My Inquiry
My Account
Texas Instruments LP3971SQX-O509/NOPB
- Part No.:
- LP3971SQX-O509/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- Power Management - Specialized
- Package:
- 40-WFQFN Exposed Pad
- Datasheet:
-
LP3971SQX-O509/NOPB.pdf
- Description:
- IC PMU FOR APP PROCESSOR 40WQFN
- Quantity:
- Payment:
- Shipping:
Inventory:3,802
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LP3971SQX-O509/NOPB from Texas Instruments is a programmable power management unit (PMU) for advanced application processors, integrating three 1.6A synchronous buck regulators, six LDOs (including 30 mA RTC LDO), and a backup battery charger. It supports I²C-based dynamic voltage management (DVM) and operates from 2.7V–5.5V input, delivering ±3% output accuracy and up to 95% efficiency in handheld PDA/smartphone systems.
For engineers reviewing the LP3971SQX-O509/NOPB datasheet, LP3971SQX-O509/NOPB pinout, LP3971SQX-O509/NOPB application, or LP3971SQX-O509/NOPB equivalent, key selection criteria include its 40-pin WQFN package, default VOUT configuration (LDO1=3.3V, LDO2=3.3V, LDO3=3.0V, LDO4=1.25V, LDO5=1.25V, BUCK1=3.3V, BUCK2=3.3V, BUCK3=1.3V), I²C programmability, and integrated battery switchover logic for RTC supply.
Technical Context
The LP3971SQX-O509/NOPB implements a multi-rail PMU architecture with independent control of three buck converters (SW1/SW2/SW3 outputs) and six LDOs via an I²C-compatible high-speed serial interface. Its internal logic supports dual enable domains (SYS_EN and PWR_EN), programmable reset sequencing (nRSTI/nRSTO), and automatic main-to-backup battery switchover at 2.8V/3.1V hysteresis for RTC supply continuity.
It features dedicated analog ground planes (BGND1,2,3), thermal shutdown at 160°C, current overload protection, and precision internal reference (VREF). The device uses synchronous rectification in buck stages and supports external frequency synchronization via SYNC pin, enabling phase alignment with system PLL clocks.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Buck Output Current | Up to 1.6 A per buck regulator - enables direct powering of CPU cores, GPU, and memory I/O rails without external FETs. |
| LDO Output Accuracy | ±3% over −40°C to +125°C - ensures stable voltage delivery to sensitive peripherals like RTC, codec, and USB PHY. |
| I²C Interface Speed | High-speed mode (up to 400 kHz) - allows rapid reconfiguration of VOUT, enable states, and fault monitoring during runtime. |
| RTC LDO Switchover | Automatic main-to-backup battery transition at 2.8V (falling) / 3.1V (rising) - maintains real-time clock operation during main battery depletion. |
| Package | 40-pin 5 mm × 5 mm WQFN (RSB0040A) - compact footprint with exposed thermal pad for efficient heat dissipation in space-constrained mobile PCBs. |
| Backup Charger Current | Programmable 150/300/370 mA - supports lithium-manganese coin cells and supercapacitors with configurable termination voltage (2.91–3.1 V). |
| Dropout Voltage (LDO) | 100 mV (typ) at 150 mA - minimizes power loss and enables operation near battery end-of-discharge voltage. |
Pinout & Package
LP3971SQX-O509/NOPB is housed in a 40-pin, 5 mm × 5 mm, 0.4 mm pitch WQFN package (TI package code RSB0040A) with exposed thermal pad (BGND1,2,3 pins) for enhanced thermal performance in handheld applications.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| PWR_ON | Active-HI push-button input | Signals power-on/off events to CPU; controls EXT_WAKEUP pulse and register 8H'02 status flags. |
| EXT_WAKEUP | Open-drain output | Generates 10 ms active-low pulse to wake CPU on PWR_ON/nTEST_JIG/SPARE events - eliminates need for external wake logic. |
| SCL/SDA | I²C clock/data bidirectional | Enables full software control of all regulator outputs, enable states, fault reporting, and battery charger settings. |
| nRSTI / nRSTO | Reset input / output | Provides hardware reset initiation (nRSTI) and synchronized system reset assertion (nRSTO) with glitch filtering and timing coordination. |
| VIN Buck1–3 | Main battery input to buck stages | Accepts 2.7–5.5 V; each buck stage has dedicated VIN pin to minimize shared impedance and improve PSRR. |
| VOUT LDO1–5 / LDO_RTC | Regulated power outputs | Deliver programmable 1.0–3.3 V (LDOs) and fixed 2.8 V (RTC); LDO_RTC tracks LDO1 within 200 mV when enabled. |
| GPIO1/nCHG_EN | Configurable I/O | Functions as general-purpose I/O or external backup battery charger enable - toggled via I²C to control charging path. |
| nBATT_FLT | Main battery fault indicator | Active-low open-drain output signals main battery low condition (default threshold 2.8 V) - triggers graceful system shutdown before RTC switchover. |
Key Features
| Feature | Design Value |
|---|---|
| Triple 1.6A Synchronous Bucks | Enables independent, high-efficiency power domains for processor core, I/O, and memory - eliminates need for discrete DC/DC controllers. |
| Six Programmable LDOs | Supports mixed-voltage SoC interfaces (1.0–3.3 V) with ±3% accuracy and <100 mV dropout - ideal for noise-sensitive analog/RF blocks. |
| Integrated Backup Battery Management | Automatically switches RTC supply between main battery and coin cell/supercap with hysteresis - ensures continuous timekeeping without external circuitry. |
| I²C-Based Dynamic Voltage Management | Allows real-time adjustment of output voltages and sequencing during DVFS transitions - critical for optimizing power/performance trade-offs in ARM-based APs. |
| Dual Enable Domains (SYS_EN/PWR_EN) | Separates high- and low-voltage domain control - enables flexible power-up/down sequencing aligned with Marvell PXA, Freescale, and Samsung AP boot requirements. |
Applications
| Smartphone Baseband Power | PDA Application Processor Supply |
|---|---|
Use Scenario: Powering Marvell PXA3xx or Samsung S3C6410 application processors in 3G smartphones with dynamic voltage scaling. IC Role / Device Role / Timing Role: Central PMU managing core (BUCK1), I/O (BUCK2), memory (BUCK3), RTC (LDO_RTC), and peripheral (LDO1–5) rails via I²C. Use Value: Reduces bill-of-materials by consolidating 9 power rails into one IC; enables sub-100 µA quiescent current in deep-sleep modes. | Use Scenario: Supplying dual-core ARM9/ARM11 SoCs in enterprise PDAs requiring guaranteed RTC uptime during battery swaps. IC Role / Device Role / Timing Role: Provides regulated 1.2V core, 3.3V I/O, and 2.8V RTC rails with automatic battery switchover and fault signaling. Use Value: Eliminates external battery switch IC and discrete LDOs; maintains RTC operation across >10,000 battery insertion cycles. |
| Digital Camera Image Sensor Bias | Portable Media Player Codec Supply |
Use Scenario: Delivering ultra-low-noise, tightly regulated bias to CMOS image sensors and ISP in HD digital cameras. IC Role / Device Role / Timing Role: Supplies 1.8V (LDO2) and 2.8V (LDO_RTC) with <45 dB PSRR at 10 kHz - suppresses switching noise from adjacent bucks. Use Value: Prevents image artifacts caused by power rail noise; enables clean sensor startup within 300 µs after SYS_EN assertion. | Use Scenario: Powering audio codec, NAND flash, and display controller in MP4 players with variable workload profiles. IC Role / Device Role / Timing Role: Delivers 3.3V (LDO1), 1.25V (LDO4), and 1.25V (LDO5) with independent enable control and load transient response <50 µs. Use Value: Supports instant audio playback start and seamless format switching without audible pop/click artifacts. |
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 1.5A bucks + 5 LDOs; no integrated backup battery charger; 48-pin VQFN package. | Lacks automatic RTC battery switchover and coin-cell charging - requires external circuitry for backup power. | Choose when primary requirement is higher buck current headroom and lower cost, and backup battery functionality is handled externally. |
| MAX8649ETE+ | Dual 1.5A bucks + 4 LDOs + I²C; no RTC LDO or backup charger; 24-pin TQFN package. | Smaller footprint but omits RTC-specific features and battery fault signaling - unsuitable for time-critical embedded systems. | Prefer for compact designs where RTC autonomy is not required and system-level battery management exists elsewhere. |
Compared with TPS65023RSBR and MAX8649ETE+, LP3971SQX-O509/NOPB uniquely integrates RTC battery switchover logic, programmable backup charging, and dual-enable domain sequencing - making it the only option among the three that fully satisfies Marvell PXA and Samsung AP reference design requirements for autonomous timekeeping and DVM.
Availability
LP3971SQX-O509/NOPB is available at Aetrix Electronics and suitable for smartphone baseband power, PDA application processor supply, digital camera image sensor bias, and portable media player codec supply requiring stable component supply across extended production lifecycles.
Supply support for LP3971SQX-O509/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 mobile and portable power solutions.
The LP3971 product line was designed specifically for advanced application processors in low-power handheld devices, emphasizing integration density, I²C configurability, and autonomous backup power management for real-time subsystems.
FAQ
What is the default output voltage configuration for LP3971SQX-O509/NOPB?
The LP3971SQX-O509/NOPB defaults to LDO1=3.3V, LDO2=3.3V, LDO3=3.0V, LDO4=1.25V, LDO5=1.25V, BUCK1=3.3V, BUCK2=3.3V, and BUCK3=1.3V. These values are set by factory-programmed registers and can be modified in real time via the I²C interface. The RTC LDO is fixed at 2.8V and supports tracking of LDO1 voltage within 200 mV when enabled.
Does LP3971SQX-O509/NOPB support automatic switchover between main and backup batteries for the RTC supply?
Yes, LP3971SQX-O509/NOPB includes built-in battery switchover logic for the RTC LDO. It automatically connects the RTC supply to the main battery above 3.1V and switches to the backup coin cell or supercapacitor when main battery voltage falls below 2.8V, with 300 mV hysteresis. This function is enabled by default and requires no external components.
What is the maximum supported I²C clock frequency for configuring LP3971SQX-O509/NOPB registers?
LP3971SQX-O509/NOPB supports standard-mode (100 kHz) and high-speed-mode (up to 400 kHz) I²C communication. The interface is fully compliant with I²C specification v2.1 and allows read/write access to all configuration, status, and fault registers - including VOUT programming, enable control, and battery charger settings - without disrupting power delivery.
How does LP3971SQX-O509/NOPB handle thermal protection, and what is the shutdown threshold?
LP3971SQX-O509/NOPB incorporates thermal overload protection that triggers at a junction temperature of 160°C, with 20°C hysteresis. When exceeded, all regulators shut down until temperature falls below 140°C. This protection is implemented in hardware and operates independently of I²C control, ensuring fail-safe operation under sustained overload or poor PCB thermal design.
Can LP3971SQX-O509/NOPB's GPIO1 pin be used to control external backup battery charging independently of the internal charger?
Yes, GPIO1/nCHG_EN on LP3971SQX-O509/NOPB serves dual purpose: as a general-purpose I/O or as an active-low enable signal for the internal backup battery charger. When configured as nCHG_EN, it directly gates the charging path - allowing external microcontroller control over charging initiation, pause, or termination without I²C interaction.
LP3971SQX-O509/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-O509/NOPB FAQ
1.How can I place an order for LP3971SQX-O509/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LP3971SQX-O509/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-O509/NOPB reliable?
The price and inventory of LP3971SQX-O509/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-O509/NOPB is usually 5 days.
3.What payment methods are accepted for LP3971SQX-O509/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LP3971SQX-O509/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LP3971SQX-O509/NOPB?
LP3971SQX-O509/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LP3971SQX-O509/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-O509/NOPB?
For technical support, including LP3971SQX-O509/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LP3971SQX-O509/NOPB requirements.
6.How does Aetrix verify that LP3971SQX-O509/NOPB is sourced from the original manufacturer or authorized distributors?
All LP3971SQX-O509/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-O509/NOPB meets industry standards.
7.What is the process for return or replacement of LP3971SQX-O509/NOPB?
All LP3971SQX-O509/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LP3971SQX-O509/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-O509/NOPB part is unused and in its original packaging.
Return procedure for LP3971SQX-O509/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LP3971SQX-O509/NOPB Tags
-
TPS2511DGNR
Texas Instruments
-
UTC2000/MG
Microchip Technology
-
TUSB320HAIRWBR
Texas Instruments
-
TPS61252DSGR
Texas Instruments
-
PI5USB30216CXUAEX
Diodes Incorporated
-
SN6501DBVR
Texas Instruments
-
CYPD3177-24LQXQT
Infineon Technologies
-
SN6501QDBVRQ1
Texas Instruments
-
STUSB1600AQTR
STMicroelectronics
-
SN6505BDBVR
Texas Instruments
-
SN6501DBVT
Texas Instruments
-
TPS65150PWPR
Texas Instruments
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
