Analog Devices Inc./Maxim Integrated MAX1735EUK25-T

Overview

MAX1735EUK25-T from Maxim Integrated is a negative-output, low-dropout linear regulator delivering a preset -2.5V output at up to 200mA with 80mV dropout at full load, ±1% output voltage accuracy over temperature, and operation from -2.5V to -6.5V input. It integrates an N-channel MOSFET pass device, supports Dual Mode (fixed or adjustable output), and targets portable battery-powered systems requiring stable negative bias.

For engineers reviewing the MAX1735EUK25-T datasheet, MAX1735EUK25-T pinout, MAX1735EUK25-T application, or MAX1735EUK25-T equivalent, key selection criteria include guaranteed -2.5V output accuracy, shutdown current ≤1nA, thermal overload protection at +160°C, stability with 1µF ceramic output capacitor, and SOT23-5 package compatibility with space-constrained PCB layouts.

Technical Context

The MAX1735EUK25-T uses an internal -1.25V reference and error amplifier to regulate output by controlling an N-channel MOSFET pass transistor. Its Dual Mode comparator selects between internal fixed feedback (SET tied to GND) and external resistive divider (for adjustable mode), enabling precise -2.5V regulation without external components in preset configuration.

Shutdown logic accepts either positive or negative enable signals (|V_SHDN| > 1.6V enables; |V_SHDN| < 0.4V disables), eliminating level-shifting circuitry when interfacing with standard TTL or negative-bias control rails. Thermal protection cycles output on/off at +160°C junction temperature with 15°C hysteresis.

Key Specifications

Pinout & Package

The MAX1735EUK25-T is housed in a 5-pin SOT23-5 package with exposed pad optimized for thermal dissipation. Pin 2 (IN) serves as both input and heatsink; soldering to a large copper area is recommended for power handling above 100mA.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM2937ET-2.5/NOPB and LT1963AES5-2.5#TRPBF, the MAX1735EUK25-T uniquely delivers true negative -2.5V regulation in SOT23-5 without external inversion circuitry, enabling direct integration into GaAsFET bias, dual-supply op-amps, and portable instrumentation where board space and efficiency are critical.

Availability

MAX1735EUK25-T is available at Aetrix Electronics and suitable for mobile wireless data modems, notebook computers, and instrumentation amplifiers requiring stable component supply across industrial temperature range (-40°C to +85°C).

Supply support for MAX1735EUK25-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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, communications, and consumer applications.

The MAX1735 series was designed specifically for portable battery-powered equipment requiring compact, efficient negative voltage regulation - targeting PDAs, cordless phones, modems, and GaAsFET bias applications with strict size and quiescent current constraints.

FAQ

What is the exact output voltage tolerance of the MAX1735EUK25-T over its full operating temperature range?

The MAX1735EUK25-T guarantees ±2% output voltage accuracy over the -40°C to +85°C temperature range at full 200mA load. At +25°C, the tolerance tightens to ±1%, and the typical output is -2.50V ±12.5mV. This specification is confirmed in the Electrical Characteristics table under "Output Voltage Accuracy" with test condition I_LOAD = -100µA to -200mA.

Can the MAX1735EUK25-T be used in adjustable mode, and what is the minimum output voltage it supports?

Yes, the MAX1735EUK25-T supports adjustable mode via the SET pin. When configured with an external resistor divider, it delivers output voltages from -1.25V to -5.5V. The -1.25V lower limit is set by the internal reference voltage; attempting to go below this violates regulation and is not supported per the datasheet's Output Voltage Selection section.

Does the MAX1735EUK25-T require special input or output capacitors for stability?

No special capacitors are required. The MAX1735EUK25-T is stable with a standard 1µF ceramic capacitor on the output (C_OUT) for -2.5V operation, and a 1µF ceramic on the input (C_IN). For outputs between -1.25V and -2.5V, a minimum 2.2µF C_OUT is required. ESR must be ≤0.2Ω for -2.5V output - easily met by common X5R/X7R MLCCs.

How does the shutdown function work on the MAX1735EUK25-T, and what voltage levels activate it?

The MAX1735EUK25-T shutdown pin (SHDN) accepts bipolar logic: driving SHDN to GND places the device in shutdown (I_Q ≤1nA), while applying either +1.6V to +7.0V or -1.6V to -7.0V enables regulation. Voltages between ±0.4V are invalid and cause undefined behavior. This dual-polarity capability eliminates level shifters when interfacing with negative control rails.

Is thermal protection active during normal operation of the MAX1735EUK25-T, and how does it behave under overload?

Thermal protection activates only during overload or poor PCB thermal design - it is not active during normal operation. When junction temperature exceeds +160°C, the MAX1735EUK25-T disables the output MOSFET; once die temperature drops by 15°C (to ~145°C), regulation resumes. This hiccup-mode cycling prevents permanent damage during sustained short-circuit or high-power-dissipation conditions.