Analog Devices Inc./Maxim Integrated MAX8559EBAJJ+T

Overview

MAX8559EBAJJ+T from Maxim Integrated is a dual, low-noise, low-dropout linear regulator delivering two independent 2.85V outputs with ≥300mA per channel, 32µVRMS output noise, 70dB PSRR at 10kHz, and 60mV dropout at 100mA load-designed for power-sensitive portable electronics requiring clean, stable dual-rail supplies.

For engineers reviewing the MAX8559EBAJJ+T datasheet, MAX8559EBAJJ+T pinout, MAX8559EBAJJ+T application, or MAX8559EBAJJ+T equivalent, key selection criteria include factory-preset 2.85V/2.85V output matching, independent logic-controlled shutdown (SHDNA/SHDNB), ultra-low quiescent current (115µA per LDO), and compatibility with small ceramic capacitors without mandatory bypass.

Technical Context

The MAX8559EBAJJ+T integrates two 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 each output via fixed internal resistor dividers set for 2.85V.

Each LDO features independent thermal shutdown (160°C trip, 10°C hysteresis), short-circuit protection, and output discharge (385Ω to GND in shutdown). The BP pin accepts a 0.01µF ceramic capacitor to form an RC filter that reduces broadband output noise below 32µVRMS (100Hz–100kHz).

Key Specifications

Pinout & Package

MAX8559EBAJJ+T is packaged in an 8-bump UCSP (2.06mm × 1.03mm, 0.5mm pitch) with exposed die attach pad-optimized for minimal PCB footprint and thermal performance in space-constrained handheld designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS7A20285PDBVR and ADP125ARHZ-2.85-R7, the MAX8559EBAJJ+T uniquely delivers matched dual 2.85V outputs with independent shutdown, sub-32µVRMS noise, and UCSP packaging-making it the only solution that satisfies compact, low-noise, dual-rail requirements in a single IC.

Availability

MAX8559EBAJJ+T is available at Aetrix Electronics and suitable for cellular handsets, digital cameras, notebook subsystems, and wireless LAN cards requiring stable component supply, long-term lifecycle support, and lead-free compliance.

Supply support for MAX8559EBAJJ+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 industrial, communications, and consumer applications.

The MAX8559 belongs to Maxim's low-noise, dual-LDO product line engineered specifically for battery-powered portable electronics-prioritizing ultra-low quiescent current, minimal footprint, and factory-preset outputs to accelerate design-in and reduce bill-of-materials complexity.

FAQ

What output voltages does the MAX8559EBAJJ+T provide?

The MAX8559EBAJJ+T provides two identical, factory-preset 2.85V outputs (V_OUTA = V_OUTB = 2.85V) with ±3% accuracy over -40°C to +85°C. This JJ-coded variant eliminates external feedback resistors, ensuring consistent voltage matching between rails and simplifying layout. The MAX8559EBAJJ+T achieves this using internal resistor dividers referenced to a 1.25V bandgap-no user adjustment is possible or required.

Does the MAX8559EBAJJ+T require an external bypass capacitor on the BP pin?

The MAX8559EBAJJ+T does not require an external capacitor on the BP pin for basic operation, but adding a 0.01µF ceramic capacitor reduces output voltage noise from 254µVRMS to 32µVRMS (100Hz–100kHz). This BP capacitor forms a low-pass filter with an internal resistor to attenuate reference amplifier noise. If system noise specifications permit higher noise, the BP capacitor may be omitted to reduce component count and board area-though PSRR and transient response remain unaffected.

What is the maximum continuous output current per channel for the MAX8559EBAJJ+T?

The MAX8559EBAJJ+T delivers up to 300mA of continuous output current per channel (OUTA and OUTB) when used with a minimum 4.7µF ceramic output capacitor and within thermal limits. At 100mA load, dropout is 60mV; at full 300mA, dropout increases proportionally due to the P-channel MOSFET's R_DS(ON). The device includes per-channel current limiting (310mA min) and thermal shutdown (160°C) to protect against overload-ensuring reliable operation even under sustained short-circuit conditions.

Can the MAX8559EBAJJ+T operate without an input bypass capacitor?

No-the MAX8559EBAJJ+T requires a minimum 2.2µF ceramic input capacitor connected between INA/INB and GND for stability and transient response. This capacitor mitigates input supply impedance, suppresses line transients, and prevents oscillation under dynamic load changes. For 300mA operation or noisy input sources (e.g., switcher outputs), a 4.7µF or larger low-ESR ceramic capacitor is recommended. Omitting the input capacitor risks instability, excessive output ripple, and potential damage during load steps.

What package type is used for the MAX8559EBAJJ+T, and how is thermal management handled?

The MAX8559EBAJJ+T uses an 8-bump UCSP package (2.06mm × 1.03mm, 0.5mm pitch) with an exposed die attach pad. Thermal management relies on soldering this exposed pad directly to the PCB's solid ground plane-acting as both electrical reference and primary heat path. The UCSP's 379mW maximum power dissipation at +70°C ambient requires careful layout: short wide traces, 2oz copper, and proximity to ground pours. For higher-power applications, the TDFN-EP variant (MAX8559ETAJJ+T) offers 1951mW dissipation via its larger exposed paddle.