Analog Devices Inc./Maxim Integrated MAX1947ETA30+T

Overview

The MAX1947ETA30+T from Maxim Integrated is a fixed-output 3.0V step-up DC-DC converter optimized for single- and dual-cell alkaline/NiMH/NiCd battery-powered systems. It features an internal 800mA n-channel switch, synchronous rectification, 94% peak efficiency, and a 75ms active-low RESET output - enabling reliable power-on reset and undervoltage detection for µP/DSP cores and I/O rails in portable medical devices and cordless peripherals.

For engineers reviewing the MAX1947ETA30+T datasheet, MAX1947ETA30+T pinout, MAX1947ETA30+T application, or MAX1947ETA30+T equivalent, key selection criteria include its 0.7V minimum input voltage, 2µA True Shutdown™ current, 3.0V ±3.3% output regulation at 25mA load, 2MHz switching capability for compact ceramic filtering, and TDFN-8 (3mm × 3mm) package with exposed paddle grounding.

Technical Context

The MAX1947ETA30+T employs a bootstrapped startup oscillator and a minimum-off-time, current-limited control architecture that merges PWM efficiency with pulse-skipping quiescent current reduction. Its synchronous rectifier uses an integrated p-channel MOSFET to eliminate external Schottky diodes and reduce conduction losses.

It operates in track mode when BATT exceeds 3.0V, fully turning on the PFET to let VOUT follow VBATT, while maintaining regulated operation below that threshold. The 75ms RESET timer activates only after VOUT reaches ≥90% of 3.0V and remains valid down to 0.9V output.

Key Specifications

Pinout & Package

MAX1947ETA30+T is housed in an 8-pin TDFN package (3mm × 3mm, 0.8mm height) with exposed thermal paddle (EP) connected to GND/PGND for enhanced thermal performance and EMI reduction.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar step-up DC-DC converter applications.

Compared with TPS61201DRCT and ADP1613ARMZ-R7, the MAX1947ETA30+T uniquely integrates a validated 75ms RESET output and True Shutdown™ with active output discharge - eliminating external components and simplifying compliance-critical power sequencing in portable medical and consumer devices.

Availability

MAX1947ETA30+T is available at Aetrix Electronics and suitable for portable medical equipment, cordless communication devices, and digital imaging systems requiring stable component supply, long-term lifecycle support, and lead-free packaging.

Supply support for MAX1947ETA30+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) is a U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, automotive, and portable applications.

The MAX1947 series was designed specifically for ultra-low-voltage battery-powered systems where extended runtime, minimal external components, and guaranteed power-on reset behavior are mandatory - targeting MP3 players, PDAs, and portable diagnostics equipment.

FAQ

What is the minimum input voltage required for the MAX1947ETA30+T to start up and regulate?

The MAX1947ETA30+T starts up from a minimum input voltage of 0.8V (typical) at +25°C, with a maximum startup voltage temperature coefficient of -2.1mV/°C. It continues regulating down to 0.7V input across the full -40°C to +85°C operating range. This enables reliable operation even with deeply discharged 1-cell alkaline or NiMH batteries, making the MAX1947ETA30+T ideal for long-life portable applications where battery voltage sag is expected.

Does the MAX1947ETA30+T require external compensation components?

No, the MAX1947ETA30+T does not require external compensation components. As a fixed-output converter (3.0V), it integrates all necessary feedback and compensation circuitry internally. The device only requires three external passive components - an inductor (typically 4.7µH), an input capacitor (≥2.2µF ceramic), and an output capacitor (4.7µF for ≤50% load or 10µF for full load) - simplifying design and reducing bill-of-materials cost.

How does the RESET output of the MAX1947ETA30+T behave during shutdown?

During shutdown (SHDN = GND), the RESET output of the MAX1947ETA30+T is actively driven low. This behavior is guaranteed across the full operating temperature range and ensures deterministic microcontroller reset assertion regardless of output voltage decay rate. The RESET remains low until SHDN is released and VOUT rises above 90% of 3.0V, after which the 75ms timer begins - providing robust power-on sequencing for safety-critical portable systems using the MAX1947ETA30+T.

What is the purpose of the exposed paddle (EP) on the MAX1947ETA30+T TDFN package?

The exposed paddle (EP) on the MAX1947ETA30+T serves dual thermal and electrical functions: it must be soldered to a PCB ground plane to provide low-thermal-resistance heat dissipation (critical for sustained 25mA output) and to establish a low-inductance, low-noise ground return path for both analog (GND) and power (PGND) pins. Failure to connect EP to ground degrades efficiency, increases output ripple, and risks thermal shutdown - making proper EP soldering essential for reliable MAX1947ETA30+T operation.

Can the MAX1947ETA30+T operate in track mode, and what triggers it?

Yes, the MAX1947ETA30+T enters track mode when three conditions are simultaneously met: VBATT > 3.0V, VOUT > 3.0V, and the minimum off-time expires. In this mode, the internal p-channel MOSFET conducts continuously, causing VOUT to closely follow VBATT minus a small drop (typically <100mV). Track mode exits automatically when VOUT falls below 3.0V, restoring regulation. This feature allows seamless transition between battery and wall-adapter operation without external circuitry - a key advantage of the MAX1947ETA30+T in hybrid-powered systems.