Texas Instruments TPS5401DGQT

Overview

TPS5401 from Texas Instruments is a 42-V input, 0.5-A synchronous step-down DC/DC converter with integrated 200-mΩ high-side MOSFET, current-mode control, and Eco-mode™ pulse-skipping for light-load efficiency. It delivers regulated output down to 0.8 V with ±3.5% reference accuracy and supports industrial power rails in 12-V/24-V systems.

For engineers reviewing the TPS5401 datasheet, TPS5401 pinout, TPS5401 application, or TPS5401 equivalent, key selection considerations include its 100-kHz–2.5-MHz adjustable switching frequency, RT/CLK synchronization capability, open-drain PWRGD monitoring, and MSOP-10 PowerPAD™ thermal package for high-power-density designs.

Technical Context

The TPS5401 implements constant-frequency peak-current-mode control with internal slope compensation to prevent subharmonic oscillation across duty cycles. Its transconductance error amplifier (97 μA/V nominal, 26 μA/V during slow-start) interfaces with external RC compensation on the COMP pin for stable loop response.

Bootstrap operation enables high-duty-cycle dropout performance: BOOT-to-PH UVLO (2.1 V threshold) allows 100% duty cycle until boot capacitor recharge fails, while the integrated boot diode eliminates an external component. The RT/CLK pin supports both resistor-set frequency tuning and PLL-based external clock synchronization with 40-ns minimum pulse width tolerance.

Key Specifications

Pinout & Package

TPS5401 is housed in a thermally enhanced 10-pin MSOP package (3.00 mm × 3.00 mm) with exposed thermal pad (Pin 11), requiring PCB connection to GND for thermal and electrical integrity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS5402DGQ and LM2678SDX-ADJ/NOPB, the TPS5401 uniquely balances 0.5-A capability, ultra-low quiescent current, and MSOP-10 thermal performance-making it the preferred choice for space-constrained, battery-aware industrial and metering applications where precise sequencing and monitoring are essential.

Availability

TPS5401 is available at Aetrix Electronics and suitable for industrial automation, smart metering, and low-power IoT node designs requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for TPS5401 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 technologies, with decades of expertise in high-reliability power conversion ICs.

The TPS5401 belongs to TI's SWIFT™ family of integrated DC/DC converters, designed specifically for industrial, metering, and automotive body electronics where wide-input-voltage operation, thermal robustness, and precise power-good signaling are critical.

FAQ

What is the minimum input voltage required for TPS5401 to start switching?

The TPS5401 has an internal undervoltage lockout threshold of 2.5 V on the VIN pin. However, the effective start voltage depends on load and output configuration: for a 5-V output, typical start occurs at ~6.5 V with light load, rising to ~8.5 V at full 0.5-A load due to dropout and boot capacitor recharge dynamics. The EN pin can be used with external resistors to raise this threshold for improved brownout immunity in TPS5401 designs.

Can TPS5401 synchronize to an external clock, and what are the timing requirements?

Yes, TPS5401 supports external clock synchronization via the RT/CLK pin. When pulled above 2.2 V, it enters PLL sync mode; the pin becomes a high-impedance clock input accepting 300–2200 kHz signals. Minimum pulse width is 40 ns, and PLL lock-in time is typically 100 μs. This feature enables noise-sensitive applications-such as audio or metrology systems-to align switching edges and reduce beat frequencies in TPS5401 implementations.

How does the TPS5401 handle thermal overload, and what happens after shutdown?

The TPS5401 incorporates thermal shutdown that triggers at 182°C junction temperature, disabling the high-side MOSFET until the die cools sufficiently. After shutdown, the device remains latched off until junction temperature falls below the hysteresis threshold (~165°C). Upon recovery, TPS5401 performs a full slow-start sequence controlled by the SS/TR capacitor-ensuring safe re-entry into regulation without output overshoot or inrush stress.

What is the role of the BOOT-to-PH UVLO, and how does it affect high-duty-cycle operation?

The BOOT-to-PH UVLO monitors the bootstrap capacitor voltage and disables the high-side MOSFET if it drops below 2.1 V. This protects gate drive integrity but also enables extended 100% duty cycle operation: as long as the capacitor retains >2.1 V, the switch stays on, allowing TPS5401 to maintain regulation even when VIN approaches VOUT. During light-load dropout, periodic restarts occur as the BOOT capacitor discharges and recovers-behavior mitigated by proper EN UVLO tuning in TPS5401 applications.

Is the TPS5401 compatible with ceramic output capacitors, and what ESR considerations apply?

Yes, the TPS5401 is fully compatible with low-ESR ceramic output capacitors-recommended for stability and transient response. Unlike older controllers, it does not require added ESR for phase margin; instead, compensation relies on the COMP pin RC network. Typical designs use 10–47 μF X7R/X5R ceramics rated ≥1.5× VOUT. The error amplifier's 97 μA/V transconductance and current-mode architecture make TPS5401 inherently stable with near-zero-ESR caps, simplifying layout and reducing output ripple in TPS5401 systems.