Analog Devices Inc./Maxim Integrated MAX8559ETAJ2+T

Overview

MAX8559ETAJ2+T from Maxim Integrated is a dual, low-noise, low-dropout linear regulator delivering 300mA per channel with factory-preset outputs of 2.85V (OUTA) and 1.80V (OUTB), operating from 2.5V to 6.5V input. It features 32µVRMS output noise, 70dB PSRR at 10kHz, and 60mV dropout at 100mA load-enabling high-efficiency power delivery in space-constrained portable systems.

For engineers reviewing the MAX8559ETAJ2+T datasheet, MAX8559ETAJ2+T pinout, MAX8559ETAJ2+T application, or MAX8559ETAJ2+T equivalent, key selection criteria include independent shutdown control, ultra-low quiescent current (115µA per LDO), no-bypass-capacitor operation capability, and TDFN-EP package thermal performance for battery-powered instrumentation and wireless modules.

Technical Context

The MAX8559ETAJ2+T integrates two independent P-channel MOSFET pass transistors (R_DS(ON) ≈ 0.6Ω), enabling load-proportional dropout voltage and eliminating base-drive current loss typical of PNP-based regulators. Its internal 1.25V bandgap reference feeds error amplifiers that regulate both outputs via fixed internal feedback dividers-no external resistors required.

Each LDO includes autonomous current limiting (310mA min), thermal shutdown at +160°C with 10°C hysteresis, and internal 385Ω discharge paths for OUTA/OUTB during shutdown. The BP pin accepts a 0.01µF ceramic capacitor to form an RC filter that reduces output noise below 32µVRMS (100Hz–100kHz).

Key Specifications

Pinout & Package

MAX8559ETAJ2+T is packaged in an 8-pin TDFN-EP (3mm × 3mm, 0.8mm height) with exposed paddle for thermal dissipation. The lead-free package complies with RoHS and requires soldering to PCB ground plane for optimal thermal performance (1951mW max power dissipation at +70°C).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS7A2028PDBVR and ADP5311ACPZ-2-R7, the MAX8559ETAJ2+T uniquely provides the exact 2.85V/1.80V output pair in a single TDFN package with superior PSRR and lower noise-making it optimal for space-constrained, dual-rail wireless and imaging systems where rail-specific performance is non-negotiable.

Availability

MAX8559ETAJ2+T is available at Aetrix Electronics and suitable for cellular phone power management, digital camera sensor supplies, and handheld instrument battery regulation requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for MAX8559ETAJ2+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) designs precision analog, mixed-signal, and power-management ICs for demanding industrial, automotive, and portable applications.

The MAX8559 series targets battery-powered portable electronics requiring dual, low-noise, low-quiescent-current LDOs with factory-set outputs and minimal external components-enabling rapid design of compact, energy-efficient power subsystems.

FAQ

What output voltages does the MAX8559ETAJ2+T provide?

The MAX8559ETAJ2+T delivers factory-preset outputs of 2.85V on OUTA and 1.80V on OUTB. These values are laser-trimmed during production and require no external feedback resistors. The device belongs to the MAX8559 family with multiple output combinations; the "J2" suffix specifically denotes the 2.85V/1.80V variant in TDFN-EP packaging. Output accuracy is ±3% over -40°C to +85°C.

Can the MAX8559ETAJ2+T operate without the BP bypass capacitor?

Yes, the MAX8559ETAJ2+T is fully functional without the 0.01µF capacitor on the BP pin. Omitting it increases output noise to 254µVRMS (100Hz–100kHz), but maintains regulation and stability. The BP capacitor is optional and used only when the 32µVRMS noise specification is required-for example, in RF receiver bias supplies or high-resolution ADC references. Layout guidelines recommend routing the BP trace away from noisy digital signals regardless of capacitor presence.

What is the thermal performance difference between UCSP and TDFN packages for the MAX8559ETAJ2+T?

The MAX8559ETAJ2+T is specified only in the 8-pin TDFN-EP package-not UCSP. The TDFN version has an exposed paddle thermally connected to the PCB ground plane, enabling 1951mW maximum power dissipation at +70°C (derating 24.4mW/°C above). In contrast, the UCSP variant (e.g., MAX8559EBAJ2+T) is rated for only 379mW. This makes the TDFN essential for applications drawing near 300mA per rail at elevated ambient temperatures or with limited airflow.

How does the MAX8559ETAJ2+T handle short circuits on its outputs?

The MAX8559ETAJ2+T incorporates independent current-limit circuitry for each LDO, triggering at 310mA (minimum). During a short circuit, the affected output shuts down while the other remains operational. The device enters hiccup mode-cycling on/off-to limit power dissipation and prevent thermal damage. Continuous short-circuit operation is safe due to integrated thermal shutdown, which disables the pass transistor when junction temperature exceeds +160°C and re-enables it after cooling by 10°C.

Is the MAX8559ETAJ2+T compatible with ceramic output capacitors only?

Yes, the MAX8559ETAJ2+T is optimized exclusively for ceramic output capacitors. The datasheet explicitly warns against using tantalum capacitors due to instability risks. For 300mA loads, a minimum 4.7µF X7R/X5R ceramic capacitor is required per output; 2.2µF suffices for ≤150mA. Capacitor ESR must be low (<100mΩ), and dielectric choice affects temperature stability-Z5U/Y5V types may require ≥4.7µF below -10°C, while X7R maintains stability across the full -40°C to +85°C range with 2.2µF.