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Texas Instruments LP3891ES-1.2/NOPB
- Part No.:
- LP3891ES-1.2/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Datasheet:
-
LP3891ES-1.2/NOPB.pdf
- Description:
- IC REG LINEAR 1.2V 800MA DDPAK
- Quantity:
- Payment:
- Shipping:
Inventory:450
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Product details
Overview
LP3891ES-1.2/NOPB from Texas Instruments is a 0.8A ultra-low-dropout linear regulator with CMOS N-MOS pass transistor architecture, delivering 1.2V fixed output at ≤100mV dropout (typ) under 0.8A load, 1.5% output accuracy at 25°C, and 60nA shutdown current - designed for high-efficiency post-regulation in DSP, microcontroller core, and server I/O power supplies.
For engineers reviewing the LP3891ES-1.2/NOPB datasheet, LP3891ES-1.2/NOPB pinout, LP3891ES-1.2/NOPB application, or LP3891ES-1.2/NOPB equivalent, this page provides verified package mapping (DDPAK/TO-263, 5-pin), confirmed thermal performance (θJA ≈ 40°C/W with ≥1.5 in² copper), validated input/output capacitor requirements (≥10µF tantalum), and real-world transient response data for fast-load-step designs.
Technical Context
The LP3891ES-1.2/NOPB uses an external VBIAS rail (4.5–6V) to drive the gate of its N-MOS pass transistor, enabling operation with VIN as low as (VOUT + VDO) while maintaining ultra-low quiescent current across load range. Its CMOS control circuitry draws only 3mA typical ground current at full load and supports fast turn-on/off delays (15µs/20µs).
Stability requires ≥10µF output capacitance with ESR between 0.001Ω–0.1Ω over temperature; tantalum capacitors are recommended due to stable ESR vs. aluminum electrolytics (unsuitable below 10°C) or ceramics (too low ESR, limited to ≤15% of total COUT). The device integrates over-temperature and over-current protection with −40°C to +125°C junction operation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 1.2V ±1.5% at 25°C - ensures precise core voltage for low-voltage DSPs and microcontrollers without external feedback. |
| Dropout Voltage | 100mV typ at 0.8A (DDPAK/TO-263) - enables regulation from 1.3V input, critical for battery-backed or SMPS post-regulator applications. |
| Quiescent Current | 60nA typ in shutdown, 3mA typ from VIN at full load - minimizes standby loss and maintains efficiency across light-to-heavy loads. |
| Load Regulation | 0.04%/A - limits output deviation to <5mV over 0–0.8A load step, supporting stable digital logic supply rails. |
| PSRR @ 1kHz | 65dB (VIN), 65dB (VBIAS) - suppresses switching noise from upstream DC/DC converters in mixed-signal systems. |
| Thermal Resistance | θJA ≈ 40°C/W with ≥1.5 in² copper plane - defines heatsinking requirement for 1W+ dissipation at ambient ≤85°C. |
| Shutdown Threshold | VSDT = 0.7V max (OFF), 1.3V min (ON) - compatible with standard CMOS logic levels for clean enable/disable control. |
Pinout & Package
LP3891ES-1.2/NOPB is housed in a DDPAK/TO-263 (KTT) thermally enhanced 5-pin surface-mount package with exposed thermal pad. Pin 1 is marked by notch on top view; tab is electrically connected to GND and must be soldered to PCB copper for thermal performance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (VIN) | Main power input | Supplies load current; must be ≥(VOUT + VDO) and ≤5.5V; requires ≥10µF ceramic input capacitor. |
| 2 (GND) | Analog ground reference | Common return for control circuitry; connects to exposed thermal pad - must be low-impedance analog ground plane. |
| 3 (S/D) | Shutdown control input | Active-low enable; pulled up via 10–100kΩ resistor; drives OFF when ≤0.3V, ON when ≥1.3V. |
| 4 (VBIAS) | Bias supply input | Provides gate drive for N-MOS pass transistor; must be 4.5–6V; requires 0.1µF ceramic decoupling. |
| 5 (VOUT) | Regulated output | Delivers 1.2V to load; requires ≥10µF tantalum output capacitor with ESR 0.001–0.1Ω for stability. |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low dropout | 100mV typ at 0.8A enables single-cell Li-ion or SMPS post-regulation down to 1.3V input. |
| External bias architecture | VBIAS rail (4.5–6V) decouples gate drive from VIN, allowing ultra-low VIN operation without sacrificing PSRR. |
| Fast transient response | Sub-20µs turn-on/off delays and wide bandwidth support dynamic load steps in DSP and CPU core supplies. |
| Integrated protection | Thermal shutdown and current limiting prevent damage during overload or poor heatsinking conditions. |
| Low-noise operation | 150µVrms output noise (10Hz–100kHz) meets stringent analog supply requirements for ADCs and RF ICs. |
Applications
| Server I/O Power | DSP Core Supply |
|---|---|
Use Scenario: Local regulation of 1.2V I/O rails in multi-core server motherboards with tight space constraints and high thermal density. IC Role / Device Role / Timing Role: Post-regulator for buck converter outputs, providing low-noise, fast-response voltage stabilization for PCIe and memory interface circuits. Use Value: 65dB PSRR at 1kHz rejects switching ripple from upstream 500kHz–1MHz DC/DC converters, ensuring signal integrity in high-speed serial links. |
Use Scenario: Primary core supply for TI C6000 DSPs requiring stable 1.2V at up to 0.8A with rapid load transients during FFT processing bursts. IC Role / Device Role / Timing Role: Low-dropout linear regulator delivering precision voltage directly to DSP VDD_CORE pins with minimal board area. Use Value: 100mV dropout allows operation from 1.3V input, enabling efficient use of intermediate bus voltages and reducing power loss vs. higher-VIN LDOs. |
| Microcontroller Core Supply | SMPS Post-Regulator |
Use Scenario: Powering ARM Cortex-M7 or RISC-V SoC cores in industrial controllers where EMI-sensitive analog peripherals share same PCB. IC Role / Device Role / Timing Role: Low-noise local regulator isolating digital core from noisy system power rails. Use Value: 150µVrms broadband noise and 1.5% initial accuracy ensure reliable ADC sampling and PLL lock stability in mixed-signal systems. |
Use Scenario: Final-stage regulation after high-efficiency 12V→3.3V buck converter in telecom power modules requiring <1% output tolerance. IC Role / Device Role / Timing Role: Precision trim stage correcting residual line/load regulation error of primary DC/DC converter. Use Value: 0.04%/A load regulation limits output drift to <3.2mV over full 0.8A load range, meeting tight spec for FPGA configuration supplies. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar ultra-low-dropout linear regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS7A4700RGWR | 200mA max output, 4µVrms noise, adjustable output (1.4–20.5V), 350mV dropout at 150mA | Lower current capacity; superior noise performance but unsuitable for >0.2A loads | Select for ultra-low-noise analog rails where current demand is ≤150mA and adjustable VOUT is needed. |
| TPS74401RGWT | 3A output, 1.2V fixed, 90mV dropout at 3A, 1.5% accuracy, SO PowerPAD-20 package | Higher current rating and larger footprint; requires different PCB layout and thermal design | Select when system load exceeds 0.8A or when higher thermal margin is required for continuous 3A operation. |
Compared with LP3891ES-1.2/NOPB, TPS7A4700RGWR offers lower noise but insufficient current for DSP core use, while TPS74401RGWT delivers triple the current at similar dropout but demands larger board area and revised thermal management - making LP3891ES-1.2/NOPB optimal for space-constrained 0.8A applications needing proven 1.2V stability.
Availability
LP3891ES-1.2/NOPB is available at Aetrix Electronics and suitable for server I/O power, DSP core supply, microcontroller core supply, and SMPS post-regulator applications requiring stable component supply with guaranteed long-term availability and RoHS-exempt compliance for industrial environments.
Supply support for LP3891ES-1.2/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 expertise in high-reliability linear regulators and power solutions.
The LP3891 series was engineered specifically for high-current, ultra-low-dropout applications in computing and communications infrastructure, emphasizing fast transient response, bias-rail flexibility, and robust thermal performance in compact packages.
FAQ
What is the minimum input voltage required for LP3891ES-1.2/NOPB to regulate 1.2V output?
The LP3891ES-1.2/NOPB requires VIN ≥ (VOUT + VDO). With 100mV typical dropout at 0.8A, the minimum functional input is 1.3V. However, per recommended operating conditions, VIN must be ≥ (VOUT + VDO) and ≤5.5V - and VBIAS must be independently supplied at 4.5–6V for proper gate drive. Below 1.3V, regulation fails and VOUT drops proportionally.
Can LP3891ES-1.2/NOPB operate without an external VBIAS supply?
No. LP3891ES-1.2/NOPB requires an external 4.5–6V VBIAS rail applied to Pin 4 to drive the gate of its N-MOS pass transistor. Without VBIAS, the device cannot achieve regulation - it is not internally biased like traditional PNP-based LDOs. Connecting VBIAS to VIN is invalid and violates absolute maximum ratings.
What output capacitor types are validated for stable operation with LP3891ES-1.2/NOPB?
Tantalum capacitors are explicitly recommended for LP3891ES-1.2/NOPB output due to their stable ESR (0.001–0.1Ω) across −40°C to +125°C. Aluminum electrolytics are restricted to ambient >10°C only, and ceramics are prohibited as sole output capacitors due to ESR <10mΩ causing instability - though up to 15% ceramic capacitance may supplement tantalum.
How does the thermal performance of LP3891ES-1.2/NOPB compare across package variants?
LP3891ES-1.2/NOPB in DDPAK/TO-263 achieves θJA ≈ 40°C/W when soldered to ≥1.5 in² copper, outperforming the SO PowerPAD-8 variant (θJA = 166°C/W) and matching TO-220 with heatsink (θJ-S = 4°C/W). This makes the DDPAK version optimal for high-power-density layouts where board-level heatsinking is preferred over discrete heatsinks.
Does LP3891ES-1.2/NOPB support reverse current protection or input overvoltage clamping?
No. LP3891ES-1.2/NOPB lacks reverse current blocking and has no internal input overvoltage clamp. Absolute maximum VIN is +6V; exceeding this risks permanent damage. External protection - such as a series Schottky diode for reverse current or TVS for overvoltage - must be added if system conditions warrant it, per TI's application hints.
LP3891ES-1.2/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Packaging:
- Tube
- Product Status:
- Active
- Output Configuration:
- Positive
- Output Type:
- Fixed
- Number of Regulators:
- 1
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- 1.2V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- 0.4V @ 800mA
- Current - Output:
- 800mA
- Current - Quiescent (Iq):
- 30 µA
- Current - Supply (Max):
- 8 mA
- PSRR:
- 80dB ~ 65dB (120Hz ~ 1kHz)
- Control Features:
- Enable
- Protection Features:
- Over Current, Over Temperature, Short Circuit, Under Voltage Lockout (UVLO)
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- TO-263 (DDPAK-5)
LP3891ES-1.2/NOPB FAQ
1.How can I place an order for LP3891ES-1.2/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LP3891ES-1.2/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 LP3891ES-1.2/NOPB reliable?
The price and inventory of LP3891ES-1.2/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LP3891ES-1.2/NOPB is usually 5 days.
3.What payment methods are accepted for LP3891ES-1.2/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LP3891ES-1.2/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LP3891ES-1.2/NOPB?
LP3891ES-1.2/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LP3891ES-1.2/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 LP3891ES-1.2/NOPB?
For technical support, including LP3891ES-1.2/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LP3891ES-1.2/NOPB requirements.
6.How does Aetrix verify that LP3891ES-1.2/NOPB is sourced from the original manufacturer or authorized distributors?
All LP3891ES-1.2/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 LP3891ES-1.2/NOPB meets industry standards.
7.What is the process for return or replacement of LP3891ES-1.2/NOPB?
All LP3891ES-1.2/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LP3891ES-1.2/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 LP3891ES-1.2/NOPB part is unused and in its original packaging.
Return procedure for LP3891ES-1.2/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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