Texas Instruments TPS54340BDDAR

Overview

TPS54340BDDAR from Texas Instruments is a 42-V input, 3.5-A synchronous step-down DC/DC converter with integrated 92-mΩ high-side MOSFET, Eco-mode™ pulse-skipping for light-load efficiency, and adjustable 100-kHz to 2.5-MHz switching frequency. It delivers regulated output voltages as low as 0.8 V in industrial power supplies requiring wide VIN range and thermal robustness.

For engineers reviewing the TPS54340BDDAR datasheet, TPS54340BDDAR pinout, TPS54340BDDAR application, or TPS54340BDDAR equivalent, key selection considerations include its 4.5–42-V input range, 146-μA no-load quiescent current, internal 0.8-V ±1% reference, BOOT-recharge FET for high-duty-cycle operation, and RT/CLK synchronization capability.

Technical Context

The TPS54340BDDAR implements peak-current-mode control with slope compensation to prevent subharmonic oscillation above 50% duty cycle. Its transconductance error amplifier (350 μS typical) drives the PWM comparator via the COMP pin, while internal soft-start (2.1 ms at 500 kHz) controls output ramp rate and suppresses overshoot.

Switching frequency is set by an external resistor on RT/CLK or synchronized to an external clock (160–2300 kHz). The device integrates BOOT capacitor recharge logic and monitors BOOT–SW voltage to maintain gate drive integrity-enabling dropout operation down to V_OUT ≈ V_IN(min) – I_OUT×R_DS(on) – V_F – I_OUT×R_DC.

Key Specifications

Pinout & Package

The TPS54340BDDAR is housed in an 8-pin HSOIC (DDA) package with exposed PowerPAD™ thermal pad (4.89 mm × 3.90 mm), requiring PCB GND connection for thermal and electrical performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM5164QDDARQ1 and MP2451DT-LF-Z, the TPS54340BDDAR uniquely combines 3.5-A output, integrated BOOT recharge, Eco-mode, and 100-kHz–2.5-MHz programmability-making it optimal for industrial 12/24 V systems needing high reliability and flexible frequency control.

Availability

TPS54340BDDAR is available at Aetrix Electronics and suitable for industrial motor drives, railway signaling systems, programmable logic controllers (PLCs), and telecom remote radio units (RRUs) requiring stable component supply across extended temperature and voltage ranges.

Supply support for TPS54340BDDAR 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 company specializing in analog and embedded processing technologies, with leadership in power management ICs for industrial, automotive, and communications markets.

The TPS54340BDDAR belongs to TI's high-voltage buck converter product line, engineered for rugged 12 V and 24 V industrial power systems demanding wide input range, high efficiency at light loads, and robust thermal protection.

FAQ

What is the minimum input voltage required for TPS54340BDDAR to regulate a 5-V output?

The minimum input voltage depends on output current, inductor DCR, Schottky diode forward voltage, and MOSFET R_DS(on). For a 5-V output at 3.5 A, Equation 1 from the datasheet yields ~6.2 V minimum under typical conditions. At light loads, TPS54340BDDAR can operate down to ~5.3 V due to low dropout behavior enabled by the integrated BOOT recharge FET.

How does the TPS54340BDDAR enter and exit Eco-mode™ during light-load operation?

TPS54340BDDAR enters Eco-mode™ when peak switch current falls below the threshold corresponding to 600 mV at the COMP pin-typically around 24 mA for standard 22-μH inductors. In this mode, switching pauses, COMP is clamped, and quiescent current drops to 146 μA. Output voltage decay lifts COMP above 600 mV, re-enabling switching to restore regulation-creating a controlled burst-mode cycle unique to TPS54340BDDAR.

Can the TPS54340BDDAR synchronize to an external clock, and what are the valid frequency and voltage levels?

Yes, TPS54340BDDAR synchronizes to external clocks applied to the RT/CLK pin when pulled above 1.55 V. Valid input clock frequencies range from 160 kHz to 2.3 MHz, with logic-high voltage between 1.55 V and 2.0 V, and logic-low below 1.2 V. The internal PLL locks within 78 μs, and the device maintains synchronization even during Eco-mode™ operation.

What thermal design considerations apply to the TPS54340BDDAR HSOIC PowerPAD™ package?

The TPS54340BDDAR DDA package has R_θJA = 42°C/W and R_θJC(bot) = 3.6°C/W. To maintain T_J ≤ 150°C at 3.5 A, the PCB must provide ≥250 mm² of 2-oz copper connected to the exposed PowerPAD™, with ≥4 thermal vias (0.3-mm diameter) to inner ground layers. Avoid solder mask over the pad to maximize thermal transfer.

Does the TPS54340BDDAR require an external bootstrap diode, and what capacitor value is recommended?

No, the TPS54340BDDAR integrates a BOOT recharge FET, eliminating the need for an external bootstrap diode. A 0.1-μF X7R or X5R ceramic capacitor rated for ≥10 V must be placed between BOOT and SW pins, with minimal trace length and direct connection to the PowerPAD™ ground plane to ensure stable gate drive and minimize noise coupling.