Texas Instruments TPS71728DCKT

Overview

TPS71728DCKT from Texas Instruments is a fixed-output, 2.8 V, 150-mA low-dropout linear regulator in a 5-pin SC-70 package. It delivers ultra-low noise (30 µV_RMS, 100 Hz–100 kHz), high PSRR (70 dB at 1 kHz), and low dropout (170 mV typical at 150 mA) for powering noise-sensitive analog and RF circuitry in portable electronics.

For engineers reviewing the TPS71728DCKT datasheet, TPS71728DCKT pinout, TPS71728DCKT application, or TPS71728DCKT equivalent, key selection criteria include output noise performance under light-to-moderate load, PSRR across 100 Hz–1 MHz, thermal behavior in compact layouts, and compatibility with 1-µF ceramic output capacitance without external compensation.

Technical Context

The TPS71728DCKT uses a PMOS pass device and BiCMOS process to achieve fast startup, low ground current (45 µA typical), and stable regulation with only 1 µF output capacitance. Its error amplifier features high gain and bandwidth to sustain PSRR >67 dB up to 100 kHz while maintaining ±3% output accuracy over –40°C to 125°C.

Fixed-output variants like TPS71728DCKT integrate a dedicated noise reduction (NR) pin that filters bandgap reference noise via an external 0.01 µF capacitor-reducing output noise to 30 µV_RMS and improving PSRR by up to 15 dB at 100 kHz. The quick-start circuit charges CNR within 160 µs, enabling rapid power-on response.

Key Specifications

Pinout & Package

TPS71728DCKT is packaged in a 5-pin SC-70 (DCK) package measuring 2.00 mm × 1.25 mm, optimized for space-constrained portable designs. Thermal resistance R_θJA is 279.2°C/W, requiring minimal PCB copper for thermal management in low-power applications.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-noise, low-dropout regulator applications.

Compared with TPL71728PDBVR and MCP1703T-2802E/MB, TPS71728DCKT uniquely balances ultra-low noise, high PSRR, and low dropout in the smallest footprint - making it optimal for space- and noise-constrained RF/analog subsystems where all three parameters are simultaneously critical.

Availability

TPS71728DCKT is available at Aetrix Electronics and suitable for camera sensor power, mobile handset baseband supplies, wireless audio codecs, and portable medical sensors requiring stable component supply across production lifecycles.

Supply support for TPS71728DCKT 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 LDO design expertise for high-reliability applications.

The TPS717 family was engineered specifically for noise-sensitive, battery-powered portable electronics - delivering best-in-class PSRR, ultra-low noise, and minimal quiescent current in sub-2 mm² packages.

FAQ

What is the minimum input voltage required for TPS71728DCKT to regulate 2.8 V output?

The minimum input voltage is determined by dropout: VIN(min) = VOUT + VDO = 2.8 V + 0.17 V = 2.97 V typical. Per datasheet, the absolute minimum VIN is 2.5 V, but regulation is only guaranteed when VIN ≥ VOUT + VDO across temperature and load. For reliable 2.8 V output at 150 mA and 125°C, use VIN ≥ 3.1 V.

Can TPS71728DCKT operate without the noise reduction (NR) capacitor?

Yes, TPS71728DCKT functions without the NR capacitor, but output noise increases significantly - from 30 µV_RMS to approximately 95 × VOUT = 266 µV_RMS. The NR pin is left floating or tied to OUT if unused; no pull-up/down is required. For noise-critical applications like image sensors, the 0.01 µF ceramic capacitor on NR is mandatory.

What is the maximum junction temperature and thermal shutdown behavior of TPS71728DCKT?

TPS71728DCKT triggers thermal shutdown at TJ ≈ 160°C and resets at ≈140°C. Its SC-70 package has R_θJA = 279.2°C/W; at 150 mA and 3.3 V input, power dissipation is ~75 mW, yielding ΔT ≈ 21°C above ambient - well below shutdown threshold with minimal copper. Continuous thermal cycling indicates inadequate heatsinking and degrades reliability.

Is TPS71728DCKT stable with a 1-µF ceramic output capacitor?

Yes, TPS71728DCKT is explicitly designed and tested for stability with ≥1 µF X5R/X7R ceramic capacitors (ESR < 10 mΩ). Unlike many LDOs, it does not require tantalum or electrolytic capacitors. Smaller values (e.g., 0.47 µF) may cause instability; larger values (up to 100 µF) improve transient response but do not affect stability.

Does TPS71728DCKT support reverse current protection?

No, TPS71728DCKT lacks integrated reverse current protection. Its PMOS pass transistor includes a body diode that conducts from OUT to IN if V_OUT > V_IN. In systems where back-driving is possible (e.g., hot-swap, multi-rail sequencing), an external Schottky diode or ideal diode controller is required to block reverse current and prevent damage or system upset.