Texas Instruments TPS51103DRCT

Overview

TPS51103DRCT from Texas Instruments is a triple-output integrated LDO power management IC for notebook computers, featuring 5-V/100-mA and 3.3-V/100-mA switch-over LDOs plus a dedicated 3.3-V/5-mA always-on RTC LDO, all in a 10-pin QFN (DRC) package with thermal pad. It supports input voltage range of 4.5 V to 28 V and includes a 250-kHz clock output for external charge pump operation.

For engineers reviewing the TPS51103DRCT datasheet, TPS51103DRCT pinout, TPS51103DRCT application, or TPS51103DRCT equivalent, key selection criteria include switchover threshold accuracy (±25 mV hysteresis), R_DS(on) of 1 Ω (5V) and 1.5 Ω (3.3V), thermal shutdown at 150°C, and guaranteed operation from –40°C to 85°C.

Technical Context

The TPS51103DRCT integrates three independent LDO regulators with active switchover logic: VREG5 and VREG3 each support 100 mA with 1-ms delay-controlled transition between VIN-derived LDO mode and direct V5IN/V3IN pass-through mode. The VRTC3 rail operates continuously after VIN application, delivering stable 3.3 V at up to 5 mA without enable control.

Its internal 250-kHz clock generator drives VCLK with 50% duty cycle and rail-to-rail swing (GND to V5IN), enabling low-cost charge-pump generation of 10 V or 15 V for N-channel load switches. Thermal shutdown is non-latching and activates at 150°C junction temperature with 20°C hysteresis.

Key Specifications

Pinout & Package

TPS51103DRCT uses a thermally enhanced 10-pin VSON (DRC) package with exposed thermal pad, measuring 3 mm × 3 mm × 0.9 mm. The PowerPAD™ design requires soldering the underside pad to PCB ground plane via multiple vias for effective heat dissipation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multi-rail LDO with switchover applications.

Compared with TPS51103DRCT, TPS51100DRCT omits two critical outputs and timing capability, limiting its use to simplified 5-V-only systems; TPS74301RGWT offers tighter voltage accuracy but lacks switchover logic and clock generation entirely, making it unsuitable for notebook power architecture optimization.

Availability

TPS51103DRCT is available at Aetrix Electronics and suitable for notebook computer power management, mobile digital consumer product design, and embedded systems requiring stable multi-rail LDO supply with switchover capability and RTC bias.

Supply support for TPS51103DRCT 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 technologies, with over 50 years of innovation in high-reliability power solutions.

The TPS51103DRCT belongs to TI's notebook power management IC family, engineered specifically to consolidate multiple LDO rails, switchover logic, and charge-pump timing into a single compact package for space-constrained portable computing platforms.

FAQ

What is the primary function of the TPS51103DRCT in a notebook power system?

The TPS51103DRCT serves as an integrated triple-LDO power manager with switchover capability. It delivers regulated 5-V/100-mA and 3.3-V/100-mA outputs that automatically transition between VIN-derived LDO mode and direct external rail connection, plus a dedicated 3.3-V/5-mA always-on RTC supply. Its VCLK output drives external charge pumps for gate drive generation. This architecture optimizes efficiency and battery life in notebook computers.

Does the TPS51103DRCT require external components to operate its switchover function?

No, the switchover function of the TPS51103DRCT is fully internal and does not require external resistors or timing components. Transition between LDO and pass-through modes is triggered automatically when V5IN exceeds 4.65 V (or V3IN exceeds 3.07 V), with built-in 1-ms delay and hysteresis. However, external ceramic capacitors (10–22 µF for VREG5/VREG3; 1–2.2 µF for VRTC3) are mandatory for output stability and must be placed close to respective pins.

Can the TPS51103DRCT be used outside notebook applications?

Yes, the TPS51103DRCT is applicable in any system requiring dual switchover LDOs with always-on auxiliary supply and clock generation - such as portable medical monitors, industrial handhelds, or automotive infotainment head units with battery-backup RTC. Its 4.5–28 V input range, –40°C to 85°C rating, and robust thermal protection support broader embedded use, though its feature set was optimized for notebook power sequencing.

How does the thermal pad on the TPS51103DRCT package affect PCB layout requirements?

The exposed thermal pad on the TPS51103DRCT's DRC package must be soldered directly to a PCB ground plane using multiple 0.33-mm vias to internal/solder-side ground layers. This connection is essential to achieve the specified 80°C/W θ_JA and sustain 1.256 W maximum power dissipation. Failure to implement proper thermal land design results in excessive junction temperature rise and premature thermal shutdown during sustained 100-mA loads.

What happens to the VRTC3 output when EN3 and EN5 are both held low?

The VRTC3 output remains fully active and continues delivering 3.3 V at up to 5 mA even when EN3 and EN5 are both low. Unlike VREG3 and VREG5, VRTC3 has no enable input and powers on as soon as VIN is applied above 4.5 V. This behavior is intentional to ensure uninterrupted real-time clock operation during system suspend, hibernate, or complete power-down sequences where main LDOs are disabled.