Analog Devices Inc./Maxim Integrated MAX77839AEWL+T

Overview

The MAX77839AEWL+T from Analog Devices is a high-efficiency, 4.4A switching current, ultra-low-quiescent-current (6μA) buck-boost regulator in a 15-bump wafer-level package. It operates from 1.8V to 5.5V input and delivers adjustable 2.3V–5.3V output for single-cell Li-ion and low-voltage battery systems. Its FPWM-enabled GPIO pin, 2.2MHz fixed-frequency operation, and seamless buck/boost transition make it ideal for space-constrained mobile power pre-regulation.

For engineers reviewing the MAX77839AEWL+T datasheet, MAX77839AEWL+T pinout, MAX77839AEWL+T application, or MAX77839AEWL+T equivalent, key selection criteria include its 4.4A current limit (A/B option), FPWM control mode, WLP package footprint (2.07mm × 1.51mm), and support for skip-mode efficiency optimization at light loads.

Technical Context

The MAX77839AEWL+T implements a four-switch H-bridge buck-boost topology with current-mode PWM control at 2.2MHz (typ), enabling compact external components and fast transient response. It uses RSEL resistor-based output voltage programming and integrates active output discharge (100Ω internal switch) for controlled shutdown.

Its dual protection architecture includes cycle-by-cycle overcurrent detection (4.4A ILIM), thermal shutdown at +150°C (15°C hysteresis), UVLO (1.75V rising threshold), and OVP (0.5V OUT–OUTS differential). The FPWM pin (GPIO) forces continuous PWM operation-critical for low-noise or high-dynamic-response applications like ToF sensor power rails.

Key Specifications

Pinout & Package

MAX77839AEWL+T is packaged in a 2.07mm × 1.51mm, 0.4mm pitch, 15-bump wafer-level package (WLP), optimized for ultra-compact mobile PCBs. Thermal resistance θJA = 61.65°C/W (4-layer board).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar buck-boost regulator applications.

Compared with TPS63900DSKR and RTQ2134BGQW, the MAX77839AEWL+T uniquely balances 4.4A current delivery, 6μA IQ, FPWM controllability, and minimal 2.07mm × 1.51mm WLP footprint-making it optimal for next-gen compact mobile and RF power systems demanding both efficiency and precision timing control.

Availability

MAX77839AEWL+T is available at Aetrix Electronics and suitable for asset tracking, smartphone ToF sensors, 5G cellular front-end modules, and RF amplifier bias supplies requiring stable component supply across high-volume production cycles.

Supply support for MAX77839AEWL+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

Analog Devices (acquired Maxim Integrated in 2021) is a global leader in high-performance analog, mixed-signal, and power management semiconductors, serving industrial, automotive, communications, and consumer markets.

The MAX77839 belongs to Maxim's ultra-low-power PMIC family designed specifically for battery-powered mobile and IoT edge devices where extended runtime, minimal footprint, and seamless voltage conversion across battery discharge curves are essential.

FAQ

What is the primary function of the GPIO pin on the MAX77839AEWL+T?

The GPIO pin on the MAX77839AEWL+T serves as an FPWM (forced-PWM) enable input for this specific variant. When driven high, it forces continuous fixed-frequency PWM operation-suppressing skip mode to eliminate output voltage ripple and ensure deterministic timing. This is critical for noise-sensitive loads like ToF sensors or RF amplifiers. When low, the MAX77839AEWL+T defaults to auto-skip mode for optimal light-load efficiency. The pin is not configurable as POK on this "A" option part.

How does the MAX77839AEWL+T achieve seamless buck-to-boost transition?

The MAX77839AEWL+T achieves seamless buck-to-boost transition using a proprietary four-switch H-bridge topology with real-time mode arbitration. Unlike dual-stage converters, it dynamically adjusts phase sequencing (Φ1–Φ4) based on instantaneous VIN/VOUT ratio-maintaining regulation without output glitches or control-loop reconfiguration. This ensures uninterrupted power delivery during Li-ion discharge from 4.2V to 2.8V, eliminating brownouts in portable systems relying on the MAX77839AEWL+T as the main system regulator.

What is the recommended RSEL resistor value to set 3.3V output on the MAX77839AEWL+T?

The recommended RSEL configuration for 3.3V output on the MAX77839AEWL+T is a direct short (0Ω) between the SEL pin and AGND. This is explicitly listed in Table 1 of the datasheet as the standard setting for 3.3V. A 1% tolerance zero-ohm jumper or 0402 chip resistor is preferred over wire bonds to ensure consistent thermal and mechanical reliability. Deviations from this value will shift VOUT per the RSEL–VOUT lookup table-e.g., 4.99kΩ yields 2.3V.

Does the MAX77839AEWL+T support active output discharge, and how is it implemented?

Yes, the MAX77839AEWL+T includes integrated active output discharge. When the EN pin is pulled low or the device latches off due to protection (e.g., thermal shutdown), an internal 100Ω MOSFET switch connects the OUT pin to PGND, safely discharging the output capacitor within milliseconds. This prevents hazardous residual voltage at the load and ensures clean power sequencing-particularly important in systems with multiple regulated rails coordinated by the MAX77839AEWL+T.

What are the key layout requirements for the MAX77839AEWL+T's WLP package?

For the MAX77839AEWL+T's 15-bump WLP, critical layout rules include: (1) placing CIN and COUT capacitors immediately adjacent to IN/OUT bumps with shortest possible traces to PGND; (2) routing LX1/LX2 traces through multiple vias directly to inner PGND planes; (3) maintaining unbroken low-impedance ground beneath the IC and all power components; (4) isolating AGND from noisy PGND return paths except at a single star point; and (5) dedicating a separate trace and 2.2μF cap for BIAS-never sharing with IN. These practices minimize parasitic inductance and EMI in high-frequency 2.2MHz operation.