Texas Instruments TPS628681ARQYR

Overview

TPS628681ARQYR from Texas Instruments is a 4-A synchronous step-down DC/DC converter with I²C interface, designed for dynamic voltage scaling in high-performance digital loads. It operates from 2.4 V to 5.5 V input, delivers 0.4 V to 1.675 V output with 5-mV step resolution, achieves >90% efficiency at 0.9-V output, and uses DCS-Control™ topology for sub-10-µs load transient response - deployed in LPDDR5 VDDQ rail supply and FPGA core power.

For engineers reviewing the TPS628681ARQYR datasheet, TPS628681ARQYR pinout, TPS628681ARQYR application, or TPS628681ARQYR equivalent, key selection criteria include I²C-configurable DVS ranges, 2.4-MHz fixed-frequency PWM mode, thermal pre-warning capability, 1% output voltage accuracy, and QFN-9 (1.5 × 2.5 mm) package compatibility with space-constrained embedded power designs.

Technical Context

The TPS628681ARQYR integrates dual MOSFETs (11-mΩ HS / 10.5-mΩ LS) and employs DCS-Control™ architecture to unify PWM and Power Save Mode operation without output disturbance. Its I²C interface supports up to 3.4 Mbps, enabling real-time register access for output discharge control, hiccup/latching short-circuit protection selection, and programmable ramp speed.

Startup output voltage is resistor-selectable between 0.4 V and 1.15 V via the VSET/VID pin, and the device features dedicated VOS sensing for ±1% output accuracy across –40°C to 125°C. Thermal warning triggers at 130°C with 20°C hysteresis, preceding 150°C shutdown.

Key Specifications

Pinout & Package

TPS628681ARQYR is housed in a thermally enhanced 9-pin QFN package (RQY), measuring 1.5 mm × 2.5 mm × 1.0 mm with 0.5-mm pitch and wettable flanks for automated optical inspection. The exposed thermal pad (Pin 2, PGND) must be soldered to PCB ground for optimal thermal performance (R_θJA = 90.9°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS628680ARQYR, TPS628681ARQYR provides higher minimum output (0.4 V vs. 0.2 V) and coarser DVS steps - better matching LPDDR5 VDDQ specifications. Against TPS628691ARQYR, it trades 2-A output headroom for lower quiescent current and optimized thermal behavior at 4-A continuous load.

Availability

TPS628681ARQYR is available at Aetrix Electronics and suitable for LPDDR5 memory supplies, FPGA core power systems, and IP network camera SoC designs requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for TPS628681ARQYR 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 TPS62868x family was developed specifically for dynamic voltage scaling in next-generation memory interfaces and programmable logic devices - emphasizing ultra-small footprint, I²C configurability, and precision regulation under fast transients.

FAQ

What is the maximum supported I²C clock frequency for TPS628681ARQYR?

The TPS628681ARQYR supports I²C high-speed mode up to 3.4 Mbps for both read and write operations when bus capacitance is ≤100 pF. At 400-pF bus load, maximum clock frequency drops to 1.7 Mbps. All timing parameters - including tLOW, tHIGH, and tSU, tDAT - are fully specified in Section 7.6 of the datasheet and remain compliant across –40°C to 125°C junction temperature.

Does TPS628681ARQYR support power-good monitoring with window comparator functionality?

Yes, TPS628681ARQYR includes a power-good (PG) indicator with window comparator functionality when configured with the VSET/VID pin assigned to PG mode. However, the TPS628681ARQYR variant uses VSET/VID for startup voltage selection and register addressing - so PG functionality is not enabled by default. To use PG, a different variant such as TPS6286810CRQYR must be selected.

What is the recommended inductor value for TPS628681ARQYR in a typical 1.2-V output design?

For the TPS628681ARQYR operating with 1.2-V output and 5-V input, Texas Instruments specifies a 220-nH shielded power inductor (e.g., Coilcraft XAL5030-221MEB or equivalent). This value balances peak inductor current, ripple magnitude (~240 mA), and transient response - and is validated in the device's typical application circuit (Figure 9-2). Lower values increase ripple; higher values degrade transient performance.

Can TPS628681ARQYR start into a pre-biased output capacitor?

Yes, TPS628681ARQYR supports pre-biased start-up. When enabled, the device detects the existing output voltage and ramps from that bias level to the target VOUT using its internal soft-start circuitry (tRamp = 0.85–1.5 ms). This prevents reverse current flow into the output capacitor and avoids disruptive voltage undershoot - critical in hot-swap and multi-rail sequencing applications.

How does thermal pre-warning work on TPS628681ARQYR, and how is it signaled?

TPS628681ARQYR monitors die temperature internally and asserts thermal pre-warning at 130°C (with 20°C hysteresis). Unlike thermal shutdown, this flag is not a pin-level signal - it is accessible only via I²C register read (STATUS register bit [THERM_WARN]). Host firmware can poll this bit to initiate cooling actions or performance throttling before reaching 150°C shutdown.