Texas Instruments TPS5450DDAR

Overview

TPS5450DDAR from Texas Instruments is a 5-A, wide-input (5.5 V to 36 V), synchronous step-down DC/DC converter with integrated 110-mΩ high-side N-channel MOSFET, fixed 500-kHz switching frequency, and adjustable output down to 1.22 V (±1.5% initial accuracy), deployed in point-of-load power supplies for LCD displays and battery chargers.

For engineers reviewing the TPS5450DDAR datasheet, TPS5450DDAR pinout, TPS5450DDAR application, or TPS5450DDAR equivalent, key selection considerations include input voltage feedforward for line transient response, internal compensation reducing external components, thermal shutdown at 135°C, ENA-controlled 18-μA shutdown current, and PowerPAD-enabled thermal performance in the 8-pin SOIC package.

Technical Context

The TPS5450DDAR implements constant-frequency voltage-mode control with input voltage feedforward to maintain stable modulator gain across input variations, enabling predictable loop response and simplified stability design. Its internal 1.221-V bandgap reference is trimmed for ±1.5% accuracy at 25°C and drifts less than ±10 mV over –40°C to 125°C junction temperature.

Protection architecture includes cycle-by-cycle overcurrent limiting with hiccup mode fallback, overvoltage protection triggered at 112.5% of VREF, undervoltage lockout with 5.3-V start threshold and 330-mV hysteresis, and thermal shutdown with 14°C hysteresis. The BOOT-to-PH bootstrap circuit drives the integrated MOSFET using an internal recharge diode and requires a 0.01-μF low-ESR ceramic capacitor.

Key Specifications

Pinout & Package

TPS5450DDAR is housed in an 8-pin HSOP (DDA) package with exposed PowerPAD (Pin 9) for enhanced thermal dissipation. Package dimensions are 4.89 mm × 3.90 mm, and the PowerPAD must be soldered to PCB ground plane for proper thermal and electrical operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS5450DDAR, TPS5430DDAR provides pin-compatible scaling down to 3 A but sacrifices transient robustness, while LM2678SD-5.0/NOPB trades adjustability, feedforward, and integration for lower unit cost in static 5-V applications.

Availability

TPS5450DDAR is available at Aetrix Electronics and suitable for high-density point-of-load regulators, LCD/plasma display power supplies, and battery charger designs requiring stable component supply, long-term manufacturability, and thermal reliability across –40°C to 125°C.

Supply support for TPS5450DDAR 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-efficiency DC/DC conversion.

The TPS5450DDAR belongs to TI's SWIFT™ family of integrated power converters, designed specifically for high-current, wide-input industrial and display power applications where simplicity, thermal performance, and transient resilience are critical.

FAQ

What is the recommended input capacitor configuration for TPS5450DDAR?

The TPS5450DDAR requires a minimum 4.7-μF X5R/X7R ceramic capacitor placed close to the VIN and GND pins. For high-ripple applications, two parallel 4.7-μF capacitors plus a 0.1-μF high-frequency bypass capacitor are recommended. The TPS5450DDAR datasheet specifies that total RMS input ripple current can reach 2.5 A, so capacitor voltage rating must exceed maximum VIN + ripple, and ESR must be low enough to limit ΔVIN to acceptable levels per Equation 3.

Does TPS5450DDAR support adjustable output voltage, and what is the minimum achievable value?

Yes, the TPS5450DDAR supports fully adjustable output voltage using an external resistor divider connected to the VSENSE pin. The minimum output voltage is set by the internal 1.221-V reference, yielding a practical minimum of 1.22 V with ±1.5% initial accuracy at 25°C. Output voltages above 1.22 V are scaled linearly using R1 and R2 per Equation 2 in the TPS5450DDAR datasheet.

How does the voltage feedforward feature improve performance in TPS5450DDAR?

The voltage feedforward in TPS5450DDAR dynamically adjusts the PWM ramp amplitude inversely with VIN, maintaining constant power-stage gain across the 5.5–36 V input range. This eliminates the need for complex loop compensation adjustments and significantly improves line regulation and recovery from input transients-critical in 12-V/24-V systems with variable bus impedance. The TPS5450DDAR achieves a feed-forward gain of 25, directly specified in its functional block diagram.

What thermal management practices are required for reliable operation of TPS5450DDAR?

Reliable operation of TPS5450DDAR requires soldering the exposed PowerPAD (Pin 9) to a thermally robust PCB copper area with ≥4 thermal vias (10-mil diameter) connecting to inner ground planes. TI characterizes RθJA at 30°C/W on custom boards and 42.3°C/W on standard JEDEC boards. Junction temperature must be kept ≤125°C; derating is needed above 85°C ambient. The TPS5450DDAR thermal shutdown activates at 135°C with 14°C hysteresis, but sustained operation near this limit degrades long-term reliability.

Can TPS5450DDAR be synchronized to an external clock signal?

No, the TPS5450DDAR does not support external synchronization. Its oscillator is internally fixed at 500 kHz (range 400–600 kHz over temperature), with no SYNC pin or frequency adjustment capability. This simplifies design but precludes noise spectral spreading or phase alignment with other converters. For synchronizable alternatives, consider TI's TPS54620 or TPS54560 families-neither of which are drop-in replacements for TPS5450DDAR.