My Inquiry
My Account
Texas Instruments LP3891EMR-1.8/NOPB
- Part No.:
- LP3891EMR-1.8/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- 8-PowerSOIC (0.154", 3.90mm Width)
- Datasheet:
-
LP3891EMR-1.8/NOPB.pdf
- Description:
- IC REG LIN 1.8V 800MA 8SO PWRPAD
- Quantity:
- Payment:
- Shipping:
Inventory:483
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LP3891EMR-1.8/NOPB from Texas Instruments is a 0.8A ultra-low-dropout linear regulator in SO PowerPAD-8 package, delivering 1.8V output with 100 mV typical dropout at full load, ±1.5% output accuracy at 25°C, and 60 nA shutdown current. It employs an N-MOS pass transistor with dual-rail operation (VIN + VBIAS) for fast transient response in microcontroller core and DSP power supplies.
For engineers reviewing the LP3891EMR-1.8/NOPB datasheet, LP3891EMR-1.8/NOPB pinout, LP3891EMR-1.8/NOPB application, or LP3891EMR-1.8/NOPB equivalent, this page delivers verified specifications, SO PowerPAD-8 thermal pad layout guidance, load regulation (0.04%/A), PSRR (65 dB @ 1 kHz), and confirmed alternatives for 1.8V LDO replacement in space-constrained industrial and embedded systems.
Technical Context
The LP3891EMR-1.8/NOPB uses a CMOS-based N-MOS pass transistor architecture requiring separate VBIAS (4.5–6V) and VIN rails to enable ultra-low dropout and minimal ground current across load range. Its control loop achieves fast transient response without external compensation due to inherent wide bandwidth and stable phase margin with ≥10 µF tantalum output capacitance.
Thermal management relies on the exposed PowerPAD bottom thermal slug soldered to PCB copper; θJA drops to ~166°C/W with standard mounting but improves significantly with added copper area or vias. Built-in overtemperature and overcurrent protection activate before junction exceeds 150°C or output shorts to ground.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 1.8 V ±1.5% at 25°C - ensures stable core voltage for 1.8V I/O or logic domains without post-regulation trimming. |
| Dropout Voltage | 115 mV typ at 0.8A (SO PowerPAD) - enables operation with VIN as low as 1.915V, critical for battery-backed or post-SMPS applications. |
| Quiescent Current | 60 nA typ in shutdown - preserves system standby power budget in always-on embedded controllers. |
| Load Regulation | 0.04%/A - maintains output within ±3.2 mV across 0–0.8A load, suitable for precision analog supply rails. |
| PSRR @ 1 kHz | 65 dB (VIN), 65 dB (VBIAS) - suppresses switching noise from upstream DC/DC converters feeding VIN or bias rail. |
| Output Noise | 90 µVrms (300 Hz–300 kHz) - low enough for noise-sensitive ADC reference or PLL VCO supply. |
| Operating Temp | −40°C to +125°C junction - supports industrial and automotive under-hood environments without derating. |
Pinout & Package
LP3891EMR-1.8/NOPB is housed in an 8-pin SO PowerPAD (DDA) package with exposed thermal pad on underside. Pin 1 is marked by notch or dot; the PowerPAD must be soldered to a dedicated PCB copper plane for thermal performance and electrical grounding.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (GND) | Ground reference | Primary analog ground return; connects internally to PowerPAD for low-impedance thermal and signal path. |
| 2 (VIN) | Main input supply | Power path input (VOUT + VDO min); requires ≥10 µF ceramic input capacitor near pin. |
| 3 (S/D) | Shutdown control | Active-low enable; pulled high via 10–100 kΩ resistor; <0.3V disables regulator with 20 µs turn-off delay. |
| 4 (VBIAS) | Bias rail input | 4.5–6V gate drive supply for N-MOS pass device; decoupled with 0.1 µF ceramic capacitor. |
| 5 (GND) | Ground reference | Second ground pin; ties to same net as Pin 1 and PowerPAD for reduced ground loop inductance. |
| 6 (VOUT) | Regulated output | 1.8V output; requires ≥10 µF tantalum capacitor with ESR 0.01–0.5 Ω placed ≤1 cm from pin. |
| 7 (GND) | Ground reference | Third ground pin; enhances thermal conduction and reduces high-frequency ground impedance. |
| 8 (NC) | No connect | Internally unconnected; must remain floating or tied to GND per layout best practice to avoid parasitic coupling. |
Key Features
| Feature | Design Value |
|---|---|
| Dual-rail input architecture | VIN + VBIAS separation allows ultra-low VIN operation while maintaining gate drive headroom for N-MOS pass device. |
| Ultra-low ground current | 3 mA typ at 0.8A load - minimizes total system power loss compared to bipolar LDOs with higher quiescent draw. |
| Fast transient response | Stable with only 10 µF output capacitance - eliminates need for complex compensation networks in compact layouts. |
| Integrated protection | Thermal shutdown and current limiting activate before damage occurs; no external circuitry required for basic reliability. |
| PowerPAD thermal interface | Exposed copper slug enables direct PCB heat sinking - achieves 166°C/W θJA baseline, scalable with copper area and vias. |
Applications
| Microcontroller Core Supply | DSP I/O Rail Regulation |
|---|---|
Use Scenario: Powering ARM Cortex-M4 core running at 180 MHz with dynamic current bursts up to 0.75A. IC Role / Device Role / Timing Role: Primary 1.8V core LDO providing clean, low-noise supply with sub-20 µs transient recovery. Use Value: Maintains core voltage within ±1.5% during 100 mA/µs load steps, preventing clock domain timing violations. |
Use Scenario: Regulating I/O voltage for TI C6000 DSP with 1.8V LVCMOS interface banks. IC Role / Device Role / Timing Role: Local point-of-load regulator isolating DSP I/O from noisy system rails. Use Value: 65 dB PSRR at 1 kHz rejects SMPS ripple from shared 3.3V bus, ensuring signal integrity on 100+ Mbps data lines. |
| SMPS Post-Regulator | Set-Top Box Local Regulator |
Use Scenario: Tight-tolerance post-regulation stage after 2.5V buck converter supplying FPGA configuration banks. IC Role / Device Role / Timing Role: Precision LDO correcting buck output drift and ripple to meet 1.8V ±1.5% FPGA spec. Use Value: 0.04%/A load regulation holds output within ±3.2 mV across full FPGA configuration current range (0–0.8A). |
Use Scenario: Powering demodulator IC and tuner front-end in cable set-top box operating at −20°C to +70°C ambient. IC Role / Device Role / Timing Role: Industrial-grade 1.8V supply supporting extended temperature operation with thermal foldback. Use Value: −40°C to +125°C junction rating and internal thermal shutdown ensure reliable operation without external thermal sensors. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 1.8V ultra-low-dropout LDO applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPL7407LPGEDR | 0.5A max, 120 mV dropout at 0.5A, 25 µA quiescent current in active mode, no VBIAS rail required. | Lacks dual-rail architecture; simpler single-supply design but higher dropout limits minimum VIN to 1.92V at full load. | Preferred where board space is constrained and VBIAS routing is undesirable; not suitable for <1.92V input scenarios. |
| TPS7A2018PDQNR | 0.3A max, 130 mV dropout at 0.3A, 6.5 µA quiescent current, integrated soft-start, no VBIAS needed. | Lower current rating and higher dropout restrict use to low-power peripherals; superior light-load efficiency. | Best for always-on sensor nodes or RTC backup rails where 0.3A suffices and ultra-low IQ dominates design priority. |
Compared with TPL7407LPGEDR and TPS7A2018PDQNR, LP3891EMR-1.8/NOPB uniquely supports 0.8A load with 115 mV dropout using VBIAS-assisted N-MOS drive - enabling operation from 1.915V input where alternatives require ≥1.92V and cannot sustain full rated current.
Availability
LP3891EMR-1.8/NOPB is available at Aetrix Electronics and suitable for microcontroller core supplies, DSP I/O regulation, SMPS post-regulation, set-top box local power, and industrial embedded systems requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for LP3891EMR-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 leader specializing in analog, embedded processing, and power management technologies, with over 50 years of innovation in high-reliability power solutions.
The LP3891 product line was designed for high-current, ultra-low-dropout regulation in thermally demanding embedded applications - emphasizing fast transient response, dual-rail flexibility, and robust thermal performance in SO PowerPAD, TO-263, and TO-220 packages.
FAQ
What is the minimum input voltage required for LP3891EMR-1.8/NOPB to regulate 1.8V at 0.8A?
The LP3891EMR-1.8/NOPB requires a minimum input voltage of 1.915V at 0.8A load, based on its 115 mV typical dropout voltage in the SO PowerPAD-8 package. This value assumes VBIAS is within 4.5–6V and ambient temperature is 25°C; at 125°C junction, dropout increases slightly to maintain regulation. Always verify margin with worst-case VDO from the Electrical Characteristics table.
Can LP3891EMR-1.8/NOPB operate without the VBIAS supply?
No - LP3891EMR-1.8/NOPB requires an external VBIAS rail between 4.5V and 6V to drive the gate of its N-MOS pass transistor. Omitting VBIAS prevents regulation entirely, as the device lacks internal charge pump or P-MOS architecture. The VBIAS pin must be decoupled with a 0.1 µF ceramic capacitor placed close to the pin.
What output capacitor type and value are mandatory for stability with LP3891EMR-1.8/NOPB?
LP3891EMR-1.8/NOPB requires ≥10 µF output capacitance with ESR between 0.01 Ω and 0.5 Ω for guaranteed stability. Tantalum capacitors are recommended due to stable ESR over temperature; aluminum electrolytics are restricted to >10°C operation; ceramic capacitors alone are unstable but may supplement up to 15% of total tantalum capacitance.
How does the PowerPAD thermal slug on LP3891EMR-1.8/NOPB connect electrically?
The exposed PowerPAD on LP3891EMR-1.8/NOPB is internally connected to GND and must be soldered to a PCB copper plane tied to the system analog ground. It serves both thermal dissipation and low-impedance grounding - floating or isolated connection degrades thermal performance and may cause instability or ground bounce in high-dI/dt conditions.
Does LP3891EMR-1.8/NOPB include reverse polarity or reverse current protection?
No - LP3891EMR-1.8/NOPB does not integrate reverse polarity or reverse current protection. If VIN falls below VOUT (e.g., during power-down), current can flow backward from VOUT to VIN through the body diode of the N-MOS pass transistor. External Schottky diode or ideal diode controller is required for backfeed prevention in multi-rail systems.
LP3891EMR-1.8/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-PowerSOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Output Configuration:
- Positive
- Output Type:
- Fixed
- Number of Regulators:
- 1
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- 1.8V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- 0.43V @ 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:
- 8-SO PowerPad
LP3891EMR-1.8/NOPB FAQ
1.How can I place an order for LP3891EMR-1.8/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LP3891EMR-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 LP3891EMR-1.8/NOPB reliable?
The price and inventory of LP3891EMR-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 LP3891EMR-1.8/NOPB is usually 5 days.
3.What payment methods are accepted for LP3891EMR-1.8/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LP3891EMR-1.8/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LP3891EMR-1.8/NOPB?
LP3891EMR-1.8/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LP3891EMR-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 LP3891EMR-1.8/NOPB?
For technical support, including LP3891EMR-1.8/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LP3891EMR-1.8/NOPB requirements.
6.How does Aetrix verify that LP3891EMR-1.8/NOPB is sourced from the original manufacturer or authorized distributors?
All LP3891EMR-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 LP3891EMR-1.8/NOPB meets industry standards.
7.What is the process for return or replacement of LP3891EMR-1.8/NOPB?
All LP3891EMR-1.8/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LP3891EMR-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 LP3891EMR-1.8/NOPB part is unused and in its original packaging.
Return procedure for LP3891EMR-1.8/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LP3891EMR-1.8/NOPB Tags
-
MIC5504-1.8YM5-TR
Microchip Technology
-
MIC5504-3.3YM5-TR
Microchip Technology
-
MIC5365-3.0YC5-TR
Microchip Technology
-
MIC5365-1.8YC5-TR
Microchip Technology
-
MIC5365-2.5YC5-TR
Microchip Technology
-
MIC5365-3.3YC5-TR
Microchip Technology
-
MIC5365-3.3YD5-TR
Microchip Technology
-
MIC5317-3.3YM5-TR
Microchip Technology
-
TLV1117LV33DCYR
Texas Instruments
-
MIC5317-3.3YMT-TZ
Microchip Technology
-
MIC5528-3.3YMT-TR
Microchip Technology
-
TLV75801PDRVR
Texas Instruments
Tech Hub
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…
LDO regulator guide covering low dropout voltage, power dissipation, thermal design, PSRR, output noise, capacitor stability, adjustable LDO circuits, LDO vs buck converter and datasheet selection chec…
Conditional Access Module guide covering CAM meaning, CI/CI+ interface, smart card authorization, DVB security workflow, TV and set-top box compatibility, internal electronics, ESD protection, connecto…
Guide to electronic component obsolescence covering EOL risk, PCN/PDN notices, last-time buy planning, replacement options, form-fit-function validation, counterfeit risk and BOM lifecycle management.
18650 battery guide covering lithium-ion cell basics, 3.6V/3.7V voltage, 4.2V charging, mAh and Wh capacity, protected cells, chargers, BMS, series-parallel packs, holders, welding and sourcing checks.…
