Analog Devices Inc./Maxim Integrated MAX8515AEXK

Overview

MAX8515AEXK from Maxim Integrated is a precision 0.6V adjustable shunt regulator designed for feedback control in isolated DC-to-DC converters, featuring ±0.5% initial accuracy at +25°C, ±1% accuracy over -40°C to +85°C, 0.2Ω dynamic output impedance, 20mA sink capability down to 0.2V output, and operation from 1.7V to 28V input supply. It enables high-bandwidth regulation in telecom base station power supplies and low-voltage isolated converters.

For engineers reviewing the MAX8515AEXK datasheet, MAX8515AEXK pinout, MAX8515AEXK application, or MAX8515AEXK equivalent, this device serves as a critical voltage reference and OVP enabler in optocoupler-based feedback loops-especially where sub-1V output regulation, tight thermal accuracy, and direct optocoupler drive are required.

Technical Context

The MAX8515AEXK implements a precision 600mV bandgap reference with high-gain error amplifier and low-impedance output stage, enabling stable closed-loop control of isolated flyback or forward converters. Its separated IN/PGND and OUT/GND domains support galvanic isolation while maintaining accurate sensing of secondary-side output voltage via FB pin.

It operates in two biasing modes: directly from converter output (1.8V–18V) or from an independent 1.7V–28V supply, allowing flexible placement on primary or secondary side. The device delivers 20mA sink current with <1mV load/line regulation and supports fast transient response due to high open-loop bandwidth (>100kHz).

Key Specifications

Pinout & Package

MAX8515AEXK is housed in a 5-pin SC70 package (2.0mm × 2.1mm, 0.65mm pitch), with exposed pad not connected internally. Pin 1 is PGND, pin 2 is GND, pin 3 is OUT, pin 4 is IN, and pin 5 is FB - all pins are surface-mount compatible and rated for reflow per JEDEC J-STD-020.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV431ACDBVR and LM4040CIM3-ADJ, the MAX8515AEXK uniquely integrates a 0.6V reference, high-current sink, and isolated supply architecture-enabling direct optocoupler interface and sub-1V regulation without external gain stages or level shifters.

Availability

MAX8515AEXK is available at Aetrix Electronics and suitable for isolated telecom power supplies, industrial 24V-to-low-voltage converters, and FPGA core regulation requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for MAX8515AEXK 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 MAX8515AEXK belongs to Maxim's isolated power management product line, engineered specifically to simplify high-accuracy feedback in optocoupler-based DC-DC converters with ultra-low output voltage requirements.

FAQ

What is the reference voltage tolerance of MAX8515AEXK over temperature?

The MAX8515AEXK features ±0.5% initial accuracy at +25°C and maintains ±1% accuracy across the full -40°C to +85°C operating range. This is verified per the Electrical Characteristics table in the datasheet, where FB threshold accuracy is specified as 0.595V to 0.605V at -40°C to +85°C for MAX8515A-grade devices like MAX8515AEXK. No derating or external calibration is needed to meet this spec.

Can MAX8515AEXK drive an optocoupler directly without external components?

Yes, MAX8515AEXK can directly drive standard optocouplers such as PC817 or SFH615A. Its 20mA sink capability at V_OUT = 0.2V and low 0.2Ω dynamic output impedance ensure reliable LED biasing across temperature. The datasheet's Typical Operating Circuit (Figure 3) shows direct connection of OUT to optocoupler anode with only R1 limiting current-no transistor buffer or additional passive components required for most designs using MAX8515AEXK.

What is the maximum input voltage rating for MAX8515AEXK?

The absolute maximum IN-to-GND voltage for MAX8515AEXK is +30V, but the recommended operating range is 1.7V to 28V per the Electrical Characteristics table. Operation above 28V risks exceeding safe power dissipation limits, especially at elevated temperatures. The device's internal BiCMOS process and thermal design support continuous operation up to 28V at full load within the -40°C to +85°C ambient range when used in the SC70 package.

How does MAX8515AEXK differ from MAX8515EXK in practical design?

MAX8515AEXK offers tighter initial accuracy (±0.5% vs. ±1% at +25°C) and better temperature stability (±1% vs. ±1.8% from -40°C to +85°C) compared to MAX8515EXK. In practice, this means MAX8515AEXK reduces output voltage error budget in high-precision applications like telecom base station supplies or FPGA core rails-where even 0.5% improvement avoids costly post-production trimming or margining. Both share identical pinout, package, and functional behavior.

What decoupling capacitors are required for stable operation of MAX8515AEXK?

Per the Applications Information section and Figure 1, MAX8515AEXK requires a 0.1µF ceramic capacitor from IN to GND (C1) and a 1.0µF ceramic capacitor from OUT to GND (C2) for stable shunt regulator operation at 0.6V output. C2 value scales inversely with output voltage-e.g., 0.1µF suffices for 6V outputs. These values are validated in the Typical Operating Characteristics plots and ensure phase margin >45° across load and input variations in MAX8515AEXK circuits.