Analog Devices Inc./Maxim Integrated MAX8840ELT33+T

Overview

MAX8840ELT33+T from Maxim Integrated is a preset 3.3V, 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. It employs a p-channel MOSFET pass transistor, operates from 2V–6V input, and targets noise-sensitive analog and RF power rails in portable electronics.

For engineers reviewing the MAX8840ELT33+T datasheet, MAX8840ELT33+T pinout, MAX8840ELT33+T application, or MAX8840ELT33+T equivalent, key selection criteria include guaranteed 3.3V output accuracy (±3%), sub-1µA shutdown current, stability with 1µF ceramic output capacitor, and µDFN-6 (1.5mm × 1.0mm) package compatibility with space-constrained PCB layouts.

Technical Context

The MAX8840ELT33+T uses an internal 1.225V bandgap reference and error amplifier to regulate output voltage via a 1Ω (typ) p-channel MOSFET pass transistor, eliminating base-drive current and enabling ultra-low ground current (40µA typical). Its dedicated BP pin accepts a 10nF bypass capacitor to suppress noise at the error amplifier's reference node.

Unlike the MAX8841 (no BP pin) and MAX8842 (FB-adjustable), the MAX8840ELT33+T implements a fixed-output architecture with factory-trimmed internal feedback divider and integrated noise-bypass circuitry-enabling 11µV_RMS noise performance without external compensation components beyond C_IN, C_OUT, and C_BP.

Key Specifications

Pinout & Package

MAX8840ELT33+T is housed in a lead-free 6-pin µDFN package measuring 1.5mm × 1.0mm × 0.8mm, with exposed thermal pad (GND-connected) for enhanced thermal dissipation in compact layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6206P332MR-G and ADP160AUJZ-3.3-R7, the MAX8840ELT33+T delivers superior noise performance (11µV_RMS vs. ≥22µV_RMS) and lower dropout (120mV vs. ≥195mV), making it optimal for RF and precision analog applications where supply purity directly impacts system-level metrics like EVM or ENOB.

Availability

MAX8840ELT33+T is available at Aetrix Electronics and suitable for cellular phone RF front-ends, digital camera image sensor bias, and portable medical sensor nodes requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX8840ELT33+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 high-performance analog, mixed-signal, and power management ICs for demanding applications in communications, computing, and industrial systems.

The MAX8840 series belongs to Maxim's ultra-low-noise LDO product line, engineered specifically for noise-critical analog and RF power domains in battery-operated portable equipment where PSRR, dropout, and quiescent current are co-optimized.

FAQ

What is the output voltage tolerance of the MAX8840ELT33+T over temperature and load?

The MAX8840ELT33+T guarantees ±3% output voltage accuracy across the full -40°C to +85°C operating temperature range and for load currents from 100µA to 80mA. At 25°C and 1mA load, the tolerance tightens to ±1%. This specification ensures reliable interface with 3.3V logic families and analog components without external trimming.

Can the MAX8840ELT33+T operate stably with a 1µF ceramic output capacitor?

Yes, the MAX8840ELT33+T is explicitly designed and tested for stability with a 1µF ceramic output capacitor across all load conditions and temperatures. X7R or X5R dielectrics are recommended; Z5U/Y5V types may require ≥2.2µF below -10°C. This eliminates need for larger, more expensive tantalum capacitors.

What is the purpose of the BP pin on the MAX8840ELT33+T, and what capacitor value is required?

The BP (Bypass) pin on the MAX8840ELT33+T connects to an external 10nF capacitor tied to the OUT pin, forming a noise-reduction network that lowers output voltage noise to 11µV_RMS. Capacitor values between 1nF and 100nF are supported, but 10nF delivers optimal noise performance; values outside this range degrade noise reduction or risk instability.

How does the MAX8840ELT33+T behave during shutdown, and what is its shutdown current?

When SHDN is pulled low (≤0.4V), the MAX8840ELT33+T disables its voltage reference, error amplifier, gate driver, and pass transistor, placing the OUT pin in high-impedance state. Shutdown current is guaranteed <0.05µA at +85°C and <1µA across the full temperature range-enabling true zero-power sleep modes.

Does the MAX8840ELT33+T include built-in protection features, and what are their thresholds?

Yes, the MAX8840ELT33+T integrates overcurrent limiting (trip range 150–300mA) and thermal shutdown (160°C trip with 10°C hysteresis). The current limiter protects against sustained short-circuit loads, while thermal shutdown prevents permanent damage during overload or poor heatsinking-both functions require no external components.