Analog Devices Inc./Maxim Integrated MAX8867EUK50+T

Overview

MAX8867EUK50+T from Maxim Integrated is a low-noise, low-dropout linear regulator with 5.0V preset output, 150mA output current capability, 165mV dropout at full load, 30µVRMS output noise, and 100µA operating supply current. It uses an internal P-channel MOSFET pass transistor and operates from 2.5V to 6.5V input, targeting battery-powered handheld instruments and PCMCIA cards requiring stable, ultra-low-noise voltage regulation.

For engineers reviewing the MAX8867EUK50+T datasheet, MAX8867EUK50+T pinout, MAX8867EUK50+T application, or MAX8867EUK50+T equivalent, key selection criteria include dropout performance at 150mA, 10nA shutdown current, reverse battery protection, BP-pin noise filtering, and SOT23-5 thermal design constraints.

Technical Context

The MAX8867EUK50+T implements a fixed-output LDO architecture with a 1.25V bandgap reference, error amplifier, and internal resistor divider setting VOUT = 5.0V ±1.4%. Its P-channel MOSFET pass device delivers 165mV dropout at 150mA and maintains 100µA quiescent current independent of load or dropout condition.

It integrates 10nA logic-controlled shutdown, thermal shutdown at +155°C with +15°C hysteresis, short-circuit protection, and reverse battery protection limiting reverse current to 1mA. The BP pin accepts a 0.01µF capacitor to form an 80Hz low-pass filter reducing output noise to 30µVRMS (10Hz–100kHz).

Key Specifications

Pinout & Package

SOT23-5 regular package (5-pin, 1.6mm × 2.9mm × 1.1mm body height); GND pin serves as electrical ground and primary thermal path - requires soldering to large copper area for thermal management.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-noise, 5V LDO applications.

Compared with TPS76350DBVR and MCP1700T-5002E/MB, the MAX8867EUK50+T uniquely combines ultra-low noise (30µVRMS), reverse battery protection, and thermal shutdown in a 5-pin SOT23 - delivering higher system-level reliability without increasing component count or board area.

Availability

MAX8867EUK50+T is available at Aetrix Electronics and suitable for handheld instruments, PCMCIA cards, palmtop computers, and cordless telephones requiring stable component supply, long-term lifecycle support, and guaranteed parametric compliance over -40°C to +85°C.

Supply support for MAX8867EUK50+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 precision analog, mixed-signal, and power management ICs for demanding industrial, medical, and portable applications.

The MAX8867/MAX8868 product line targets battery-powered portable electronics requiring ultra-low noise, low quiescent current, and robust fault protection in minimal SOT23 footprint.

FAQ

What is the output voltage tolerance of the MAX8867EUK50+T over temperature?

The MAX8867EUK50+T guarantees ±1.4% output voltage accuracy over the full -40°C to +85°C operating temperature range. At +25°C, typical deviation is tighter, and the device exhibits excellent line and load regulation (±0.15%/V and ±0.04%/mA respectively), ensuring stable 5.0V operation across varying input and load conditions. This specification is confirmed in the Electrical Characteristics table of the official datasheet.

Does the MAX8867EUK50+T include auto-discharge functionality?

No, the MAX8867EUK50+T does not include auto-discharge. That feature is exclusive to the MAX8868 variant (e.g., MAX8868EUK50+T). When the MAX8867EUK50+T is placed in shutdown via the SHDN pin, the output remains floating at its last regulated voltage; it does not actively discharge to ground. Designers requiring output discharge must select the MAX8868 version or add external circuitry.

What capacitor values are required for stable operation of the MAX8867EUK50+T?

For stable operation, the MAX8867EUK50+T requires a minimum 1µF ceramic input capacitor (CIN) and a 1µF–10µF ceramic output capacitor (COUT) with ESR ≤0.2Ω. A 0.01µF ceramic capacitor on the BP pin is mandatory for achieving the specified 30µVRMS noise. X7R or X5R dielectrics are recommended for COUT to ensure stable capacitance across temperature; Z5U/Y5V types may require ≥2.2µF for low-temperature stability.

Can the MAX8867EUK50+T operate with a 2.7V input supply?

Yes, the MAX8867EUK50+T can operate with a 2.7V input, but it will be in dropout since the output is fixed at 5.0V. Dropout occurs when VIN < VOUT + dropout voltage; at 2.7V input, the device cannot regulate 5.0V and will not function as intended. Minimum valid input is 2.5V, but for 5.0V regulation, VIN must exceed ~5.165V (5.0V + 165mV dropout). It is suitable for 5V input rails or higher-voltage battery configurations only.

How does the BP pin affect startup time and noise performance in the MAX8867EUK50+T?

The BP pin connects internally to a 200kΩ resistor forming an RC filter with the external capacitor. Using the recommended 0.01µF capacitor achieves optimal 30µVRMS noise while keeping startup time minimal. Increasing BP capacitance (e.g., to 0.1µF) slightly reduces noise but significantly increases startup delay - exceeding 0.1µF provides negligible noise benefit and is not recommended per the datasheet's Shutdown Exit Delay characterization curves.