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STMicroelectronics LD1117DT28TR
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- Part No.:
- LD1117DT28TR
- Manufacturer:
- STMicroelectronics
- Package:
- TO-252-3, DPAK (2 Leads + Tab), SC-63
- Datasheet:
-
LD1117DT28TR.pdf
- Description:
- IC REG LINEAR 2.85V 800MA DPAK
- Quantity:
- Payment:
- Shipping:
Inventory:2,204
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Product details
Overview
LD1117DT28TR from STMicroelectronics is a fixed-output 2.85 V low-dropout linear voltage regulator in DPAK (TO-252) package, delivering up to 800 mA output current with 1.1 V typical dropout at 800 mA, ±1 % output voltage tolerance at 25 °C, and 75 dB supply voltage rejection at 120 Hz - used for post-regulation in industrial power supplies and embedded microcontroller core rails.
For engineers reviewing the LD1117DT28TR datasheet, LD1117DT28TR pinout, LD1117DT28TR application, or LD1117DT28TR equivalent, this page provides verified technical context, real-world design meaning of key specs, validated pin functions, application-specific implementation guidance, and confirmed alternative parts with documented functional differences.
Technical Context
The LD1117DT28TR uses an NPN pass transistor architecture to minimize quiescent current draw into the load rather than ground, enabling high efficiency at light loads. Its internal bandgap reference and error amplifier maintain regulation across input voltages from 4.85 V to 15 V while supporting stable operation with only a 10 µF ceramic output capacitor.
Thermal protection and current limiting are integrated on-die, with junction temperature operating range specified from −40 °C to +125 °C for the 'C' grade variant. The device achieves ±1 % initial output accuracy at 25 °C and maintains ≤0.5 % temperature stability over full operating range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 2.85 V (±1 % at 25 °C); ensures precise core voltage for 3.3 V I/O–compatible MCUs without external feedback network. |
| Max Output Current | 800 mA continuous; supports single-rail powering of ARM Cortex-M microcontrollers with peripherals active. |
| Dropout Voltage | 1.1 V typ. at 800 mA; enables regulation from 4.85 V input (e.g., USB-powered 5 V rail minus diode drop). |
| Supply Voltage Rejection | 75 dB typ. at 120 Hz; suppresses ripple from upstream switching converters in mixed-signal systems. |
| Output Noise | 100 µV RMS (10 Hz–10 kHz); low enough for analog sensor front-ends and ADC reference stability. |
| Thermal Resistance | RthJA = 100 °C/W (DPAK); requires ≥2 cm² copper pour for full 800 mA operation at 50 °C ambient. |
| Operating Junction Temp | −40 °C to +125 °C; qualified for industrial and automotive under-hood auxiliary power applications. |
Pinout & Package
DPAK (TO-252) package with exposed thermal pad connected to VOUT; surface-mount footprint optimized for thermal performance and PCB space efficiency.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 (IN) | Input voltage supply | Accepts 4.85–15 V DC; must be decoupled with ≥10 µF ceramic capacitor near pin. |
| Pin 2 (OUT) | Regulated output | Delivers stable 2.85 V; connects directly to thermal pad and load; requires 10 µF output capacitance. |
| Pin 3 (GND) | Ground reference | Low-impedance return path for error amplifier and bias circuitry; routed separately from power ground. |
| Tab (VOUT) | Output voltage connection | Exposed metal tab is electrically tied to OUT pin; must be soldered to large copper area for thermal conduction. |
Key Features
| Feature | Design Value |
|---|---|
| Low dropout | 1.1 V at 800 mA enables use with marginal input margins (e.g., 5 V rail after Schottky drop). |
| High accuracy | ±1 % output tolerance at 25 °C reduces need for system-level calibration in precision analog subsystems. |
| Integrated protection | Thermal shutdown and current limiting prevent damage during overload or poor heatsinking. |
| Stability with ceramic caps | Guaranteed stable with standard 10 µF X5R/X7R MLCC - eliminates need for tantalum or electrolytic. |
| NPN pass transistor | Quiescent current flows primarily into load, improving light-load efficiency vs. PNP-based regulators. |
Applications
| Industrial PLC I/O Module | Automotive Body Control Unit |
|---|---|
|
Use Scenario: Powering isolated CAN transceiver and digital I/O drivers from a 5 V bus. IC Role / Device Role / Timing Role: Post-regulator providing clean 2.85 V for 3.3 V-tolerant logic and interface ICs. Use Value: 75 dB SVR suppresses switching noise from upstream DC/DC converter, ensuring CAN bit error rate < 10⁻⁹. |
Use Scenario: Supplying microcontroller core voltage in door module with wide ambient temperature swing. IC Role / Device Role / Timing Role: Primary LDO for MCU VCORE, operating from 7–14 V battery-derived 5 V rail. Use Value: −40 °C to +125 °C rating and 1.1 V dropout allow reliable startup at cold cranking (6.5 V battery). |
| Medical Patient Monitor Sensor Subsystem | Networking Edge Router Management Controller |
|
Use Scenario: Biasing low-noise op-amps and 16-bit SAR ADC in ECG front-end. IC Role / Device Role / Timing Role: Ultra-low-noise 2.85 V analog supply, decoupled from digital domains. Use Value: 100 µV RMS noise ensures < 1 LSB error in 16-bit conversion at 100 kSPS sampling. |
Use Scenario: Providing standby power to BMC (Baseboard Management Controller) during main CPU sleep. IC Role / Device Role / Timing Role: Always-on LDO supplying 2.85 V to RTC, watchdog, and wake-up logic. Use Value: 5 mA minimum load requirement met by internal pull-ups; no external dummy load needed. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar fixed-output LDO regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLV1117-285CDR | 2.85 V fixed, 800 mA, dropout 1.2 V @ 800 mA, ±2 % tolerance over temp, SO-8 only | Lacks DPAK thermal option; higher dropout limits use with 5 V input under worst-case conditions | Select when SO-8 footprint required and thermal margin >15 °C suffices |
| MCP1703T-285E/MB | 2.85 V fixed, 250 mA, dropout 600 mV @ 250 mA, ±0.4 % initial accuracy, SOT-23-5 | Lower current rating and smaller package; unsuitable for >300 mA loads | Select only for ultra-low-power, space-constrained applications where 250 mA is sufficient |
Compared with TLV1117-285CDR, LD1117DT28TR offers superior thermal performance via DPAK and tighter initial tolerance; versus MCP1703T-285E/MB, it delivers >3× output current but requires larger board area and more careful thermal layout.
Availability
LD1117DT28TR is available at Aetrix Electronics and suitable for industrial automation controllers, automotive body electronics, medical sensor modules, and networking management subsystems requiring stable component supply with long-term manufacturability.
Supply support for LD1117DT28TR 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
STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, power, microcontroller, and sensor solutions for industrial, automotive, and consumer markets.
The LD1117 series belongs to ST's high-reliability linear regulator product line, engineered specifically for cost-sensitive industrial and automotive applications demanding robust thermal behavior, tight output tolerance, and long-lifecycle availability.
FAQ
What is the minimum input voltage required for LD1117DT28TR to regulate at full 800 mA?
The minimum input voltage is calculated as VOUT + VDROP = 2.85 V + 1.2 V = 4.05 V (max dropout at 800 mA per datasheet Table 12). For guaranteed regulation across temperature and process variation, ST specifies 4.85 V minimum input in typical applications - allowing margin for line drop and ripple.
Can LD1117DT28TR be used with a 10 µF X5R ceramic capacitor only, or is an ESR requirement needed?
Yes - the LD1117DT28TR is explicitly characterized and guaranteed stable with a standard 10 µF X5R or X7R ceramic capacitor (no ESR requirement). Unlike older LDOs, it does not need added series resistance or tantalum capacitors, simplifying BOM and layout.
Is the thermal pad (tab) electrically connected, and how must it be handled on the PCB?
The DPAK thermal pad is internally connected to the VOUT pin. It must be soldered to a dedicated copper pour tied to the output net - not to ground or floating. This connection provides both electrical continuity and primary thermal conduction path; omitting it causes immediate thermal shutdown at >300 mA.
Does LD1117DT28TR include reverse-polarity or reverse-current protection?
No - the LD1117DT28TR has no built-in reverse-polarity or reverse-current protection. If input can be reversed (e.g., during hot-swap or battery insertion), an external series Schottky diode is required on the IN pin to prevent destruction. Reverse current flow from VOUT to VIN is also unblocked.
LD1117DT28TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- TO-252-3, DPAK (2 Leads + Tab), SC-63
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Output Configuration:
- Positive
- Output Type:
- Fixed
- Number of Regulators:
- 1
- Voltage - Input (Max):
- 15V
- Voltage - Output (Min/Fixed):
- 2.85V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- 1.2V @ 800mA
- Current - Output:
- 800mA
- Current - Quiescent (Iq):
- 10 mA
- Current - Supply (Max):
- -
- PSRR:
- 75dB (120Hz)
- Control Features:
- -
- Protection Features:
- Over Current, Over Temperature
- Operating Temperature:
- 0°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DPAK
LD1117DT28TR FAQ
1.How can I place an order for LD1117DT28TR through Aetrix?
Please submit a Request for Quotation (RFQ) for LD1117DT28TR 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 LD1117DT28TR reliable?
The price and inventory of LD1117DT28TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LD1117DT28TR is usually 5 days.
3.What payment methods are accepted for LD1117DT28TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LD1117DT28TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LD1117DT28TR?
LD1117DT28TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LD1117DT28TR 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 LD1117DT28TR?
For technical support, including LD1117DT28TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LD1117DT28TR requirements.
6.How does Aetrix verify that LD1117DT28TR is sourced from the original manufacturer or authorized distributors?
All LD1117DT28TR 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 LD1117DT28TR meets industry standards.
7.What is the process for return or replacement of LD1117DT28TR?
All LD1117DT28TR units undergo pre-shipment inspection (PSI). If there is an issue with LD1117DT28TR, 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 LD1117DT28TR part is unused and in its original packaging.
Return procedure for LD1117DT28TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LD1117DT28TR Tags
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MIC5504-1.8YM5-TR
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MIC5504-3.3YM5-TR
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MIC5365-3.0YC5-TR
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MIC5365-2.5YC5-TR
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MIC5365-3.3YD5-TR
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MIC5317-3.3YM5-TR
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TLV1117LV33DCYR
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MIC5528-3.3YMT-TR
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