Analog Devices Inc./Maxim Integrated MAX8805WEWEDD+T

Overview

MAX8805WEWEDD+T from Maxim Integrated is a 2MHz, 650mA high-frequency PWM step-down converter with integrated 60mΩ bypass FET and dual 200mA low-noise LDOs, optimized for dynamic power control of WCDMA/NCDMA power amplifiers in mobile handsets. It supports analog voltage positioning via REFIN input (2.5V/V gain), delivers 7.5µs settling time for 0.8V–3.4V output transitions, and operates from 2.7V–5.5V input.

For engineers reviewing the MAX8805WEWEDD+T datasheet, MAX8805WEWEDD+T pinout, MAX8805WEWEDD+T application, or MAX8805WEWEDD+T equivalent, key selection criteria include its dual-mode PA power architecture (PWM + bypass), REFIN-controlled linear output adjustment, 2mm × 2mm UCSP package, thermal shutdown, and ultra-low 0.1µA shutdown current.

Technical Context

The MAX8805WEWEDD+T implements a hysteretic PWM control scheme enabling fast transient response and stable regulation with minimal external components. Its feedback network samples the LX node directly-eliminating phase lag from output capacitance-and incorporates voltage-positioning load regulation to reduce overshoot during load or output-voltage transients.

Bypass mode is triggered either automatically (when VREFIN exceeds 0.372 × VIN2) or forcibly (via HP logic input), engaging a 60mΩ p-channel MOSFET to connect IN1A/IN1B directly to PAA/PAB. The device integrates two independent LDOs with 35µVRMS noise, 70dB PSRR, and individual enable controls (EN1/EN2).

Key Specifications

Pinout & Package

The MAX8805WEWEDD+T is housed in a 16-bump, 2mm × 2mm × 0.7mm UCSP (Ultra-Compact Silicon Package) with 0.4mm pitch, designed for high-density mobile PCB layouts and compatible with JEDEC J-STD-020A reflow profiles.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PA power management applications.

Compared with MAX8805YEREWDD+T and MAX8805XEREWDD+T, the MAX8805WEWEDD+T offers the optimal balance of 2MHz efficiency, 650mA drive, and 2.5V/V gain for mainstream WCDMA PA applications-delivering superior thermal performance over MAX8805X while supporting higher PA loads than MAX8805Y.

Availability

MAX8805WEWEDD+T is available at Aetrix Electronics and suitable for WCDMA handset design, smartphone RF front-end development, and wireless PDA power management requiring stable component supply, RoHS-compliant packaging, and long-term production continuity.

Supply support for MAX8805WEWEDD+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 semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for communications, computing, and consumer applications.

The MAX8805W/MAX8805X/MAX8805Y/MAX8805Z product line was engineered specifically for dynamic PA power control in 3G cellular handsets-integrating step-down conversion, bypass FET, and LDO biasing into a single ultra-compact UCSP package.

FAQ

What is the switching frequency of the MAX8805WEWEDD+T?

The MAX8805WEWEDD+T operates at a fixed 2MHz switching frequency. This frequency enables the use of small 2.2µF ceramic input and output capacitors while maintaining low output-voltage ripple and high efficiency across the 2.7V–5.5V input range. It is selected to balance solution size and thermal performance for WCDMA PA applications.

How does the MAX8805WEWEDD+T enter bypass mode?

The MAX8805WEWEDD+T enters bypass mode in two ways: automatically when VREFIN exceeds 0.372 × VIN2 (using IN2 as reference to avoid noise coupling), or forcibly when the HP pin is driven high. In bypass mode, the internal 60mΩ p-channel FET connects IN1A/IN1B directly to PAA/PAB, achieving low-dropout operation without PWM losses.

What is the REFIN-to-PA output voltage gain for the MAX8805WEWEDD+T?

The MAX8805WEWEDD+T has a REFIN-to-PA output voltage gain of 2.5V/V. For example, applying 0.72V to REFIN sets the nominal PA output to 1.8V (0.72V × 2.5). This linear scaling allows precise, DAC-driven PA power control. The actual output includes a small correction term for inductor DCR drop under load.

Can the LDO1 and LDO2 outputs of the MAX8805WEWEDD+T be used independently?

Yes, LDO1 and LDO2 in the MAX8805WEWEDD+T are fully independent: each has its own enable input (EN1 and EN2), can be powered from the same IN2 supply, and delivers up to 200mA with 35µVRMS noise and 70dB PSRR. They support staggered turn-on, selective shutdown, and different load conditions-ideal for biasing multi-stage PA architectures.

What package type and dimensions does the MAX8805WEWEDD+T use?

The MAX8805WEWEDD+T uses a 16-bump, 2mm × 2mm × 0.7mm UCSP (Ultra-Compact Silicon Package) with 0.4mm bump pitch. This RoHS-compliant, lead-free package is optimized for high-density mobile PCBs and requires JEDEC J-STD-020A-compliant reflow profiling-including preheating and no hand/wave soldering.