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Texas Instruments LP38690DT-1.8/NOPB
- Part No.:
- LP38690DT-1.8/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- TO-252-3, DPAK (2 Leads + Tab), SC-63
- Datasheet:
-
LP38690DT-1.8/NOPB.pdf
- Description:
- IC REG LINEAR 1.8V 1A TO252-3
- Quantity:
- Payment:
- Shipping:
Inventory:155
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Product details
Overview
LP38690DT-1.8/NOPB from Texas Instruments is a 1-A, 1.8-V fixed-output low-dropout CMOS linear regulator in TO-252 (DPAK) package, featuring 2.5% output accuracy at 25°C, 950 mV dropout at 1 A load (VOUT = 1.8 V), and stable operation with only 1-µF ceramic output capacitor. It delivers precision power to core logic rails in space-constrained portable systems.
For engineers reviewing the LP38690DT-1.8/NOPB datasheet, LP38690DT-1.8/NOPB pinout, LP38690DT-1.8/NOPB application, or LP38690DT-1.8/NOPB equivalent, this page provides verified technical context, package-specific pin functions, real-world application constraints, and validated alternative options for battery-powered digital systems requiring tight regulation and low quiescent current.
Technical Context
The LP38690DT-1.8/NOPB uses a PMOS pass transistor architecture enabling ultra-low ground pin current (55 µA typical at full load) independent of input voltage, load, or temperature. Its trimmed bandgap reference and internal feedback network ensure ±2.5% output tolerance over –40°C to +125°C.
No enable pin is present - unlike the LP38692 variant - making it a permanently enabled, three-terminal regulator. It lacks remote sense (SNS) functionality, confirming its TO-252-3 configuration with IN, OUT, and GND terminals only.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 1.8 V ±2.5% at 25°C; maintains regulation across –40°C to +125°C. |
| Max Output Current | 1 A continuous; limited by thermal design and dropout headroom. |
| Dropout Voltage | 950 mV at 1 A (VOUT = 1.8 V); defines minimum VIN = 2.75 V for full-load regulation. |
| Quiescent Current | 55 µA typical at full load; enables high light-load efficiency in battery systems. |
| Input Voltage Range | 2.7 V to 10 V; supports single-cell Li-ion (fully charged) and multi-cell alkaline inputs. |
| Stability | Guaranteed with ≥1-µF ceramic output capacitor; no ESR requirement. |
| Thermal Protection | Thermal shutdown activates at ~160°C junction temperature with 10°C hysteresis. |
Pinout & Package
LP38690DT-1.8/NOPB is housed in a 3-pin TO-252 (DPAK) thermally enhanced package (6.58 mm × 6.10 mm), with the exposed tab electrically connected to GND and serving as primary thermal path to PCB copper.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| IN (Pin 3) | Input supply connection | Accepts 2.7–10 V DC; must be decoupled with ≥1 µF ceramic capacitor near pin. |
| OUT (Pin 1) | Regulated output node | Delivers stable 1.8 V; requires ≥1 µF ceramic capacitor directly at pin for stability. |
| GND (Pin 2) | Power and signal reference | Common return for IN/OUT; thermally tied to exposed tab - must be soldered to ≥1 cm² copper pour. |
Key Features
| Feature | Design Value |
|---|---|
| PMOS pass element | Eliminates base-drive current, keeping ground pin current ≤100 µA across all loads and temperatures. |
| Ceramic-capacitor stability | Operates stably with 1-µF X5R/X7R ceramic output cap - no tantalum or electrolytic required. |
| Wide temperature range | Specified for –40°C to +125°C junction operation; supports industrial and automotive under-hood environments. |
| Foldback current limiting | Protects against short-circuit faults: limits to ~450 mA when VIN–VOUT > 5 V; ~1500 mA when < 4 V. |
| Low-noise regulation | 0.7 µV/√Hz output noise (10 Hz–10 kHz, VOUT = 3.3 V); suitable for noise-sensitive analog/digital cores. |
Applications
| Mobile Application Processor Core Rail | Notebook SoC I/O Supply |
|---|---|
Use Scenario: Powers ARM Cortex-A series CPU core at 1.8 V in handheld tablets with Li-ion battery input (3.0–4.2 V). IC Role / Device Role / Timing Role: Primary LDO delivering clean, tightly regulated core voltage with fast transient response to dynamic load changes. Use Value: Maintains 1.8 V ±45 mV under 1-A step load while consuming only 55 µA quiescent current - extending battery runtime. |
Use Scenario: Supplies 1.8-V I/O bank for Intel Atom or AMD Ryzen Embedded processors in fanless notebooks. IC Role / Device Role / Timing Role: Fixed-output post-regulator converting 3.3-V system rail to processor I/O voltage with minimal board area. Use Value: Enables use of low-ESR ceramic caps only, eliminating bulk capacitance and reducing BOM count by 2–3 components. |
| Industrial PLC Digital I/O Module | Portable Medical Sensor Hub |
Use Scenario: Provides isolated 1.8-V logic supply for FPGA-configured digital I/O in DIN-rail mounted controllers operating at 70°C ambient. IC Role / Device Role / Timing Role: High-reliability, thermally robust LDO ensuring consistent FPGA configuration voltage despite wide input variation (5–24 V via intermediate buck). Use Value: TO-252 package dissipates 0.8 W at 70°C ambient with 29.7°C/W RθJB, avoiding derating or heatsinks. |
Use Scenario: Powers low-power ADC, BLE radio, and microcontroller in handheld glucose meter powered by CR2032 coin cell (2.0–3.0 V). IC Role / Device Role / Timing Role: Efficiency-optimized LDO stepping down marginal input to precise 1.8-V sensor interface rail. Use Value: 950-mV dropout allows regulation down to 2.75 V input - extracting >15% more usable energy from aging coin cell. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar fixed-output LDO applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TSS721AIDR | 1.8-V, 1-A LDO with integrated reset monitor and 1.5% initial accuracy; higher IQ (120 µA). | Requires external reset timing components; adds supervisory function not present in LP38690DT-1.8/NOPB. | Choose when system-level power-on reset coordination is needed alongside regulation. |
| MCP1703T-1802E/MB | 1.8-V, 250-mA LDO in SOT-23; 2% accuracy, 600-mV dropout at 250 mA; lower current rating. | Not suitable for 1-A loads; used in ultra-low-power peripherals rather than main logic rails. | Choose only for sub-250-mA applications where TO-252 footprint is prohibitive. |
Compared with TSS721AIDR and MCP1703T-1802E/MB, LP38690DT-1.8/NOPB uniquely balances 1-A capability, TO-252 thermal performance, and ceramic-capacitor simplicity without added supervisory complexity or current limitation.
Availability
LP38690DT-1.8/NOPB is available at Aetrix Electronics and suitable for notebook computers, portable instrumentation, and battery-powered devices requiring stable component supply with long-term manufacturability and industrial temperature support.
Supply support for LP38690DT-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 designing analog ICs, embedded processors, and power management solutions for industrial, automotive, and consumer applications.
The LP38690DT-1.8/NOPB belongs to TI's LP386xx family of low-noise, ceramic-stable LDOs targeting portable digital systems - engineered for minimal external components, high PSRR, and reliable operation across extended temperature ranges.
FAQ
What is the minimum input voltage required for LP38690DT-1.8/NOPB to regulate 1.8 V at 1 A?
The LP38690DT-1.8/NOPB requires a minimum input voltage of 2.75 V to maintain regulation at 1 A load, based on its 950-mV dropout specification at VOUT = 1.8 V. Below this, output voltage collapses linearly with input. The device also requires VIN ≥ 2.7 V to power internal circuitry - so 2.75 V is the practical lower limit for full-load operation.
Does LP38690DT-1.8/NOPB include an enable pin or shutdown functionality?
No, LP38690DT-1.8/NOPB does not include an enable (EN) pin - it is a permanently enabled, three-terminal LDO. This distinguishes it from the LP38692 variant, which adds EN and SNS pins. To disable LP38690DT-1.8/NOPB, the input supply must be removed or interrupted externally.
Can LP38690DT-1.8/NOPB be used with a 1-µF output capacitor, and what type is recommended?
Yes, LP38690DT-1.8/NOPB is explicitly characterized and guaranteed stable with a single 1-µF ceramic capacitor (X5R or X7R dielectric). No minimum ESR is required, eliminating need for tantalum or aluminum electrolytic capacitors. TI recommends placing the capacitor within 5 mm of the OUT and GND pins for optimal transient response.
What thermal considerations apply to LP38690DT-1.8/NOPB in TO-252 package?
LP38690DT-1.8/NOPB in TO-252 has RθJA = 50.5°C/W (high-K board) and RθJB = 29.7°C/W. For 1-A operation at 2.75 V input (0.95 W dissipation), a 40°C ambient requires ≥1.5 cm² GND copper pour to keep junction temperature below 125°C. Thermal shutdown activates at ~160°C with 10°C hysteresis.
Is LP38690DT-1.8/NOPB compatible with reverse-voltage conditions at the output pin?
LP38690DT-1.8/NOPB contains a parasitic body diode in its PMOS pass transistor. If VOUT exceeds VIN by >500 mV (e.g., during battery swap or output capacitor hold-up), reverse current flows through this diode. Continuous reverse current must be limited to <1 A; peak must stay <5 A. A series Schottky diode at the input is recommended for dual-supply or hot-swap systems.
LP38690DT-1.8/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- TO-252-3, DPAK (2 Leads + Tab), SC-63
- Packaging:
- Tube
- Product Status:
- Active
- Output Configuration:
- Positive
- Output Type:
- Fixed
- Number of Regulators:
- 1
- Voltage - Input (Max):
- 10V
- Voltage - Output (Min/Fixed):
- 1.8V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- 1.6V @ 1A
- Current - Output:
- 1A
- Current - Quiescent (Iq):
- 55 µA
- Current - Supply (Max):
- 100 µA
- PSRR:
- 55dB (120Hz)
- Control Features:
- -
- Protection Features:
- Over Temperature
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- TO-252-3
LP38690DT-1.8/NOPB FAQ
1.How can I place an order for LP38690DT-1.8/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LP38690DT-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 LP38690DT-1.8/NOPB reliable?
The price and inventory of LP38690DT-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 LP38690DT-1.8/NOPB is usually 5 days.
3.What payment methods are accepted for LP38690DT-1.8/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LP38690DT-1.8/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LP38690DT-1.8/NOPB?
LP38690DT-1.8/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LP38690DT-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 LP38690DT-1.8/NOPB?
For technical support, including LP38690DT-1.8/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LP38690DT-1.8/NOPB requirements.
6.How does Aetrix verify that LP38690DT-1.8/NOPB is sourced from the original manufacturer or authorized distributors?
All LP38690DT-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 LP38690DT-1.8/NOPB meets industry standards.
7.What is the process for return or replacement of LP38690DT-1.8/NOPB?
All LP38690DT-1.8/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LP38690DT-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 LP38690DT-1.8/NOPB part is unused and in its original packaging.
Return procedure for LP38690DT-1.8/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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