Texas Instruments LP3988IMF-2.85/NOPB

Overview

LP3988IMF-2.85/NOPB from Texas Instruments is a micropower, ultra-low-dropout CMOS voltage regulator delivering 150 mA at fixed 2.85 V output, with integrated Power Good (PG) flag and logic-controlled enable. It operates from 2.5 V to 6 V input, achieves 80 mV typical dropout at full load, consumes ≤1 µA in shutdown, and supports ceramic capacitors as small as 1 µF. It is used in GSM/CDMA handset power rails for baseband processors requiring precise, low-noise 2.85 V supply.

For engineers reviewing the LP3988IMF-2.85/NOPB datasheet, LP3988IMF-2.85/NOPB pinout, LP3988IMF-2.85/NOPB application, or LP3988IMF-2.85/NOPB equivalent, key selection criteria include its 2.85 V ±3% output tolerance, 10 µs PG response time, 45 dB PSRR at 10 kHz, thermal shutdown at 160°C, and SOT-23-5 package compatibility with space-constrained portable designs.

Technical Context

The LP3988IMF-2.85/NOPB integrates a PMOS pass transistor with internal voltage reference and error amplifier to maintain regulation across 2.5–6 V input and −40°C to +125°C junction temperature. Its open-drain PG output asserts low when VOUT falls below 93% of nominal (2.66 V), with 2.6% hysteresis between trip thresholds.

Enable control uses TTL-compatible thresholds (VIH = 1.2 V, VIL = 0.5 V), and the device enters dropout when VIN < VOUT + 80 mV (typical). Quiescent current rises only marginally in dropout-critical for battery runtime-and short-circuit protection limits output to 600 mA while thermal shutdown activates at ~160°C with 20°C hysteresis.

Key Specifications

Pinout & Package

LP3988IMF-2.85/NOPB is packaged in a 5-pin SOT-23 (DBV) with 2.90 mm × 1.60 mm body size and gull-wing leads. The package is RoHS-compliant and optimized for reflow soldering on high-density PCBs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-dropout regulator applications.

Compared with TCS2102-2.85 and MCP1700T-285I/TT, LP3988IMF-2.85/NOPB uniquely combines ultra-low dropout (80 mV), integrated PG, and sub-1-µA shutdown in a standard SOT-23-5-enabling robust, space-efficient power management in battery-critical wireless systems without external supervision circuitry.

Availability

LP3988IMF-2.85/NOPB is available at Aetrix Electronics and suitable for GSM handset baseband supplies, CDMA transceiver bias rails, and portable memory retention circuits requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for LP3988IMF-2.85/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 leader specializing in analog, embedded processing, and power management technologies, with decades of experience in high-reliability, low-power IC design.

The LP3988 product line delivers micropower, ultra-low-dropout regulators with integrated Power Good for portable wireless and battery-powered applications-designed to maximize runtime while ensuring deterministic power sequencing and fault reporting.

FAQ

What is the output voltage tolerance of LP3988IMF-2.85/NOPB over temperature?

The LP3988IMF-2.85/NOPB has a guaranteed output voltage tolerance of ±3% over the full operating junction temperature range of −40°C to +125°C. This specification applies to the fixed 2.85 V output option and is verified across process, voltage, and temperature corners per TI's production test flow. The LP3988IMF-2.85/NOPB maintains this tolerance without external trimming or feedback components.

Does LP3988IMF-2.85/NOPB require an external pullup resistor on the PG pin?

Yes, LP3988IMF-2.85/NOPB requires an external pullup resistor on the PG pin because it is an open-drain output. The resistor must connect PG to a supply rail ≤6 V-commonly VOUT or VIN-and values between 10 kΩ and 100 kΩ are typical. Without this pullup, the PG signal cannot assert high to indicate "VOUT OK," rendering the power-good function inoperative in LP3988IMF-2.85/NOPB systems.

Can LP3988IMF-2.85/NOPB operate with a 2.5 V input voltage?

Yes, LP3988IMF-2.85/NOPB can operate with a 2.5 V input voltage, but only if the device is not required to deliver full 150 mA output. At 2.5 V input, the maximum sustainable output current is limited by dropout: since typical dropout is 80 mV at 150 mA, the minimum input for full load is 2.93 V. At 2.5 V input, LP3988IMF-2.85/NOPB enters dropout mode and delivers reduced current-verified in TI's electrical characteristics tables under recommended operating conditions.

What is the thermal shutdown behavior of LP3988IMF-2.85/NOPB?

LP3988IMF-2.85/NOPB activates thermal shutdown at approximately 160°C junction temperature, disabling the output to halt power dissipation. It recovers automatically when the junction cools to ~140°C, providing 20°C hysteresis. This cycling protects against permanent damage during sustained overload but is not intended as a substitute for proper thermal design-continuous operation in thermal shutdown may degrade LP3988IMF-2.85/NOPB reliability over time.

Is LP3988IMF-2.85/NOPB stable with ceramic capacitors smaller than 1 µF?

No, LP3988IMF-2.85/NOPB is not guaranteed stable with ceramic output capacitors smaller than 1 µF. The datasheet specifies 1 µF as the minimum value for stability across all operating conditions, and performance validation-including PSRR, transient response, and phase margin-is based on ≥1 µF X7R or Z5U ceramics. Using sub-1-µF capacitors may cause oscillation or excessive ringing in LP3988IMF-2.85/NOPB applications, especially under dynamic load steps.