN package with exposed thermal pad (pin 5 is N.C., not internally connected). The GND pin serves dual electrical and thermal functions - must be soldered to a large PCB copper area for optimal thermal performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-noise LDO applications.

Compared with TPS7A2026PDQNR and MCP1703T-2602E/MB, the MAX8840ELT26+ delivers the lowest output noise and highest PSRR in a 1.5mm × 1.0mm footprint - making it the preferred choice for RF and precision analog subsystems where noise floor and supply rejection directly impact system-level SNR.

Availability

MAX8840ELT26+ is available at Aetrix Electronics and suitable for cellular front-end power, Bluetooth audio codec supply, digital camera image sensor bias, and portable medical pulse oximeter applications requiring stable component supply across extended production lifecycles.

Supply support for MAX8840ELT26+ 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, communications, and consumer applications.

The MAX8840 family targets ultra-low-noise power regulation in space-constrained portable electronics - specifically engineered to replace discrete noise-filtering solutions with integrated, capacitor-minimized LDOs for RF and sensor signal chains.

FAQ

What is the output voltage tolerance of the MAX8840ELT26+ over temperature and load?

The MAX8840ELT26+ guarantees ±3% output voltage accuracy across the full -40°C to +85°C operating temperature range and for output currents from 100µA to 80mA. At 25°C and 1mA load, the tolerance tightens to ±1%. This specification ensures reliable operation of 2.6V-tolerant RF ICs without external trimming, and the MAX8840ELT26+ maintains this accuracy even near dropout conditions.

Can the MAX8840ELT26+ operate stably with less than 1µF output capacitance?

No - the MAX8840ELT26+ is characterized and guaranteed stable only with ≥1µF ceramic output capacitance. Reducing C_OUT below this value risks oscillation or degraded transient response, especially under heavy load steps. The device's internal compensation is optimized for 1µF, and the datasheet explicitly states "stable with 1µF ceramic capacitor for any load." Using smaller values voids stability assurance for the MAX8840ELT26+.

What is the function of the BP pin on the MAX8840ELT26+, and is it required?

The BP (Bypass) pin on the MAX8840ELT26+ connects to an internal noise-reduction network tied to the bandgap reference. A 10nF capacitor between BP and OUT reduces output voltage noise from ~230µV_RMS (typical for non-BP LDOs) to 11µV_RMS. It is required to achieve the specified ultra-low-noise performance; omitting the BP capacitor degrades noise by >20× and invalidates the 11µV_RMS rating for the MAX8840ELT26+.

Does the MAX8840ELT26+ support adjustable output voltages?

No - the MAX8840ELT26+ is a factory-preset, fixed 2.6V output regulator. Adjustable output is exclusive to the MAX8842 variant, which uses the FB pin and external resistor divider. The MAX8840ELT26+ has no FB pin; pin 4 is BP, and pin 5 is N.C. Attempting to modify the output voltage of the MAX8840ELT26+ via external components is not supported and will not yield predictable regulation.

How does the MAX8840ELT26+ behave during shutdown, and what is its shutdown current?

When SHDN is pulled low (<0.4V), the MAX8840ELT26+ disables its voltage reference, error amplifier, gate driver, and pass transistor. The OUT pin enters high-impedance state, and total supply current drops to <0.05µA at +85°C (typically <0.01µA at +25°C). During shutdown, the BP pin is internally shorted to OUT, and the device remains thermally protected. This ultra-low shutdown current makes the MAX8840ELT26+ ideal for battery-powered systems requiring long-term sleep modes.