Analog Devices Inc./Maxim Integrated MAX8633ETA+T

Overview

MAX8633ETA+T from Maxim Integrated is a dual-output, pin-programmable LDO linear regulator in an 8-pin 3mm × 3mm TDFN package. It delivers up to 300mA per output from a 2.7V–5.5V input, with 90mV typical dropout at 100mA and 54µA typical quiescent current. Its integrated open-drain active-low RESET output monitors OUT2 for undervoltage detection in battery-powered portable electronics.

For engineers reviewing the MAX8633ETA+T datasheet, MAX8633ETA+T pinout, MAX8633ETA+T application, or MAX8633ETA+T equivalent, key selection criteria include dual-output voltage programmability via P1/P2 logic states, RESET timeout (120ms min), thermal shutdown (+165°C), and compatibility with ceramic capacitors ≥2.2µF for stability across –40°C to +85°C.

Technical Context

The MAX8633ETA+T uses internal p-channel MOSFET pass transistors (R_DS(ON) ≈ 0.9Ω) to achieve low dropout and minimal quiescent current. Its control loop incorporates a 1.50V internal reference, error amplifiers, and fixed internal feedback dividers-eliminating external resistors for nine preset OUT1/OUT2 voltage combinations selected at power-on by P1/P2 states.

RESET functionality is tightly coupled to OUT2 regulation: it asserts low when V_OUT2 falls below 82.5% of nominal, releases high-impedance after 120ms once V_OUT2 rises above 87%, and supports external pull-up to VIN or another rail. Power-on sequencing enforces OUT2 enablement before OUT1 activation.

Key Specifications

Pinout & Package

MAX8633ETA+T is housed in an 8-pin, 3mm × 3mm TDFN package with exposed paddle (EP) for enhanced thermal dissipation. The EP must be soldered to a PCB ground plane to meet power dissipation limits (1904mW at +70°C, derated 23.8mW/°C above).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX8633ELA+, the MAX8633ETA+T offers 5× higher thermal power handling and identical electrical performance; versus TPS70245PWPR, it integrates RESET and eliminates external resistors but uses a single SHDN for both outputs.

Availability

MAX8633ETA+T is available at Aetrix Electronics and suitable for cellular handsets, digital cameras, notebook subsystems, and wireless LAN cards requiring stable component supply with guaranteed long-term availability and RoHS-compliant packaging.

Supply support for MAX8633ETA+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 applications in industrial, communications, and consumer markets.

The MAX8633–MAX8636 family targets battery-powered portable electronics, delivering ultra-low quiescent current, small-footprint dual regulation, and integrated supervision functions to simplify power architecture in space- and energy-constrained devices.

FAQ

What output voltage combinations does the MAX8633ETA+T support?

The MAX8633ETA+T supports nine preset output-voltage pairs determined by the logic states (Open/GND/IN) of P1 and P2 at power-on. Examples include OUT1=2.80V/OUT2=1.50V (P1=P2=Open), OUT1=3.00V/OUT2=2.80V (P1=IN, P2=IN), and OUT1=2.80V/OUT2=2.60V (P1=IN, P2=GND). These values are fixed at startup and cannot be changed dynamically without cycling power or asserting SHDN.

How does the RESET function operate on the MAX8633ETA+T?

The MAX8633ETA+T features an open-drain, active-low RESET output that monitors only OUT2. It asserts low when V_OUT2 drops below 82.5% of its nominal value and releases to high-impedance 120ms after V_OUT2 rises above 87%. An external pull-up resistor is mandatory. This function replaces external reset supervisors in applications requiring simple, accurate power-good signaling tied to the secondary rail.

Can the MAX8633ETA+T be used with ceramic output capacitors smaller than 2.2µF?

Yes, but with constraints: output capacitance may be reduced to 1µF per rail only for load currents under 150mA. For full 300mA capability or improved transient response, 2.2µF or larger X7R/X5R ceramic capacitors are required. Using Z5U or Y5V dielectrics may necessitate larger values to maintain stability below –10°C, and tantalum capacitors are not recommended due to higher ESR.

What is the maximum allowable power dissipation for the MAX8633ETA+T package?

The MAX8633ETA+T in its 3mm × 3mm TDFN package has a maximum continuous power dissipation of 1904mW at +70°C, derating linearly by 23.8mW/°C above that temperature. Exceeding this limit risks thermal shutdown activation. Power dissipation is calculated as P_D = (V_IN(MAX) − V_OUT1) × I_OUT1 + (V_IN(MAX) − V_OUT2) × I_OUT2, and must remain below P_DMAX under worst-case operating conditions.

Does the MAX8633ETA+T require special PCB layout considerations?

Yes. Key layout requirements for the MAX8633ETA+T include: (1) connecting the exposed paddle (EP) directly to a large PCB ground plane for thermal conduction; (2) placing input (≥2.2µF), output (≥2.2µF), and optional BP bypass (0.01µF) capacitors as close as possible to their respective pins; (3) keeping IN, OUT1, OUT2, and GND traces short and wide; and (4) routing the BP net away from noise sources to preserve low-noise performance-though BP is unused on MAX8633ETA+T since it lacks the BP pin.