Analog Devices Inc./Maxim Integrated MAX4837EUT25BD3

Overview

MAX4837EUT25BD3 from Maxim Integrated is a 500mA low-dropout linear regulator with integrated current-limiting switch and active-low push-pull RESET output, delivering a precise 2.5V output from 2.5V–5.5V input. It features 90µA quiescent current, 330mV dropout at 500mA, reverse-current protection, thermal shutdown, and 225ms RESET timeout (D3 suffix). It serves as a fault-aware power supply for USB ports and SDIO interfaces in portable electronics.

For engineers reviewing the MAX4837EUT25BD3 datasheet, MAX4837EUT25BD3 pinout, MAX4837EUT25BD3 application, or MAX4837EUT25BD3 equivalent, key selection criteria include guaranteed 500mA load capability, 2.5V preset output accuracy (±2%), RESET assertion at 87.5% VOUT, shutdown discharge via internal 900Ω resistor, and SOT23-6 package compatibility with space-constrained designs.

Technical Context

The MAX4837EUT25BD3 implements a BiCMOS-based LDO architecture with an internal P-channel pass transistor, precision bandgap reference, and error amplifier. Its RESET function monitors VOUT against a fixed 87.5% threshold and asserts low during undervoltage, thermal shutdown, SHDN activation, or VOUT > VIN conditions.

It integrates soft-start control via external capacitor on SS pin (tSS = CSS in nF), blanking-free overload response (unlike MAX4836), and shutdown discharge through a dedicated 900Ω internal path from OUT to GND - a feature absent in FLAG variants. The device operates across –40°C to +85°C with guaranteed stability using ≥3.3µF ceramic output capacitance (ESR < 0.2Ω).

Key Specifications

Pinout & Package

MAX4837EUT25BD3 is housed in a 6-pin SOT23-6 package (JEDEC MO-178AA) with exposed pad internally connected to GND. Pin 1 = IN, Pin 2 = GND, Pin 3 = SHDN, Pin 4 = RESET, Pin 5 = SS, Pin 6 = OUT. The compact 2.9mm × 2.8mm footprint supports high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX4837EUT25BD3, the TDFN variant offers superior thermal management in dense layouts, while the MAX4835EUT25BD2 provides a pin-compatible but derated alternative for lower-power subsystems - neither is a drop-in replacement without verifying current demand and timing requirements.

Availability

MAX4837EUT25BD3 is available at Aetrix Electronics and suitable for USB ports, SDIO interfaces, notebook subsystems, and GPS module bias rails requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX4837EUT25BD3 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 and mixed-signal ICs for power management, sensing, and interface applications in industrial, automotive, and portable electronics.

The MAX4836/MAX4837 product line delivers fault-aware LDO regulators targeting portable systems needing current-limiting, RESET signaling, and ultra-low quiescent current in minimal footprint.

FAQ

What is the exact output voltage tolerance of the MAX4837EUT25BD3 over temperature?

The MAX4837EUT25BD3 guarantees ±2% output voltage accuracy over the full –40°C to +85°C operating range, with typical deviation tighter at room temperature. This 2.5V ±50mV tolerance ensures compatibility with 2.5V I/O standards such as SDIO and USB transceivers without requiring external trimming.

Does the MAX4837EUT25BD3 provide output discharge during shutdown?

Yes, the MAX4837EUT25BD3 includes internal shutdown output discharge via a 900Ω resistor from OUT to GND. When SHDN is pulled low, this path actively discharges the output capacitor, preventing residual voltage from interfering with downstream logic states or causing latch-up in connected devices.

What is the RESET timeout period for MAX4837EUT25BD3, and how is it set?

The MAX4837EUT25BD3 has a 225ms RESET timeout period, indicated by the "D3" suffix in its part number. This duration is factory-programmed and non-adjustable; it defines how long the RESET pin remains asserted low after a fault condition (e.g., VOUT recovery) ends, ensuring sufficient time for system-level stabilization before release.

Can the MAX4837EUT25BD3 operate with input voltage equal to its 2.5V output?

No - the MAX4837EUT25BD3 requires minimum headroom: dropout voltage is 330mV at 500mA, so VIN must be ≥2.83V to sustain 2.5V output under full load. At light loads, dropout drops, but VIN must still exceed VOUT by at least 100mV to avoid regulation loss or RESET assertion.

How does reverse-current protection work in the MAX4837EUT25BD3?

The MAX4837EUT25BD3 disables its internal P-channel pass transistor when VOUT exceeds VIN, limiting reverse current to ≤2µA (typical) even with VOUT = 5.5V and VIN = 0V. This eliminates the need for an external blocking diode in applications with shared or hot-swappable power domains.