Analog Devices Inc./Maxim Integrated MAX8559ETA22+

Overview

MAX8559ETA22+ from Maxim Integrated is a dual, low-noise, low-dropout linear regulator delivering 300mA per channel with factory-preset 1.8V outputs, 60mV dropout at 100mA, 32µVRMS output noise, and independent logic-controlled shutdown-designed for space-constrained battery-powered systems such as digital cameras and handheld instruments.

For engineers reviewing the MAX8559ETA22+ datasheet, MAX8559ETA22+ pinout, MAX8559ETA22+ application, or MAX8559ETA22+ equivalent, key selection criteria include dual-output voltage accuracy (±3%), thermal shutdown at +160°C, TDFN-EP package thermal performance, and compatibility with ceramic capacitors down to 2.2µF for 150mA loads.

Technical Context

The MAX8559ETA22+ integrates two independent P-channel MOSFET pass transistors (R_DS(ON) ≈ 0.6Ω), each with dedicated error amplifiers, internal 1.25V bandgap reference, and autodischarge circuitry. Its feedback loop uses internal resistor dividers to set fixed 1.8V outputs without external components.

Shutdown control is fully decoupled: SHDNA and SHDNB independently disable LDO A and B, reducing supply current to 0.01µA when both are low. Thermal protection operates per-regulator with +160°C trip point and 10°C hysteresis, enabling pulsed operation under sustained overload.

Key Specifications

Pinout & Package

MAX8559ETA22+ is housed in an 8-pin TDFN-EP package (3mm × 3mm × 0.8mm) with exposed paddle soldered to PCB ground for thermal dissipation (1951mW max power at +70°C ambient).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS7A2028PDBVR and ADP125ARHZ-1.8-R7, the MAX8559ETA22+ uniquely combines factory-set dual 1.8V outputs, independent shutdown, BP noise filtering, and 32µVRMS performance in a thermally enhanced TDFN-EP-making it optimal for compact, battery-sensitive dual-rail systems where layout area and noise are constrained.

Availability

MAX8559ETA22+ is available at Aetrix Electronics and suitable for digital cameras, handheld instruments, cellular phone baseband power, and PCMCIA card designs requiring stable component supply, long-term lifecycle support, and lead-free compliance.

Supply support for MAX8559ETA22+ 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 U.S.-based 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, low-quiescent-current LDO family-engineered specifically for battery-powered portable electronics demanding minimal solution size, high PSRR, and precise dual-rail regulation without external feedback components.

FAQ

What output voltages does the MAX8559ETA22+ provide?

The MAX8559ETA22+ delivers two fixed 1.8V outputs-one on OUTA and one on OUTB-as indicated by the "22" suffix in the part number per Maxim's Output Voltage Selector Guide. These voltages are factory-trimmed and require no external resistors. The device maintains ±3% accuracy across -40°C to +85°C and load currents from 0.1mA to 300mA, making it ideal for tightly regulated dual-rail applications like digital camera sensors and baseband processors.

Does the MAX8559ETA22+ require an external bypass capacitor on the BP pin?

Yes-the MAX8559ETA22+ requires a 0.01µF low-leakage ceramic capacitor between BP and GND to achieve its specified 32µVRMS output noise. Omitting this capacitor increases noise to 254µVRMS (100Hz–100kHz). The BP pin connects to an internal RC filter that suppresses reference noise; using the recommended capacitor ensures optimal noise performance for analog-sensitive circuits such as ADC references or RF bias rails.

How does thermal protection operate in the MAX8559ETA22+?

The MAX8559ETA22+ features independent thermal sensors per LDO with a +160°C trip point and 10°C hysteresis. When either regulator's junction temperature exceeds +160°C, its pass transistor shuts off until the die cools to +150°C, then resumes regulation-resulting in pulsed output under continuous overload. This per-channel protection preserves functionality of the unaffected LDO and avoids system-wide failure, critical in multi-rail portable systems where one rail may be overloaded while another remains active.

Can the MAX8559ETA22+ operate without output capacitors?

No-the MAX8559ETA22+ requires minimum output capacitance for stability: 2.2µF ceramic (X7R/X5R) for ≤150mA loads per channel, or 4.7µF for full 300mA capability. The device is optimized for ceramic capacitors and explicitly warns against tantalum types due to ESR-related instability risks. Removing output capacitors causes oscillation and violates absolute maximum ratings, risking damage during transient events.

What is the purpose of the exposed paddle on the MAX8559ETA22+ TDFN package?

The exposed paddle on the MAX8559ETA22+ TDFN package serves as both a thermal heatsink and electrical ground connection. It must be soldered to the PCB ground plane to achieve the rated 1951mW maximum power dissipation at +70°C ambient. Failure to connect the paddle degrades thermal performance by >50%, risks thermal shutdown under moderate load, and violates JEDEC MO-229 WEEC mechanical specifications-compromising reliability in sustained operation.