Analog Devices Inc. LTC3862IUH#TRPBF

Overview

LTC3862IUH#TRPBF from Analog Devices is a two-phase, constant-frequency, peak current mode boost/SEPIC DC/DC controller driving N-channel MOSFETs. It operates from 4V to 36V input, delivers up to 96% max duty cycle, supports 75kHz–500kHz programmable switching frequency, and features internal 5V/3.8V LDOs for gate drive and analog circuitry. It enables high-efficiency 48V telecom and industrial power supplies.

For engineers reviewing the LTC3862IUH#TRPBF datasheet, LTC3862IUH#TRPBF pinout, LTC3862IUH#TRPBF application, or LTC3862IUH#TRPBF equivalent, key selection criteria include phase synchronization capability (SYNC/CLKOUT), adjustable slope compensation, leading-edge blanking control, and AEC-Q100-qualified temperature grade (–40°C to 125°C).

Technical Context

The LTC3862IUH#TRPBF implements fixed-frequency peak current mode control with dual independent channels operating 180° out of phase. Its error amplifier (EA) compares FB voltage against a ±1% 1.223V reference and drives ITH to modulate peak inductor current. Slope compensation gain is programmable via SLOPE pin (0.625× to 1.66× nominal), and minimum on-time is configurable (180–340ns) via BLANK pin.

Phase coordination is managed through PHASEMODE (0V/float/3.8V) to set CH1–CH2 and CH1–CLKOUT relationships (120°/180°/180° and 240°/60°/90° respectively). The internal PLL allows synchronization to external clocks from 50kHz to 650kHz at SYNC, while DMAX pin sets precise max duty cycle (75%/84%/96%) derived from a 12× internal clock.

Key Specifications

Pinout & Package

Package: 24-lead (5mm × 5mm) plastic QFN (UH package), exposed thermal pad connected to PGND. Requires soldering of exposed pad to PCB ground plane for thermal and electrical performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC3862EUH#TRPBF, the LTC3862IUH#TRPBF offers extended temperature operation critical for automotive integration, while LTC3862-1IUH#TRPBF trades logic-level compatibility for higher gate drive voltage - making the original LTC3862IUH#TRPBF optimal for compact, high-efficiency 48V systems using low-Q_G MOSFETs.

Availability

LTC3862IUH#TRPBF is available at Aetrix Electronics and suitable for telecom power supplies, automotive ADAS subsystems, and industrial PoE++ midspans requiring stable component supply, AEC-Q100 qualification, and long-term production continuity.

Supply support for LTC3862IUH#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 (now part of Analog Devices, Inc., a wholly owned subsidiary of Analog Devices, Inc.) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors.

The LTC3862 product line delivers high-efficiency, multi-phase boost/SEPIC controllers for demanding 48V power architectures in automotive, telecom, and industrial applications - emphasizing precision regulation, thermal robustness, and synchronization flexibility.

FAQ

What is the maximum output voltage achievable with the LTC3862IUH#TRPBF in boost configuration?

The LTC3862IUH#TRPBF itself does not impose a hard upper limit on output voltage; it is constrained by external component ratings and layout. In typical applications, it reliably generates 48V from 12V input (4× step-up) with 96% max duty cycle. Output voltages above 60V require careful attention to MOSFET V_DS, diode PIV, and PCB creepage - and may necessitate the LTC3862-1 variant for higher gate drive.

Does the LTC3862IUH#TRPBF support synchronization to an external clock, and what is the valid frequency range?

Yes, the LTC3862IUH#TRPBF supports external clock synchronization via its SYNC pin. It accepts input frequencies from 50kHz to 650kHz, with rising-edge alignment to GATE1. This feature enables EMI reduction in multi-converter systems and deterministic timing in synchronized power architectures - a core capability confirmed in the device's PLL architecture and electrical characteristics table.

How does the PHASEMODE pin affect channel timing in the LTC3862IUH#TRPBF?

The PHASEMODE pin on the LTC3862IUH#TRPBF configures both inter-channel and daisy-chain timing: at 0V it sets CH1–CH2 to 180° and CH1–CLKOUT to 90°; at float it maintains 180° and 60°; at 3.8V it sets CH1–CH2 to 120° and CH1–CLKOUT to 240°. These settings are explicitly defined in the Pin Functions section and validated in the Electrical Characteristics table under "CH1-CH2" and "CH1-CLKOUT" parameters.

Can the LTC3862IUH#TRPBF drive standard-threshold MOSFETs, or is it limited to logic-level devices?

The LTC3862IUH#TRPBF is optimized for logic-level N-channel MOSFETs with 5V gate drive (INTVCC = 5V). Its gate drivers are rated for 6V absolute max - insufficient for reliable enhancement of standard-threshold MOSFETs (typically requiring ≥10V). For such devices, Analog Devices specifies the LTC3862-1IUH#TRPBF, which provides 10V gate drive and higher UVLO thresholds.

What thermal considerations apply to the LTC3862IUH#TRPBF in continuous 5A output operation?

In continuous 5A output operation, the LTC3862IUH#TRPBF's 5mm × 5mm QFN package (θJA = 44°C/W) requires adequate copper area and thermal vias under the exposed PGND pad. Junction temperature must stay ≤125°C; at 24V input/48V output, typical dissipation is ~1.2W - resulting in ~53°C rise above 25°C ambient. Board layout per Figure 1 (bypass caps near pins, kelvin SGND return) is essential to maintain stability and thermal margin.