Texas Instruments TPS65051RSMR

Overview

TPS65051RSMR from Texas Instruments is a 6-channel power-management IC integrating two step-down DC-DC converters (DCDC1: 1 A, DCDC2: 600 mA) and four low-input-voltage LDOs (two 400-mA and two 200-mA) for single-cell Li-Ion/Li-Polymer systems. It operates from 2.5 V to 6 V input, features 2.25-MHz fixed-frequency switching, digital voltage selection for LDOs and DCDC2, and supports power-save mode with 32-μA quiescent current per converter. It powers core/I/O rails in OMAP™ and TMS320™ DSP-based portable devices.

For engineers reviewing the TPS65051RSMR datasheet, TPS65051RSMR pinout, TPS65051RSMR application, or TPS65051RSMR equivalent, key selection considerations include its dual-buck + quad-LDO architecture, externally adjustable output voltages, 180° out-of-phase operation for reduced input ripple, ±1% DCDC output accuracy in PWM mode, and support for digital LDO/DCDC2 voltage selection via DEFLDOx/DEFDCDC2 pins.

Technical Context

The TPS65051RSMR implements two synchronous buck converters with integrated high-side and low-side MOSFETs (rDS(on) ≤630 mΩ P-ch, ≤450 mΩ N-ch), operating at 2.25 MHz with selectable PFM/PWM mode via the MODE pin. DCDC1 supports 0.6 V to VIN output range; DCDC2 supports externally adjustable or digitally selected outputs (e.g., 1.05 V / 1.3 V).

Four LDOs are independently enabled: VLDO1/VLDO2 deliver 400 mA each with 70 dB PSRR at 10 kHz and dropout as low as 280 mV; VLDO3/VLDO4 deliver 200 mA each with same PSRR and 280 mV dropout. All LDOs accept 1.5 V–6.5 V input and feature ±2% output accuracy, 10-μs load regulation time, and internal discharge resistors (350 Ω) when disabled.

Key Specifications

Pinout & Package

TPS65051RSMR uses a 32-pin VQFN package (4.0 mm × 4.0 mm) with exposed thermal pad connected to GND for thermal management.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multi-rail power management applications.

Compared with TPS65054RSMR and TPS65056RSMR, the TPS65051RSMR uniquely provides 1-A DCDC1 current capability and fully adjustable DCDC1 output voltage, making it optimal for high-performance processors requiring scalable core voltage and robust I/O rail delivery.

Availability

TPS65051RSMR is available at Aetrix Electronics and suitable for smartphone baseband power, OMAP™ application processor supply, portable media player audio subsystems, and TMS320™ low-power DSP systems requiring stable component supply across production lifecycles.

Supply support for TPS65051RSMR 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 company specializing in analog, embedded processing, and power management technologies with over 50 years of innovation in energy-efficient electronics.

The TPS6505x product line was designed specifically for single-cell Li-Ion/Li-Polymer portable systems requiring tightly regulated, sequenced, and digitally configurable multi-rail power delivery for application processors, DSPs, and multimedia SoCs.

FAQ

What is the maximum output current capability of the DCDC1 converter in the TPS65051RSMR?

The TPS65051RSMR DCDC1 converter delivers up to 1 A of continuous output current, enabling it to power high-current I/O rails such as memory interfaces or USB transceivers. This distinguishes it from TPS65050/TPS65054 variants rated at 600 mA. The 1-A rating is validated across the full 2.5–6 V input range and –40°C to 85°C ambient temperature.

How does the MODE pin affect the operation of the TPS65051RSMR DC-DC converters?

The MODE pin on the TPS65051RSMR selects between Power Save Mode (PFM at light loads, PWM at heavy loads) when pulled low, and forced PWM mode when pulled high. Forced PWM eliminates frequency variation and associated EMI, critical for noise-sensitive applications like audio or RF. In PFM mode, the TPS65051RSMR achieves 32–40 μA quiescent current with both converters active but unloaded.

Can the TPS65051RSMR support independent sequencing of its six power rails?

Yes, the TPS65051RSMR supports full independent sequencing via dedicated enable pins: EN_DCDC1, EN_DCDC2, EN_LDO1, EN_LDO2, EN_LDO3, and EN_LDO4. Each is active-high with no internal pull resistors, allowing precise external control using GPIOs or dedicated sequencers. This enables strict power-up/power-down order required by processors like OMAP-L138 or TMS320C55xx.

What is the purpose of the DEFLDO1–DEFLDO4 pins on the TPS65051RSMR?

The DEFLDO1–DEFLDO4 pins on the TPS65051RSMR form a 4-bit digital input that sets the default output voltage of all four LDOs at power-on, eliminating the need for external feedback resistors in standard configurations. The mapping is LSB (DEFLDO1) to MSB (DEFLDO4), allowing 16 possible voltage combinations pre-programmed into the device's internal LDO reference network.

Does the TPS65051RSMR include built-in protection features?

Yes, the TPS65051RSMR integrates thermal shutdown (140°C trip, 20°C hysteresis), overcurrent limiting on both DC-DC channels (1.19–1.65 A forward limit), undervoltage lockout (1.8–2.0 V on VCC), and short-circuit protection on all LDOs (750 mA for LDO1, 850 mA for LDO2, 420 mA for LDO3/LDO4). These protections operate autonomously without external components.