Analog Devices Inc./Maxim Integrated MAX1983EUT+T

Overview

MAX1983EUT+T from Maxim Integrated is an adjustable-output, low-dropout linear regulator with external 5V bias supply, delivering 0.8V to 2.0V at up to 300mA from a 1.25V–5.5V input. It features ±3% output voltage accuracy over temperature and load, 175mV dropout at 150mA, and integrated thermal shutdown and current limiting. It is used in notebook CPU core power supplies requiring precise low-voltage regulation.

For engineers reviewing the MAX1983EUT+T datasheet, MAX1983EUT+T pinout, MAX1983EUT+T application, or MAX1983EUT+T equivalent, key selection criteria include its adjustable output range (0.8V–2.0V), external bias architecture enabling ultra-low VIN operation, PGOOD-compatible enable control, SOT23-6 footprint compatibility, and guaranteed -40°C to +85°C performance.

Technical Context

The MAX1983EUT+T uses an N-channel pass transistor driven by a dedicated 4.5V–5.5V BIAS supply, decoupling gate drive from input voltage and enabling stable regulation even when VIN is as low as 1.25V - far below typical LDO limits. Its ADJ pin accepts a resistor divider to set output between 0.8V and 2.0V with ±3% accuracy across load (1–300mA) and temperature (-40°C to +85°C).

It integrates undervoltage lockout on BIAS (4.2V threshold), 1ms PGOOD propagation delay (rising edge), 10µs fault response, and thermal shutdown at +160°C with 20°C hysteresis. Shutdown current is ≤5µA, and total quiescent current (IBIAS + IIN) is 165µA typical - critical for battery-powered VID applications.

Key Specifications

Pinout & Package

MAX1983EUT+T is housed in a lead-free, RoHS-compliant 6-pin SOT23-6 package (top mark ABEB+), with 0.95mm pitch and 2.9mm × 1.6mm footprint. Thermal pad is not present; PCB layout must maximize copper area on GND pin for heat dissipation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar adjustable low-dropout regulator applications.

Compared with TPS79533DCQ and LT1963AES5-1.5, the MAX1983EUT+T uniquely supports sub-1.0V outputs with ultra-low dropout from 1.25V inputs - making it irreplaceable in modern low-power mobile SoC power domains where bias separation and voltage scalability are mandatory.

Availability

MAX1983EUT+T is available at Aetrix Electronics and suitable for notebook computers, PDAs, cell phones, and low-dropout regulators with external bias supply requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX1983EUT+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 demanding industrial, computing, and communications applications.

The MAX1982/MAX1983 family was engineered specifically for low-voltage, high-efficiency VID power supplies in portable computing - prioritizing ultra-low dropout, external bias independence, and compact SOT23 integration.

FAQ

What output voltage range does the MAX1983EUT+T support?

The MAX1983EUT+T supports an adjustable output voltage from 0.8V to 2.0V, set using an external resistor divider connected to the ADJ pin. This range is guaranteed across the full operating temperature (-40°C to +85°C) and load (1mA to 300mA) conditions, with ±3% accuracy. The MAX1983EUT+T does not support fixed outputs or voltages outside this band.

How does the external BIAS supply improve performance of the MAX1983EUT+T?

The external 4.5V–5.5V BIAS supply powers the gate driver and control circuitry independently of the IN rail, allowing the MAX1983EUT+T to regulate down to 0.8V even when IN is as low as 1.25V. This architecture reduces dropout voltage dependency on input level and improves efficiency versus conventional LDOs - a key advantage in battery-powered systems where VIN may sag significantly.

Can the MAX1983EUT+T be used without the PGOOD function?

Yes - unlike the MAX1982EUT+T, the MAX1983EUT+T does not include a PGOOD pin; Pin 4 is ADJ, not PGOOD. Therefore, no PGOOD functionality is present or required for basic operation. The MAX1983EUT+T relies solely on SHDN for enable/disable control and ADJ for feedback - simplifying designs where power-good monitoring is handled externally or omitted.

What are the minimum capacitor requirements for stable operation of the MAX1983EUT+T?

For stable operation, the MAX1983EUT+T requires a ≥10µF low-ESR ceramic output capacitor (ESR ≤35mΩ) on OUT, a ≥10µF ceramic input capacitor on IN, and a ≥0.1µF ceramic bypass capacitor on BIAS. These values are specified in the datasheet to ensure phase margin >45°, suppress load transients, and prevent oscillation - especially critical when operating near dropout or with high-frequency digital loads.

Is the MAX1983EUT+T RoHS-compliant and lead-free?

Yes - the "+T" suffix in MAX1983EUT+T explicitly denotes a lead(Pb)-free, RoHS-compliant package per Maxim's ordering information. It uses a 6-pin SOT23-6 package with top mark ABEB+, and meets JEDEC J-STD-020 moisture sensitivity level 1 (MSL-1) for standard surface-mount assembly without baking.