Analog Devices Inc. LT1965IDD-1.8#TRPBF

Overview

LT1965IDD-1.8#TRPBF from Analog Devices (formerly Linear Technology) is a fixed-output, low-noise, low-dropout linear regulator delivering 1.1A at 1.8V with 310mV typical dropout voltage, 40µVRMS output noise (10Hz–100kHz), and <1µA shutdown quiescent current. It serves as a precision post-regulator for switching supplies in RF power amplifiers and DSP core supplies where clean, stable 1.8V bias is critical.

For engineers reviewing the LT1965IDD-1.8#TRPBF datasheet, LT1965IDD-1.8#TRPBF pinout, LT1965IDD-1.8#TRPBF application, or LT1965IDD-1.8#TRPBF equivalent, this page provides verified package mapping (8-lead 3mm × 3mm DFN), thermal performance data (θJA = 65°C/W), SENSE pin functionality, ceramic capacitor stability (10µF min), and real-world load regulation specs (±12mV over 1mA–1.1A).

Technical Context

The LT1965IDD-1.8#TRPBF uses a precision bandgap reference and error amplifier to maintain 1.8V output within ±1.5% over temperature and load. Its SENSE pin enables Kelvin sensing for high-accuracy regulation, eliminating PCB trace IR drop effects - critical in high-current, low-voltage applications like FPGA I/O banks.

Internal protection includes reverse-battery protection, foldback current limiting, thermal shutdown, and reverse-current blocking. Quiescent current remains tightly controlled (<600µA active, <1µA shutdown) and does not rise in dropout - unlike conventional LDOs - ensuring predictable battery life in portable instrumentation.

Key Specifications

Pinout & Package

LT1965IDD-1.8#TRPBF is housed in an 8-lead 3mm × 3mm plastic DFN package with exposed thermal pad (Pin 9 = GND). The package delivers θJA = 65°C/W and θJC = 3°C/W, enabling high-power dissipation in space-constrained layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS7A2018PDQNR and MCP1703T-1802E/MB, the LT1965IDD-1.8#TRPBF uniquely combines 1.1A capability, 40µVRMS noise, Kelvin SENSE, and full reverse-protection - making it irreplaceable in high-fidelity RF and battery-critical designs where all four attributes are mandatory.

Availability

LT1965IDD-1.8#TRPBF is available at Aetrix Electronics and suitable for RF power amplifier bias, DSP core supply, and portable medical sensor node applications requiring stable component supply, long-term lifecycle support, and guaranteed DFN package consistency.

Supply support for LT1965IDD-1.8#TRPBF 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 legacy of high-performance analog ICs with rigorous automotive and industrial qualification.

The LT1965 series was designed specifically for noise-sensitive, high-current applications such as RF transceivers, precision instrumentation, and battery-powered systems demanding robust protection and stable regulation.

FAQ

What is the minimum input voltage required for LT1965IDD-1.8#TRPBF to regulate 1.8V at 1.1A?

The LT1965IDD-1.8#TRPBF requires a minimum input voltage of 2.11V to maintain 1.8V output at 1.1A, based on its 310mV typical dropout voltage. At higher temperatures or worst-case conditions, the guaranteed dropout is 490mV, so design margin should assume ≥2.29V minimum input for full-load operation across temperature.

Can LT1965IDD-1.8#TRPBF operate with a 10µF ceramic output capacitor?

Yes, the LT1965IDD-1.8#TRPBF is explicitly characterized and guaranteed stable with ≥10µF ceramic or tantalum output capacitors - no ESR requirements. This eliminates need for bulk electrolytic caps and simplifies layout in space-constrained RF modules.

How does the SENSE pin function on LT1965IDD-1.8#TRPBF?

On the LT1965IDD-1.8#TRPBF, Pin 3 is the SENSE input to the error amplifier. For best accuracy, connect it directly to the load (Kelvin sense) to cancel PCB trace resistance. If unused, tie it to the OUT pin. Its 100µA bias current is factored into load regulation specs.

Does LT1965IDD-1.8#TRPBF provide reverse-current protection?

Yes, the LT1965IDD-1.8#TRPBF blocks reverse current flow from OUT to IN - critical when backup batteries hold up the output while main input is disconnected. This eliminates need for external blocking diodes and prevents power loss or system instability.

What thermal derating applies to LT1965IDD-1.8#TRPBF in a 4-layer PCB?

With the exposed pad soldered to a 1-in² internal ground plane on a 4-layer PCB, the LT1965IDD-1.8#TRPBF achieves θJA ≈ 65°C/W. At 25°C ambient, max continuous power dissipation is ~1.4W (1.1A × 1.27V dropout), limiting usable input-to-output differential to ≤1.15V at full load to stay below 125°C junction temperature.