Analog Devices Inc./Maxim Integrated MAX38902BETA+

Overview

MAX38902BETA+ from Analog Devices is a low-noise, 500mA LDO linear regulator in an 8-pin TDFN package, delivering ±1% DC output accuracy over load/line/temperature with only 100mV dropout at full load and 10.5µVRMS noise (10Hz–100kHz). It features resistor-adjustable output (0.6V–5.3V), active-low POK output, programmable soft-start, and integrated overcurrent/thermal protection - deployed in high-resolution data acquisition systems requiring ultra-low noise power rails.

For engineers reviewing the MAX38902BETA+ datasheet, MAX38902BETA+ pinout, MAX38902BETA+ application, or MAX38902BETA+ equivalent, key selection criteria include its 365µA no-load quiescent current, 70dB PSRR at 10kHz, 800Ω active discharge, reverse-current protection, and compatibility with 2µF minimum ceramic output capacitance.

Technical Context

The MAX38902BETA+ employs a pMOS pass transistor architecture with internal 0.6V reference and feedback loop stabilized by external resistor divider on FB pin. Its control circuitry samples EN for enable/disable sequencing and asserts open-drain POK when VOUT reaches ≥91% of regulation voltage.

It integrates thermal shutdown (trip at +165°C, restart at +150°C), current limiting (~700mA typ), and reverse-voltage detection that disables conduction when VIN falls 10mV below VOUT - preventing destructive reverse current during power-down transients.

Key Specifications

Pinout & Package

MAX38902BETA+ uses an 8-pin, 2mm × 2mm TDFN package (package code T822+3C) with exposed thermal pad (EP) connected to GND for optimal heat dissipation. Pin pitch is 0.5mm; land pattern follows JEDEC MS-012AC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS7A4700RGWR and LT3045EDD#PBF, MAX38902BETA+ uniquely balances ultra-low noise (10.5µVRMS), resistor-adjustability (0.6V–5.3V), active discharge, and POK in a compact 2mm × 2mm TDFN - making it optimal for space-constrained, multi-rail systems requiring both precision and controllability.

Availability

MAX38902BETA+ is available at Aetrix Electronics and suitable for communication circuitry, high-resolution data acquisition systems, and industrial sensor signal conditioning requiring stable component supply across automotive-grade temperature range (−40°C to +125°C).

Supply support for MAX38902BETA+ 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

Analog Devices, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets since 1965.

The MAX38902 family was designed specifically for noise-sensitive analog and RF power domains - delivering ultra-low-noise regulation with integrated protection and sequencing features in miniature WLP and TDFN packages.

FAQ

What output voltage range does the MAX38902BETA+ support?

The MAX38902BETA+ supports an adjustable output voltage range of 0.6V to 5.3V, set by an external resistor divider connected to the FB pin. Its internal 0.6V reference enables precise scaling - for example, a 2.5V output requires R3 = 950kΩ when R2 = 300kΩ. This flexibility eliminates the need for multiple fixed-voltage regulators in diverse system architectures, and the MAX38902BETA+ maintains ±1% accuracy across the full range under load, line, and temperature variations.

Does the MAX38902BETA+ include power-good signaling?

Yes, the MAX38902BETA+ features an active-low, open-drain POK (Power-OK) output that asserts low when the regulated output reaches ≥91% of its target voltage. This signal requires an external pull-up resistor to a compatible logic rail and is used for system-level power sequencing, FPGA configuration lock, or microcontroller reset coordination. The POK remains low during normal operation and goes high only during startup delay, overload, or shutdown - ensuring reliable status feedback without additional monitoring circuitry, and the MAX38902BETA+ integrates this function natively within its 8-pin TDFN footprint.

How does the MAX38902BETA+ handle reverse current protection?

The MAX38902BETA+ incorporates built-in reverse-current protection that activates when the input voltage (VIN) falls 10mV below the output voltage (VOUT), such as during input rail collapse or hot-swap events. Upon detection, the internal pMOS pass device is disabled, blocking reverse current flow from the output capacitor back into the input source. This prevents damage to upstream supplies and avoids uncontrolled discharge paths - a critical feature in systems with large hold-up capacitance or redundant power architectures. Unlike external diode solutions, this protection is fully integrated and requires no additional components, and the MAX38902BETA+ implements it without sacrificing dropout performance or quiescent current.

What is the minimum output capacitance required for stability with the MAX38902BETA+?

The MAX38902BETA+ requires a minimum output capacitance of 2µF, including voltage and temperature derating, using a low-ESR ceramic capacitor (X5R or X7R dielectric recommended). A 4.7µF capacitor is typical for robust transient response and noise suppression. The regulator remains stable with ESR values below 0.03Ω and tolerates capacitance down to 2µF even under worst-case DC bias conditions - enabling use of compact 0402 or 0603 MLCCs in space-constrained layouts. This low minimum capacitance reduces BOM count and board area versus legacy LDOs requiring ≥10µF, and the MAX38902BETA+ guarantees stability across the full operating temperature range (−40°C to +125°C) with this value.

Can the MAX38902BETA+ be used in thermally demanding environments?

Yes, the MAX38902BETA+ is rated for continuous operation from −40°C to +125°C and includes thermal shutdown with hysteresis (trip at +165°C, restart at +150°C). Its 2mm × 2mm TDFN package features an exposed thermal pad (EP) that must be soldered to a dedicated GND plane with ≥4 thermal vias to achieve θJA ≤102°C/W on a 4-layer PCB. Under 500mA load at 3.6V input, junction temperature rise remains within safe limits when layout guidelines are followed - making the MAX38902BETA+ suitable for enclosed industrial enclosures or automotive under-hood applications where ambient temperatures exceed 85°C. Its thermal protection operates autonomously without external intervention, and the MAX38902BETA+ resumes regulation once cooled, ensuring graceful degradation rather than catastrophic failure.