Analog Devices Inc. LT1310EMSE#TRPBF

Overview

LT1310EMSE#TRPBF from Analog Devices (formerly Linear Technology) is a 1.5A current-mode boost DC/DC converter with integrated phase-locked loop (PLL), operating from 2.8V to 18V input and delivering adjustable output up to 35V. It features 240mV V_CE(SAT) at 1A, 1.255V feedback reference, and supports synchronization up to 4.5MHz - used in ultrasound imaging power supplies requiring precise frequency control and low-noise 12V generation from 5V.

For engineers reviewing the LT1310EMSE#TRPBF datasheet, LT1310EMSE#TRPBF pinout, LT1310EMSE#TRPBF application, or LT1310EMSE#TRPBF equivalent, key selection criteria include PLL lock range (±50% at 220pF), thermal performance in MSOP-10 with exposed pad, CT-capacitor–based frequency tuning, and compatibility with all-ceramic capacitor designs for EMI-sensitive avionics and data acquisition systems.

Technical Context

The LT1310EMSE#TRPBF implements current-mode PWM control with an internal 1.5A NPN switch and dual-loop architecture: a fast current-limit loop (cycle-by-cycle peak detection) and a slower voltage feedback loop compensated via the VC pin. Its PLL subsystem compares external SYNC edges to the internal VCO signal, sourcing or sinking up to 140µA at the PLL-LPF pin to adjust oscillator frequency between 10kHz and 4.5MHz.

Switching frequency is set by a single external CT capacitor (e.g., 100pF for 1.6MHz), with a wide capture range (~2:1) enabling use of ±10% NP0 capacitors. The device operates in free-running or synchronized mode, and its 80–84% maximum duty cycle (CT-dependent) supports high step-up ratios while maintaining stability across –40°C to 85°C.

Key Specifications

Pinout & Package

The LT1310EMSE#TRPBF is housed in a thermally enhanced 10-lead MSOP package (MSE) with an exposed pad that must be soldered to PCB ground for proper thermal and electrical performance. Pin 5 and the exposed pad share the same GND function.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LT1618EMS#TRPBF and LTC3402EDE#TRPBF, the LT1310EMSE#TRPBF uniquely combines PLL-based frequency agility, bipolar switch ruggedness for high-VOUT, and MSOP-10 thermal performance - making it the only option among the three for synchronized, wide-output-range boost conversion in safety-critical systems.

Availability

LT1310EMSE#TRPBF is available at Aetrix Electronics and suitable for ultrasound imaging, avionics display bias, and portable instrumentation requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for LT1310EMSE#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 analog and power management product lines with rigorous automotive and industrial qualification.

The LT1310EMSE#TRPBF belongs to Linear's precision DC/DC converter family designed for EMI-sensitive, high-reliability applications including medical imaging, aerospace, and test equipment where frequency control and thermal robustness are mandatory.

FAQ

What is the minimum input voltage required for LT1310EMSE#TRPBF to operate?

The LT1310EMSE#TRPBF has an undervoltage lockout threshold of 2.8V. Operation begins only when VIN rises above this level, and the device shuts down automatically if VIN drops below 2.8V. This ensures reliable startup and prevents erratic behavior during brownout conditions in systems powered by partially discharged batteries or unregulated supplies.

Can LT1310EMSE#TRPBF synchronize to a 2.5MHz external clock?

Yes, the LT1310EMSE#TRPBF supports synchronization up to 4.5MHz, and its PLL lock range at 220pF CT is ±50% around the center frequency. For a 2.5MHz target, a 47pF NP0 capacitor yields a nominal VCO frequency of ~3.3MHz, placing 2.5MHz well within the guaranteed lock window - confirmed in Figure G08 of the datasheet.

How should the exposed pad of LT1310EMSE#TRPBF be connected on the PCB?

The exposed pad of LT1310EMSE#TRPBF must be soldered directly to the PCB's solid ground plane using multiple thermal vias (≥4, 0.3mm diameter) placed within 2mm of the pad perimeter. This connection serves both as the primary thermal path (θ_JA = 40°C/W) and as the signal ground return - failure to solder it results in thermal shutdown or functional failure.

What is the purpose of the PLL-LPF pin on LT1310EMSE#TRPBF?

The PLL-LPF pin on LT1310EMSE#TRPBF functions as both the phase detector output and the voltage-controlled oscillator (VCO) input. It sources or sinks up to 140µA to adjust the VCO frequency during lock acquisition. When not synchronizing, it must be pulled up to ≥2.4V (e.g., with 11.6kΩ to 5V) to fix the oscillator at its maximum frequency.

Does LT1310EMSE#TRPBF require an external Schottky diode, and if so, what is a recommended part?

Yes, LT1310EMSE#TRPBF requires an external Schottky diode for the boost rectifier. The Microsemi UPS120 is explicitly recommended in the datasheet for ≤20V VIN-to-VOUT differential; for higher differentials (e.g., 5V→35V), the UPS140 (40V-rated) is specified. Both handle 1A average forward current and minimize reverse recovery losses.