Texas Instruments TPS55340QRTERQ1

Overview

TPS55340QRTERQ1 from Texas Instruments is an automotive-grade, monolithic non-synchronous DC/DC converter with integrated 5-A/40-V low-side MOSFET, supporting boost, SEPIC, and isolated flyback topologies. It operates from 2.9 V to 38 V input, delivers ±0.7% reference accuracy, features 100 kHz–2.5 MHz adjustable switching frequency, and includes cycle-by-cycle current limit and thermal shutdown - used in automotive pre-boost for start-stop systems.

For engineers reviewing the TPS55340QRTERQ1 datasheet, TPS55340QRTERQ1 pinout, TPS55340QRTERQ1 application, or TPS55340QRTERQ1 equivalent, key selection considerations include input voltage range compatibility, soft-start programmability, synchronization capability, pulse-skipping efficiency at light loads, and AEC-Q100 Grade 1 qualification for under-hood environments.

Technical Context

The TPS55340QRTERQ1 implements fixed-frequency current-mode PWM control with internal slope compensation to prevent subharmonic oscillation above 50% duty cycle. Its transconductance error amplifier (240–440 µmho) drives the COMP pin for loop compensation via external RC network, while the 1.229-V reference enables precise output regulation via FB-resistor divider.

Switching frequency is set either by resistor on FREQ pin (480 kΩ → ~100 kHz; 18 kΩ → ~2.5 MHz) or synchronized to external clock (200 kHz–1 MHz). The device enters pulse-skipping mode below minimum on-time (77 ns typ.), and activates frequency foldback (to 25% nominal) when FB drops below 0.9 V during overcurrent events.

Key Specifications

Pinout & Package

TPS55340QRTERQ1 is housed in a thermally enhanced 3 mm × 3 mm WQFN-16 package with exposed PowerPad for PCB-level heat dissipation. The PowerPad must be soldered to AGND with thermal vias for optimal thermal performance (R_θJB = 14.5°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM5122MQX/NOPB and TPS40210DRCT, the TPS55340QRTERQ1 offers superior integration (5-A switch + soft-start + sync), AEC-Q100 compliance, and smaller footprint - making it optimal for space-constrained automotive and USB-PD designs where input stays ≤38 V.

Availability

TPS55340QRTERQ1 is available at Aetrix Electronics and suitable for automotive start-stop systems, USB power delivery sources, and industrial 24 V rail boosters requiring stable component supply, long-term lifecycle support, and AEC-Q100 traceability.

Supply support for TPS55340QRTERQ1 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 specializing in analog, embedded processing, and power management ICs, with deep expertise in automotive-grade reliability and functional safety.

The TPS55340-Q1 product line delivers highly integrated, AEC-Q100 qualified DC/DC converters targeting automotive power architectures - specifically engineered for pre-boost, USB-PD, and isolated auxiliary supplies in harsh-temperature environments.

FAQ

What is the maximum output voltage achievable with TPS55340QRTERQ1 in boost configuration?

The TPS55340QRTERQ1 supports output voltages up to 38 V in boost topology, limited by its 40-V internal MOSFET breakdown rating and absolute maximum SW pin voltage. Output is set via FB resistor divider referenced to the 1.229-V internal reference; practical design margins recommend staying ≥2 V below 40 V to ensure reliability under transients. The TPS55340QRTERQ1 datasheet confirms VO ≤ 38 V under recommended operating conditions.

Does TPS55340QRTERQ1 support synchronization to an external clock, and what are the valid frequency and logic levels?

Yes, TPS55340QRTERQ1 supports external clock synchronization via the SYNC pin, accepting logic-level signals from 200 kHz to 1 MHz with high threshold ≥1.2 V and low threshold ≤0.4 V. The external clock must be within ±20% of the frequency set by the FREQ resistor; for example, if R(FREQ) sets 600 kHz, the sync signal must be 480–720 kHz. The TPS55340QRTERQ1 requires the FREQ pin to remain connected to AGND even during sync operation.

How does the soft-start function work on TPS55340QRTERQ1, and what capacitor value is needed for a 10-ms ramp?

The TPS55340QRTERQ1 soft-start uses a 6-µA internal current source charging an external capacitor on the SS pin; 1.8 V at SS ends the ramp. For a 10-ms soft-start time, use C(SS) = 1.8 V / 6 µA ≈ 3.0 µF. Ceramic or tantalum capacitors are recommended; the TPS55340QRTERQ1 datasheet specifies that SS discharge occurs through a 5-kΩ internal resistor when EN is pulled low for ≥1 ms.

What protection features are built into TPS55340QRTERQ1, and how do they behave during fault conditions?

The TPS55340QRTERQ1 integrates cycle-by-cycle overcurrent limit (5.25–7.75 A), thermal shutdown (165°C trip, 15°C hysteresis), undervoltage lockout (2.5 V turn-off), and frequency foldback (reduces switching frequency to 25% when FB < 0.9 V). During overcurrent, the device continues switching at reduced frequency until fault clears; UVLO prevents operation below 2.5 V; thermal shutdown disables all switching until junction cools.

Can TPS55340QRTERQ1 be used in SEPIC or flyback topologies, and what design considerations apply?

Yes, TPS55340QRTERQ1 is explicitly validated for SEPIC and isolated flyback configurations per its datasheet. In SEPIC, the coupled inductor requires careful winding polarity and saturation margin; in flyback, primary-side regulation eliminates optocoupler needs but demands accurate transformer turns ratio and leakage inductance control. The TPS55340QRTERQ1's non-synchronous architecture and wide duty cycle (up to 96%) support both topologies across full input range.