Texas Instruments TPS65250RHAT

Overview

TPS65250RHAT from Texas Instruments is a triple-output synchronous buck converter IC with integrated high-side/low-side FETs, designed for xDSL/xPON modems and home gateways. It delivers 3 A (Buck 1), 2 A (Buck 2), and 2 A (Buck 3) across a 4.5–18 V input range, features 0.8 V ±1% reference accuracy, adjustable 300 kHz–2.2 MHz switching frequency, and on-chip dying gasp storage/release circuitry supporting 10.5 V release voltage and 20 V storage.

For engineers reviewing the TPS65250RHAT datasheet, TPS65250RHAT pinout, TPS65250RHAT application, or TPS65250RHAT equivalent, this device is selected for high-current, multi-rail power management in broadband access equipment requiring sequenced startup, soft-start control, current-limit tuning via external resistors, and robust input voltage sag response during dying gasp events.

Technical Context

The TPS65250RHAT integrates three current-mode controlled buck regulators with independent enable, soft-start, compensation, and current-limit pins. Buck 1 operates at up to 3.5 A peak with 95 mΩ/50 mΩ R_DS(on), while Bucks 2 and 3 operate in-phase and 180° out-of-phase with Buck 1 to minimize input ripple. Each regulator supports external resistor-set switching frequency (ROSC) or synchronization (SYNC) with deglitching and blanking after PGOOD assertion.

Its dedicated dying gasp circuit includes STRG, BSTDG, VINDG, LDODG, and GASP terminals - enabling controlled precharge of an external storage capacitor to 20 V, followed by regulated dump into VIN when input drops below 10.5 V. The low-power mode (LOW_P) reduces quiescent current from 20 mA to 1.5 mA, and internal supervisor monitors all three outputs to assert open-drain PGOOD after sequencing and timeout.

Key Specifications

Pinout & Package

TPS65250RHAT is housed in a thermally enhanced 40-pin QFN package (RHA), 6 mm × 6 mm, with exposed power pad soldered to PCB ground for optimal thermal dissipation (θ_JA = 30°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar triple-buck PMIC applications.

Compared with TPS65250RHAT, TPS65261RHAR offers extended input voltage but removes dying gasp functionality and reduces channel count, while RTQ2132B-QA adds functional safety features at the cost of missing the core storage/release circuit - making TPS65250RHAT uniquely suited for broadband access equipment with strict brownout hold-up requirements.

Availability

TPS65250RHAT is available at Aetrix Electronics and suitable for xDSL modems, home gateways, and wireless routers requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for TPS65250RHAT 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 and embedded processing technologies, with decades of expertise in power management IC design and manufacturing.

The TPS65250RHAT belongs to TI's broadband power management product line, engineered specifically for multi-rail, high-reliability power delivery in DSL, PON, and cable access infrastructure where dying gasp compliance and thermal efficiency are critical.

FAQ

What is the maximum storage voltage supported by the dying gasp circuit in TPS65250RHAT?

The TPS65250RHAT dying gasp circuit supports a maximum storage voltage of 20.1 V ±5%, limited by internal clamping and specified as VSTORAGE in the datasheet. This value is derived from the 2×VIN − 1.5 V constraint, allowing safe operation up to 20 V when powered from a 12 V input. Exceeding this voltage risks damage to the STRG terminal, which has an absolute maximum rating of 30 V but is not intended for continuous operation above 20.1 V.

Does TPS65250RHAT support pin-to-pin replacement with other TI PMICs like TPS65261?

No, TPS65250RHAT does not support pin-to-pin replacement with TPS65261 or other TI PMICs. Its 40-pin RHA package includes unique terminals - STRG, VINDG, LDODG, GASP, and BSTDG - absent in TPS65261. Pin functions, counts, and spacing differ significantly; for example, TPS65261 uses a 32-pin VQFN package and lacks dying gasp control logic entirely. Board redesign is required for substitution.

How is the switching frequency set on TPS65250RHAT, and what resistor value yields 1.14 MHz?

The TPS65250RHAT switching frequency is set via an external resistor (ROSC) from pin 6 to GND. Per Figure 30 in the datasheet, a 118-kΩ resistor sets f_SW ≈ 1.14 MHz. The relationship follows f_OSC(kHz) = 174 × R_OSC(kΩ)^−1.122. For synchronization, the SYNC pin accepts external clocks from 0.2–2.2 MHz; when unused, it must be tied to GND to avoid noise coupling.

What is the purpose of the GASP pin on TPS65250RHAT, and how is it used?

The GASP pin on TPS65250RHAT is an open-drain output that asserts low during the dying gasp dump phase, signaling the host processor that input voltage has dropped below 10.5 V and stored energy is being transferred to VIN. It enables firmware to initiate graceful shutdown, save state, or reduce load before final power loss. The signal remains active until VIN recovers above the release threshold or the storage capacitor depletes.

Can TPS65250RHAT operate with all three bucks enabled simultaneously at full rated current?

Yes, TPS65250RHAT is rated for simultaneous operation: Buck 1 at 3 A, Buck 2 at 2 A, and Buck 3 at 2 A, provided thermal design supports the total power dissipation. At 12 V input and typical efficiencies (~88% for Buck 1, ~85% for Bucks 2/3), total power loss exceeds 2.5 W. The RHA package requires adequate copper area and thermal vias under the exposed pad to maintain T_J ≤ 125°C in continuous operation.