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Texas Instruments LP3891ESX-1.2/NOPB
- Part No.:
- LP3891ESX-1.2/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Datasheet:
-
LP3891ESX-1.2/NOPB.pdf
- Description:
- IC REG LINEAR 1.2V 800MA DDPAK
- Quantity:
- Payment:
- Shipping:
Inventory:952
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Product details
Overview
LP3891ESX-1.2/NOPB from Texas Instruments is a 0.8A ultra-low-dropout linear regulator in DDPAK/TO-263-5 package, delivering 1.2V output with ±1.5% accuracy at 25°C, 100mV typical dropout at 0.8A, and 60nA shutdown current - designed for high-efficiency post-regulation in DSP and microcontroller core supplies.
For engineers reviewing the LP3891ESX-1.2/NOPB datasheet, LP3891ESX-1.2/NOPB pinout, LP3891ESX-1.2/NOPB application, or LP3891ESX-1.2/NOPB equivalent, this page delivers verified technical context, package-specific thermal behavior, CMOS-based low-quiescent-current operation, and real-world stability requirements for tantalum-output-capacitor designs.
Technical Context
The LP3891ESX-1.2/NOPB uses an N-MOS pass transistor driven by an external VBIAS rail (4.5–6V), enabling stable regulation even when VIN is as low as VOUT + VDO - unlike bipolar LDOs, its CMOS architecture maintains 3mA typical ground current at full load and draws only 60nA in shutdown. Its fast transient response stems from wide bandwidth and minimal external capacitance requirements (≥10µF input/output).
Stability depends critically on output capacitor ESR: 0.001–1Ω over full load range (0–0.8A), with tantalum capacitors strongly recommended due to stable ESR across −40°C to +125°C; ceramic caps alone are unstable but may supplement up to 15% of total output capacitance.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 1.2V ±1.5% at 25°C - ensures precise core voltage for 1.2V logic domains without external feedback. |
| Dropout Voltage | 100mV typ at 0.8A (DDPAK/TO-263) - enables operation with VIN as low as 1.3V while sustaining full load. |
| Quiescent Current | 60nA typ in shutdown - preserves battery life in always-on systems with periodic wake-up cycles. |
| Load Regulation | 0.04%/A - limits output deviation to ≤3.2mV across 0–0.8A load step, critical for noise-sensitive analog subsystems. |
| PSRR @ 1kHz | 65dB (VIN), 65dB (VBIAS) - suppresses switching noise from upstream SMPS or bias rails into regulated output. |
| Junction Temp Range | −40°C to +125°C - supports industrial and automotive under-hood applications with validated thermal derating. |
| Thermal Resistance θJA | ~40°C/W (DDPAK soldered to ≥1.5 in² copper) - defines heatsink-free power limit: ~1.75W max at TA = 85°C. |
Pinout & Package
LP3891ESX-1.2/NOPB is housed in a 5-pin DDPAK/TO-263 thermally enhanced package with exposed thermal pad (pin 5 = GND). The package requires soldering the tab to a large PCB copper plane for effective heat dissipation and meets JEDEC Level-3 moisture sensitivity (245°C peak reflow).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - VIN | Main power input | Supplies load current; must be ≥(VOUT + VDO) and ≤5.5V; bypass with ≥10µF ceramic capacitor. |
| 2 - S/D | Shutdown control | Active-low enable: <0.3V = OFF (60nA IQ), >1.3V = ON; requires pull-up resistor if driven by open-drain source. |
| 3 - VBIAS | Bias supply input | Drives N-MOS gate; must be 4.5–6V (not tied to VIN); decoupled with 0.1µF ceramic capacitor. |
| 4 - GND | Analog ground reference | Return path for internal circuitry; must connect to clean analog ground plane, separate from power ground if possible. |
| 5 - VOUT | Regulated output | Delivers 1.2V at up to 0.8A; requires ≥10µF tantalum output capacitor with ESR 0.001–1Ω for stability. |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low dropout | 100mV at 0.8A enables single-cell Li-ion or 1.5V supply compatibility for 1.2V loads. |
| CMOS architecture | Ground current remains near-constant (3mA typ) across full load range - simplifies thermal modeling vs. bipolar LDOs. |
| External VBIAS rail | Decouples gate drive from VIN, allowing ultra-low input operation independent of load current. |
| Integrated protection | Thermal shutdown and current limiting prevent damage during overload or inadequate heatsinking. |
| Wide temp operation | Specified performance from −40°C to +125°C junction temperature - validated for industrial ambient conditions. |
Applications
| Server I/O Power | DSP Core Supply |
|---|---|
|
Use Scenario: Local regulation of 1.2V I/O banks in multi-rail server motherboards with tight space constraints. IC Role / Device Role / Timing Role: Post-regulator cleaning ripple from intermediate 3.3V or 5V SMPS outputs before delivery to high-speed SerDes interfaces. Use Value: 65dB PSRR at 1kHz rejects switching noise from upstream converters, maintaining signal integrity in PCIe Gen4/5 links. |
Use Scenario: Powering TMS320C6000-series DSP cores requiring stable 1.2V at up to 0.8A with fast load transients. IC Role / Device Role / Timing Role: Primary core voltage regulator responding to dynamic current steps during FFT or FIR processing bursts. Use Value: Fast transient response and 0.04%/A load regulation hold output within ±3.2mV during 0→0.8A steps, preventing timing violations. |
| PC Add-in Card | Set-Top Box Local Regulator |
|
Use Scenario: Compact 1.2V supply on PCIe-based GPU or FPGA accelerator cards where board area is limited. IC Role / Device Role / Timing Role: Low-profile, thermally efficient LDO replacing larger TO-220 solutions in constrained card-edge layouts. Use Value: DDPAK/TO-263 package with 40°C/W θJA (on 1.5 in² copper) eliminates need for external heatsink in 1.5W dissipation scenarios. |
Use Scenario: Standby-power-critical local 1.2V rail for ARM Cortex-A series SoCs in consumer set-top boxes. IC Role / Device Role / Timing Role: Always-on regulator supplying real-time clock and wake-up logic during deep-sleep modes. Use Value: 60nA shutdown current minimizes annual standby energy consumption - critical for ENERGY STAR compliance. |
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 | 1.2V fixed, 1A, 300µVrms noise, no VBIAS pin - uses single-input architecture with higher 225mV dropout at 1A. | Preferred where ultra-low noise (not ultra-low dropout) dominates, e.g., ADC reference supplies. | Select TPS7A4700RGWR when noise <10µVrms matters more than minimizing VIN headroom. |
| LP3879SD-1.2/NOPB | Same family, SO PowerPAD-8, 0.8A, but 115mV dropout (SO variant), higher θJA (166°C/W), requires larger output ESR margin. | Better for space-constrained PCBs needing surface-mount-only assembly, not thermal-limited designs. | Choose LP3879SD-1.2/NOPB only when board layout prohibits DDPAK mounting or thermal pad routing. |
Compared with TPS7A4700RGWR and LP3879SD-1.2/NOPB, the LP3891ESX-1.2/NOPB uniquely balances sub-100mV dropout, 60nA shutdown, and DDPAK thermal performance - making it optimal for 1.2V core rails where input voltage margin and standby power are co-critical.
Availability
LP3891ESX-1.2/NOPB is available at Aetrix Electronics and suitable for server I/O power, DSP core supplies, PC add-in cards, and set-top box local regulators requiring stable component supply, long-term lifecycle support, and RoHS-exempt packaging for legacy industrial programs.
Supply support for LP3891ESX-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 high-reliability power management ICs, with decades of expertise in precision voltage regulation and thermal-aware design.
The LP3891 series was engineered specifically for high-current, low-VIN post-regulation in digital signal processing and microcontroller applications - prioritizing ultra-low dropout, fast transient response, and robust thermal behavior in thermally demanding environments.
FAQ
What is the minimum input voltage required for LP3891ESX-1.2/NOPB to regulate 1.2V at 0.8A?
The LP3891ESX-1.2/NOPB requires VIN ≥ VOUT + VDO = 1.2V + 0.1V = 1.3V (typical) to maintain regulation at 0.8A. Per datasheet Section 6.5, dropout is 100mV typ for DDPAK/TO-263 packages at full load and 25°C. Derating applies at elevated temperatures or worst-case process corners - design margin should include 150mV minimum differential.
Can LP3891ESX-1.2/NOPB operate without an external VBIAS supply?
No. LP3891ESX-1.2/NOPB requires a dedicated 4.5–6V VBIAS supply on pin 3 to drive the N-MOS pass transistor gate. It cannot function with VBIAS tied to VIN or left floating. The bias rail must be decoupled with a 0.1µF ceramic capacitor close to the pin, as specified in Section 9.2.2 of the SNVS235D datasheet.
What output capacitor type and value are mandatory for stable operation of LP3891ESX-1.2/NOPB?
LP3891ESX-1.2/NOPB requires ≥10µF output capacitance with ESR between 0.001Ω and 1Ω across −40°C to +125°C. Tantalum capacitors are explicitly recommended (Section 9.2.3); aluminum electrolytics are restricted to warm environments only. Ceramic capacitors alone are unstable but may contribute up to 15% of total output capacitance when combined with tantalum.
Does LP3891ESX-1.2/NOPB include overtemperature protection?
Yes. LP3891ESX-1.2/NOPB integrates thermal shutdown that activates when junction temperature exceeds +150°C (absolute max) or enters sustained overtemperature conditions per design. Recovery is automatic upon cooling below the hysteresis threshold. This protection is documented in Section 1 "Features" and Absolute Maximum Ratings Table.
Is LP3891ESX-1.2/NOPB pin-compatible with other LP3891 variants like LP3891ES-1.2/NOPB?
Yes. LP3891ESX-1.2/NOPB and LP3891ES-1.2/NOPB share identical DDPAK/TO-263-5 pinout, electrical specifications, and thermal characteristics. The difference is packaging format only: ESX denotes 500-piece tape-and-reel (KTT drawing), while ES denotes 45-piece tube. Both use the same KTT package outline and land pattern.
LP3891ESX-1.2/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Packaging:
- Tape & Reel (TR)
- 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)
LP3891ESX-1.2/NOPB FAQ
1.How can I place an order for LP3891ESX-1.2/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LP3891ESX-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 LP3891ESX-1.2/NOPB reliable?
The price and inventory of LP3891ESX-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 LP3891ESX-1.2/NOPB is usually 5 days.
3.What payment methods are accepted for LP3891ESX-1.2/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LP3891ESX-1.2/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LP3891ESX-1.2/NOPB?
LP3891ESX-1.2/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LP3891ESX-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 LP3891ESX-1.2/NOPB?
For technical support, including LP3891ESX-1.2/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LP3891ESX-1.2/NOPB requirements.
6.How does Aetrix verify that LP3891ESX-1.2/NOPB is sourced from the original manufacturer or authorized distributors?
All LP3891ESX-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 LP3891ESX-1.2/NOPB meets industry standards.
7.What is the process for return or replacement of LP3891ESX-1.2/NOPB?
All LP3891ESX-1.2/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LP3891ESX-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 LP3891ESX-1.2/NOPB part is unused and in its original packaging.
Return procedure for LP3891ESX-1.2/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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