Texas Instruments LP3972SQ-A514/NOPB

Overview

LP3972SQ-A514/NOPB from Texas Instruments is a programmable power management unit (PMU) integrating three synchronous buck regulators, six low-dropout linear regulators (including RTC LDO), backup battery charger, I²C interface, and dual GPIOs - configured for Marvell PXA and Samsung application processors. It delivers 1.6-A output per buck, ±3% voltage accuracy, and supports dynamic voltage management in smart phones and media players.

For engineers reviewing the LP3972SQ-A514/NOPB datasheet, LP3972SQ-A514/NOPB pinout, LP3972SQ-A514/NOPB application, or LP3972SQ-A514/NOPB equivalent, this page provides verified regulator configurations (BUCK1 @ 1.4 V, LDO5 @ 1.4 V, LDO_RTC @ 2.8 V), WQFN-40 package mapping, thermal shutdown at 160°C, I²C timing compliance (400 kHz), and validated alternative options for PMU replacement in handheld SoC platforms.

Technical Context

The LP3972SQ-A514/NOPB implements a multi-rail PMU architecture with independent enable control via SYS_EN and PWR_EN signals, supporting hierarchical power sequencing for application processors. Its three buck converters operate with internal 2-MHz oscillator or external SYNC input, while six LDOs include dedicated RTC supply with automatic main-to-backup battery switchover.

Regulator outputs are fully software-programmable over I²C, including voltage levels, enable states, and nBATT_FLT threshold (default 2.8 V). The device integrates thermal shutdown (160°C), current limiting (2.4-A peak per buck), and short-circuit protection across all rails - with quiescent current as low as 0.1 µA in shutdown mode.

Key Specifications

Pinout & Package

LP3972SQ-A514/NOPB uses a 40-pin WQFN package (5.0 mm × 5.0 mm) with exposed thermal pad (BGND1,2,3 pins 34 and GND pins 10,18,33,38). Pin functions are validated per TI SNVS468L Rev L datasheet.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar power management unit applications.

Compared with LP3972SQ-A514/NOPB, the A413 variant offers identical performance with a minor LDO4 voltage shift, while the I514 variant changes power-up sequencing behavior - both retain full register compatibility and thermal/current protection features.

Availability

LP3972SQ-A514/NOPB is available at Aetrix Electronics and suitable for smartphone power management, media player SoC supply, digital camera sensor power, and application processor reference platforms requiring stable component supply across extended production cycles.

Supply support for LP3972SQ-A514/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 for portable electronics.

The LP3972 product line was designed specifically for advanced application processors (Marvell PXA, Freescale i.MX, Samsung S3C) requiring integrated, software-programmable power delivery with dynamic voltage management and backup battery support.

FAQ

What is the factory-default output voltage of BUCK1 on LP3972SQ-A514/NOPB?

The LP3972SQ-A514/NOPB has BUCK1 factory-configured to 1.4 V, as specified in Table 2 of the SNVS468L datasheet for Version A. This matches the VCC_APPS rail requirement for Marvell PXA application processors. The voltage remains programmable via I²C register writes after power-up, but boots to 1.4 V without host intervention. LP3972SQ-A514/NOPB maintains this default across temperature and load conditions within ±3% tolerance.

Does LP3972SQ-A514/NOPB support automatic switchover to backup battery for the RTC supply?

Yes, LP3972SQ-A514/NOPB provides automatic main-to-backup battery switchover on the LDO_RTC rail. When main battery voltage falls below TP1 (2.9 V), it transitions to backup source; when rising above TP2 (3.0 V), it switches back. This function is hardware-controlled and requires no I²C command. LP3972SQ-A514/NOPB implements this using dedicated comparators and internal switching FETs, ensuring uninterrupted RTC operation during battery replacement or discharge.

What is the maximum supported I²C clock frequency for LP3972SQ-A514/NOPB?

LP3972SQ-A514/NOPB supports standard-mode and fast-mode I²C operation up to 400 kHz, as confirmed in Section 7.10 of the SNVS468L datasheet. The interface uses open-drain SDA/SCL pins requiring external pull-up resistors (2–20 kΩ). Timing parameters including tCLKHP (0.6 µs min), tCLKLP (1.3 µs min), and tSU (0.6 µs min) are fully compliant with I²C Specification v2.1. LP3972SQ-A514/NOPB does not support high-speed mode (3.4 MHz).

How does the nBATT_FLT pin function on LP3972SQ-A514/NOPB?

The nBATT_FLT pin on LP3972SQ-A514/NOPB is an active-low open-drain output that asserts when main battery voltage falls below a programmable threshold - defaulting to 2.8 V per Table 2. It sinks up to 0.4 mA and is intended to signal the host processor to initiate graceful shutdown. The threshold is adjustable via I²C register 0x1F, and LP3972SQ-A514/NOPB retains its default setting unless explicitly reprogrammed, making it immediately usable in battery-fault detection circuits.

What thermal protection mechanisms are implemented in LP3972SQ-A514/NOPB?

LP3972SQ-A514/NOPB incorporates thermal shutdown at 160°C with 20°C hysteresis, as specified in Section 7.5. It also includes per-buck current limiting (2.4-A peak) and short-circuit protection for all LDOs. These protections are hardware-based and operate independently of I²C communication. The device resumes normal operation automatically once junction temperature falls below 140°C. LP3972SQ-A514/NOPB's RθJA of 25°C/W (WQFN-40) enables reliable operation up to 85°C ambient when properly mounted on a 4-layer PCB with thermal vias.