Analog Devices Inc. LTC3812IFE-5#TRPBF

Overview

LTC3812IFE-5#TRPBF from Analog Devices (formerly Linear Technology) is a 60V input synchronous step-down switching regulator controller using constant on-time valley current mode control. It delivers precise 0.8V ±0.5% reference accuracy, supports up to 25MHz error amplifier bandwidth for fast transient response, and drives dual N-channel MOSFETs with 1Ω pull-down gate drivers-enabling high-current telecom and automotive power supplies.

For engineers reviewing the LTC3812IFE-5#TRPBF datasheet, LTC3812IFE-5#TRPBF pinout, LTC3812IFE-5#TRPBF application, or LTC3812IFE-5#TRPBF equivalent, key selection factors include its 60V max input rating, no external sense resistor requirement, programmable minimum on-time (<100ns), adjustable cycle-by-cycle current limit via VRNG, and thermally enhanced 16-pin TSSOP package with exposed ground pad.

Technical Context

The LTC3812IFE-5#TRPBF implements a constant on-time valley current mode architecture that eliminates need for a discrete current sense resistor by leveraging the bottom MOSFET's R_DS(ON). Its 25MHz error amplifier enables sub-microsecond load transient recovery, while the ITH pin provides direct control of valley current threshold across 0–2.6V range.

Frequency is set externally via ION pin current (100–3000μA), yielding t_ON from 1.55μs down to <100ns; t_OFF(MIN) is fixed at 250–350ns. The controller supports dual operating modes-forced continuous or pulse-skipping-selected via FCB pin voltage, with automatic INTVCC supply sourcing from VIN (startup) or VOUT (steady-state) using integrated bias control.

Key Specifications

Pinout & Package

Package: 16-lead plastic TSSOP with exposed thermal pad (Pin 17 = GND), rated for –40°C to 125°C junction temperature and θ_JA = 38°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC3892IFE-2#TRPBF and MP2918GL-Z, the LTC3812IFE-5#TRPBF provides unmatched minimum on-time (<100ns) and analog-programmable current limit-making it optimal for high VIN/VOUT ratio converters requiring tight overcurrent tolerance and minimal external components beyond MOSFETs and passives.

Availability

LTC3812IFE-5#TRPBF is available at Aetrix Electronics and suitable for telecom base station power supplies, automotive ADAS ECUs, and industrial PLC I/O modules requiring stable component supply with guaranteed long-term availability.

Supply support for LTC3812IFE-5#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, Inc. (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and power management semiconductors.

The LTC3812IFE-5#TRPBF belongs to Linear's high-voltage synchronous buck controller product line, designed specifically for rugged 48V/60V intermediate bus conversion in telecom, automotive, and industrial environments where reliability, precision, and thermal performance are critical.

FAQ

What is the maximum input voltage supported by the LTC3812IFE-5#TRPBF?

The LTC3812IFE-5#TRPBF supports a maximum continuous input voltage of 60V, with absolute maximum ratings allowing up to 70V for ≤400ms. This makes it suitable for 48V telecom systems, automotive battery inputs including load-dump conditions, and industrial 24–60V rails. Operation above 60V requires external clamping or pre-regulation per the Absolute Maximum Ratings table.

Does the LTC3812IFE-5#TRPBF require an external current sense resistor?

No, the LTC3812IFE-5#TRPBF does not require an external current sense resistor. It uses the on-resistance (R_DS(ON)) of the external bottom N-channel MOSFET as the current sense element, measuring voltage between PGND and SW pins. This reduces component count, board area, and power loss while maintaining accurate cycle-by-cycle current limiting.

How is the switching frequency set on the LTC3812IFE-5#TRPBF?

The switching frequency of the LTC3812IFE-5#TRPBF is set by an external resistor connected from VIN to the ION pin (Pin 1). The resulting current (100–3000μA) determines the one-shot on-time: 100μA yields ~1.55μs, 300μA yields ~515ns, and 2500μA yields <100ns minimum on-time. Frequency varies inversely with input voltage due to constant on-time architecture.

What protection features does the LTC3812IFE-5#TRPBF include?

The LTC3812IFE-5#TRPBF includes cycle-by-cycle current limiting (adjustable via VRNG), output overvoltage/undervoltage detection (±10% window with 120μs delay), INTVCC undervoltage lockout (4.2V turn-on), thermal shutdown, and foldback current limiting during short-circuit events. These features ensure robust operation in harsh environments without requiring external protection circuitry.

Can the LTC3812IFE-5#TRPBF operate with a 3.3V output from a 48V input?

Yes, the LTC3812IFE-5#TRPBF can generate 3.3V from 48V input. Its <100ns minimum on-time enables high step-down ratios at practical frequencies (e.g., 250kHz), while the 25MHz error amplifier ensures stable regulation despite the large duty cycle (~7%). External component selection-especially low-R_DS(ON) MOSFETs and appropriate inductor value-is critical for efficiency and thermal performance.