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Texas Instruments LP3991TLX-1.8/NOPB
- Part No.:
- LP3991TLX-1.8/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- 4-WFBGA, DSBGA
- Datasheet:
-
LP3991TLX-1.8/NOPB.pdf
- Description:
- IC REG LINEAR 1.8V 300MA 4DSBGA
- Quantity:
- Payment:
- Shipping:
Inventory:2,402
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Product details
Overview
LP3991TLX-1.8/NOPB from Texas Instruments is a fixed 1.8-V, 300-mA low-dropout linear regulator in a 4-pin DSBGA package, designed for post-regulation after DC-DC converters in space-constrained portable systems. It operates from 1.65 V to 4 V input, delivers ±1% output accuracy at room temperature, maintains 125-mV dropout at full load, and draws only 50 µA quiescent current at 1-mA load.
For engineers reviewing the LP3991TLX-1.8/NOPB datasheet, LP3991TLX-1.8/NOPB pinout, LP3991TLX-1.8/NOPB application, or LP3991TLX-1.8/NOPB equivalent, key selection criteria include ceramic-capacitor stability (down to 0402 size), enable-controlled shutdown with 1.2-MΩ internal pulldown, thermal/short-circuit protection, and PSRR of 65 dB at 1 kHz - all validated across –40°C to +125°C junction temperature.
Technical Context
The LP3991TLX-1.8/NOPB implements a PMOS pass transistor architecture enabling ultra-low dropout and fast start-up (100 µs to 95% for 1.8-V output). Its internal bandgap reference and error amplifier deliver tight line/load regulation (≤1%/V and ≤60 µV/mA) while supporting no-load stability - critical for CMOS RAM keep-alive circuits.
Thermal management relies on direct heat conduction via four solder bumps to the PCB, with RθJA = 189.7°C/W on high-K board. The EN pin features active-high logic with 0.95-V turn-on threshold and integrated 1.2-MΩ pulldown, eliminating external biasing in always-on configurations.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 1.8 V ±1% at 25°C; stable over –40°C to +125°C junction range |
| Max Output Current | 300 mA continuous; supports peak inrush up to 1000 mA without latch-off |
| Dropout Voltage | 125 mV at 300 mA load; enables operation from Li-ion battery down to 1.93 V |
| Quiescent Current | 50 µA at 1 mA load; rises to 225 µA at 300 mA - optimized for battery longevity |
| PSRR @ 1 kHz | 65 dB - suppresses switching noise from upstream buck converters |
| Output Noise | 280 µVRMS (10 Hz–100 kHz); suitable for noise-sensitive analog/RF circuitry |
| Enable Threshold | VIH = 0.95 V, VIL = 0.4 V; compatible with 1.2-V and 1.8-V logic families |
Pinout & Package
LP3991TLX-1.8/NOPB uses a 4-pin DSBGA (YZR) package measuring 1.43 mm × 0.96 mm (nominal), with bottom-side solder bumps for thermal and electrical connection. The package is optimized for 0402-size ceramic capacitors and requires no external pull-up on EN due to internal 1.2-MΩ pulldown.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A1 | GND | Common ground reference; must connect directly to PCB thermal pad for optimal thermal performance |
| A2 | EN | Active-high enable input; pulls down to GND internally; drives regulator into <1-µA shutdown state when ≤0.4 V |
| B1 | OUT | Regulated 1.8-V output; requires 4.7-µF X7R/X5R ceramic capacitor (2.2 µF acceptable for VOUT ≤1.3 V) |
| B2 | IN | Input supply (1.65–4 V); requires 1-µF ceramic capacitor placed within 1 cm of pin |
Key Features
| Feature | Design Value |
|---|---|
| Ceramic capacitor stability | Stable with 4.7-µF (or 2.2-µF for lower VOUT) X7R/X5R ceramics as small as 0402 - eliminates need for tantalum or large footprint caps |
| Inrush current control | Limits peak inrush to 600–1000 mA during start-up - prevents input rail collapse in battery-powered systems |
| Thermal & short-circuit protection | Auto-shutdown at 160°C junction temp with 20°C hysteresis; limits short-circuit current to 550–900 mA - ensures robust field reliability |
| No-load regulation | Maintains 1.8-V output with zero load current - enables use in standby/keep-alive circuits without external discharge path |
| Fast transient response | Load step (0→300 mA) causes ≤140-mV dip; recovers within microseconds - preserves signal integrity in digital core supplies |
Applications
| Mobile Baseband Processor Core Supply | Wearable Sensor Hub Power Rail |
|---|---|
Use Scenario: Powers ARM Cortex-A/M cores in smartphones after a 2.5-V buck converter, filtering residual switching ripple. IC Role / Device Role / Timing Role: Post-buck LDO providing clean, low-noise 1.8-V supply with fast load transient response. Use Value: Reduces system EMI by >20 dB vs. standalone buck; maintains 1.8-V accuracy across battery discharge (3.6 V → 2.8 V). | Use Scenario: Supplies ultra-low-power MCU and MEMS sensors in hearables with intermittent 300-mA burst loads. IC Role / Device Role / Timing Role: Primary regulated rail enabling deep-sleep current <1 µA via EN-controlled shutdown. Use Value: Extends coin-cell life by 3× vs. non-LDO solutions; 50-µA IQ minimizes quiescent drain during 95% idle time. |
| Industrial IoT Edge Node Logic Supply | Automotive Infotainment Display Interface |
Use Scenario: Provides 1.8-V I/O voltage for SPI/I²C peripherals in temperature-hardened gateways operating from 12-V DC-DC. IC Role / Device Role / Timing Role: Isolated logic-level translator supply decoupled from noisy main power domain. Use Value: Ensures data integrity across –40°C to +105°C ambient via guaranteed 125-mV dropout and ±3% tolerance over full range. | Use Scenario: Powers LVDS serializer/deserializer ICs in automotive displays where EMI immunity is critical. IC Role / Device Role / Timing Role: Low-noise, high-PSRR local regulator for timing-critical video interface rails. Use Value: 65-dB PSRR at 1 kHz rejects AM-band switching noise from adjacent DC-DC stages; 280-µV RMS noise avoids pixel jitter. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LDO regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPL720F18-DBVR | Same 1.8-V fixed output, 300-mA rating, and DSBGA-4 package; 35-µA IQ (lower), but 200-mV dropout at 300 mA (higher) | Preferred for ultra-low-power always-on nodes; less suitable for Li-ion end-of-discharge operation | Select when IQ <40 µA is mandatory and input headroom ≥2.0 V is guaranteed |
| MCP1700T-1802E/TT | 1.8-V SOT-23-5 LDO; 2.5-µA IQ, but only 250-mA max output and 600-mV dropout at full load | Better for micropower sensor nodes; unsuitable for 300-mA digital loads or tight input headroom | Choose for cost-sensitive, low-current designs where PCB area is secondary to BOM cost |
Compared with TPL720F18-DBVR, LP3991TLX-1.8/NOPB offers 40% lower dropout for extended battery runtime; versus MCP1700T-1802E/TT, it delivers 20% higher current capacity and 2× better PSRR - making it optimal for noise-sensitive, medium-current digital rails.
Availability
LP3991TLX-1.8/NOPB is available at Aetrix Electronics and suitable for mobile baseband supplies, wearable sensor hubs, industrial IoT edge nodes, and automotive display interfaces requiring stable component supply across extended temperature and long production lifecycles.
Supply support for LP3991TLX-1.8/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, embedded processing, and connectivity technologies, with leadership in power management innovation since 1930.
The LP3991TLX-1.8/NOPB belongs to TI's precision LDO portfolio targeting portable and battery-operated systems, engineered to replace discrete post-regulation filters with monolithic, thermally robust, and capacitor-minimized solutions.
FAQ
What is the minimum input voltage required for LP3991TLX-1.8/NOPB to maintain regulation?
The LP3991TLX-1.8/NOPB requires a minimum input voltage of 1.65 V to remain in regulation. At 300-mA load, its 125-mV dropout means it sustains 1.8-V output down to VIN = 1.93 V. Below 1.65 V, the device drops out of regulation and output collapses - verified per Section 6.3 Recommended Operating Conditions in the SNVS296J datasheet.
Can LP3991TLX-1.8/NOPB operate without an external output capacitor?
No, LP3991TLX-1.8/NOPB requires an external output capacitor for stability. For 1.8-V output, a 4.7-µF X7R or X5R ceramic capacitor (ESR 5–500 mΩ) is mandatory; 2.2-µF is only permitted for outputs ≤1.3 V. Omitting COUT causes oscillation and loss of regulation - confirmed in Section 8.2.2.3 and Figure 12 of the datasheet.
Does LP3991TLX-1.8/NOPB support shutdown mode, and what is its quiescent current in that state?
Yes, LP3991TLX-1.8/NOPB supports active-high enable-controlled shutdown. When EN ≤0.4 V, the device enters shutdown with typical supply current of 2 nA - not 50 µA (which applies only in active mode at 1-mA load). This ultra-low shutdown current is specified in Section 6.5 Electrical Characteristics under ENABLE CONTROL CHARACTERISTICS.
Is LP3991TLX-1.8/NOPB stable with 0402-size ceramic capacitors?
Yes, LP3991TLX-1.8/NOPB is explicitly designed for stability with 0402-case ceramic capacitors, as stated in Features and Section 7.1 Overview. However, capacitor selection must meet minimum capacitance (4.7 µF) and ESR (5–500 mΩ) requirements across temperature and DC bias - X7R/X5R dielectrics are required; Y5V/Z5U are unstable.
What thermal protection features does LP3991TLX-1.8/NOPB include?
LP3991TLX-1.8/NOPB integrates thermal shutdown at 160°C junction temperature with 20°C hysteresis, plus current limiting that caps short-circuit output at 550–900 mA. These protections are internal, require no external components, and are guaranteed across –40°C to +125°C operation per Sections 6.5 and 7.1 of the datasheet.
LP3991TLX-1.8/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 4-WFBGA, DSBGA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Output Configuration:
- Positive
- Output Type:
- Fixed
- Number of Regulators:
- 1
- Voltage - Input (Max):
- 4V
- Voltage - Output (Min/Fixed):
- 1.8V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- 0.16V @ 300mA
- Current - Output:
- 300mA
- Current - Quiescent (Iq):
- 100 µA
- Current - Supply (Max):
- 225 µA
- PSRR:
- 65dB (1kHz)
- Control Features:
- Enable
- Protection Features:
- Over Temperature, Short Circuit
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 4-DSBGA (1x1)
LP3991TLX-1.8/NOPB FAQ
1.How can I place an order for LP3991TLX-1.8/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LP3991TLX-1.8/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 LP3991TLX-1.8/NOPB reliable?
The price and inventory of LP3991TLX-1.8/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LP3991TLX-1.8/NOPB is usually 5 days.
3.What payment methods are accepted for LP3991TLX-1.8/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LP3991TLX-1.8/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LP3991TLX-1.8/NOPB?
LP3991TLX-1.8/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LP3991TLX-1.8/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 LP3991TLX-1.8/NOPB?
For technical support, including LP3991TLX-1.8/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LP3991TLX-1.8/NOPB requirements.
6.How does Aetrix verify that LP3991TLX-1.8/NOPB is sourced from the original manufacturer or authorized distributors?
All LP3991TLX-1.8/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 LP3991TLX-1.8/NOPB meets industry standards.
7.What is the process for return or replacement of LP3991TLX-1.8/NOPB?
All LP3991TLX-1.8/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LP3991TLX-1.8/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 LP3991TLX-1.8/NOPB part is unused and in its original packaging.
Return procedure for LP3991TLX-1.8/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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