Analog Devices Inc./Maxim Integrated MAX8556ETE/V+

Overview

The MAX8556ETE/V+ from Maxim Integrated is a 4A ultra-low-input-voltage LDO regulator with p-channel MOSFET pass device, adjustable output (0.5V to VIN − 0.2V), 100mV typical dropout at 4A, ±1% output accuracy over load/line/temperature, and integrated Power-OK (POK) output. It operates from 1.425V–3.6V input and targets point-of-load regulation in high-density server and optical module power supplies.

For engineers reviewing the MAX8556ETE/V+ datasheet, MAX8556ETE/V+ pinout, MAX8556ETE/V+ application, or MAX8556ETE/V+ equivalent, key selection criteria include its 1.425V minimum input capability, POK fault signaling, thermal shutdown behavior, and TQFN-EP package thermal performance under 4A continuous load.

Technical Context

The MAX8556ETE/V+ uses an internal 25mΩ p-channel MOSFET pass transistor enabling stable regulation down to 1.425V input without charge pump or external bias supply. Its error amplifier regulates FB to 0.500V (±5mV) with 0.001–1µA input bias current, supporting precise resistor-divider-based output programming.

Protection architecture includes foldback current limiting (5–9A regulated limit), thermal shutdown at +160°C (rising) / +115°C (falling), and logic-controlled shutdown reducing GND current to 150µA max. The open-drain POK output asserts low when VOUT deviates >±10% from nominal or during thermal fault/shutdown.

Key Specifications

Pinout & Package

The MAX8556ETE/V+ is housed in a 16-pin TQFN (5mm × 5mm) package with exposed thermal paddle (EP), requiring solder connection to PCB ground plane for thermal and electrical integrity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS7A8300RGRT and LT3086EFE#PBF, the MAX8556ETE/V+ uniquely combines 4A delivery from 1.425V input, integrated POK, and TQFN thermal performance-making it optimal for space-constrained, fault-aware infrastructure power rails where dropout and supervision are critical.

Availability

MAX8556ETE/V+ is available at Aetrix Electronics and suitable for server point-of-load regulation, optical transceiver power, and industrial baseband processing requiring stable component supply, automotive-grade temperature qualification (−40°C to +85°C), and RoHS-compliant packaging.

Supply support for MAX8556ETE/V+ 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 industrial, communications, and computing applications.

The MAX8556ETE/V+ belongs to Maxim's ultra-low-input-voltage LDO family, engineered specifically for high-current, low-headroom point-of-load regulation in next-generation servers, optical modules, and telecom infrastructure where traditional NPN-based LDOs fail.

FAQ

What is the minimum input voltage supported by the MAX8556ETE/V+?

The MAX8556ETE/V+ supports a minimum input voltage of 1.425V, verified across temperature and load conditions. This enables direct regulation from single-cell Li-ion batteries or low-voltage intermediate distribution buses. Operation below 1.425V is prohibited per Absolute Maximum Ratings, and undervoltage lockout activates at ~1.35V (rising) to prevent unstable regulation. The MAX8556ETE/V+ maintains full 4A output capability down to this 1.425V threshold with only 100mV typical dropout.

Does the MAX8556ETE/V+ require external components for stability?

Yes, the MAX8556ETE/V+ requires external capacitors for stable operation: two 10µF ceramic capacitors between IN and GND, and two 10µF low-ESR (≤50mΩ) ceramic capacitors between OUT and GND. These values ensure stability across −40°C to +85°C and up to 4A load. The FB pin connects to a resistor divider (R2/R3) to set output voltage, with R3 ≤ 1kΩ recommended for light-load stability. No additional compensation network is needed.

How does the POK output on the MAX8556ETE/V+ behave during thermal fault?

During thermal overload, the MAX8556ETE/V+ POK output immediately pulls low-identical to its behavior during output voltage deviation (>±10%) or shutdown. This provides unified fault signaling without requiring separate thermal monitors. The POK remains low until both thermal recovery (junction cooling to +115°C) and output re-regulation within ±10% occur. Internal 50µs glitch immunity prevents false triggering during brief transients, ensuring reliable system-level power sequencing.

Can the MAX8556ETE/V+ be used in automotive applications?

Yes-the "/V" suffix in MAX8556ETE/V+ denotes automotive qualification per AEC-Q100 Grade 3 (−40°C to +85°C). It includes enhanced process controls, extended temperature validation, and failure-modes analysis. While not rated for under-hood 125°C environments, the MAX8556ETE/V+ is approved for cabin- and chassis-mounted electronics such as infotainment power supplies, ADAS sensor interfaces, and telematics modules requiring 4A low-dropout regulation with POK supervision.

What is the thermal resistance (θ_JA) of the MAX8556ETE/V+ in standard PCB layout?

The MAX8556ETE/V+ has a junction-to-ambient thermal resistance (θ_JA) of approximately 45°C/W when mounted on a JEDEC-standard 4-layer 3″×3″ test board (2oz copper, nine 12-mil thermal vias under EP). This yields 2667mW maximum power dissipation at +70°C ambient. Actual θ_JA improves significantly with optimized layout: connecting EP to solid GND planes on inner layers and removing solder mask over thermal pads can reduce θ_JA to <30°C/W in production designs, directly increasing allowable I_OUT at elevated ambient temperatures.