Texas Instruments LV14340DDAR

Overview

LV14340DDAR from Texas Instruments is a 40V-input, 3.5A synchronous step-down DC-DC converter with integrated 100mΩ high-side MOSFET, 200kHz–2MHz adjustable switching frequency, current-mode control, and internal compensation. It delivers regulated power in automotive battery regulation, industrial supplies, and telecom systems where wide VIN (4–40V) and thermal robustness are critical.

For engineers reviewing the LV14340DDAR datasheet, LV14340DDAR pinout, LV14340DDAR application, or LV14340DDAR equivalent, key selection considerations include minimum on-time (100ns), precision enable threshold (1.2V), shutdown current (1µA), thermal shutdown (170°C), and RT/SYNC dual-mode frequency programming-enabling optimization for efficiency, EMI, or board space.

Technical Context

The LV14340DDAR implements fixed-frequency peak current-mode control with slope compensation to ensure stability at duty cycles >50%. Its internal error amplifier drives PWM logic using a 0.75V reference, enabling precise output voltage regulation via external resistor divider.

It supports two operating modes on the RT/SYNC pin: resistor-programmed frequency (200–2000kHz) or external clock synchronization (250–2000kHz). The BOOT-to-SW bootstrap circuit enables ~97% maximum duty cycle, while cycle-by-cycle current limiting and frequency foldback provide short-circuit protection without external components.

Key Specifications

Pinout & Package

LV14340DDAR uses an 8-pin HSOIC (DDA) package with exposed thermal pad (4.9mm × 6mm), optimized for low junction-to-board thermal resistance (R_θJB = 16.4°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar step-down converter applications.

Compared with LMR51440RGER and TLVM13640RGER, LV14340DDAR uniquely supports 40V input and includes dedicated SS and RT/SYNC pins in an 8-pin SOIC - making it the only option among the three for 40V automotive applications requiring programmable soft-start and external clock sync without module-level trade-offs.

Availability

LV14340DDAR is available at Aetrix Electronics and suitable for automotive battery regulation, industrial power supplies, and telecom/datacom systems requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for LV14340DDAR 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

Texas Instruments is a global semiconductor leader delivering analog, embedded processing, and connectivity solutions with emphasis on reliability, longevity, and automotive-grade qualification.

The LV14340 belongs to TI's high-voltage buck converter product line, designed specifically for ruggedized power conversion in automotive, industrial, and telecom infrastructure where input transients, thermal constraints, and functional safety margins are critical.

FAQ

What is the absolute maximum input voltage rating for LV14340DDAR?

The LV14340DDAR has an absolute maximum input voltage rating of 44V on the VIN pin relative to GND. This exceeds its recommended 4–40V operating range and provides margin against load-dump transients in automotive applications. Operation beyond 40V is not recommended for continuous use, and thermal design must account for increased power dissipation at elevated input voltages.

Does LV14340DDAR require external compensation components?

No, LV14340DDAR does not require external compensation components. It features fully internal loop compensation optimized for stability across all recommended output capacitors and loads. This eliminates the need for external Type-II or Type-III compensation networks, reducing bill-of-materials count and simplifying layout while maintaining phase margin >45° over temperature and line/load variations.

How is the switching frequency set on LV14340DDAR?

The switching frequency of LV14340DDAR is set either by connecting a resistor between the RT/SYNC pin and GND (for 200kHz–2MHz), or by applying an external clock signal (250kHz–2MHz) to the same pin. When using resistor programming, a 49.9kΩ resistor sets 500kHz; the device automatically switches to sync mode if the pin voltage exceeds the PLL upper threshold (~1.7V). The pin must never be left floating.

What thermal performance can be expected from LV14340DDAR in a standard 2-layer PCB layout?

In a standard 2-layer PCB with 2oz copper and a 4cm² thermal pad connected to inner ground plane, LV14340DDAR achieves a junction-to-ambient thermal resistance (R_θJA) of 43.2°C/W. At 3.5A output and 12V input, this yields ~35°C junction rise above ambient - well within the 125°C max operating junction temperature. For higher ambient or sustained full-load operation, adding thermal vias under the pad further improves performance.

Can LV14340DDAR operate in dropout mode, and what is its maximum duty cycle?

Yes, LV14340DDAR supports high-duty-cycle operation up to approximately 97%, enabled by its integrated bootstrap recharge circuit. When VIN approaches VOUT (e.g., 5.5V→5V), the device sustains regulation by extending on-time and periodically refreshing the BOOT capacitor through the low-side path. This eliminates need for external low-side switches in low-dropout applications while maintaining current-mode control integrity.