Analog Devices Inc./Maxim Integrated MAX8969EWL35+

Overview

The MAX8969EWL35+ from Maxim Integrated is a 1A, 3.5V-output synchronous step-up DC-DC converter in a 1.25mm × 1.25mm WLP package, designed for single-cell Li-ion battery systems. It delivers up to 1A continuous output current with 90%+ efficiency, supports 2.5V–5.5V input, features True Shutdown™ (1µA), and operates in boost, track, and automatic track modes for optimized battery life in handheld devices.

For engineers reviewing the MAX8969EWL35+ datasheet, MAX8969EWL35+ pinout, MAX8969EWL35+ application, or MAX8969EWL35+ equivalent, key selection criteria include its 3.5V fixed output, 3MHz switching frequency, 30µA track-mode IQ, 65µA automatic track-mode IQ, and integrated short-circuit/overtemperature/UVLO protection - all critical for compact, battery-sensitive portable power designs.

Technical Context

The MAX8969EWL35+ employs a fixed-frequency PWM architecture with adaptive control logic enabling three distinct operating states: boost mode (synchronous switching), track mode (pMOS current-limited pass-through, 30µA IQ), and automatic track mode (ATM, pMOS active when VIN ≥ 95% of 3.5V target, 65µA IQ). Its 3MHz switching frequency enables use of a 1µH inductor and ultra-small ceramic capacitors.

Control is managed via dual logic inputs: EN prioritizes mode selection (EN=high forces boost or ATM), while TREN enables track mode or True Shutdown. Internal soft-start limits inrush current to 480mA, and thermal shutdown activates at +165°C with 20°C hysteresis. The device uses internal pMOS and nMOS switches with on-resistances of 115mΩ and 63mΩ respectively at VOUT = 3.5V.

Key Specifications

Pinout & Package

MAX8969EWL35+ is housed in a 1.25mm × 1.25mm, 9-bump wafer-level package (WLP) with 0.4mm pitch. Bump assignment follows standard top-view (bump side down) layout.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS610993DSER and RT9086AGQW, the MAX8969EWL35+ uniquely combines fixed 3.5V output, 30µA track-mode IQ, automatic VIN-following (ATM), and True Shutdown™ in a 1.25mm² WLP - making it optimal for space-constrained, battery-life-critical handhelds where input voltage closely tracks the regulated rail.

Availability

MAX8969EWL35+ is available at Aetrix Electronics and suitable for smartphones, GPS/PNDs, e-readers, and mobile internet devices requiring stable component supply, RoHS-compliant packaging, and long-term production continuity.

Supply support for MAX8969EWL35+ 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 portable, industrial, and communications applications.

The MAX8969 product line is designed specifically for ultra-compact, high-efficiency step-up conversion in single-cell Li-ion battery systems - emphasizing low quiescent current, small footprint, and intelligent mode transitions to maximize battery runtime.

FAQ

What output voltage does the MAX8969EWL35+ provide, and how accurate is it?

The MAX8969EWL35+ provides a fixed 3.5V output with ±3.5% accuracy (3.40V–3.60V) at no load, as specified in the electrical characteristics table. Under load (0–600mA), output voltage remains within 3.15V–3.65V across temperature and input voltage variations, ensuring reliable operation for 3.3V–3.6V logic and analog circuits. This accuracy is achieved via factory-trimmed internal feedback and does not require external resistors.

How does the MAX8969EWL35+ manage efficiency across varying input voltages?

The MAX8969EWL35+ uses three complementary techniques: skip mode under light load (≤10mA), automatic track mode (ATM) when VIN ≥ 3.35V (95% of 3.5V), and automatic frequency reduction (to ~1.6MHz or ~1MHz) when VIN exceeds 83% of VOUT. These ensure >90% efficiency from 2.5V to 4.5V input at moderate loads, and extend battery life significantly compared to fixed-frequency-only boost converters.

What protection features are integrated into the MAX8969EWL35+?

The MAX8969EWL35+ integrates undervoltage lockout (UVLO at 2.2V with 75mV hysteresis), cycle-by-cycle inductor current limiting (2.6A peak), overtemperature shutdown (+165°C with 20°C hysteresis), short-circuit detection (shuts down if VOUT drops below 2.52V), and True Shutdown™ to block reverse current flow from LX_ to OUT_. All protections operate across all modes - boost, track, and ATM.

Can the MAX8969EWL35+ be used with a 2.5V input to deliver 3.5V at 1A?

Yes - the MAX8969EWL35+ supports 2.5V minimum input and delivers up to 1A peak output current in boost mode. However, continuous 1A operation at 2.5V input is thermally limited; the datasheet specifies 0.8A continuous at VOUT = 3.5V under typical PCB conditions (TA ≤ +70°C). For sustained 1A loads, input voltage should be ≥2.8V or thermal design must be enhanced.

What are the PCB layout requirements for the MAX8969EWL35+?

Key layout rules for the MAX8969EWL35+ include: (1) placing the 22µF output capacitor directly adjacent to OUT1/OUT2 pins, (2) shorting OUT1/OUT2, LX1/LX2, and GND1/GND2 under the IC, (3) using a solid ground plane with multiple vias, and (4) routing high-current paths (IN→LX, LX→inductor) as short and wide as possible. Poor layout increases EMI, reduces efficiency, and risks instability - refer to Maxim's EV kit layout for validated implementation.