Texas Instruments LP3879SDX-1.2

Overview

LP3879SDX-1.2 from Texas Instruments is a micropower, low-noise, fixed-output 1.2 V linear voltage regulator delivering up to 800 mA with 1% initial output accuracy, 18 µV_RMS broadband noise (100 Hz–100 kHz), and operation from 2.5 V to 6 V input. It employs a vertically integrated PNP (VIP) process, supports ceramic output capacitors down to 10 µF, and targets precision low-voltage power rails in FPGA, ASIC, and medical instrumentation.

For engineers reviewing the LP3879SDX-1.2 datasheet, LP3879SDX-1.2 pinout, LP3879SDX-1.2 application, or LP3879SDX-1.2 equivalent, key selection criteria include its 1.2 V fixed output, ultra-low shutdown current (<10 µA), remote sense capability for improved load regulation, and WSON-8 package thermal performance with exposed thermal pad.

Technical Context

The LP3879SDX-1.2 uses a VIP-based PNP pass transistor architecture enabling low dropout and high PSRR (60 dB at 1 kHz), with internal compensation optimized for stability with ceramic capacitors. Its feedback loop incorporates a dedicated SENSE pin for remote voltage sensing, decoupling regulation accuracy from PCB trace IR drop.

Operation includes over-temperature and over-current protection, a dedicated BYPASS pin for noise reduction via 10 nF capacitor, and a logic-level SHUTDOWN pin with 1.4 V turn-on threshold. Ground pin current scales from 200 µA at light load to 5.5 mA at full 800 mA load.

Key Specifications

Pinout & Package

LP3879SDX-1.2 is packaged in an 8-pin WSON (NGT) surface-mount package with an exposed thermal pad on the bottom, optimized for low θ_J−A (~40°C/W with 4-layer board and thermal vias). The package requires soldering the thermal pad to a PCB ground plane for thermal and electrical integrity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS7A2012PDBVR and TPL7407LPGQDR, LP3879SDX-1.2 uniquely combines 800 mA output, 1.2 V fixed accuracy, remote SENSE, and BYPASS-enabled ultra-low noise-making it the only viable option for high-fidelity, high-current 1.2 V regulation where load placement or noise sensitivity precludes alternatives.

Availability

LP3879SDX-1.2 is available at Aetrix Electronics and suitable for FPGA power supplies, medical instrumentation, SMPS post-regulation, and ASIC core rails requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for LP3879SDX-1.2 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 expertise in high-reliability linear regulators and power solutions.

The LP3879 product line was engineered for low-noise, micropower, ceramic-capacitor-compatible regulation in space-constrained, thermally demanding applications such as portable medical devices and high-performance computing subsystems.

FAQ

What is the maximum input voltage the LP3879SDX-1.2 can withstand?

The LP3879SDX-1.2 has an absolute maximum input voltage rating of +16 V for survival, but its specified operating input range is 2.5 V to 6 V. Exceeding 6 V during normal operation risks violating safe operating area limits and may trigger internal protection or cause reliability degradation. Always maintain VIN ≤6 V in functional designs using LP3879SDX-1.2.

Does the LP3879SDX-1.2 require an external bypass capacitor, and why?

Yes, the LP3879SDX-1.2 requires a 10 nF capacitor between the BYPASS pin and ground. This capacitor reduces reference noise and is essential for loop stability. Its leakage current must stay below 100 nA to avoid degrading the 1.2 V output accuracy-low-leakage NPO/COG ceramic or polypropylene film capacitors are recommended for use with LP3879SDX-1.2.

Can the LP3879SDX-1.2 be used without connecting the SENSE pin?

Yes-the SENSE pin of the LP3879SDX-1.2 may be tied directly to the OUTPUT pin for standard local regulation. Leaving it unconnected is not allowed; it must be either shorted to OUTPUT or routed to the load's point-of-load. Using SENSE improves load regulation accuracy by compensating for PCB trace resistance, especially critical in LP3879SDX-1.2 applications delivering 800 mA.

What thermal considerations apply to the LP3879SDX-1.2 in WSON package?

The LP3879SDX-1.2 in WSON-8 requires soldering its exposed thermal pad to a PCB copper pour connected to ground. With proper 4-layer board layout and thermal vias, θ_J−A is ~40°C/W. At 800 mA and 3.3 V input, power dissipation is ~1.7 W-requiring adequate copper area to keep junction temperature ≤125°C. Thermal shutdown activates if exceeded, making heatsinking design essential for LP3879SDX-1.2 continuous operation.

Is the LP3879SDX-1.2 RoHS compliant and lead-free?

Yes, the LP3879SDX-1.2 is RoHS compliant and lead-free. Per TI's packaging documentation, it carries "SN" (matte tin) lead finish and meets JEDEC Level-1 moisture sensitivity standards for the WSON package. The part marking "79SD1.2" and packaging in 1000-piece tape-and-reel confirm its production-grade, environmentally compliant status for LP3879SDX-1.2.