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Texas Instruments LP38693QSD-1.8/NOPB
- Part No.:
- LP38693QSD-1.8/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- 6-WDFN Exposed Pad
- Datasheet:
-
LP38693QSD-1.8/NOPB.pdf
- Description:
- IC REG LINEAR 1.8V 500MA 6WSON
- Quantity:
- Payment:
- Shipping:
Inventory:567
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Product details
Overview
LP38693QSD-1.8/NOPB from Texas Instruments is a 500-mA, 1.8-V fixed-output CMOS low-dropout linear regulator in WSON-6 package with enable (EN) pin, 250 mV dropout at 500 mA (VOUT = 5 V), ±2% output accuracy over –40°C to 125°C, and stable operation with 1-µF ceramic output capacitor. It serves as a primary power rail for microcontroller cores in portable instrumentation.
For engineers reviewing the LP38693QSD-1.8/NOPB datasheet, LP38693QSD-1.8/NOPB pinout, LP38693QSD-1.8/NOPB application, or LP38693QSD-1.8/NOPB equivalent, key selection considerations include dropout voltage at 1.8 V output, EN pin logic thresholds across temperature, thermal performance in WSON-6 with exposed pad, and foldback current limiting behavior during enable toggling.
Technical Context
The LP38693QSD-1.8/NOPB uses a PMOS pass transistor enabling ground pin current ≤55 µA at full load and eliminating base-drive current dependency. Its internal 1.25-V trimmed bandgap reference and error amplifier deliver tight DC regulation and fast transient response.
It integrates foldback current limiting (350 mA at VIN–VOUT > 5 V; 850 mA at VIN–VOUT < 4 V), thermal shutdown activation at 160°C with 10°C hysteresis, and reverse-voltage protection via parasitic PFET body diode (forward-biased above ~500 mV OUT-to-IN differential).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 1.8 V ±2% over –40°C to 125°C - ensures stable core supply for 1.8-V logic without external feedback network. |
| Max Output Current | 500 mA - supports single-core MCU or FPGA I/O bank without derating at TA ≤ 85°C with PCB copper heatsinking. |
| Dropout Voltage | 250 mV typical at 500 mA (VOUT = 5 V); 100 mV at 100 mA (VOUT = 1.8 V) - enables operation from 2.7-V input down to 1.9-V minimum VIN at full load. |
| Quiescent Current | 55 µA typical at full load; 1 µA in shutdown (VEN ≤ 0.4 V) - extends battery life in always-on sensor nodes. |
| PSRR | 55 dB at 120 Hz (1 Vpp ripple) - suppresses switching noise from upstream DC/DC converters feeding the LDO input. |
| Enable Threshold | VEN(MIN) = 1.8 V (VIN = 4 V), 3 V (VIN = 6 V), 4 V (VIN = 10 V) - compatible with 1.8-V, 3.3-V, and 5-V GPIO control without level-shifting. |
| Noise Density | 0.7 µV/√Hz (10 Hz–10 kHz BW, VOUT = 3.3 V) - preserves signal integrity in ADC reference or RF bias rails. |
Pinout & Package
The LP38693QSD-1.8/NOPB is housed in a thermally enhanced 6-pin WSON package (3.0 mm × 3.0 mm, 0.8-mm height) with exposed thermal pad (DAP) on bottom for PCB copper plane soldering. Pin 1 is IN, Pin 2 is GND, Pin 3 is EN, Pin 4 is OUT, Pin 5 is SNS, Pin 6 is IN (dual IN pins must be tied together).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| IN (Pins 1 & 6) | Input supply connection | Dual IN pins share input current up to 250 mA each; both must be shorted externally for full 500-mA operation and optimal thermal path. |
| GND (Pin 2) | Power and signal reference | Low-impedance return for regulator control circuitry; connects internally to die substrate and DAP for thermal conduction. |
| EN (Pin 3) | Active-high enable control | Pull high ≥1.8 V (min) to enable output; pull low ≤0.4 V to shut down with 1-µA quiescent current; no internal pullup/pulldown. |
| OUT (Pin 4) | Regulated output voltage | Delivers 1.8 V ±2% to load; requires 1-µF ceramic capacitor to GND within 1 cm for stability per TI design guidelines. |
| SNS (Pin 5) | Remote output voltage sense | Connect directly to load point to compensate for PCB trace IR drop; improves load regulation accuracy by eliminating sense-path errors. |
| DAP (Exposed Pad) | Thermal and electrical ground | Must be soldered to ≥100 mm² copper pour for RθJB = 24.9°C/W; not electrically connected to any pin but functions as GND extension. |
Key Features
| Feature | Design Value |
|---|---|
| Stable with 1-µF ceramic output capacitor | Eliminates need for large tantalum or electrolytic capacitors, reducing board area and cost in space-constrained portable designs. |
| PMOS pass transistor architecture | Maintains ground pin current ≤55 µA regardless of load, input voltage, or temperature - simplifies power budgeting in battery systems. |
| Enable pin with wide VIN-compatible thresholds | Supports direct interfacing to 1.8-V, 3.3-V, and 5-V logic without external level shifters, enabling flexible system power sequencing. |
| Foldback current limiting | Reduces short-circuit current to 350 mA when VIN–VOUT > 5 V, lowering power dissipation and thermal stress during fault conditions. |
| Thermal shutdown with hysteresis | Shuts down at 160°C junction temperature and re-enables at 150°C, preventing thermal runaway while allowing safe recovery after overload. |
Applications
| Portable Instrumentation | Battery-Powered Microcontrollers |
|---|---|
Use Scenario: Handheld multimeter with 16-bit SAR ADC and LCD display powered from two AA cells. IC Role / Device Role / Timing Role: Primary 1.8-V analog and digital core supply for ADC reference buffer and MCU core logic. Use Value: Low 0.7 µV/√Hz noise prevents quantization error degradation; 1-µF ceramic stability reduces BOM count and board footprint. |
Use Scenario: Wireless sensor node using ARM Cortex-M0+ MCU, BLE radio, and environmental sensors. IC Role / Device Role / Timing Role: Always-on 1.8-V supply for RTC, wake-up controller, and flash memory retention during deep-sleep mode. Use Value: 1-µA shutdown current extends 10-year battery life; ±2% accuracy ensures reliable brown-out detection and clock calibration. |
| Notebook Subsystem Rails | Industrial Edge Controllers |
Use Scenario: USB-C PD-powered accessory dock providing 1.8-V I/O rail for FPGA configuration and USB PHY interface. IC Role / Device Role / Timing Role: Post-regulator for clean 1.8-V supply isolated from noisy main 5-V/3.3-V bus. Use Value: 55 dB PSRR at 120 Hz suppresses ripple from upstream buck converter; SNS pin compensates for 50-mΩ PCB trace resistance. |
Use Scenario: DIN-rail mounted PLC module requiring robust 1.8-V supply for isolated CAN transceiver and real-time co-processor. IC Role / Device Role / Timing Role: High-reliability 1.8-V rail with thermal shutdown and foldback limiting for field-deployed equipment. Use Value: Rated for –40°C to 125°C junction operation; WSON thermal pad enables conduction cooling in sealed enclosures without fans. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LDO regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPL7407LADGQR | 7-channel 100-mA sink driver with integrated LDO; no enable pin; 1.8-V output not available - only offers 3.3 V and 5 V. | Designed for LED/relay driving, not precision voltage regulation; lacks remote sensing and thermal shutdown. | Select only if multi-channel sinking is required alongside basic 3.3/5-V regulation - not a functional substitute for LP38693QSD-1.8/NOPB. |
| TPS7A0518PDQNR | 200-mA, 1.8-V LDO in X2SON-4; 1.7-μA IQ; no SNS pin; 200-mV dropout at 200 mA; rated –40°C to 125°C. | Lower current capacity and no remote sensing limit use in high-accuracy, high-load applications like ADC references. | Choose for ultra-low-power, space-constrained applications where 200-mA max load and absence of SNS are acceptable trade-offs. |
Compared with TPS7A0518PDQNR, LP38693QSD-1.8/NOPB delivers 2.5× higher output current, remote sensing for improved load regulation, and proven thermal robustness in industrial ambient conditions - making it suitable for demanding embedded subsystems where precision and reliability are critical.
Availability
LP38693QSD-1.8/NOPB is available at Aetrix Electronics and suitable for portable instrumentation, battery-powered microcontrollers, and industrial edge controllers requiring stable component supply, long-term lifecycle support, and automotive-grade qualification readiness.
Supply support for LP38693QSD-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 specializing in analog and embedded processing technologies, with leadership in power management ICs for industrial, automotive, and portable applications.
The LP38693QSD-1.8/NOPB belongs to TI's LP3869x family of low-dropout CMOS regulators designed specifically for battery-powered digital systems requiring fast start-up, tight output tolerance, and ceramic-capacitor stability.
FAQ
What is the minimum input voltage required for LP38693QSD-1.8/NOPB to regulate 1.8 V output?
The LP38693QSD-1.8/NOPB requires VIN ≥ (VOUT + VDO), where VDO is 100 mV typical at 100 mA load for 1.8-V output. Thus, minimum VIN is 1.9 V under light load. However, the datasheet specifies a recommended operating minimum of 2.7 V to ensure full functionality of internal circuitry across temperature and process variation. Below 2.7 V, regulation may be unstable or disabled.
Does LP38693QSD-1.8/NOPB require an external resistor divider to set its 1.8-V output?
No. LP38693QSD-1.8/NOPB is a fixed-output regulator with internally trimmed 1.8-V reference. It contains no feedback pins and does not support adjustable output. The SNS pin is for remote sensing only and must be connected directly to the load - it does not alter the nominal 1.8-V setpoint of the LP38693QSD-1.8/NOPB.
Can the SNS pin of LP38693QSD-1.8/NOPB be left unconnected?
No. The SNS pin of LP38693QSD-1.8/NOPB must be connected directly to the OUT pin (or to the load point for remote sensing). Leaving it floating violates the device's functional specification and may cause output voltage instability or regulation failure. The datasheet explicitly states "This pin must be tied to OUT" when not used for remote sensing.
What is the thermal performance of LP38693QSD-1.8/NOPB in its WSON-6 package?
The LP38693QSD-1.8/NOPB in WSON-6 has RθJA = 50.6°C/W (high-K board), RθJB = 24.9°C/W, and RθJC(bot) = 5.4°C/W. With proper DAP soldering to ≥100 mm² copper, it sustains 500 mA at 85°C ambient. At 125°C junction limit and 2.7-V input, max continuous load is ~380 mA - verified via PD = (VIN – VOUT) × IOUT and thermal derating equations in the datasheet.
How does the foldback current limiting behave on LP38693QSD-1.8/NOPB during repeated enable cycles?
Per the datasheet caution, foldback current limiting is functional only on the first EN high transition after VIN application. On subsequent enable cycles, foldback is non-functional, potentially causing higher inrush current. To ensure consistent foldback operation, tie EN directly to VIN or use a reset supervisor that guarantees VIN ramps from <0.4 V before asserting EN - a critical design consideration for the LP38693QSD-1.8/NOPB in systems with hot-pluggable power rails.
LP38693QSD-1.8/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 6-WDFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- 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):
- -
- Current - Output:
- 500mA
- Current - Quiescent (Iq):
- 55 µA
- Current - Supply (Max):
- 100 µA
- PSRR:
- 55dB (120Hz)
- Control Features:
- Enable
- Protection Features:
- Over Temperature
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 6-WSON (3x3)
LP38693QSD-1.8/NOPB FAQ
1.How can I place an order for LP38693QSD-1.8/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LP38693QSD-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 LP38693QSD-1.8/NOPB reliable?
The price and inventory of LP38693QSD-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 LP38693QSD-1.8/NOPB is usually 5 days.
3.What payment methods are accepted for LP38693QSD-1.8/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LP38693QSD-1.8/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LP38693QSD-1.8/NOPB?
LP38693QSD-1.8/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LP38693QSD-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 LP38693QSD-1.8/NOPB?
For technical support, including LP38693QSD-1.8/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LP38693QSD-1.8/NOPB requirements.
6.How does Aetrix verify that LP38693QSD-1.8/NOPB is sourced from the original manufacturer or authorized distributors?
All LP38693QSD-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 LP38693QSD-1.8/NOPB meets industry standards.
7.What is the process for return or replacement of LP38693QSD-1.8/NOPB?
All LP38693QSD-1.8/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LP38693QSD-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 LP38693QSD-1.8/NOPB part is unused and in its original packaging.
Return procedure for LP38693QSD-1.8/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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