Texas Instruments TPS28225D

Overview

TPS28225D from Texas Instruments is a high-frequency dual N-channel MOSFET gate driver optimized for synchronous buck converters, featuring 14 ns adaptive dead time, 4 A sink / 2 A source lower gate drive, 7–8 V optimal gate drive voltage, and SOIC-8 packaging. It enables multi-phase DC/DC conversion up to 2 MHz in desktop VRMs and server power supplies.

For engineers reviewing the TPS28225D datasheet, TPS28225D pinout, TPS28225D application, or TPS28225D equivalent, key selection criteria include its 0.4 Ω LGATE sink resistance for dV/dt shoot-through prevention, integrated bootstrap diode, 3-state PWM input support, EN/PG dual-function pin, and thermal pad grounding requirement in SOIC-8 layout.

Technical Context

The TPS28225D implements adaptive dead-time control by sensing PHASE node transitions to prevent shoot-through during high dV/dt switching. Its upper gate driver uses a bootstrap architecture with an internal 1.0 V forward-drop diode, while the lower gate driver delivers 4 A sink current with 0.4 Ω on-resistance to hold the low-side MOSFET gate below threshold during fast phase-node transitions.

It supports 3-state PWM input via self-adjusting thresholds (1.0 V fixed low, ~75% of input amplitude high), requiring ≥250 ns hold-off before forcing both outputs low. The EN/PG pin provides bidirectional communication: pulled low internally during UVLO (<3.0 V) or thermal shutdown (>150 °C), enabling system-level fault coordination without external logic.

Key Specifications

Pinout & Package

TPS28225D uses the SOIC-8 (D) package (4.90 mm × 3.91 mm) with exposed thermal pad connected to GND. Pin 1 is UGATE; pin 4 is GND; pin 7 is EN/PG (dual-function enable/power-good); pin 8 is PHASE. Thermal pad must be soldered and electrically tied to GND plane for thermal performance and EMI control.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual N-channel gate driver applications.

Compared with LM5113SD and UCC27211D, the TPS28225D uniquely balances high-speed timing (14 ns), integrated protection (UVLO, thermal shutdown), system interface (EN/PG, 3-state PWM), and integration (bootstrap diode) in a standard SOIC-8 package-making it optimal for mid-to-high-performance VRMs where reliability and controller interoperability matter.

Availability

TPS28225D is available at Aetrix Electronics and suitable for multi-phase VRMs, desktop/server CPU regulators, and notebook synchronous buck converters requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for TPS28225D 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 power conversion solutions.

The TPS28225D belongs to TI's high-frequency gate driver product line, designed specifically for high-current, high-efficiency synchronous buck converters in computing and communications infrastructure where adaptive dead time, shoot-through immunity, and system-level fault signaling are critical.

FAQ

What is the recommended PCB layout practice for the thermal pad on the TPS28225D SOIC-8 package?

The thermal pad on the TPS28225D SOIC-8 package must be soldered and electrically connected to the GND pin and the main GND plane using multiple vias in the shortest possible path. This ensures effective heat dissipation, lowers junction temperature under load, and reduces EMI emissions. Failure to connect the pad compromises thermal performance and may trigger thermal shutdown during sustained operation. Always verify solder joint integrity and GND connectivity in production inspection for every TPS28225D unit.

How does the TPS28225D prevent shoot-through current in high dV/dt applications?

The TPS28225D prevents shoot-through current through three coordinated mechanisms: (1) 14 ns adaptive dead-time control that enforces non-overlapping UGATE/LGATE drive, (2) 0.4 Ω LGATE sink on-resistance that rapidly pulls the low-side MOSFET gate below threshold during fast phase-node transitions, and (3) internal shoot-through protection logic that monitors PHASE node slew rate. These features collectively eliminate cross-conduction even under extreme dV/dt conditions encountered in high-frequency, high-current VRMs-ensuring reliable operation of the TPS28225D across its full operating range.

Can the TPS28225D operate with a 5 V VDD supply, and what impact does that have on gate drive strength?

Yes, the TPS28225D supports VDD from 4.5 V to 8 V, including 5 V operation. At 5 V VDD, gate drive voltage is reduced versus the optimal 7–8 V range, resulting in lower MOSFET transconductance and increased conduction losses-especially in high-current phases. While functional, 5 V operation degrades efficiency and thermal margin. For best performance, the TPS28225D should be powered from a dedicated 7–8 V bias rail. The datasheet specifies 7.2 V as nominal, and all key specs (e.g., 4 A LGATE sink, 14 ns dead time) are characterized at that voltage.

What happens to the TPS28225D outputs when the EN/PG pin is pulled low externally?

When the EN/PG pin is pulled low externally, the TPS28225D disables both UGATE and LGATE outputs, forcing them into high-impedance (tri-state) mode-effectively turning off both high- and low-side MOSFETs. This provides clean power-stage shutdown independent of the PWM input signal. During disable, the TPS28225D draws <350 µA bias current. The EN/PG pin also serves as a power-good indicator: it is internally pulled low during UVLO or thermal shutdown, allowing the host controller to detect fault conditions without additional monitoring circuitry-enhancing system reliability in critical applications using the TPS28225D.

Does the TPS28225D require an external bootstrap capacitor, and what are the key selection criteria?

Yes, the TPS28225D requires an external bootstrap capacitor connected between BOOT and PHASE pins. Key selection criteria include: (1) capacitance ≥100 nF to sustain UGATE drive during minimum on-time at 2 MHz, (2) low-ESR ceramic construction (X7R/X5R) to minimize AC impedance, and (3) voltage rating ≥16 V to handle worst-case VBOOT = VPHASE + VDD. The internal 1.0 V bootstrap diode enables efficient recharge, but capacitor size and placement directly affect high-frequency stability. Incorrect sizing causes UGATE droop or premature high-side FET turn-off-so proper selection is essential for robust TPS28225D operation in demanding VRM designs.