Texas Instruments LP2988IMM-2.8/NOPB

Overview

LP2988IMM-2.8/NOPB from Texas Instruments is a micropower, 200 mA ultra-low-dropout linear voltage regulator with programmable power-on reset delay and bypass pin for noise reduction. It delivers 2.8 V output at ±0.5% accuracy (A-grade), 180 mV dropout at 200 mA, and 20 µV_RMS output noise (BW = 300 Hz–50 kHz) when using 0.01 µF bypass capacitor. It is used in noise-sensitive portable electronics requiring stable low-noise bias for RF sections or precision analog circuitry.

For engineers reviewing the LP2988IMM-2.8/NOPB datasheet, LP2988IMM-2.8/NOPB pinout, LP2988IMM-2.8/NOPB application, or LP2988IMM-2.8/NOPB equivalent, key selection criteria include its 2.8 V fixed output, <2 µA shutdown current, 1.23 V internal reference, Bypass pin functionality, and SOIC-8/VSSOP-8 package compatibility - all critical for battery-powered, low-EMI embedded systems.

Technical Context

The LP2988IMM-2.8/NOPB uses a vertically integrated PNP (VIP) pass transistor architecture to achieve ultra-low dropout and low ground current across load range. Its error comparator monitors output via internal 1.23 V reference and resistive divider, asserting open-collector ERROR/RESET when output falls >5% below nominal.

Power-on reset delay is implemented by charging an external capacitor on the DELAY pin using a 2.2 µA current source; the ERROR pin transitions high once DELAY pin voltage reaches 1.23 V. The Bypass pin connects directly to the bandgap reference node, enabling external capacitor filtering of reference noise to reduce output voltage noise spectral density.

Key Specifications

Pinout & Package

VSSOP-8 (DGK) package: 3.0 mm × 3.0 mm, 0.65 mm pitch, exposed thermal pad, RoHS-compliant CU-SN finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LP2988IMM-2.8/NOPB, the LP2988IMM-3.3/NOPB offers identical noise, dropout, and packaging but targets 3.3 V logic domains, while TLS850F0TESA1 adds watchdog and automotive qualification at the cost of higher quiescent current and non-compatible footprint.

Availability

LP2988IMM-2.8/NOPB is available at Aetrix Electronics and suitable for cellular phone RF biasing, portable medical sensor nodes, and industrial IoT edge controllers requiring stable component supply with guaranteed long-term availability.

Supply support for LP2988IMM-2.8/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 specializing in analog and embedded processing technologies, with leadership in power management ICs since the 1980s.

The LP2988 series belongs to TI's precision LDO portfolio designed for noise-critical portable and industrial applications demanding ultra-low dropout, micropower shutdown, and integrated power-on reset functionality.

FAQ

What is the maximum input voltage rating for LP2988IMM-2.8/NOPB?

The LP2988IMM-2.8/NOPB has an absolute maximum input voltage of +16 V and a recommended operating range of 2.1 V to +16 V. Exceeding 16 V may cause permanent damage. For dual-supply systems where output could exceed input, an external Schottky diode from INPUT to OUTPUT (cathode to INPUT) is required to clamp reverse voltage to ≤0.3 V, per TI application hints.

How does the Bypass pin reduce output noise in LP2988IMM-2.8/NOPB?

The Bypass pin connects directly to the internal bandgap reference node of LP2988IMM-2.8/NOPB. Adding a 0.01 µF low-leakage capacitor (e.g., NPO/C0G ceramic or film) filters reference noise, reducing output voltage noise from ~100 µV_RMS (LP2987-level) to 20 µV_RMS (300 Hz–50 kHz). This is essential for powering RF LNAs and precision ADCs where supply noise couples into signal paths.

What capacitor value is needed for a 100-ms power-on reset delay with LP2988IMM-2.8/NOPB?

Using the formula C_DLY = T_DELAY / (5.59 × 10⁵), a 100-ms delay requires C_DLY = 0.1 / 559000 ≈ 0.179 µF. A standard 0.18 µF (180 nF) capacitor meets this requirement. TI recommends keeping C_DLY ≤ 1 µF and using low-leakage types (tantalum, C0G ceramic, or film); aluminum electrolytics are prohibited due to excessive leakage.

Is LP2988IMM-2.8/NOPB pin-compatible with LP2987IMM-2.8/NOPB?

Yes - LP2988IMM-2.8/NOPB and LP2987IMM-2.8/NOPB share identical VSSOP-8 (DGK) pinout, electrical specifications, and package dimensions. The only functional difference is the presence of the Bypass pin on LP2988IMM-2.8/NOPB (pin 1), which is No Connect (N/C) on LP2987IMM-2.8/NOPB. Systems designed for LP2988IMM-2.8/NOPB can use LP2987IMM-2.8/NOPB without layout change, but will forfeit low-noise capability.

What is the thermal resistance (θ_J−A) of the VSSOP-8 package for LP2988IMM-2.8/NOPB?

The VSSOP-8 (DGK) package used by LP2988IMM-2.8/NOPB has a junction-to-ambient thermal resistance (θ_J−A) of 200°C/W under standard JEDEC test conditions (single-layer board, no copper pour). With proper PCB layout - including thermal vias under the exposed pad and ≥1 in² copper area - θ_J−A can be reduced to ~60°C/W, enabling continuous 200 mA operation at ambient temperatures up to +85°C.