Texas Instruments TPS5401DGQ

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 adjustable switching frequency from 100 kHz to 2.5 MHz - used in industrial power rails, e-meter auxiliary supplies, and 24-V embedded systems.

For engineers reviewing the TPS5401 datasheet, TPS5401 pinout, TPS5401 application, or TPS5401 equivalent, key selection considerations include its MSOP-10 PowerPAD™ package thermal performance, BOOT–PH UVLO behavior at high duty cycles, PWRGD open-drain power-good monitoring with 94–107% window, and EN-pin programmable UVLO hysteresis for system-level sequencing control.

Technical Context

The TPS5401 implements fixed-frequency peak-current-mode control with internal slope compensation to prevent subharmonic oscillation across full duty-cycle range. Its transconductance error amplifier (97 μA/V normal, 26 μA/V during slow-start) drives COMP for loop stability using external RC compensation.

It features dual-mode RT/CLK pin: resistor-set frequency (100–2500 kHz) or PLL-synchronized clock input (300–2200 kHz), plus integrated boot charge diode and BOOT-to-PH UVLO (2.1 V threshold) enabling >99% effective duty cycle in dropout. Thermal shutdown activates at 182°C with frequency foldback during overload.

Key Specifications

Pinout & Package

TPS5401 is housed in a thermally enhanced 10-pin MSOP package with exposed PowerPAD™ thermal pad (3.00 mm × 3.00 mm body). The PowerPAD must be soldered to a PCB copper pour for proper thermal dissipation and electrical grounding.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LMR14006XDDAR and TPS54202HDDCR, the TPS5401 uniquely balances 0.5-A capability, comprehensive system integration (PWRGD, SS/TR, EN-programmable UVLO), and thermal robustness in MSOP-PowerPAD - making it optimal for space-constrained industrial and metering applications requiring sequencing, monitoring, and wide-input resilience.

Availability

TPS5401 is available at Aetrix Electronics and suitable for industrial automation, smart metering, and automotive body electronics requiring stable component supply, long-term lifecycle support, 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 DC/DC converter innovation.

The TPS5401 belongs to TI's SWIFT™ family of high-voltage buck regulators designed for industrial, metering, and automotive power-supply applications demanding wide VIN range, integrated FETs, and system-level features like PWRGD and sequencing.

FAQ

What is the maximum duty cycle achievable with the TPS5401?

The TPS5401 supports effective 100% duty cycle operation as long as the BOOT-to-PH voltage remains above 2.1 V. This is enforced by an internal UVLO circuit that disables the high-side MOSFET when BOOT–PH drops below threshold, allowing the low-side path to recharge the boot capacitor. In practice, this enables dropout operation down to VIN ≈ VOUT + 2.1 V, verified across temperature and load conditions per Figure 25–26 in the TPS5401 datasheet.

How does the TPS5401 implement power-good monitoring?

The TPS5401 uses an open-drain PWRGD pin that asserts low when the VSENSE voltage falls below 92% or rises above 109% of the 0.8-V reference. It deasserts (goes high-impedance) only when VSENSE is within the 94–107% window - requiring an external pull-up resistor. This precise window ensures reliable system reset signaling without false triggers during transient load steps or input line variations.

Can the TPS5401 synchronize to an external clock, and how is it configured?

Yes, the TPS5401 synchronizes to an external clock via the RT/CLK pin. When pulled above 1.9 V (with 0.5–0.7 V hysteresis), the internal amplifier disables and the pin becomes a high-impedance clock input to the internal PLL. Clock edges must meet minimum 40-ns pulse width; loss of clock causes automatic reversion to resistor-set mode. This feature avoids EMI peaks in noise-sensitive applications like metering or audio subsystems.

What is the role of the SS/TR pin beyond slow-start?

Beyond controlling output voltage ramp rate via external capacitor, the SS/TR pin enables precise power-supply tracking and sequencing. By applying a voltage ramp (e.g., from another regulator's output), the TPS5401's output follows that reference - critical for FPGA or multi-core processor power sequencing. During faults, SS/TR is actively discharged to ensure repeatable restart behavior, unlike passive RC-based solutions.

Does the TPS5401 require an external bootstrap diode?

No, the TPS5401 integrates the bootstrap diode internally, eliminating the need for an external component between BOOT and PH. This reduces BOM count, PCB area, and potential failure points. A 0.1-μF X7R/X5R ceramic capacitor (10-V rating minimum) is still required between BOOT and PH to sustain gate drive voltage for the high-side MOSFET during switching cycles.