Analog Devices Inc. LTC3124HFE#TRPBF

Overview

LTC3124HFE#TRPBF from Analog Devices (formerly Linear Technology) is a dual-phase, synchronous step-up DC/DC converter with true output disconnect and inrush current limiting, delivering up to 15V output from inputs as low as 1.8V start-up and sustaining operation down to 500mV after startup. It features programmable switching frequency (100kHz–3MHz), 2.5A per-phase peak current limit, and Burst Mode® operation achieving 25µA quiescent current - ideal for powering RF power amplifiers and piezo actuators from single-cell Li-ion or backup capacitors.

For engineers reviewing the LTC3124HFE#TRPBF datasheet, LTC3124HFE#TRPBF pinout, LTC3124HFE#TRPBF application, or LTC3124HFE#TRPBF equivalent, key selection considerations include its −40°C to +150°C junction temperature rating, thermally enhanced 16-lead TSSOP package with exposed PGND pad, dual-phase ripple reduction architecture, and true output disconnect during shutdown - all critical for high-reliability industrial and automotive auxiliary rail generation.

Technical Context

The LTC3124HFE#TRPBF employs current-mode PWM control with adaptive slope compensation and dual-phase interleaving at 180° phase shift, enabling reduced output capacitor ripple current and higher effective ripple frequency. Its internal N-channel MOSFET switches (0.13Ω R_DS(ON)) and P-channel synchronous rectifiers support up to 95% efficiency across load ranges.

Operation includes programmable soft-start (10ms), integrated VCC LDO (4.25V regulated rail), CAP pin referenced to VOUT for synchronous gate drive biasing, and robust protection including thermal shutdown (170°C trip), output overvoltage lockout (16.5V), and short-circuit current limiting - all implemented without external sense resistors.

Key Specifications

Pinout & Package

Package: 16-lead plastic TSSOP with exposed thermal pad (Pin 17 = PGND), rated θ_JA = 40°C/W, θ_JC = 10°C/W. Exposed pad must be soldered to PCB ground plane for thermal and electrical performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC3122EFE#TRPBF and TPS61088RHLR, the LTC3124HFE#TRPBF uniquely combines dual-phase ripple suppression, true output disconnect, −40°C to +150°C operation, and 0.5V sustained input capability - making it the only option qualified for high-reliability, thermally constrained, or ultra-low-input-voltage boost applications.

Availability

LTC3124HFE#TRPBF is available at Aetrix Electronics and suitable for RF power amplifier biasing, piezo actuator driving, and 12V analog rail generation requiring stable component supply across extended temperature and long product lifecycles.

Supply support for LTC3124HFE#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 high-performance power management portfolio with rigorous automotive and industrial qualification standards.

The LTC3124 belongs to Linear's high-efficiency synchronous boost converter family, designed specifically for demanding applications requiring ultra-low input voltage operation, true output isolation, and robust thermal performance in compact packages.

FAQ

What is the minimum input voltage required to start up the LTC3124HFE#TRPBF?

The LTC3124HFE#TRPBF requires a minimum of 1.6V (typical 1.8V) on VIN to initiate startup. Once running, it continues regulating output voltages ≥2.5V even as VIN drops to 0.5V - a key feature for maximizing energy extraction from aging batteries or backup capacitors. This behavior is confirmed in the Electrical Characteristics table under "Minimum Start-Up Voltage" and "Input Voltage Range".

Does the LTC3124HFE#TRPBF provide true output disconnect, and how is it implemented?

Yes, the LTC3124HFE#TRPBF provides true output disconnect: when SD is pulled low (<0.25V), both internal P-channel synchronous rectifiers turn off and VOUT is fully isolated from VIN. This is verified in the Functional Description ("Output Disconnects from Input When Shut Down") and Pin Functions section, where VOUTA/VOUTB are explicitly described as the "source of the internal synchronous rectifier MOSFETs" and disconnected during shutdown.

What package type and thermal specifications apply to the LTC3124HFE#TRPBF?

The LTC3124HFE#TRPBF uses a 16-lead plastic TSSOP package with exposed thermal pad (Pin 17 = PGND), rated for −40°C to +150°C junction temperature. Its thermal resistance is θ_JA = 40°C/W and θ_JC = 10°C/W - significantly better than the DFN variant - and the exposed pad must be soldered to the PCB ground plane to achieve rated performance, as stated in the "ORDER INFORMATION" and "PIN CONFIGURATION" sections.

How is switching frequency programmed on the LTC3124HFE#TRPBF, and what is the valid range?

Switching frequency is set via an external resistor (RT) from Pin 8 to SGND, using the formula f_SW ≈ 28/RT (MHz). The supported range is 100kHz to 3MHz, corresponding to RT values from 316kΩ to 8.06kΩ - detailed in Table 1 and confirmed in the "ELECTRICAL CHARACTERISTICS" table where "Switching Frequency" is specified as 0.83–1.17MHz (typical at RT = 28kΩ) with full-range programmability noted in the FEATURES and OPERATION sections.

What protection features are integrated into the LTC3124HFE#TRPBF?

The LTC3124HFE#TRPBF integrates thermal shutdown (170°C trip), output overvoltage protection (16.5V lockout), short-circuit current limiting (2.5A/phase peak), and undervoltage lockout on VCC (<1.5V). These are explicitly listed under "FEATURES", "ABSOLUTE MAXIMUM RATINGS", and "OPERATION" sections - with thermal shutdown and OVP described as auto-recovering, and current limiting implemented via internal comparators without external components.