My Inquiry
My Account
Texas Instruments LP38691DT-5.0
- Part No.:
- LP38691DT-5.0
- Manufacturer:
- Texas Instruments
- Package:
- TO-252-3, DPAK (2 Leads + Tab), SC-63
- Datasheet:
-
LP38691DT-5.0.pdf
- Description:
- IC REG LINEAR 5V 500MA TO252-3
- Quantity:
- Payment:
- Shipping:
Inventory:4,313
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LP38691DT-5.0 from Texas Instruments is a 500-mA, 5.0-V fixed-output low-dropout CMOS linear regulator in TO-252 (DPAK) package, featuring 250 mV dropout at full load, ±2% output accuracy over –40°C to 125°C, and stable operation with only 1-µF ceramic output capacitance. It delivers regulated power to microcontroller cores and I/O rails in battery-powered instrumentation.
For engineers reviewing the LP38691DT-5.0 datasheet, LP38691DT-5.0 pinout, LP38691DT-5.0 application, or LP38691DT-5.0 equivalent, key selection criteria include dropout voltage at 500 mA, thermal performance in TO-252, ground pin current under load, ripple rejection at 120 Hz, and compatibility with low-ESR ceramic capacitors without external compensation.
Technical Context
The LP38691DT-5.0 uses a PMOS pass transistor architecture enabling ultra-low ground pin current (55 µA typical at full load) independent of input voltage or temperature. Its internal trimmed bandgap reference and feedback loop ensure tight DC regulation and fast transient response without requiring external resistors.
No enable pin is present - unlike the LP38693 variant - making it a simple ON/OFF device controlled solely by input voltage. Thermal shutdown activates at 160°C with 10°C hysteresis, and foldback current limiting engages based on VIN–VOUT differential (e.g., ~350 mA limit when ΔV > 5 V).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 5.0 V ±2% over –40°C to 125°C - eliminates need for external feedback resistors and ensures consistent logic-level compliance. |
| Max Output Current | 500 mA continuous - supports moderate-power MCU subsystems and peripheral ICs without derating at 25°C ambient. |
| Dropout Voltage | 250 mV at 500 mA (VOUT = 5 V) - enables operation down to VIN = 5.25 V, critical for single-cell Li-ion or multi-cell alkaline systems. |
| Ground Pin Current | 55 µA typical at full load - minimizes system quiescent loss and preserves battery life in always-on monitoring circuits. |
| Ripple Rejection | 55 dB at 120 Hz (1 Vp-p) - suppresses AC line noise and switching supply coupling into analog sensor front-ends. |
| Input Voltage Range | 2.7 V to 10 V - accommodates wide-input industrial supplies and unregulated adapter outputs without pre-regulation. |
| Thermal Shutdown | Activates at 160°C junction temperature with 10°C hysteresis - provides self-protection during sustained overload or poor PCB heatsinking. |
Pinout & Package
LP38691DT-5.0 is housed in a 3-pin TO-252 (DPAK) thermally enhanced package with exposed tab (GND), offering 50.5°C/W junction-to-ambient thermal resistance (High-K board). The tab must be soldered to a large copper plane for rated current delivery.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| IN (Pin 1) | Input supply connection | Accepts 2.7–10 V; requires 1-µF ceramic capacitor to GND within 1 cm for stability. |
| OUT (Pin 2) | Regulated output | Delivers fixed 5.0 V; stable with ≥1-µF ceramic capacitor (low ESR); no external feedback needed. |
| GND (Tab) | Power and thermal ground | Internally connected to die substrate and exposed thermal pad; must be soldered to ≥200 mm² copper for full 500-mA capability. |
Key Features
| Feature | Design Value |
|---|---|
| Stable with 1-µF ceramic output cap | Eliminates need for tantalum or electrolytic capacitors - reduces BOM cost, footprint, and aging-related drift. |
| PMOS pass transistor | Enables <100 µA ground current across full load/temperature range - ideal for battery runtime-critical applications. |
| ±2% output accuracy (25°C) | Meets tight tolerance requirements for ADC references and precision analog circuitry without post-production trimming. |
| Foldback current limiting | Reduces output current as VOUT collapses (e.g., short-circuit), lowering power dissipation and preventing thermal runaway. |
| Thermal overload protection | Shuts down output at 160°C junction temp and recovers at ~150°C - protects against sustained overloads without external circuitry. |
Applications
| Hard Disk Drive Power Rail | Notebook System I/O Supply |
|---|---|
Use Scenario: Powers 5-V interface circuitry (SATA PHY, LED drivers) in portable HDD enclosures with limited airflow. IC Role / Device Role / Timing Role: Primary LDO delivering clean, low-noise 5-V rail isolated from noisy 12-V SMPS input. Use Value: 250 mV dropout allows operation from 5.25-V minimum input, extending usable battery life by 8–12% versus higher-dropout alternatives. |
Use Scenario: Supplies USB controller, card reader, and keyboard backlight in ultraportable notebooks. IC Role / Device Role / Timing Role: Fixed-output LDO providing stable 5-V bus decoupled from main system DC/DC converter. Use Value: 55 µA ground current at full load reduces total system quiescent consumption by ~0.3 mW versus bipolar-based regulators. |
| Battery-Powered Data Logger | Industrial Sensor Node |
Use Scenario: Powers microcontroller, SD card, and RS-232 transceiver in field-deployed environmental loggers running on 3×AA cells. IC Role / Device Role / Timing Role: Main power regulator converting 3.6–4.8 V battery stack to precise 5.0 V for mixed-signal peripherals. Use Value: Stable operation down to 2.7 V input enables full utilization of battery capacity - extends logging duration by 15–20%. |
Use Scenario: Supplies 5-V analog front-end (op-amps, ADCs) and digital isolator in explosion-proof process sensors. IC Role / Device Role / Timing Role: Precision LDO ensuring <±10 mV output deviation across –40°C to 125°C ambient extremes. Use Value: ±2% accuracy over full temperature range eliminates need for calibration compensation in firmware or hardware. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar low-dropout linear regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TSS721AIDR | 500-mA, 5-V LDO in SOIC-8; 350 mV dropout at 500 mA; higher ground current (250 µA typ); no thermal shutdown. | Lacks integrated thermal protection and has 40% higher dropout - unsuitable for thermally constrained or low-input-voltage designs. | Select only if SOIC-8 footprint is mandatory and thermal margin exceeds 25°C; verify external thermal management. |
| MCP1703T-5002E/MB | 250-mA, 5-V LDO in SOT-23; 600 mV dropout at 250 mA; 2.5-µA quiescent current; no foldback limiting. | Lower current rating and higher dropout restrict use to ultra-low-power subcircuits - not a functional replacement for 500-mA loads. | Consider only for auxiliary rails with <200 mA demand; avoid where full LP38691DT-5.0 current capability is required. |
Compared with TSS721AIDR and MCP1703T-5002E/MB, the LP38691DT-5.0 uniquely combines 500-mA capability, 250-mV dropout, integrated thermal shutdown, and 55-µA ground current in a thermally robust TO-252 package - making it the only option qualified for continuous high-current operation across industrial temperature ranges.
Availability
LP38691DT-5.0 is available at Aetrix Electronics and suitable for hard disk drives, notebook computers, and battery-powered devices requiring stable component supply, long-term lifecycle support, and guaranteed traceability.
Supply support for LP38691DT-5.0 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 connectivity solutions for industrial, automotive, and consumer markets.
The LP3869x family was developed specifically for portable, battery-powered digital systems needing accurate, low-noise, low-quiescent-power regulation with minimal external components - targeting space-constrained and thermally demanding applications.
FAQ
What is the maximum input voltage rating for LP38691DT-5.0?
The absolute maximum input voltage for LP38691DT-5.0 is 12 V, but the recommended operating range is 2.7 V to 10 V. Exceeding 10 V continuously may accelerate parametric drift and reduce long-term reliability. The device's internal protection circuits do not guard against sustained overvoltage beyond 12 V, so external clamping is advised in unregulated supply environments.
Does LP38691DT-5.0 require an enable pin to operate?
No, LP38691DT-5.0 does not have an enable (EN) pin - it operates continuously whenever valid input voltage (≥2.7 V) is applied. This distinguishes it from the LP38693 variant, which includes an EN pin. The LP38691DT-5.0 is intended for always-on or input-controlled applications where external sequencing is handled upstream.
Can LP38691DT-5.0 be used with a 0.47-µF output capacitor?
No - LP38691DT-5.0 requires a minimum 1-µF ceramic output capacitor for guaranteed stability per the datasheet. Using 0.47 µF risks oscillation or poor transient response, especially under dynamic load changes. TI validates stability only with ≥1 µF, and lower values fall outside the characterized design window.
What is the thermal resistance (RθJA) of LP38691DT-5.0 in its TO-252 package?
The junction-to-ambient thermal resistance (RθJA) for LP38691DT-5.0 in the TO-252 package is 50.5°C/W under High-K board conditions (JEDEC JESD51-7). This value assumes a 1-in² copper pad connected to the exposed tab (GND) - reducing copper area increases RθJA and limits safe operating current at elevated ambient temperatures.
Is LP38691DT-5.0 suitable for automotive applications?
LP38691DT-5.0 is not AEC-Q100 qualified. For automotive use, TI offers the pin-compatible LP38691-Q1 variant (WSON-6), which meets Grade 1 (–40°C to 125°C) requirements and includes enhanced ESD robustness. The standard LP38691DT-5.0 lacks automotive qualification testing and should not be deployed in safety-critical vehicle systems.
LP38691DT-5.0 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- TO-252-3, DPAK (2 Leads + Tab), SC-63
- Packaging:
- Tube
- Product Status:
- Discontinued at Digi-Key
- Output Configuration:
- Positive
- Output Type:
- Fixed
- Number of Regulators:
- 1
- Voltage - Input (Max):
- 10V
- Voltage - Output (Min/Fixed):
- 5V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- 0.45V @ 500mA
- Current - Output:
- 500mA
- 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
LP38691DT-5.0 FAQ
1.How can I place an order for LP38691DT-5.0 through Aetrix?
Please submit a Request for Quotation (RFQ) for LP38691DT-5.0 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 LP38691DT-5.0 reliable?
The price and inventory of LP38691DT-5.0 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LP38691DT-5.0 is usually 5 days.
3.What payment methods are accepted for LP38691DT-5.0?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LP38691DT-5.0 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LP38691DT-5.0?
LP38691DT-5.0 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LP38691DT-5.0 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 LP38691DT-5.0?
For technical support, including LP38691DT-5.0 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LP38691DT-5.0 requirements.
6.How does Aetrix verify that LP38691DT-5.0 is sourced from the original manufacturer or authorized distributors?
All LP38691DT-5.0 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 LP38691DT-5.0 meets industry standards.
7.What is the process for return or replacement of LP38691DT-5.0?
All LP38691DT-5.0 units undergo pre-shipment inspection (PSI). If there is an issue with LP38691DT-5.0, 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 LP38691DT-5.0 part is unused and in its original packaging.
Return procedure for LP38691DT-5.0:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LP38691DT-5.0 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.…
