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Texas Instruments LP3971SQX-U511/NOPB
- Part No.:
- LP3971SQX-U511/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- Power Management - Specialized
- Package:
- 40-WFQFN Exposed Pad
- Datasheet:
-
LP3971SQX-U511/NOPB.pdf
- Description:
- IC PMU FOR APP PROCESSOR 40WQFN
- Quantity:
- Payment:
- Shipping:
Inventory:4,579
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Product details
Overview
LP3971SQX-U511/NOPB from Texas Instruments is a programmable power management unit (PMU) designed for advanced application processors, integrating three 1.6A buck regulators, six LDOs (including 30 mA RTC LDO), I²C-controlled voltage programming, and a backup battery charger for lithium-manganese coin cells or supercapacitors. It delivers ±3% output voltage accuracy, up to 95% buck efficiency, and operates across −40°C to +85°C ambient.
For engineers reviewing the LP3971SQX-U511/NOPB datasheet, LP3971SQX-U511/NOPB pinout, LP3971SQX-U511/NOPB application, or LP3971SQX-U511/NOPB equivalent, this PMU supports dynamic voltage management in resource-constrained handheld platforms requiring precise sequencing, low-noise analog supplies, and seamless RTC battery switchover.
Technical Context
The LP3971SQX-U511/NOPB implements a multi-rail, digitally configurable power architecture with independent enable control via SYS_EN and PWR_EN signals, synchronized switching across three buck converters (2 MHz internal oscillator or external SYNC input), and hardware-based battery fault detection (nBATT_FLT) with programmable 2.4–3.4 V threshold. Its I²C interface (400 kHz high-speed mode) enables real-time voltage reconfiguration and status register readback.
It integrates dedicated analog ground planes (BGND1,2,3), thermal shutdown at 160°C, current overload protection per regulator, and automatic RTC LDO switchover between main and backup batteries based on hysteresis (2.8 V disconnect / 3.1 V reconnect). The device uses internal reference tracking and supports LDO_RTC voltage tracking of LDO1 within ±200 mV down to 2.8 V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Buck Output Current | Up to 1.6 A per buck regulator - supports core voltage rails for application processors like Marvell PXA or Samsung SoCs. |
| LDO Output Accuracy | ±3% over −40°C to +125°C - ensures stable I/O and peripheral supply under thermal stress. |
| I²C Interface Speed | High-speed mode (400 kHz) - enables fast configuration updates without blocking system boot sequences. |
| RTC LDO Switchover | Automatic main-to-backup transition at 2.8 V (hysteresis 3.1 V) - guarantees uninterrupted real-time clock operation during main battery depletion. |
| Backup Charger Current | Programmable 150/300/370 mA - configurable via I²C to match lithium-manganese coin cell or supercapacitor charging profiles. |
| Package | 40-pin WQFN (5 mm × 5 mm, RSB0040A) - compact footprint with exposed thermal pad for handheld thermal management. |
| Operating Temperature | −40°C to +85°C ambient - qualified for consumer portable electronics environments. |
Pinout & Package
LP3971SQX-U511/NOPB is housed in a 40-pin WQFN package (Package Number RSB0040A) with 0.4 mm pitch and exposed thermal pad (BGND1,2,3 pins 34, 10, 18, 33, 38). Pin 1 is marked by a circle on top view.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| PWR_ON | Active-HI push-button input | Initiates power-on/off sequencing events; controls EXT_WAKEUP pulse and register 8H'02 content selection. |
| EXT_WAKEUP | 10 ms pulse output | Signals CPU wake-up event triggered by PWR_ON, nTEST_JIG, or SPARE inputs; flags register interrogation. |
| nRSTO | Active-low reset output | Drives processor reset line; asserts during internal fault or power-on reset, synchronized to SYS_EN/PWR_EN logic. |
| SCL/SDA | I²C clock/data bidirectional | Enables full digital control of all regulator voltages, enable states, and status registers without external logic. |
| VIN Buck1/2/3 | Main battery input to bucks | Accepts 2.7–5.5 V; shared input allows single-source powering of multiple DC/DC stages with independent feedback (FB1/FB2/FB3). |
| VIN LDO4/LDO5 | Flexible LDO input source | Can be connected to main battery, buck output, or separate 1.8 V rail - supports mixed-supply domain partitioning. |
| GPIO1/nCHG_EN | Configurable I/O / charger enable | When used as nCHG_EN, enables/disables backup battery charging; toggled via I²C or direct processor control. |
Key Features
| Feature | Design Value |
|---|---|
| Three independent buck regulators | Each programmable 0.725–3.3 V output with 50–600 mV step resolution - supports core, memory, and I/O voltage scaling for application processors. |
| Six precision LDOs | LDO_RTC (30 mA), LDO1 (300 mA), LDO2–LDO4 (150 mA each), LDO5 (370 mA); ±3% accuracy and <100 mV dropout - powers noise-sensitive analog blocks and peripherals. |
| Backup battery management | Integrated charger with 150/300/370 mA options and automatic switchover circuitry - eliminates need for discrete battery switch and charge controller. |
| I²C programmability | Full register access for voltage, enable, fault mask, and tracking configuration - enables runtime DVM and adaptive power policy in OS-level power managers. |
| Thermal and current protection | 160°C thermal shutdown with 20°C hysteresis and per-regulator current limiting - prevents damage during overload or PCB thermal runaway. |
Applications
| Smartphone Baseband Power | Digital Camera Sensor Supply |
|---|---|
|
Use Scenario: Powers Marvell PXA or Freescale i.MX application processor in dual-mode smartphone with cellular modem and multimedia subsystems. IC Role / Device Role / Timing Role: Central PMU managing core voltage (BUCK1), memory I/O (BUCK2), display interface (BUCK3), RTC (LDO_RTC), audio codec (LDO2), and USB PHY (LDO5). Use Value: Reduces BOM count by consolidating 9 power rails into one IC; I²C programmability enables dynamic core voltage scaling during video encode/decode. |
Use Scenario: Supplies image sensor, ISP, and flash LED driver in compact digital camera with battery life optimization. IC Role / Device Role / Timing Role: Provides low-noise 2.8 V for CMOS sensor analog front-end (LDO2), 1.8 V for ISP core (BUCK2), and 3.3 V for flash driver (LDO5), with RTC backup maintained during sleep. Use Value: LDO dropout <100 mV at 150 mA ensures stable sensor bias under battery sag; automatic RTC switchover preserves timekeeping during 10-day standby. |
| Personal Media Player System | Application Processor Reference Platform |
|
Use Scenario: Powers ARM-based media player with NAND flash, LCD, audio DAC, and Bluetooth radio. IC Role / Device Role / Timing Role: Generates 1.2 V core (BUCK1), 3.3 V I/O (LDO5), 1.8 V SDIO (LDO4), 2.5 V audio (LDO3), and 3.0 V LCD (LDO1), with RTC powered from coin cell. Use Value: 95% buck efficiency at 500 mA extends playback time; I²C allows firmware to adjust LDO voltages for different codec configurations. |
Use Scenario: Used on Samsung or TI reference design boards for application processor evaluation and software development. IC Role / Device Role / Timing Role: Delivers sequenced, monitored, and reconfigurable power to processor cores, DDR interface, and debug interfaces (JTAG, UART). Use Value: Register-based fault reporting (nBATT_FLT, thermal flags) enables bootloader-level power health diagnostics; SYNC pin allows clock domain alignment with SoC PLL. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar power management unit applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS65023RSBR | Three buck + six LDO, but lacks integrated backup battery charger and RTC switchover logic; uses fixed-voltage options instead of I²C programmability. | Best suited for systems where backup battery is omitted or managed externally; less flexible for DVM-capable processors. | Select when cost sensitivity outweighs need for programmable RTC switchover and charger integration. |
| MAX8649ETE+ | Three buck + four LDO; includes I²C interface and thermal protection, but no backup battery support and only 1.2 A buck current rating. | Applicable to lower-power application processors (e.g., ARM9-based) without RTC backup requirements. | Choose for simpler designs needing basic DVM without battery management complexity. |
Compared with TPS65023RSBR and MAX8649ETE+, LP3971SQX-U511/NOPB uniquely combines full I²C-programmable voltage control, integrated backup battery charging, and automatic RTC switchover - making it the only option among the three that satisfies complete power autonomy for always-on timekeeping in battery-powered handhelds.
Availability
LP3971SQX-U511/NOPB is available at Aetrix Electronics and suitable for smartphone baseband power, digital camera sensor supply, personal media player system, and application processor reference platform requiring stable component supply across extended production cycles.
Supply support for LP3971SQX-U511/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 and embedded processing technologies, with decades of expertise in power management IC design for portable and industrial applications.
The LP3971 product line was engineered specifically for advanced application processors in handheld devices, delivering tightly integrated, software-configurable power rails with minimal external components and robust battery-aware operation.
FAQ
What is the default output voltage configuration for LP3971SQX-U511/NOPB?
The LP3971SQX-U511/NOPB defaults to factory-programmed voltage settings per its U511 variant code: LDO_RTC = 2.8 V, LDO1 = 3.3 V (SYS_EN enabled), LDO2 = 3.0 V, LDO3 = 3.0 V, LDO4 = 1.3 V (PWR_EN enabled), LDO5 = 1.1 V (PWR_EN enabled), BUCK1 = 1.4 V (PWR_EN enabled), BUCK2 = 3.0 V (SYS_EN enabled), and BUCK3 = 1.8 V (SYS_EN enabled). These values are stored in nonvolatile configuration registers and can be modified via I²C.
Does LP3971SQX-U511/NOPB support dynamic voltage scaling (DVS) for application processors?
Yes, LP3971SQX-U511/NOPB supports full dynamic voltage scaling through its I²C interface, allowing real-time adjustment of all three buck regulator outputs (0.725–3.3 V in 50–600 mV steps) and six LDOs (1.0–3.3 V). This enables processor firmware to scale core and I/O voltages in lockstep with performance states, reducing active power consumption without hardware changes.
How does the backup battery switchover function in LP3971SQX-U511/NOPB?
LP3971SQX-U511/NOPB automatically switches the RTC LDO input between main battery and backup battery based on voltage thresholds: disconnection from main battery occurs at ~2.8 V, and reconnection requires >3.1 V. This hysteresis prevents oscillation during battery recovery. The nBATT_FLT pin provides early warning (programmable 2.4–3.4 V) before switchover, enabling system-level power-save actions.
What thermal protection features does LP3971SQX-U511/NOPB include?
LP3971SQX-U511/NOPB incorporates thermal shutdown at 160°C (with 20°C hysteresis) and per-regulator current limiting. When junction temperature exceeds 160°C, all regulators disable and remain off until temperature falls below 140°C. Additionally, each buck converter has peak current limiting (~2.4 A), and LDOs feature short-circuit current limits (e.g., 400 mA for LDO1–LDO4).
Can LP3971SQX-U511/NOPB operate with an external clock synchronization signal?
Yes, LP3971SQX-U511/NOPB accepts an external clock on the SYNC pin to synchronize its internal 2 MHz oscillator across multiple PMUs or align switching frequencies with system clocks. When SYNC is driven with a 10.4–15.6 MHz signal, the device locks its buck converter switching frequency to harmonics of the input, reducing EMI in multi-rail systems and avoiding beat frequencies with other clock domains.
LP3971SQX-U511/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 40-WFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Applications:
- Processor
- Current - Supply:
- 60µA
- Voltage - Supply:
- 2.7V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 40-WQFN (5x5)
LP3971SQX-U511/NOPB FAQ
1.How can I place an order for LP3971SQX-U511/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LP3971SQX-U511/NOPB on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for LP3971SQX-U511/NOPB reliable?
The price and inventory of LP3971SQX-U511/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LP3971SQX-U511/NOPB is usually 5 days.
3.What payment methods are accepted for LP3971SQX-U511/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LP3971SQX-U511/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LP3971SQX-U511/NOPB?
LP3971SQX-U511/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LP3971SQX-U511/NOPB order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for LP3971SQX-U511/NOPB?
For technical support, including LP3971SQX-U511/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LP3971SQX-U511/NOPB requirements.
6.How does Aetrix verify that LP3971SQX-U511/NOPB is sourced from the original manufacturer or authorized distributors?
All LP3971SQX-U511/NOPB products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LP3971SQX-U511/NOPB meets industry standards.
7.What is the process for return or replacement of LP3971SQX-U511/NOPB?
All LP3971SQX-U511/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LP3971SQX-U511/NOPB, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The LP3971SQX-U511/NOPB part is unused and in its original packaging.
Return procedure for LP3971SQX-U511/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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