Texas Instruments TPS799315DDCT

Overview

TPS799315DDCT from Texas Instruments is a 200-mA, fixed-output 3.15-V low-dropout linear regulator with enable (EN), ultralow noise (10.5 × V_OUT μV_RMS), high PSRR (66 dB at 1 kHz), and 40-μA quiescent current - designed for powering RF circuitry, VCOs, and precision analog blocks in space-constrained portable systems.

For engineers reviewing the TPS799315DDCT datasheet, TPS799315DDCT pinout, TPS799315DDCT application, or TPS799315DDCT equivalent, this device is selected for ultra-low-noise biasing of sensitive RF stages, fast transient response in wearable power rails, and stable operation with 2.2-μF ceramic output capacitance in DSBGA or SOT-23-THIN packages.

Technical Context

The TPS799315DDCT employs a PMOS pass element with advanced BiCMOS process to achieve 100-mV typical dropout at 200 mA and maintain high PSRR down to 100 mV headroom. Its feedback loop uses a precision 1.193-V internal reference and achieves ±2% total output accuracy across –40°C to +125°C, load (0.5–200 mA), and line (2.7–6.5 V) variations.

It integrates inrush current protection triggered by EN toggle, overshoot detection (5% threshold), and a dedicated NR pin for external noise-reduction capacitor (0.01 μF typical) that bypasses bandgap noise - enabling sub-35 μV_RMS output noise at 3.15 V while preserving fast 50-μs start-up time.

Key Specifications

Pinout & Package

TPS799315DDCT is packaged in a 5-pin SOT-23-THIN (DDC) measuring 2.90 mm × 1.60 mm, with exposed pad not present. This thermally enhanced thin-outline package supports 225.3°C/W junction-to-ambient resistance and is compatible with standard SMT reflow profiles.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-noise LDO applications.

Compared with TPS799315DBVR, the TPS799315DDCT offers marginally better thermal performance in identical SOT-23-THIN footprint; versus ADP125ARHZ-3.15-R7, it delivers 50-mA higher current, NR-enabled noise reduction, and tighter accuracy - making it superior for RF-critical designs.

Availability

TPS799315DDCT is available at Aetrix Electronics and suitable for RF power amplifier bias, VCO core supply, wearable sensor hub rails, and industrial wireless transceiver applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for TPS799315DDCT 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 connectivity technologies, with decades of LDO innovation focused on power integrity and signal-chain performance.

The TPS799 series was engineered specifically for ultra-low-noise, high-PSRR regulation in RF and precision analog subsystems - targeting VCOs, ADCs, DACs, and wireless transceivers where supply ripple directly impacts system-level SNR and phase noise.

FAQ

What is the maximum input voltage rating for the TPS799315DDCT?

The absolute maximum input voltage for the TPS799315DDCT is 7.0 V, per the Absolute Maximum Ratings table. However, the recommended operating range is 2.7 V to 6.5 V. Exceeding 6.5 V may trigger internal UVLO or cause reliability concerns, and operation below 2.7 V is only valid if VIN ≥ VOUT + VDO (i.e., ≥3.25 V for full 200-mA capability). The TPS799315DDCT must never be subjected to input transients beyond 7.0 V.

Does the TPS799315DDCT require an external noise-reduction capacitor to achieve its specified output noise?

Yes - the TPS799315DDCT achieves its ultralow 33.2 μV_RMS output noise (10 Hz–100 kHz) only when a 0.01-μF ceramic capacitor is connected between the NR pin and ground. Without this capacitor, output noise rises to ~94 × V_OUT = 297 μV_RMS. The NR pin is high-impedance, so low-leakage X7R/X5R ceramics are mandatory; aluminum electrolytics or high-ESR types will degrade noise performance and stability.

Can the TPS799315DDCT operate stably with less than 2.2 μF output capacitance?

No - the TPS799315DDCT is specified and characterized for stability only with ≥2.2 μF ceramic output capacitance (X5R/X7R, ESR < 1.0 Ω). Using smaller values risks oscillation, poor transient response, and failure to meet PSRR/noise specifications. While some lab tests may show marginal stability at 1.0 μF, TI does not guarantee performance or reliability below 2.2 μF, and the TPS799315DDCT datasheet explicitly requires this minimum for production use.

What is the shutdown current of the TPS799315DDCT, and how is it achieved?

The TPS799315DDCT draws 150 nA typical shutdown current when the EN pin is driven below 0.4 V. This ultra-low state is achieved by internally disconnecting the bandgap reference, error amplifier, and pass transistor gate drive - effectively disabling all active circuitry except a minimal UVLO monitor. The 150-nA figure is measured at V_IN = 2.7–6.5 V and T_J = 25°C; it remains ≤1 μA across –40°C to +125°C, ensuring negligible battery drain in always-off modes.

Is the TPS799315DDCT pin-compatible with other TPS799 variants in the same SOT-23-THIN package?

Yes - all TPS799 fixed-output variants (e.g., TPS799125DDCT, TPS79918DDCT, TPS79933DDCT) share identical 5-pin SOT-23-THIN (DDC) pinout: Pin 1 = IN, Pin 2 = GND, Pin 3 = EN, Pin 4 = NR, Pin 5 = OUT. This allows direct substitution within the same voltage family without PCB changes, provided input/output capacitor values and thermal layout accommodate the specific V_OUT and load requirements of the TPS799315DDCT.