Analog Devices Inc. LT1376HVIS8#TRPBF

Overview

LT1376HVIS8#TRPBF from Analog Devices (formerly Linear Technology) is a 500kHz, 1.5A monolithic buck switching regulator in an 8-lead SOIC package, featuring fixed 5V output, 0.4Ω switch on-resistance, 2.5mA quiescent current, and 20µA shutdown current. It delivers up to 1.25A at 5V from 6V–25V input for battery-powered systems and portable computing power rails.

For engineers reviewing the LT1376HVIS8#TRPBF datasheet, LT1376HVIS8#TRPBF pinout, LT1376HVIS8#TRPBF application, or LT1376HVIS8#TRPBF equivalent, key selection criteria include input voltage range (6V–25V), guaranteed 5V ±2% output accuracy over temperature, cycle-by-cycle current limiting, thermal shutdown, and compatibility with standard surface-mount 5µH inductors and tantalum output capacitors.

Technical Context

The LT1376HVIS8#TRPBF implements current-mode control with a 500kHz fixed-frequency oscillator and internal slope compensation to prevent subharmonic oscillation. Its bipolar NPN power switch is driven via an external BOOST capacitor to achieve saturation, reducing conduction loss equivalent to a 0.4Ω FET.

It integrates error amplifier transconductance of 2000 µMho, 2.42V reference (for adjustable variants) or 5.0V sense threshold (fixed -5 version), and dual-threshold shutdown logic: 2.38V UVLO and 0.4V deep-sleep mode. The BIAS pin (present only on LT1376) enables efficiency optimization by sourcing bias current from the regulated output when VIN ≫ VOUT.

Key Specifications

Pinout & Package

LT1376HVIS8#TRPBF is housed in an 8-lead plastic SOIC (S8) package with θ_JA = 120–150°C/W depending on PCB layout. Pin 1 is marked with a beveled corner; GND pins (pins 3 and 8) must be connected to a low-impedance ground plane to ensure load regulation and minimize EMI.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC3605EDE#TRPBF and TPS5430DDAR, LT1376HVIS8#TRPBF offers optimal balance of integration (single-chip 1.5A switch), fixed 5V accuracy, and BIAS-enabled efficiency at 12–24V inputs-making it ideal for cost-sensitive, thermally constrained 5V distributed power nodes.

Availability

LT1376HVIS8#TRPBF is available at Aetrix Electronics and suitable for portable computers, battery-powered systems, and distributed power architectures requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for LT1376HVIS8#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 full technical and manufacturing continuity for legacy Linear power products.

The LT1376 belongs to Linear's high-frequency monolithic buck regulator family, designed specifically for compact, efficient DC/DC conversion in space- and thermal-constrained applications where fixed 5V output and minimal external components are critical.

FAQ

What is the guaranteed output voltage tolerance for LT1376HVIS8#TRPBF across temperature?

The LT1376HVIS8#TRPBF features a fixed 5V output with ±2% tolerance over the full operating junction temperature range of –40°C to 125°C. This specification is guaranteed by design and verified per the Electrical Characteristics table in the official datasheet, where the Sense Voltage parameter is listed as 4.94V to 5.06V at TJ = 25°C and 4.90V to 5.10V over temperature. No external resistor network is required, eliminating drift sources inherent in adjustable regulators.

Does LT1376HVIS8#TRPBF require an external BOOST capacitor, and what happens if it's omitted?

Yes, LT1376HVIS8#TRPBF requires an external BOOST capacitor (typically 10nF–100nF) and catch diode (e.g., 1N5818) connected between VIN and BOOST. If omitted, the internal NPN power switch cannot saturate, resulting in increased V_CE(sat) (~1.5V), reduced efficiency (<75%), excessive die heating, and potential thermal shutdown. The BOOST network is essential to achieve the specified 0.4Ω effective switch resistance and >87% efficiency.

How does the BIAS pin improve efficiency in LT1376HVIS8#TRPBF, and what is the minimum supported output voltage?

The BIAS pin on LT1376HVIS8#TRPBF allows internal bias circuitry to draw current from the regulated 5V output instead of VIN, reducing total input-referred quiescent current. This improves efficiency by >10% at VIN = 20V, VOUT = 5V, and I_OUT = 25mA. The minimum supported output voltage for BIAS operation is 3.3V, though LT1376HVIS8#TRPBF is a fixed 5V part-so BIAS functionality is fully enabled and beneficial in all intended applications.

What protection features are built into LT1376HVIS8#TRPBF, and how do they behave during a short circuit?

LT1376HVIS8#TRPBF includes cycle-by-cycle current limiting, thermal shutdown with hysteresis, and dual-threshold shutdown (UVLO at 2.38V and deep-sleep at 0.4V). During a short circuit, the FB/SENSE pin voltage collapses, triggering frequency foldback (reducing switching frequency ~5:1 below 1V) and current foldback (lowering peak switch current below 1.7V), limiting power dissipation in both the IC and external components without requiring external circuitry.

Can LT1376HVIS8#TRPBF operate with input voltages below 6V, and what are the limitations?

No-LT1376HVIS8#TRPBF has a guaranteed minimum input voltage of 6V, as stated in the Absolute Maximum Ratings and confirmed in the Typical Performance Characteristics (Figure G12). Operation below 6V may result in failure to start, unstable regulation, or violation of the 2.38V UVLO threshold. For 4.5V–12V inputs, Analog Devices specifies the functionally identical LT1507, which is not a direct replacement for LT1376HVIS8#TRPBF due to different pinout and internal architecture.