Analog Devices Inc. LTC3872HTS8-1#TRMPBF

Overview

LTC3872HTS8-1#TRMPBF from Analog Devices (formerly Linear Technology) is a constant-frequency current-mode boost DC/DC controller driving an external N-channel MOSFET without requiring a sense resistor. It operates from 2.75V to 9.8V input, delivers up to 60V output, features ±1.5% voltage reference accuracy, 550kHz switching frequency, and supports –40°C to 150°C junction temperature. It is used in high-efficiency 3.3V-to-5V telecom and industrial boost converters.

For engineers reviewing the LTC3872HTS8-1#TRMPBF datasheet, LTC3872HTS8-1#TRMPBF pinout, LTC3872HTS8-1#TRMPBF application, or LTC3872HTS8-1#TRMPBF equivalent, key selection criteria include No RSENSE operation, adjustable current limit via IPRG pin, internal soft-start, pulse-skipping at light load, and TS8 (ThinSOT-23) thermal performance at 150°C junction rating.

Technical Context

The LTC3872HTS8-1#TRMPBF implements a No RSENSE current-sensing architecture that monitors voltage drop across the power MOSFET's R_DS(ON), eliminating external sense resistors and improving efficiency. Its current-mode control loop uses the ITH pin as error amplifier output and current comparator threshold reference, enabling fast line/load transient response.

It integrates a 550kHz oscillator, undervoltage lockout (UVLO) with 2.3V rising threshold, RUN/SS shutdown control with 0.85V falling threshold, and internal slope compensation for stable operation above 50% duty cycle. Unlike the standard LTC3872, it omits frequency foldback during current limit, preserving constant switching frequency under overload.

Key Specifications

Pinout & Package

Package: 8-lead ThinSOT-23 (TS8), 1mm profile, exposed pad (GND), θ_JA = 195°C/W. Designed for space-constrained PCBs with thermal relief via soldered exposed pad.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar boost controller applications.

Compared with LTC3872ITS8-1#TRPBF, the LTC3872HTS8-1#TRMPBF provides 25°C higher maximum junction temperature and tighter thermal derating margin; versus MAX17595ATP+T, it eliminates sense-resistor losses and supports lower VIN, but requires external MOSFET selection and layout attention to SW-node ringing.

Availability

LTC3872HTS8-1#TRMPBF is available at Aetrix Electronics and suitable for telecom power supplies, 42V automotive systems, and 24V industrial controls requiring stable component supply across extended temperature and long product lifecycles.

Supply support for LTC3872HTS8-1#TRMPBF 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 and power management portfolio with rigorous automotive and industrial qualification standards.

The LTC3872HTS8-1#TRMPBF belongs to Linear's No RSENSE boost controller family, designed specifically for high-efficiency, low-component-count DC/DC conversion in thermally demanding environments where sense-resistor losses and board space are critical constraints.

FAQ

What is the maximum output voltage supported by the LTC3872HTS8-1#TRMPBF?

The LTC3872HTS8-1#TRMPBF supports output voltages up to 60V, as confirmed by its SW pin absolute maximum rating and typical application circuits. This enables use in 48V telecom systems, PoE midspans, and 42V automotive auxiliary rails. The actual achievable VOUT depends on external MOSFET BVDSS, diode PIV rating, and inductor saturation current - all must be selected to sustain 60V under worst-case transients.

How does the No RSENSE architecture work in the LTC3872HTS8-1#TRMPBF?

The LTC3872HTS8-1#TRMPBF senses current by monitoring the voltage drop across the R_DS(ON) of the external N-channel MOSFET connected to the SW and NGATE pins. It compares this voltage against an internally generated threshold (80–310mV, set by IPRG) to terminate each switching cycle. This eliminates the power loss and board area of a discrete sense resistor while maintaining accurate current limiting.

What is the purpose of the IPRG pin on the LTC3872HTS8-1#TRMPBF?

The IPRG pin on the LTC3872HTS8-1#TRMPBF selects the peak current limit threshold: 80mV (IPRG = GND), 145mV (IPRG = floating), or 240mV (IPRG = VIN). This adjusts the maximum allowable inductor current without changing external components, allowing one PCB layout to support multiple MOSFETs with different R_DS(ON) values or varying load requirements.

Can the LTC3872HTS8-1#TRMPBF operate from a 3.3V input to generate 5V at 2A?

Yes - the LTC3872HTS8-1#TRMPBF is explicitly characterized in a 3.3V-to-5V/2A boost application (Typical Application, Figure TA01b). With its 2.75V minimum input, 550kHz frequency, and No RSENSE architecture, it achieves >92% efficiency in this configuration using a 1µH inductor and appropriate MOSFET/diode selection per the datasheet guidelines.

What thermal considerations apply to the LTC3872HTS8-1#TRMPBF in its TS8 package?

The LTC3872HTS8-1#TRMPBF in TS8 package has θ_JA = 195°C/W. To maintain ≤150°C junction temperature at full load, the PCB must provide adequate copper area under the exposed pad (soldered to GND) and minimize ambient temperature rise. Derating is required above 85°C ambient; thermal simulation or IR imaging is recommended for high-power or enclosed applications.