Analog Devices Inc./Maxim Integrated MAX8878EZK36

Overview

MAX8878EZK36 from Maxim Integrated is a low-noise, low-dropout linear regulator with preset 3.6V output, delivering up to 150mA from 2.5V–6.5V input. It features 30µVRMS output noise, 165mV dropout at 150mA, 100µA operating supply current, and auto-discharge functionality during shutdown. It serves as a precision power source for battery-powered portable electronics requiring stable, clean voltage rails.

For engineers reviewing the MAX8878EZK36 datasheet, MAX8878EZK36 pinout, MAX8878EZK36 application, or MAX8878EZK36 equivalent, key selection criteria include its SOT23-5 thin-package footprint, 1.4% output voltage accuracy, reverse battery protection, thermal shutdown at 155°C, and BP-capacitor–enabled noise filtering - all critical for space-constrained, low-power embedded designs.

Technical Context

The MAX8878EZK36 uses an internal P-channel MOSFET pass transistor (1.1Ω typical R_DS(ON)) to achieve low dropout and eliminate base-drive current loss. Its error amplifier compares a 1.25V bandgap reference against feedback from an internal resistor divider tied to the OUT pin, enabling precise regulation without external resistors.

It integrates logic-controlled shutdown (10nA I_SHDN), thermal overload protection with 15°C hysteresis, short-circuit current limiting (160–390mA), and reverse battery protection that limits reverse current to 1mA. The MAX8878 variant uniquely adds active output discharge via a 300Ω internal resistance when SHDN is asserted.

Key Specifications

Pinout & Package

MAX8878EZK36 is housed in a 5-pin thin SOT23 package (JEDEC MO-178AA), optimized for high-density PCB layouts and improved thermal performance (θ_JB = 110°C/W). The GND pin serves dual roles: electrical reference and thermal path to PCB ground plane.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX8878EZK36, MAX8877EZK36 omits auto-discharge but matches all other electrical and mechanical attributes, while MCP1703T-3602E/MB trades higher dropout and no reverse protection for marginally lower noise - making MAX8878EZK36 optimal for battery longevity, safety, and predictable shutdown behavior.

Availability

MAX8878EZK36 is available at Aetrix Electronics and suitable for cellular handsets, PCMCIA cards, hand-held instruments, and electronic planners requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for MAX8878EZK36 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 markets.

The MAX8877/MAX8878 product line was designed specifically for battery-powered portable electronics demanding ultra-low quiescent current, low noise, and robust fault protection - targeting applications where runtime, reliability, and board space are critical constraints.

FAQ

What is the output voltage tolerance of the MAX8878EZK36 over temperature and load?

The MAX8878EZK36 guarantees ±1.4% output voltage accuracy across the full -40°C to +85°C operating temperature range and for load currents from 0.1mA to 120mA. At room temperature and light load (0.1mA), the tolerance tightens to ±1.4% minimum; worst-case deviation remains bounded per the datasheet's Electrical Characteristics table, ensuring reliable operation in precision analog and digital subsystems.

Does the MAX8878EZK36 require external components to operate stably?

Yes - the MAX8878EZK36 requires three external capacitors: a ≥1µF ceramic capacitor from IN to GND, a ≥1µF (ESR <0.2Ω) ceramic capacitor from OUT to GND, and a 0.01µF ceramic capacitor from BP to GND. These are mandatory for stability, noise reduction, and transient response; omitting the BP capacitor increases output noise to >100µVRMS, while undersized output capacitance risks oscillation under load steps.

How does the auto-discharge feature of the MAX8878EZK36 work during shutdown?

When the SHDN pin is pulled low, the MAX8878EZK36 activates an internal 300Ω switch between the OUT pin and GND, actively discharging the output capacitor. This ensures V_OUT falls rapidly to near-zero volts - preventing residual voltage from powering downstream circuitry or causing undefined logic states. Discharge time depends on C_OUT; for a 1µF capacitor, V_OUT drops from 3.6V to <100mV in under 4ms.

Can the MAX8878EZK36 be used with input voltages below 2.5V?

No - the absolute minimum input voltage for the MAX8878EZK36 is 2.5V, as specified in Absolute Maximum Ratings and Electrical Characteristics. Operation below this threshold may cause improper regulation, increased dropout, or failure to start. For sub-2.5V inputs, alternative regulators such as the MAX1726 or TPS7A05 series must be considered.

What thermal considerations apply to the MAX8878EZK36 in a thin SOT23 package?

The MAX8878EZK36 in thin SOT23 has θ_JB = 110°C/W. To avoid thermal shutdown at 155°C, maximum allowable power dissipation is ~727mW at +70°C ambient. For a 3.6V output at 150mA with 3.0V input (0.6V dropout), power dissipation is 90mW - well within limits. However, PCB layout must use a large GND pad (≥25mm²) to dissipate heat effectively and maintain junction temperature below 150°C under worst-case conditions.