Texas Instruments LP5900SDX-2.7/NOPB

Overview

LP5900SDX-2.7/NOPB from Texas Instruments is a 150-mA ultra-low-noise LDO regulator designed for RF and analog circuits, delivering 2.7 V output with ±2% tolerance, 6.5 μV_RMS output noise, 75 dB PSRR at 1 kHz, and 80 mV typical dropout voltage. It operates across 2.5 V–5.5 V input range and supports stable regulation with only 0.47-μF ceramic input/output capacitors-no noise bypass capacitor required-making it ideal for space-constrained cellular RF front-ends.

For engineers reviewing the LP5900SDX-2.7/NOPB datasheet, LP5900SDX-2.7/NOPB pinout, LP5900SDX-2.7/NOPB application, or LP5900SDX-2.7/NOPB equivalent, key selection considerations include its no-bypass-capacitor architecture, thermal shutdown (160°C), logic-controlled enable with 1-MΩ internal pull-down, 25 μA quiescent current in active mode, and compatibility with DSBGA-4 (YZR) package for ultra-thin portable designs.

Technical Context

The LP5900SDX-2.7/NOPB employs an innovative low-noise reference architecture with integrated first-order RC filtering to suppress internal reference noise before reaching the output buffer-eliminating need for external noise-bypass capacitance. Its EN pin features a guaranteed VIH ≥1.2 V and VIL ≤0.4 V with 1-MΩ internal pull-down, enabling robust logic-level control without external biasing.

Stability is ensured with 0.47-μF ceramic capacitors on both IN and OUT pins (ESR 5–500 mΩ), and the device maintains regulation down to zero load. Thermal protection activates at ~160°C junction temperature with ~20°C hysteresis, and dropout is specified at 80 mV (typ) / 150 mV (max) under 150 mA load across –40°C to 125°C.

Key Specifications

Pinout & Package

LP5900SDX-2.7/NOPB is packaged in a 4-pin DSBGA (YZR) with 1.108 mm × 1.083 mm body size and exposed thermal pad on bottom. The package requires soldering to PCB copper area with thermal vias for optimal heat dissipation; thermal pad may be connected to GND or left floating but must not connect to any other potential.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPL7407LPGEDR, LP5900SDX-2.7/NOPB delivers superior RF-grade noise suppression and enable control, while TPS7A2027PDQNR offers higher current headroom in a larger but thermally enhanced package-neither is pin-compatible, but both serve overlapping low-noise LDO roles with distinct trade-offs in integration and layout.

Availability

LP5900SDX-2.7/NOPB is available at Aetrix Electronics and suitable for cellular handset RF modules, wireless LAN transceivers, PDA baseband processors, and portable medical sensor analog front-ends requiring stable component supply, consistent parametric performance, and long-term manufacturability.

Supply support for LP5900SDX-2.7/NOPB 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 company headquartered in Dallas, Texas, specializing in analog and embedded processing technologies with broad portfolio coverage across power management, signal chain, and interface solutions.

LP5900SDX-2.7/NOPB belongs to TI's ultra-low-noise LDO family engineered specifically for RF and precision analog applications where PSRR, output noise, and capacitor-free simplicity are critical-targeting mobile, wearable, and medical electronics.

FAQ

What is the minimum input voltage required for LP5900SDX-2.7/NOPB to regulate 2.7 V output?

The LP5900SDX-2.7/NOPB requires input voltage ≥2.5 V to power internal circuitry, but regulation at 2.7 V demands VIN ≥ VOUT + VDO. With 80 mV typical dropout, minimum functional input is 2.78 V. At 150 mA load and 125°C junction temperature, max dropout rises to 150 mV, so VIN ≥2.85 V is recommended for full-spec operation across temperature.

Does LP5900SDX-2.7/NOPB require an external bypass capacitor for noise reduction?

No-LP5900SDX-2.7/NOPB does not require an external noise-bypass capacitor. Its internal reference stage includes a first-order RC filter that attenuates reference noise before the output buffer, achieving 6.5 μV_RMS output noise with only 0.47-μF input and output ceramic capacitors.

What is the function of the thermal pad on the LP5900SDX-2.7/NOPB DSBGA package?

The exposed thermal pad on the LP5900SDX-2.7/NOPB DSBGA (YZR) package must be soldered to a PCB copper area with thermal vias to dissipate heat. It may be connected to GND or left floating, but must never connect to any voltage other than the same GND potential seen at pin 3 (B1). This pad reduces θ_JA from 177.7°C/W to improve thermal performance.

Can LP5900SDX-2.7/NOPB operate with no load connected to the OUT pin?

Yes-LP5900SDX-2.7/NOPB remains stable and maintains regulation with zero load current. Its design ensures output voltage accuracy and loop stability even when sourcing 0 mA, making it suitable for biasing high-impedance nodes like crystal oscillator circuits or op-amp reference inputs.

What are the enable logic thresholds for LP5900SDX-2.7/NOPB, and how is the EN pin biased?

LP5900SDX-2.7/NOPB EN pin has V_IH = 1.2 V (min) and V_IL = 0.4 V (max) across –40°C to 125°C. An internal 1-MΩ pull-down resistor connects EN to GND, ensuring default-disable state when left unconnected. Driving EN ≥1.2 V enables regulation; ≤0.4 V disables output and reduces IQ to <1 μA.