Analog Devices Inc. LT3015IDD-3#PBF

Overview

LT3015IDD-3#PBF from Analog Devices (formerly Linear Technology) is a fixed-output –3V, 1.5A negative low-dropout linear regulator in an 8-lead 3mm × 3mm DFN package. It delivers ultra-low 60µVRMS output noise (10Hz–100kHz), 310mV typical dropout at full load, and <1µA shutdown current - ideal for precision analog front-ends and low-noise instrumentation requiring stable negative bias rails.

For engineers reviewing the LT3015IDD-3#PBF datasheet, LT3015IDD-3#PBF pinout, LT3015IDD-3#PBF application, or LT3015IDD-3#PBF equivalent, key selection criteria include guaranteed –3V output accuracy over temperature, reverse output protection, thermal limit with hysteresis, compatibility with 10µF ceramic output capacitors, and precise current limit with foldback for fault robustness.

Technical Context

The LT3015IDD-3#PBF uses a PNP pass transistor architecture enabling fast transient response and tightly controlled quiescent current in dropout. Its internal reference is trimmed to ±1% over temperature, and the SENSE/ADJ pin (Pin 6) connects directly to the output for fixed-voltage operation without external resistors.

It integrates precision current limiting with foldback activation at |VIN – VOUT| ≥ 8V, thermal shutdown with hysteresis (TJ = 125°C trip, ~110°C reset), and reverse output protection that prevents damage when VOUT exceeds VIN. The device operates across –40°C to 125°C junction temperature and accepts input voltages from –1.8V to –30V.

Key Specifications

Pinout & Package

LT3015IDD-3#PBF uses an 8-lead 3mm × 3mm × 0.75mm plastic DFN package with exposed IN pad (Pin 9) for thermal performance. Pin 6 functions as SENSE for fixed-output variants.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar negative linear regulator applications.

Compared with LT3015EDD-3#PBF, the LT3015IDD-3#PBF offers identical performance with enhanced reliability screening for mission-critical industrial use; versus LT3015IMSE-3#PBF, it provides superior power density and lower profile (0.75mm) at the cost of higher thermal resistance - making it optimal for space-constrained, high-volume production.

Availability

LT3015IDD-3#PBF is available at Aetrix Electronics and suitable for industrial process control, precision instrumentation, and dual-rail analog signal conditioning requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for LT3015IDD-3#PBF 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

Analog Devices acquired Linear Technology in 2017 and maintains its high-performance analog portfolio. Linear Technology pioneered precision power management ICs with emphasis on low noise, high PSRR, and robust protection.

The LT3015 series was designed specifically for noise-sensitive negative rail applications - including post-regulation of switching supplies, bipolar op-amp biasing, and instrumentation where conventional NPN-based regulators fail to meet noise or dropout targets.

FAQ

What is the output voltage tolerance of the LT3015IDD-3#PBF over temperature and load?

The LT3015IDD-3#PBF delivers –3.0V with ±1% initial accuracy and maintains ±1.5% regulation over –40°C to 125°C junction temperature and full –1mA to –1.5A load range. This is verified per the Electrical Characteristics table (Page 5), where min/max output voltage is specified as –2.94V to –3.06V at ILOAD = –1mA and –2.97V to –3.03V at ILOAD = –1.5A.

Does the LT3015IDD-3#PBF require an external resistor divider to set the output voltage?

No. The LT3015IDD-3#PBF is a fixed-output variant with internal feedback; Pin 6 (SENSE) connects directly to the output internally. Unlike the adjustable LT3015, no external resistors are needed - simplifying design and improving accuracy by eliminating resistor tolerance and thermal drift effects.

What is the minimum input voltage required for the LT3015IDD-3#PBF to maintain regulation at 1.5A?

The LT3015IDD-3#PBF requires a minimum input voltage of –3.3V to sustain –3.0V output at –1.5A, based on its 310mV typical dropout voltage. Per Absolute Maximum Ratings and Note 12, operation below –3.3V causes dropout; the device remains functional but output drops linearly as VIN approaches VOUT + VDROPOUT.

Can the LT3015IDD-3#PBF safely drive a 10µF ceramic output capacitor without oscillation?

Yes. The LT3015IDD-3#PBF is explicitly characterized for stability with ≥10µF ceramic capacitors (X7R, X5R) and does not require added ESR. This is confirmed in the Features list ("Stable with Ceramic, Tantalum or Aluminum Capacitors") and Typical Application schematic (Page 1), which shows a 10µF ceramic at VOUT.

How does the current limit foldback function in the LT3015IDD-3#PBF during overvoltage conditions?

The LT3015IDD-3#PBF initiates current limit foldback when |VIN – VOUT| ≥ 8V (e.g., –11V input with –3V output). As differential voltage increases, the current limit decreases from 1.7A to ~1.0A at |VIN – VOUT| = 15V - reducing power dissipation and preventing thermal runaway during sustained overvoltage faults.