Texas Instruments TPS54218RTET

Overview

TPS54218RTET from Texas Instruments is a 2.95-V to 6-V input, 2-A synchronous step-down DC/DC converter with integrated 30-mΩ high- and low-side MOSFETs, 2-MHz maximum switching frequency, ±1% voltage reference accuracy over –40°C to 150°C, and power-good monitoring for industrial power rails in factory automation and wireless infrastructure systems.

For engineers reviewing the TPS54218RTET datasheet, TPS54218RTET pinout, TPS54218RTET application, or TPS54218RTET equivalent, key selection considerations include its WQFN-16 thermal-pad package, RT/CLK synchronization capability, adjustable soft-start via external capacitor, UVLO programmability on EN, and 350-μA quiescent current at full load.

Technical Context

The TPS54218RTET implements peak-current-mode control with internal slope compensation to prevent subharmonic oscillation across 0–100% duty cycle. Its constant-frequency PWM architecture supports external synchronization via RT/CLK pin and enables stable regulation using only a single feedback resistor divider on VSENSE.

It integrates boot recharge circuitry and monitors BOOT-PH voltage with UVLO (2.1 V threshold) to sustain high-side conduction; the COMP pin serves as error amplifier output and current comparator input, with clamped min/max voltages for transient response and overload protection.

Key Specifications

Pinout & Package

TPS54218RTET uses a thermally enhanced 3-mm × 3-mm, 16-pin WQFN package with exposed PowerPad (GND-connected) for optimal thermal dissipation. Pin numbering follows top-view layout with Pin 1 at top-left corner.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS54218RTET, TPS54228RTET offers faster transient recovery at the expense of deterministic EMI profile, while MP2315DJ-LF-Z trades feature completeness for size and BOM cost-making TPS54218RTET the balanced choice for industrial timing-critical designs.

Availability

TPS54218RTET is available at Aetrix Electronics and suitable for factory automation PLCs, broadband DSLAM line cards, wireless infrastructure RRUs, and industrial embedded vision nodes requiring stable component supply across extended temperature and long production lifecycles.

Supply support for TPS54218RTET 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 decades of expertise in high-reliability power conversion solutions.

The TPS54218RTET belongs to TI's SWIFT™ synchronous buck converter family, designed specifically for space-constrained, thermally demanding industrial and communications equipment requiring precision regulation and robust fault handling.

FAQ

What is the recommended inductor value for TPS54218RTET at 1.8-V output and 2-MHz switching?

For TPS54218RTET operating at 2 MHz and 1.8-V output, a 0.47-μH to 1.0-μH shielded power inductor with ≥3-A saturation current is recommended. At 2 MHz, 0.68-μH provides optimal balance of ripple current (<30% of 2-A load), core loss, and physical size. TI's WEBENCH® Power Designer confirms 0.68-μH yields 1.2-A peak inductor current and <15-mV output ripple with standard 22-μF output capacitance.

Does TPS54218RTET support output voltages below 0.8 V?

No, TPS54218RTET does not support output voltages below its internal 0.803-V reference voltage. The VSENSE pin is internally biased to this reference, and the feedback divider ratio determines VOUT = 0.803 V × (1 + R1/R2). Minimum practical output is therefore 0.803 V, achievable with R2 = ∞ (i.e., no R2) and R1 = 0 - though layout parasitics and noise make sub-0.85-V designs impractical without external amplification.

How is the soft-start time calculated for TPS54218RTET?

The soft-start time for TPS54218RTET is calculated as t_SS = C_SS × 0.803 V / I_CHG, where I_CHG = 2.07 μA (typical) and C_SS is the capacitor on the SS pin. For example, a 100-nF capacitor yields t_SS ≈ 39 ms. The SS pin discharges fully before restart after fault conditions, ensuring repeatable ramp-up behavior in TPS54218RTET-based power systems.

Can TPS54218RTET be synchronized to an external 1-MHz clock?

Yes, TPS54218RTET supports external clock synchronization via the RT/CLK pin across 300 kHz to 2 MHz. When driven with a clean 1-MHz square wave (VIH ≥ 1.6 V, VIL ≤ 0.6 V, t_MIN ≥ 75 ns), the internal PLL locks within 14 μs, aligning PH rising edges to CLK falling edges. This eliminates beat frequencies in multi-converter systems and simplifies EMI filtering for TPS54218RTET deployments.

What is the thermal performance of TPS54218RTET on a 2-layer PCB?

On a standard 2-layer PCB (1 oz. copper, no internal planes), TPS54218RTET's junction-to-ambient thermal resistance (θ_JA) rises to ~75°C/W - limiting continuous 2-A output to ≤55°C ambient. For full-rated operation, TI specifies a 4-layer JEDEC board (2 oz. internal GND planes + 4 thermal vias under PowerPad), achieving θ_JA = 37°C/W and enabling 2-A output up to 70°C ambient. Derating curves in the TPS54218RTET datasheet SLVS974F confirm this dependency.