Texas Instruments TPS56221DQPR

Overview

TPS56221 from Texas Instruments is a 25-A synchronous buck DC-DC converter with integrated NexFET™ power MOSFETs, 4.5–14-V input range, 0.6-V ±1% reference voltage, and programmable 300/500/1000-kHz switching frequency. It delivers high-current POL power for telecom baseband cards and server VRMs.

For engineers reviewing the TPS56221 datasheet, TPS56221 pinout, TPS56221 application, or TPS56221 equivalent, key selection criteria include its voltage-mode feed-forward control, ILIM-programmable overcurrent threshold (12–100 mV), thermal shutdown at 145°C, and 22-pin PQFN PowerPAD™ package with dual GND thermal pad.

Technical Context

The TPS56221 implements voltage-mode control with feed-forward compensation to dynamically adjust duty cycle in response to VIN transients. Its adaptive anti-cross conduction circuitry uses SW node sensing to prevent shoot-through during high/low-side FET transitions.

Overcurrent protection combines fixed 54-A high-side pulse-by-pulse limiting with programmable low-side valley current detection via ILIM resistor. Soft-start is closed-loop, using EN/SS pin voltage (ramped by 10 µA source) level-shifted by 800 mV to drive the error amplifier's second noninverting input.

Key Specifications

Pinout & Package

TPS56221 is housed in a thermally enhanced 22-pin LSON-CLIP (DQP) PQFN package measuring 5.0 mm × 6.0 mm with exposed thermal pad (GND). The package features six parallel VIN pins, five parallel SW pins, and dual GND connections (pins 3 and thermal pad) for low-inductance power delivery and efficient heat dissipation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-current synchronous buck applications.

Compared with MP87651GQ-Z and ISL9123IRZ-T7A, the TPS56221 uniquely supports 25-A continuous output with analog-programmable frequency, OCP, and soft-start in a thermally optimized PQFN-making it optimal for high-density, high-reliability POL where analog flexibility and thermal headroom are critical.

Availability

TPS56221 is available at Aetrix Electronics and suitable for telecom baseband cards, server VRMs, industrial PLC CPU modules, and networking switch ASIC supplies requiring stable component supply across long production lifecycles.

Supply support for TPS56221 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 TPS56221 belongs to TI's SWIFT™ synchronous buck converter family, engineered for high-current, high-density point-of-load power delivery in telecom, enterprise computing, and industrial infrastructure.

FAQ

What is the maximum output current capability of the TPS56221?

The TPS56221 supports up to 25 A of continuous output current under recommended operating conditions (TJ ≤ 125°C, proper PCB thermal design). This is enabled by its integrated 4.5 mΩ high-side and 1.9 mΩ low-side NexFET™ MOSFETs and 22-pin PQFN PowerPAD™ package with low 0.3°C/W junction-to-board thermal resistance. Derating is required above 85°C ambient or with insufficient copper area.

How does the TPS56221 implement overcurrent protection?

The TPS56221 implements dual-path overcurrent protection: fixed 54-A pulse-by-pulse limiting on the high-side FET, and programmable low-side valley current detection via the ILIM pin. A resistor from ILIM to GND sets a 10-µA current source voltage; the device latches 2× that voltage as the OCP threshold across the low-side FET (range: 12–100 mV), supporting precise current-limit tuning for different inductor DCR values.

Can the TPS56221 start up into a prebiased output?

Yes, the TPS56221 supports prebiased output startup. Its control architecture prevents reverse current flow during initial power-on by disabling the high-side FET until the feedback voltage rises above the reference. This feature is confirmed in the datasheet's Feature Description section and eliminates risk of damaging sensitive downstream loads such as FPGAs or ASICs with charged output capacitors.

What package type and thermal characteristics does the TPS56221 use?

The TPS56221 uses a 22-pin LSON-CLIP (DQP) PQFN package measuring 5.0 mm × 6.0 mm with an exposed thermal pad. Its thermal metrics include RθJA = 34.6°C/W (JEDEC high-K board) and RθJC(bot) = 0.3°C/W, enabling high-power operation with standard PCB layouts. The thermal pad must be soldered to a solid ground plane for both electrical grounding and heat conduction.

How is switching frequency selected on the TPS56221?

Switching frequency on the TPS56221 is selected by connecting a resistor from the COMP pin to GND: 40.2 kΩ sets 300 kHz, no resistor defaults to 500 kHz, and 13.3 kΩ sets 1 MHz. This resistor is sampled during a 1.9-ms calibration phase at power-on. The frequency selection directly affects output filter size, efficiency trade-offs, and EMI profile-higher frequencies allow smaller inductors but increase switching losses.