Texas Instruments LM26480QSQX-AA/NOPB

Overview

LM26480QSQX-AA/NOPB from Texas Instruments (formerly National Semiconductor) is an automotive-grade power management IC integrating two 1.5A synchronous step-down DC/DC converters and two 300 mA low-noise LDOs in a single 4×4×0.8 mm LLP-24 package. It delivers core digital power for applications processors, supports dual-rail voltage sequencing with programmable nPOR delay, and operates across −40°C to +125°C junction temperature.

For engineers reviewing the LM26480QSQX-AA/NOPB datasheet, LM26480QSQX-AA/NOPB pinout, LM26480QSQX-AA/NOPB application, or LM26480QSQX-AA/NOPB equivalent, key selection criteria include AEC-Q100 Grade 1 qualification, dual-buck + dual-LDO integration, 2 MHz switching frequency, ±3% feedback accuracy, and external enable/POR control for safety-critical power sequencing.

Technical Context

The LM26480QSQX-AA/NOPB implements voltage-mode PWM control with automatic PWM-to-PFM mode transition under light loads, achieving up to 96% efficiency at 250 mA. Its buck regulators feature internal PFET/NFET synchronous rectification, 2.0 MHz nominal oscillator (±20%), and 100% duty-cycle capability for ultra-low dropout operation down to VIN = VOUT + I_LOAD × (R_DS(ON),PFET + R_INDUCTOR).

Each LDO provides ±3% output voltage accuracy, 25 mV typical dropout at 50 mA, 45 dB PSRR at 10 kHz, and stable no-load regulation. The device includes integrated thermal shutdown (160°C trip, 20°C hysteresis), current-limit protection (2.0–2.4 A peak per buck), and undervoltage lockout (2.9 V rising, 2.7 V falling on VINLDO12).

Key Specifications

Pinout & Package

LM26480QSQX-AA/NOPB uses a thermally enhanced 24-pin LLP (Leadless Leadframe Package) measuring 4 mm × 4 mm × 0.8 mm, with exposed DAP (Die Attach Pad) recommended for soldering to improve thermal dissipation. Pin numbering follows top-view layout per Figure 2 in the datasheet.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multi-rail PMIC applications.

Compared with TPS65023RSBR and MAX20004AATP+T, the LM26480QSQX-AA/NOPB offers optimal balance of automotive qualification, compact 4×4 mm footprint, and flexible nPOR sequencing-making it ideal for cost- and space-sensitive ADAS and telematics modules where 1.5A per buck suffices.

Availability

LM26480QSQX-AA/NOPB is available at Aetrix Electronics and suitable for automotive ADAS camera modules, infotainment SoC power delivery, and telematics control units requiring stable component supply with full AEC-Q100 compliance and long-term production support.

Supply support for LM26480QSQX-AA/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 acquired National Semiconductor in 2011 and maintains its high-reliability analog and power management portfolio. TI is a global leader in semiconductor design and manufacturing, serving automotive, industrial, and communications markets.

The LM26480QSQX-AA/NOPB belongs to TI's automotive-qualified power management unit (PMU) product line, designed specifically to consolidate multiple voltage rails in safety-conscious vehicle subsystems while meeting stringent thermal, reliability, and qualification requirements.

FAQ

What is the AEC-Q100 qualification status of LM26480QSQX-AA/NOPB?

The LM26480QSQX-AA/NOPB is AEC-Q100 Grade 1 qualified, meaning it has been tested and certified for operation from −40°C to +125°C junction temperature. This qualification covers stress tests including HTOL, TC, UHAST, and ESD, confirming suitability for automotive cabin and engine-compartment-adjacent applications. LM26480QSQX-AA/NOPB carries the "Q" prefix explicitly denoting automotive grade.

How does the nPOR function work on LM26480QSQX-AA/NOPB?

The nPOR pin on LM26480QSQX-AA/NOPB is an open-drain output that asserts LOW when either Buck1 or Buck2 output voltage falls below 82% of its target value, or remains LOW until both outputs exceed 92% of target for ≥60 ms (default delay). It supports external pull-up (e.g., 100 kΩ) and enables safe SoC reset sequencing. The delay is factory-set to 60 ms for LM26480QSQX-AA/NOPB and cannot be reconfigured externally.

Can LM26480QSQX-AA/NOPB operate with only one buck enabled?

Yes, LM26480QSQX-AA/NOPB supports independent enable control: ENSW1 and ENSW2 are separate logic inputs, allowing Buck1 and Buck2 to be powered up/down individually. Disabling one buck reduces quiescent current (to ~33 µA in PFM mode for active buck) and eliminates associated switching noise. Both bucks remain fully functional when enabled simultaneously, with no cross-regulation penalty.

What are the minimum external components required for LM26480QSQX-AA/NOPB?

LM26480QSQX-AA/NOPB requires four external components per buck: input capacitor (≥10 µF ceramic), output capacitor (≥10 µF ceramic), inductor (2.2 µH, 2.5 A saturation current), and FB resistor divider. Each LDO needs only output capacitor (0.47–1.0 µF) and optional EN pull-up. No bootstrap capacitor or external compensation network is needed due to internal compensation and integrated FETs.

Does LM26480QSQX-AA/NOPB support forced PWM mode?

No, LM26480QSQX-AA/NOPB operates exclusively in auto-mode (PWM/PFM transition based on load), as indicated by its "AA" suffix in the ordering table. Forced PWM variants like LM26480QSQ-CF exist but are distinct part numbers. The LM26480QSQX-AA/NOPB automatically enters PFM below ~70 mA load to achieve 33 µA typical quiescent current, optimizing battery runtime in low-power states.