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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Voltage Regulators - DC DC Switching Regulators

Texas Instruments TPS542951RSAR

Name: TPS542951RSAR
Brand: Texas Instruments
SKU: TPS542951RSAR
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: TPS542951RSAR

Manufacturer:: Texas Instruments

Category:: Voltage Regulators - DC DC Switching Regulators

Package:: 16-VQFN Exposed Pad

Datasheet:: TPS542951RSAR.pdf

Description:: IC REG BUCK ADJ 2A/3A DL 16QFN

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Product details

Overview

TPS542951 from Texas Instruments is a dual-channel synchronous step-down DC/DC converter with integrated 150 mΩ high-side and 100 mΩ low-side N-channel MOSFETs per channel, supporting 2 A on CH1 and 3 A on CH2. It operates from 4.5 V to 18 V input, delivers adjustable output voltages from 0.76 V to 7.0 V, and uses D-CAP2™ adaptive on-time control for fast transient response without external compensation - widely deployed in digital TV, STB, and gaming console power rails.

For engineers reviewing the TPS542951 datasheet, TPS542951 pinout, TPS542951 application, or TPS542951 equivalent, key selection considerations include its dual-output capability with independent soft-start (SS1/SS2), non-sinking pre-biased startup, cycle-by-cycle over-current protection, and thermal shutdown at 155°C - all in a thermally enhanced 16-pin HTSSOP (RSA) package with PowerPAD™.

Technical Context

The TPS542951 implements D-CAP2™ control - combining adaptive on-time PWM with internal ramp-based ripple simulation - enabling stable operation with ceramic output capacitors and eliminating need for external loop compensation. Its two independent channels share no internal coupling, each featuring dedicated feedback (VFB1/VFB2), enable (EN1/EN2), soft-start (SS1/SS2), and bootstrap (VBST1/VBST2) pins.

Each channel employs loss-less low-side rDS(on) current sensing with thermal compensation (4000 ppm/°C), 700 kHz pseudo-fixed switching frequency, and Auto-Skip Eco-mode™ for >90% efficiency at light loads. Protection includes hiccup-mode OCP, UVLO on VREG5, UVP/OVP thresholds at 68%–73% of reference, and thermal shutdown with 25°C hysteresis.

Key Specifications

Parameter	Value and Actual Design Meaning
Input Voltage Range	4.5 V to 18 V - supports wide industrial and consumer DC bus inputs including 5 V, 12 V, and 15 V rails.
Output Current Capability	CH1: 2 A continuous / CH2: 3 A continuous - enables independent point-of-load regulation for core and I/O rails.
Feedback Reference Voltage	0.765 V ±7 mV - sets precise output voltage via resistor divider; temperature coefficient ±115 ppm/°C ensures stability across –40°C to 85°C.
Switching Frequency	~700 kHz (adaptive on-time) - balances EMI, efficiency, and component size; varies <±5% with VIN and VOUT.
Thermal Shutdown Threshold	155°C typical with 25°C hysteresis - protects against sustained overload; junction-to-board θJB = 11.8°C/W in RSA package.
Current Limit Accuracy	CH1: 2.7–4.5 A / CH2: 3.5–5.4 A - cycle-by-cycle valley detection with thermally compensated rDS(on) sensing ensures repeatable fault response.
Soft-Start Charge Current	–8.0 µA typical (SSx to GND) - enables precise, capacitor-programmable startup ramp time without external circuitry.

Pinout & Package

TPS542951 is housed in a 4 mm × 4 mm, 16-pin VQFN package (RSA) with exposed PowerPAD™ thermal pad soldered to PCB ground for optimal thermal dissipation (θJB = 11.8°C/W). Pin numbering follows standard top-view orientation with Pin 1 at bottom-left corner.

Pin/Terminal	Circuit Role	Design Meaning
VIN1 / VIN2	Power Input	Independent input supplies for CH1 and CH2; each accepts 4.5–18 V; must be decoupled with ≥10 µF ceramic + 0.1 µF local cap.
VBST1 / VBST2	Bootstrap Supply	Drives high-side gate; requires 0.1 µF X5R/X7R ceramic between VBSTx and SWx; internal diode charges from VREG5.
SW1 / SW2	Switch Node	Connection point between high- and low-side FETs; carries high di/dt; routing must minimize loop area and parasitic inductance.
PGND1 / PGND2	Power Ground	Low-side FET source return; separate paths required for each channel to avoid cross-talk in current sensing.
EN1 / EN2	Enable Control	Active-high logic inputs (2.0 V H-threshold, 0.4 V L-threshold); internal 450 kΩ pull-down; supports independent channel sequencing.
VFB1 / VFB2	Feedback Input	Connects to resistor divider from VOx; 0.765 V reference; input bias current ±0.4 µA - impacts high-resistor-divider accuracy.
SS1 / SS2	Soft-Start	Sinks –8 µA to GND; capacitor value sets ramp time; enables non-sinking pre-biased startup by modulating low-side gate pulse width.
VREG5	Internal LDO Output	5.5 V regulated supply powering internal circuitry and VBSTx charge pump; requires ≥1 µF X5R/X7R ceramic bypass to GND.
GND	Signal Ground	Analog reference for VFBx and SSx; must be connected at single-point star ground near VFBx dividers to minimize noise coupling.
PowerPAD™	Thermal & Electrical Ground	Exposed copper pad; must be soldered to large PCB ground plane with ≥6 thermal vias (0.3 mm diameter) for reliable thermal performance.

Key Features

Feature	Design Value
D-CAP2™ Control Mode	Enables zero-external-compensation design with ceramic output capacitors; achieves <10 µs load transient recovery without tuning.
Non-Sinking Pre-Biased Soft Start	Prevents reverse current flow during startup into pre-charged outputs - critical for hot-swap and multi-rail sequencing applications.
Loss-Less Low-Side Current Sensing	Uses rDS(on) of low-side FET instead of sense resistor; eliminates power loss and board space; thermally compensated for accuracy.
Auto-Skip Eco-mode™	Disables switching cycles under light load to maintain >92% efficiency at 10 mA - extends battery life in always-on subsystems.
Hiccup-Mode Overload Protection	Shuts down for 7×UVP-enable-delay upon sustained OCP, then auto-retries - limits average power dissipation during fault conditions.
Independent Dual-Channel Operation	No shared control or sensing paths; allows asymmetric configurations (e.g., 3.3 V @ 2 A + 1.2 V @ 3 A) with separate EN/SS/VFB pins.

Applications

Digital Television Power Supply	Networking Home Terminal
Use Scenario: Powers SoC core (1.2 V), memory interface (1.5 V), and HDMI PHY (3.3 V) from single 12 V input in compact TV chassis. IC Role / Device Role / Timing Role: Dual-channel buck regulator delivering tightly regulated, low-noise DC rails with independent soft-start sequencing. Use Value: Eliminates need for discrete compensation networks and reduces BOM count by 40% vs traditional voltage-mode controllers.	Use Scenario: Supplies FPGA I/O bank (2.5 V), transceiver core (1.0 V), and USB PHY (3.3 V) in DSL/cable modem with strict thermal envelope. IC Role / Device Role / Timing Role: High-efficiency dual buck converter with Eco-mode extending standby runtime and thermal headroom. Use Value: Achieves >90% efficiency at 50 mA load per channel, reducing heatsink requirements and enabling fanless operation.
Digital Set-Top Box (STB)	Gaming Console System Rail
Use Scenario: Generates 1.1 V CPU core, 1.8 V DDR3, and 3.3 V peripheral rails from 12 V adapter in space-constrained STB enclosure. IC Role / Device Role / Timing Role: Dual synchronous buck with D-CAP2™ control ensuring fast transient response to bursty video decode workloads. Use Value: Maintains <±1% output regulation during 2 A step load transients with only 44 µF total ceramic output capacitance.	Use Scenario: Delivers GPU core (0.95 V), memory controller (1.35 V), and audio codec (3.3 V) in handheld gaming device with aggressive thermal limits. IC Role / Device Role / Timing Role: Thermally optimized dual buck with PowerPAD™ and θJB = 11.8°C/W enabling 3 A continuous on CH2 without derating. Use Value: Supports 150°C max junction temperature with hiccup-mode protection preventing thermal runaway during sustained GPU load.

Digital Television Power Supply

Networking Home Terminal

Use Scenario: Powers SoC core (1.2 V), memory interface (1.5 V), and HDMI PHY (3.3 V) from single 12 V input in compact TV chassis.

IC Role / Device Role / Timing Role: Dual-channel buck regulator delivering tightly regulated, low-noise DC rails with independent soft-start sequencing.

Use Value: Eliminates need for discrete compensation networks and reduces BOM count by 40% vs traditional voltage-mode controllers.

Use Scenario: Supplies FPGA I/O bank (2.5 V), transceiver core (1.0 V), and USB PHY (3.3 V) in DSL/cable modem with strict thermal envelope.

IC Role / Device Role / Timing Role: High-efficiency dual buck converter with Eco-mode extending standby runtime and thermal headroom.

Use Value: Achieves >90% efficiency at 50 mA load per channel, reducing heatsink requirements and enabling fanless operation.

Digital Set-Top Box (STB)

Gaming Console System Rail

Use Scenario: Generates 1.1 V CPU core, 1.8 V DDR3, and 3.3 V peripheral rails from 12 V adapter in space-constrained STB enclosure.

IC Role / Device Role / Timing Role: Dual synchronous buck with D-CAP2™ control ensuring fast transient response to bursty video decode workloads.

Use Value: Maintains <±1% output regulation during 2 A step load transients with only 44 µF total ceramic output capacitance.

Use Scenario: Delivers GPU core (0.95 V), memory controller (1.35 V), and audio codec (3.3 V) in handheld gaming device with aggressive thermal limits.

IC Role / Device Role / Timing Role: Thermally optimized dual buck with PowerPAD™ and θJB = 11.8°C/W enabling 3 A continuous on CH2 without derating.

Use Value: Supports 150°C max junction temperature with hiccup-mode protection preventing thermal runaway during sustained GPU load.

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-channel synchronous buck converter applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
TPS542950RSAR	Same pinout and package, but rated for 2 A/2 A (not 2 A/3 A); identical D-CAP2™ control, VFB reference, and protections.	Not suitable for 3 A CH2 loads; requires redesign if second rail exceeds 2 A or needs higher current margin.	Select TPS542950RSAR only when both channels demand ≤2 A and cost optimization is prioritized over headroom.
MP2492D-LF-Z	Monolithic dual buck with fixed 500 kHz frequency, no Eco-mode, requires external compensation, and lacks pre-biased soft start.	Higher external component count; less efficient below 100 mA; unsuitable for hot-swap or multi-rail sequencing.	Choose MP2492D-LF-Z only when fixed-frequency EMI profile is mandatory and light-load efficiency is secondary.

Compared with TPS542951, TPS542950RSAR offers identical functionality at lower current rating, while MP2492D-LF-Z trades integration and advanced features for simpler frequency control - making TPS542951 optimal for space-constrained, high-transient, and thermally sensitive dual-rail designs.

Availability

TPS542951 is available at Aetrix Electronics and suitable for digital TV, STB, and gaming console power supply designs requiring stable component supply, dual independent output regulation, and automotive-grade thermal reliability.

Supply support for TPS542951 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 TPS542951 belongs to TI's D-CAP2™ synchronous buck converter family, engineered for low-component-count, high-transient-response point-of-load regulation in consumer electronics where board space, thermal performance, and startup robustness are critical.

FAQ

What is the maximum recommended output current for each channel of the TPS542951?

The TPS542951 supports up to 2 A continuously on Channel 1 and 3 A continuously on Channel 2 under recommended operating conditions (TA ≤ 85°C, proper PCB thermal design). These ratings assume use of the RSA package with PowerPAD™ soldered to a 4-layer board with ≥6 thermal vias and adequate copper area. Exceeding these currents without thermal derating risks triggering thermal shutdown at 155°C.

Does the TPS542951 require external compensation components for stability?

No, the TPS542951 does not require external compensation components thanks to its D-CAP2™ control architecture. The internal adaptive on-time loop with built-in ramp generation provides inherent stability with ceramic or low-ESR polymer output capacitors. This eliminates the need for type-II or type-III compensation networks, reducing BOM count and layout complexity while maintaining >60° phase margin across load and input voltage ranges.

Can the TPS542951 safely start up into a pre-biased output voltage?

Yes, the TPS542951 supports non-sinking pre-biased soft start. When the output voltage is already present at startup, the controller gradually increases low-side FET conduction time cycle-by-cycle rather than forcing immediate full synchronous rectification. This prevents reverse current flow from the output into the converter, protecting downstream circuitry and ensuring monotonic voltage ramp-up - a key requirement in multi-rail systems with staggered power sequencing.

What is the purpose of the VREG5 pin on the TPS542951?

The VREG5 pin on the TPS542951 outputs a regulated 5.5 V supply used internally to power control circuitry and the VBSTx charge pump. It must be bypassed with ≥1 µF X5R/X7R ceramic capacitor to GND. VREG5 is active only when VIN1 is above UVLO threshold (~3.83 V); its UVLO hysteresis ensures clean startup/shutdown. Do not connect external loads to VREG5 - it is rated for internal use only (max 75 mA sink capability).

How does the TPS542951 handle over-current conditions?

The TPS542951 uses cycle-by-cycle valley current limiting based on low-side FET rDS(on) sensing, with thermal compensation (4000 ppm/°C) for accuracy. Upon over-current detection, it holds the low-side FET on until current falls below threshold, then resumes normal switching. If overload persists, UVP triggers hiccup mode: the device shuts down for 7×UVP-enable-delay (~10–15 ms), then retries. This limits average power dissipation and prevents thermal damage during sustained faults.

TPS542951RSAR Specifications

Product attributes: Attribute value

Manufacturer:: Texas Instruments

Series:: D-CAP2™, Eco-Mode™

Package/Case:: 16-VQFN Exposed Pad

Packaging:: Tape & Reel (TR)

Product Status:: Active

Function:: Step-Down

Output Configuration:: Positive

Topology:: Buck

Output Type:: Adjustable

Number of Outputs:: 2

Voltage - Input (Min):: 4.5V

Voltage - Input (Max):: 18V

Voltage - Output (Min/Fixed):: 0.76V

Voltage - Output (Max):: 7V

Current - Output:: 2A, 3A

Frequency - Switching:: 700kHz

Synchronous Rectifier:: Yes

Operating Temperature:: -40°C ~ 85°C (TA)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 16-QFN (4x4)

TPS542951RSAR FAQ

1.How can I place an order for TPS542951RSAR through Aetrix?

Please submit a Request for Quotation (RFQ) for TPS542951RSAR on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for TPS542951RSAR reliable?

The price and inventory of TPS542951RSAR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TPS542951RSAR is usually 5 days.

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TPS542951RSAR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your TPS542951RSAR order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for TPS542951RSAR?

For technical support, including TPS542951RSAR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TPS542951RSAR requirements.

6.How does Aetrix verify that TPS542951RSAR is sourced from the original manufacturer or authorized distributors?

All TPS542951RSAR products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that TPS542951RSAR meets industry standards.

7.What is the process for return or replacement of TPS542951RSAR?

All TPS542951RSAR units undergo pre-shipment inspection (PSI). If there is an issue with TPS542951RSAR, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The TPS542951RSAR part is unused and in its original packaging.

Return procedure for TPS542951RSAR:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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