Texas Instruments LP2966IMMX-1833

Overview

LP2966IMMX-1833 from National Semiconductor is a dual-channel ultra-low-dropout linear regulator delivering 150mA per output with fixed 1.8V and 3.3V outputs in an MSOP-8 package. It operates from 2.7V to 7.0V input, features independent shutdown control (SD1/SD2), open-drain error flags (ERROR1/ERROR2), and ±1% output voltage accuracy over temperature - ideal for powering core logic and I/O rails in portable GPS receivers and handheld test equipment.

For engineers reviewing the LP2966IMMX-1833 datasheet, LP2966IMMX-1833 pinout, LP2966IMMX-1833 application, or LP2966IMMX-1833 equivalent, key selection criteria include dropout voltage at 150mA (135mV max), ground current under load (340µA at 100mA), error flag threshold (−10% VOUT), thermal shutdown (165°C), and compatibility with 1µF ceramic output capacitors.

Technical Context

The LP2966IMMX-1833 integrates two independent PMOS-based LDOs sharing a common input and ground, each with dedicated shutdown and error flag pins. Its architecture enables low-noise regulation (150µV_rms, 10Hz–100kHz) and high PSRR (60dB at 120Hz) without requiring external compensation.

Each regulator uses a precision bandgap reference and internal current-limiting with foldback protection (600mA knee), while cross-regulation remains below 0.4µV/mA - critical for mixed-voltage systems where one rail's load transient must not disturb the other.

Key Specifications

Pinout & Package

LP2966IMMX-1833 is housed in an MSOP-8 surface-mount package (3.0mm × 3.0mm × 0.85mm, NS package code MUA08A), optimized for space-constrained portable designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TSM1022AIDGKR and MCP1826S-1833E/DB, the LP2966IMMX-1833 offers the lowest dropout and integrated open-drain error flags in the smallest MSOP-8 footprint - making it optimal for space- and battery-life-constrained dual-rail systems where fault visibility is critical.

Availability

LP2966IMMX-1833 is available at Aetrix Electronics and suitable for GPS receivers, handheld multimeters, USB-powered test tools, portable wireless data terminals, and battery-backed instrumentation requiring stable component supply and long-term obsolescence support.

Supply support for LP2966IMMX-1833 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

National Semiconductor was a U.S.-based analog semiconductor company acquired by Texas Instruments in 2011, known for high-performance power management and interface ICs.

The LP2966 series was designed specifically for battery-powered portable electronics requiring dual, independently controlled, ultra-low-noise LDO regulation in minimal PCB area.

FAQ

What are the exact output voltages of the LP2966IMMX-1833?

The LP2966IMMX-1833 provides fixed 1.8V on VOUT1 and 3.3V on VOUT2, with guaranteed ±1% accuracy at room temperature and ±1.5% over the full −40°C to +125°C junction temperature range. These values are laser-trimmed during manufacturing and do not require external feedback resistors.

Can the LP2966IMMX-1833 operate from a single 3.0V lithium-ion cell?

Yes - the LP2966IMMX-1833 supports input voltages down to 2.7V and has a maximum dropout voltage of 135mV at 150mA. With a 3.0V input, it can maintain regulation on the 1.8V output down to 2.93V input and on the 3.3V output down to 3.43V input; thus, the 3.3V rail requires a higher input, making the 1.8V rail viable across the full battery discharge curve.

How should the ERROR1 and ERROR2 pins be interfaced to a microcontroller?

ERROR1 and ERROR2 are open-drain outputs that sink current when their respective output drops >10% below nominal. Connect each to a microcontroller GPIO via a 100kΩ–1MΩ pull-up resistor to VIN or VCC. The MCU reads logic-low on the pin to detect fault. If unused, tie ERROR1 and ERROR2 directly to GND to prevent floating nodes.

Does the LP2966IMMX-1833 require external capacitors, and what types are recommended?

Yes - the LP2966IMMX-1833 requires ≥1µF output capacitance per rail for stability. Ceramic (X7R/X5R), tantalum, or polymer aluminum electrolytic capacitors are supported. For 1.8V/3.3V outputs, 1µF–10µF X7R ceramics are preferred due to low ESR, small size, and stability; avoid high-DC-bias MLCCs that lose capacitance under bias.

What protection features does the LP2966IMMX-1833 include?

The LP2966IMMX-1833 integrates overcurrent foldback protection (600mA knee), thermal shutdown at 165°C with 25°C hysteresis, reverse-current blocking via internal PMOS structure, and ESD rating of 2kV (HBM). It also features independent shutdown inputs (SD1/SD2) that reduce total quiescent current to <1µA when both are asserted.