Analog Devices Inc./Maxim Integrated MAX1735EUK30-T

Overview

MAX1735EUK30-T from Maxim Integrated is a negative-output, low-dropout linear regulator delivering a guaranteed -3.0V output at up to 200mA with 80mV dropout at full load, ±1% output voltage accuracy over temperature, and 85µA quiescent current. It uses an internal N-channel MOSFET pass device and supports both fixed-output and adjustable modes via the SET pin, making it suitable for GaAsFET biasing and portable telecom power rails.

For engineers reviewing the MAX1735EUK30-T datasheet, MAX1735EUK30-T pinout, MAX1735EUK30-T application, or MAX1735EUK30-T equivalent, key selection criteria include guaranteed -3.0V output voltage, SOT23-5 package thermal performance, shutdown threshold compatibility with TTL/CMOS logic, stability with 1µF ceramic output capacitance, and PSRR >60dB at 100Hz for noise-sensitive analog subsystems.

Technical Context

The MAX1735EUK30-T implements a Dual Mode™ architecture with an internal -1.25V reference and error amplifier driving an N-channel MOSFET pass transistor. Its feedback path is selected by the SET pin voltage: grounded for fixed -3.0V output, or biased via external resistors for adjustable operation between -1.25V and -5.5V.

Shutdown control accepts either positive or negative logic levels (|V_SHDN| > 1.6V enables; |V_SHDN| < 0.4V disables), enabling direct interface with standard 3.3V/5V logic without level shifting. Thermal protection activates at +160°C junction temperature with 15°C hysteresis, and short-circuit current is limited to -515mA typical.

Key Specifications

Pinout & Package

Package: SOT23-5 - compact surface-mount package with exposed pad for thermal dissipation; requires soldering IN pin to large PCB copper area to maintain θ_JA ≤ 140°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX1735EUK30-T, both alternatives lack negative-output capability, Dual Mode™ adjustability, and sub-100µA quiescent current - making them unsuitable drop-in replacements for GaAsFET bias or portable telecom applications requiring -3.0V regulation.

Availability

MAX1735EUK30-T is available at Aetrix Electronics and suitable for GaAsFET biasing, mobile phone RF front-ends, and portable instrumentation amplifier power rails requiring stable component supply across industrial temperature ranges.

Supply support for MAX1735EUK30-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 high-performance analog and mixed-signal ICs for power management, data conversion, and interface applications.

The MAX1735EUK30-T belongs to Maxim's low-dropout linear regulator product line, engineered specifically for battery-powered portable electronics requiring negative voltage regulation with ultra-low quiescent current and compact packaging.

FAQ

What is the exact output voltage of the MAX1735EUK30-T?

The MAX1735EUK30-T is factory-trimmed to deliver a precise -3.0V output voltage when the SET pin is connected to GND. This preset value is guaranteed over the full -40°C to +85°C operating temperature range with ±2% tolerance. The device also supports adjustable operation from -1.25V to -5.5V when external resistors are used on the SET pin, but the MAX1735EUK30-T variant defaults to -3.0V in fixed mode.

Does the MAX1735EUK30-T require external components to operate?

Yes - the MAX1735EUK30-T requires at minimum a 1µF ceramic capacitor between IN and GND, and another 1µF ceramic capacitor between OUT and GND for stable operation. These capacitors reduce source impedance and ensure loop stability. No additional compensation components are needed, and the device remains stable with output capacitance up to 10µF and ESR ≤ 0.2Ω.

Can the MAX1735EUK30-T be used with a positive logic shutdown signal?

Yes - the MAX1735EUK30-T SHDN pin accepts positive logic: driving SHDN above +1.6V enables the regulator, while pulling it to GND disables it. This allows direct connection to standard 3.3V or 5V CMOS/TTL outputs without level-shifting circuitry. The same pin also accepts negative logic (below -1.6V), offering flexibility in mixed-voltage system designs.

What thermal considerations apply to the MAX1735EUK30-T in SOT23-5 package?

The MAX1735EUK30-T's SOT23-5 package relies heavily on PCB layout for thermal performance. Pin 2 (IN) serves as the primary thermal path - it must be soldered to a large copper pour or internal ground/power plane to achieve θ_JA ≈ 140°C/W. Without adequate copper, power dissipation is limited to 571mW at +70°C ambient, restricting usable input-output differential at full 200mA load.

How does the MAX1735EUK30-T compare to positive-output LDOs in terms of efficiency and noise?

The MAX1735EUK30-T achieves comparable efficiency to positive-output LDOs at light loads due to its 85µA quiescent current, but its N-channel MOSFET architecture delivers lower dropout (80mV vs. typical 200–300mV for PNP-based positive LDOs). Its 160µV_RMS output noise and >60dB PSRR at 100Hz match or exceed many positive LDOs, making it especially effective for noise-sensitive analog biasing where negative rails are required.