Texas Instruments TPS65266-1RHBT

Overview

TPS65266-1 from Texas Instruments is a triple-output synchronous step-down DC/DC converter with independent 3-A, 2-A, and 2-A channels, operating from 2.7 V to 6 V input. It integrates high-side/low-side MOSFETs per channel, features 0.6 V ±1% feedback reference, adjustable 250 kHz–2.4 MHz switching frequency via ROSC pin, and delivers power-good monitoring across all outputs. It is used in multi-rail power systems for digital TV and home gateways.

For engineers reviewing the TPS65266-1 datasheet, TPS65266-1 pinout, TPS65266-1 application, or TPS65266-1 equivalent, key selection considerations include per-channel enable/soft-start control, peak-current-mode regulation with phase-shifted clocks to reduce input ripple, PSM mode for light-load efficiency, and thermal shutdown at 160°C with 20°C hysteresis.

Technical Context

The TPS65266-1 implements peak-current-mode control with dedicated COMPx pins for external loop compensation per buck channel, enabling fast transient response and stable operation with small inductors. Each channel has independent ENx and SSx pins, supporting monotonic startup into prebiased loads and flexible power sequencing via capacitor-based timing or resistor-divider UVLO adjustment.

Its clock architecture uses 180° phase shift between Buck1 and Buck2/Buck3 to minimize input current ripple and reduce required input capacitance. The device supports external clock synchronization (250 kHz–2.4 MHz), pulse-skipping mode below ~10% load, and hiccup-mode overcurrent protection with 512-cycle wait and 16,382-cycle restart delay.

Key Specifications

Pinout & Package

VQFN-32 (RHB) package, 5.00 mm × 5.00 mm body size, with exposed thermal pad soldered to PCB ground for optimal thermal performance (R_θJC(bot) = 2.8°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS65266-1, the TPS65266RHBT offers identical electrical performance with extended temperature qualification, while MP2451DT-LF-Z requires three separate ICs and external coordination to match basic functionality - making TPS65266-1 the only monolithic solution for compact, sequenced, triple-rail power delivery.

Availability

TPS65266-1 is available at Aetrix Electronics and suitable for digital TV, home gateway, and surveillance camera applications requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for TPS65266-1 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 TPS65266-1 belongs to TI's high-density, multi-output DC/DC converter product line, engineered specifically for space-constrained consumer and industrial systems needing reliable, sequenced, and thermally robust power delivery from low-voltage inputs.

FAQ

What is the maximum supported switching frequency for the TPS65266-1?

The TPS65266-1 supports an adjustable switching frequency range from 250 kHz to 2.4 MHz, set via an external resistor on the ROSC pin. At ROSC = 51.1 kΩ, the nominal frequency is 1 MHz. Operation above 2.4 MHz is not guaranteed and may compromise stability or efficiency due to internal timing constraints and gate driver limitations.

Can the TPS65266-1 safely start up into prebiased output capacitors?

Yes, the TPS65266-1 is explicitly designed for monotonic startup into prebiased loads. Its soft-start circuitry regulates the internal feedback voltage to track the SSx pin voltage, preventing reverse current flow and ensuring controlled ramp-up even when output capacitors are initially charged - a critical feature for hot-swap and redundant power systems.

How does the PGOOD pin behave during power sequencing?

The PGOOD pin remains low until all three buck outputs reach regulation (±5% of target) and complete their programmed power-up sequence. It asserts high only after the last channel stabilizes and internal sequencing logic confirms valid operation - providing a single, reliable system-ready signal for processors or FPGAs without external monitoring circuitry.

What is the purpose of the VINQ pin on the TPS65266-1?

VINQ supplies bias power to the internal controller, reference, and logic circuits. It must be decoupled with a 1-µF capacitor to AGND and is electrically independent of VIN1/VIN2/VIN3. This separation ensures stable regulation even when input rails experience dropout or noise - critical for maintaining PGOOD integrity and soft-start accuracy.

Does the TPS65266-1 support external clock synchronization?

Yes, the TPS65266-1 accepts an external clock signal on the ROSC pin within the same 250 kHz–2.4 MHz range. The sync input requires TTL-compatible levels (V_{SYNC_HI} ≥ 2 V, V_{SYNC_LO} ≤ 0.4 V) and minimum pulse width of 80 ns. This enables deterministic timing across multiple TPS65266-1 devices or with system master clocks to suppress beat frequencies and simplify EMI filtering.