Texas Instruments TPS720105YZUR

Overview

TPS720105YZUR from Texas Instruments is a 350 mA ultra-low VIN, RF low-dropout linear regulator with bias pin, designed for dual-rail power management in space-constrained RF and portable systems. It delivers 1.05 V output at ±2% accuracy over –40°C to 125°C, achieves 110 mV dropout at full load, and maintains 48 μVRMS output noise (10 Hz–100 kHz) - enabling clean power for RF transceivers and high-speed ADCs in cellular camera phones.

For engineers reviewing the TPS720105YZUR datasheet, TPS720105YZUR pinout, TPS720105YZUR application, or TPS720105YZUR equivalent, key selection criteria include its dual-rail architecture (VIN + VBIAS), 38 μA quiescent current, 140 μs startup time, and stable operation with only 2.2 μF ceramic output capacitance - critical for battery-powered, low-noise, fast-transient applications.

Technical Context

The TPS720105YZUR employs an NMOS pass transistor with integrated body diode and uses a precision bandgap reference with high-gain error amplifier to achieve 2% total output accuracy across load, line, temperature, and process. Its dual-supply architecture separates the main power path (VIN) from the control circuit bias rail (VBIAS), allowing VIN as low as VOUT + 0.5 V while VBIAS ≥ VOUT + 1.4 V or 2.5 V (whichever is greater).

It features built-in soft-start limiting inrush current to 100 mA + ILOAD, monotonic VOUT rise with ≤3% overshoot, and independent PSRR optimization: 80 dB at 10 kHz for VIN and 70 dB at 10 kHz for VBIAS. Transient response is specified at ±15 mV for 0→350 mA load steps in 1 μs and ±200 μV for ±400 mV VIN steps in 1 μs.

Key Specifications

Pinout & Package

TPS720105YZUR is packaged in a 1.33 mm × 0.96 mm, 5-ball DSBGA (YZU) package with bottom-side solder balls. The thermal pad is not electrically connected and requires no external connection.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LDO regulator applications.

Compared with TPS72012YZUR, the TPS720105YZUR provides tighter alignment with sub-1.1 V core logic; compared with TPS795105DRVR, it enables 43% lower quiescent current and dual-rail flexibility at the cost of one additional supply rail and ball count.

Availability

TPS720105YZUR is available at Aetrix Electronics and suitable for cellular camera phones, wireless LAN modules, and handheld medical devices requiring stable component supply, long-term lifecycle support, and traceable sourcing for FDA-regulated production.

Supply support for TPS720105YZUR 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 decades of LDO design heritage and automotive-grade reliability validation.

The TPS720 family targets ultra-low-noise, dual-rail power management in portable RF and imaging systems - engineered to replace discrete bias networks and improve efficiency in space-constrained PMUs.

FAQ

What is the minimum input voltage required for TPS720105YZUR to regulate at full 350 mA load?

The TPS720105YZUR requires VIN ≥ VOUT + 0.5 V = 1.55 V under recommended operating conditions. However, its ultra-low dropout architecture allows regulation down to VIN = VOUT + 110 mV = 1.16 V at 350 mA, provided VBIAS ≥ 2.45 V and thermal limits are observed. This 1.16 V minimum enables operation directly from partially discharged Li-ion cells.

Can TPS720105YZUR operate with the IN pin disconnected, and what is the maximum supported load in that mode?

Yes, the TPS720105YZUR supports regulated output with IN floating under light-load conditions. In this mode, the BIAS pin supplies up to 500 μA while maintaining 1.05 V output within ±1% accuracy. This feature is intended for standby states where upstream DC-DC converters are disabled but core logic must retain state - the TPS720105YZUR delivers precisely this capability without external circuitry.

What is the purpose of the BIAS pin on TPS720105YZUR, and how should it be implemented?

The BIAS pin powers the internal control circuitry independently from the main power path (IN). It must be supplied with ≥2.45 V (min UVLO threshold) and ≥VOUT + 1.4 V - so for TPS720105YZUR's 1.05 V output, VBIAS ≥ 2.45 V. TI recommends a 0.1 μF ceramic capacitor from BIAS to GND near the package to ensure transient immunity. This architecture decouples control-loop stability from VIN quality, enabling high PSRR and low noise.

Does TPS720105YZUR require an input capacitor on the IN pin for stability?

No, the TPS720105YZUR is internally compensated and stable without an input capacitor on IN. However, TI recommends a 0.1–1 μF low-ESR ceramic capacitor close to the IN pin to improve transient response, reduce high-frequency noise coupling, and counteract source impedance effects - especially when the IN supply originates from a switching regulator or long PCB traces. This is a best-practice design guideline, not a stability requirement.

How does the enable function work on TPS720105YZUR, and what happens in shutdown mode?

The EN pin is active-high with VIH ≥1.1 V to enable regulation and VIL ≤0.4 V to disable. When disabled, the TPS720105YZUR enters shutdown mode, reducing ground current to ≤2 μA (typical 0.5 μA). During shutdown, OUT is actively discharged through an internal switch to prevent floating voltage, ensuring predictable system reset behavior. This controlled discharge is intrinsic to the TPS720105YZUR's architecture and requires no external components.