Analog Devices Inc./Maxim Integrated MAX1735EUK50-T

Overview

MAX1735EUK50-T from Maxim Integrated is a negative-output, low-dropout linear regulator delivering guaranteed 200mA at -5.0V output with 80mV dropout at full load, ±1% output voltage accuracy over temperature, and 85µA quiescent current - designed for GaAsFET bias, mobile wireless data modems, and portable instrumentation requiring stable negative rail generation.

For engineers reviewing the MAX1735EUK50-T datasheet, MAX1735EUK50-T pinout, MAX1735EUK50-T application, or MAX1735EUK50-T equivalent, key selection criteria include negative-input voltage range (-2.5V to -6.5V), shutdown threshold compatibility (±1.6V enable / ±0.4V disable), SOT23-5 thermal performance (θJA ≈ 0.140°C/mW), and stability with 1µF ceramic output capacitor.

Technical Context

The MAX1735EUK50-T integrates an internal -1.25V reference, error amplifier, and N-channel MOSFET pass transistor in a Dual Mode™ architecture - enabling fixed -5.0V output when SET is grounded or adjustable operation from -1.25V to -5.5V via external resistive divider. Its N-MOSFET topology eliminates base-drive current, maintaining 125µA ground-pin current even at 200mA load and in dropout.

Shutdown logic accepts either positive or negative control voltages: |V_SHDN| > 1.6V enables regulation; |V_SHDN| < 0.4V forces shutdown with <1nA supply current. Thermal protection activates at +160°C junction temperature with 15°C hysteresis, cycling output during sustained short-circuit faults.

Key Specifications

Pinout & Package

MAX1735EUK50-T is housed in a 5-pin SOT23-5 package with exposed pad thermal enhancement. The IN pin serves as both input and heatsink - requires soldering to large PCB copper area for optimal thermal dissipation (θJA ≈ 0.140°C/mW).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LT1963AEMS-5 and TPS7A3301RGWR, the MAX1735EUK50-T delivers true plug-in -5.0V regulation in the smallest footprint (SOT23-5), with lowest quiescent current and simplest external component count - making it optimal for space- and power-constrained portable negative-rail applications.

Availability

MAX1735EUK50-T is available at Aetrix Electronics and suitable for GaAsFET bias, mobile wireless data modems, and notebook computer subsystems requiring stable component supply, long-term lifecycle assurance, and consistent parametric performance across production lots.

Supply support for MAX1735EUK50-T 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 industrial, automotive, communications, and consumer applications.

The MAX1735EUK50-T belongs to Maxim's high-efficiency negative LDO family, engineered specifically for battery-powered portable equipment needing ultra-low IQ, small form factor, and robust fault protection in harsh thermal environments.

FAQ

What is the maximum input voltage range supported by the MAX1735EUK50-T?

The MAX1735EUK50-T operates from a -2.5V to -6.5V input voltage range. Absolute maximum ratings specify -7.0V on the IN pin relative to GND. Exceeding -6.5V may cause excessive power dissipation or thermal shutdown, especially at high ambient temperatures or full load. The device is optimized for use with standard negative supply rails including -5V and -3.3V systems.

Can the MAX1735EUK50-T be used in adjustable mode, and what is the output voltage range?

Yes, the MAX1735EUK50-T supports adjustable mode by connecting an external resistive divider between OUT and SET pins. In this configuration, the output voltage is set using V_OUT = -1.25V × (1 + R1/R2), yielding a range of -1.25V to -5.5V. The MAX1735EUK50-T's internal -1.25V reference and <100nA SET pin bias current ensure high accuracy and low divider power loss. Fixed -5.0V operation is selected by grounding the SET pin.

What is the thermal shutdown behavior of the MAX1735EUK50-T during continuous overload?

The MAX1735EUK50-T features thermal shutdown that activates at +160°C junction temperature with 15°C hysteresis. During a continuous short-circuit condition, the device cycles ON and OFF - enabling the pass transistor until the die reaches +160°C, then disabling it until the temperature drops to +145°C. This protects the MAX1735EUK50-T from permanent damage while allowing automatic recovery once cooling occurs, without requiring external reset circuitry.

Does the MAX1735EUK50-T require special output capacitance for stability, and what type is recommended?

The MAX1735EUK50-T is stable with a minimum 1µF ceramic output capacitor for output voltages between -2.5V and -5.5V. For -1.25V to -2.45V outputs, a 2.2µF capacitor is required. Ceramic capacitors with ESR ≤ 0.2Ω are recommended; low-ESR tantalum is acceptable, but aluminum electrolytics are discouraged due to high ESR and size. The MAX1735EUK50-T does not require external compensation components, simplifying layout and reducing bill-of-materials cost.

How does the shutdown functionality of the MAX1735EUK50-T work with both positive and negative control signals?

The MAX1735EUK50-T's SHDN pin accepts either polarity: driving SHDN above +1.6V or below -1.6V enables regulation, while |V_SHDN| < 0.4V places the device in shutdown with <1nA supply current. This dual-polarity compatibility allows direct interfacing with 3.3V/5V GPIOs (positive drive) or negative logic rails (negative drive) without level shifters. For always-on operation, SHDN can be tied directly to IN, eliminating external control circuitry.