Analog Devices Inc./Maxim Integrated MAX8636ETA+

Overview

MAX8636ETA+ from Maxim Integrated is a dual 300mA pin-programmable LDO linear regulator in an 8-pin 3mm x 3mm TDFN package, operating from 2.7V to 5.5V input with 90mV typical dropout at 100mA and 45µVRMS output noise. It features independent p-channel MOSFET pass transistors, low 54µA quiescent current (both LDOs on), and thermal shutdown. It is used in space-constrained battery-powered systems requiring stable dual-rail low-noise power, such as wireless LAN cards and handheld instruments.

For engineers reviewing the MAX8636ETA+ datasheet, MAX8636ETA+ pinout, MAX8636ETA+ application, or MAX8636ETA+ equivalent, key selection criteria include its dual-output programmability via P1/P2 logic states, low-noise BP bypass capability, single SHDN control for both regulators, and guaranteed 300mA per channel with current limiting and thermal protection across –40°C to +85°C.

Technical Context

The MAX8636ETA+ integrates two independent LDO regulators sharing a common input and shutdown control, each regulated by internal 1.50V reference, error amplifier, and p-channel MOSFET pass transistor. Output voltages are set at power-on by the logic states of P1 and P2 (nine preset combinations), and remain fixed until power cycle or simultaneous SHDN assertion.

It implements low-noise operation via dedicated BP pin accepting a 0.01µF ceramic capacitor to filter the internal reference, achieving 45µVRMS (10Hz–100kHz). Thermal shutdown activates at +165°C with 15°C hysteresis, and undervoltage lockout disables regulation below 2.25V (typ) input.

Key Specifications

Pinout & Package

MAX8636ETA+ uses an 8-pin, 3mm x 3mm TDFN package with exposed paddle (EP) soldered to PCB ground for enhanced thermal performance. Pin numbering follows standard top-view orientation with Pin 1 at top-left corner.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX8636ELA+, the MAX8636ETA+ offers 5× higher thermal power handling for sustained 300mA loads; compared with TPS70245PWPR, it delivers programmable outputs, lower quiescent current, and integrated noise reduction-making it superior for compact, battery-powered, noise-sensitive dual-rail systems.

Availability

MAX8636ETA+ is available at Aetrix Electronics and suitable for cellular baseband power, wireless LAN card core supply, handheld instrument sensor bias, and small LCD display backlight driver support requiring stable component supply across industrial temperature ranges.

Supply support for MAX8636ETA+ 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, automotive, and communications applications.

The MAX8633–MAX8636 product line delivers dual, pin-programmable LDOs optimized for space-constrained, battery-powered portable electronics requiring low noise, low quiescent current, and flexible output voltage configuration without external resistors.

FAQ

What output voltage combinations does the MAX8636ETA+ support?

The MAX8636ETA+ supports nine preset output-voltage combinations determined by the logic states (IN, GND, or Open) of P1 and P2 pins at power-on. Examples include 2.80V/1.50V, 2.90V/1.50V, 3.00V/1.50V, 2.60V/1.80V, 2.80V/1.80V, 3.00V/2.50V, 3.00V/2.80V, 2.85V/2.85V, and 3.00V/3.00V. These values are fixed after startup unless the device is power-cycled or fully shut down via SHDN.

How does the MAX8636ETA+ achieve low output noise?

The MAX8636ETA+ achieves 45µVRMS output noise (10Hz–100kHz) by routing its internal reference through the BP pin, which accepts an external 0.01µF ceramic capacitor to GND. This forms a low-pass filter that suppresses reference noise before it modulates the error amplifier. Omitting the BP capacitor increases noise to ~60µVRMS; the MAX8636ETA+ requires this capacitor for specified low-noise performance.

What is the power-on sequencing behavior of the MAX8636ETA+?

The MAX8636ETA+ enforces controlled power-on sequencing: OUT2 powers up first, and OUT1 remains disabled until OUT2 reaches 87% of its nominal output voltage. Only then does OUT1 enable. This behavior prevents latch-up or improper initialization in downstream circuits requiring strict rail-ordering, such as processors with separate core/I/O supplies. The sequence is inherent to the MAX8636ETA+ design and requires no external timing components.

Does the MAX8636ETA+ include current limiting and thermal protection?

Yes, the MAX8636ETA+ includes per-channel current limiting (400mA min, 500mA typ) and thermal shutdown protection. Each output independently limits current to prevent damage during short-circuit or overload events. Thermal shutdown activates at +165°C junction temperature and holds both outputs off until the die cools by 15°C. These protections are fully integrated and require no external components to function.

What is the maximum continuous output current per channel for the MAX8636ETA+?

The MAX8636ETA+ guarantees 300mA continuous output current per channel (OUT1 and OUT2) under thermal limits defined by its 8-pin TDFN package. At ambient +70°C, the package supports up to 1904mW power dissipation (derated by 23.8mW/°C above +70°C). Sustained 300mA operation is feasible across the full –40°C to +85°C range provided PCB layout includes adequate copper area connected to the exposed paddle for heat spreading.