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Semtech Corporation SC431LC5SK-1 TR
- Part No.:
- SC431LC5SK-1 TR
- Manufacturer:
- Semtech Corporation
- Category:
- Voltage Reference
- Package:
- SC-74A, SOT-753
- Datasheet:
-
SC431LC5SK-1 TR.pdf
- Description:
- IC VREF SHUNT ADJ 1% SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:2,505
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Product details
Overview
SC431LC5SK-1 TR from Semtech is a precision adjustable shunt regulator in SOT-23-5 package, functioning as a programmable voltage reference with 1.24 V to 20 V output range via two external resistors. It delivers 0.25% initial reference voltage tolerance, 0.05 Ω typical dynamic impedance, and operates from 100 µA to 100 mA cathode current - ideal for feedback control in isolated DC-DC converters and low-voltage instrumentation.
For engineers reviewing the SC431LC5SK-1 TR datasheet, pinout, applications, or equivalent options, key selection criteria include its ±0.25% VREF accuracy over −40°C to +125°C, thermal stability up to +150°C junction temperature, SOT-23-5 pin-compatible layout with dedicated reference and cathode terminals, and proven replacement capability for TLV431A in space-constrained power management designs.
Technical Context
The SC431LC5SK-1 TR implements a trimmed bandgap reference core with active output circuitry enabling sharp turn-on characteristics and stable regulation down to 1.24 V. Its internal architecture supports precise voltage setting via external resistor divider while maintaining low dynamic impedance (0.05 Ω typ.) across 100 µA–100 mA cathode current range.
It is specified for industrial temperature operation (−40°C to +125°C ambient), features absolute maximum cathode voltage of 20 V and cathode current limit of 100 mA, and exhibits minimal reference voltage drift (±20 ppm/°C typical) over full operating range - making it suitable for closed-loop feedback in switching regulators and precision analog monitoring circuits.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VREF Initial Accuracy | ±0.25% at 25°C - enables high-precision output voltage setting without calibration in feedback networks. |
| Reference Voltage Range | 1.24 V to 20 V - set externally via R1/R2 divider; supports wide-range adjustable regulation without component change. |
| Dynamic Impedance | 0.05 Ω typical - ensures minimal output voltage perturbation under fast load transients in power supply feedback paths. |
| Cathode Current Range | 100 µA to 100 mA - accommodates both ultra-low-power biasing and high-current shunt applications. |
| Operating Temperature | −40°C to +125°C ambient - validated for industrial-grade reliability in embedded power systems. |
| Junction Temp Limit | +150°C max - allows sustained operation under high-power dissipation conditions in compact layouts. |
| Package | SOT-23-5 - surface-mount, RoHS-compliant, 3.0 mm × 1.75 mm footprint with defined thermal pad for PCB heat sinking. |
Pinout & Package
SOT-23-5 package with exposed thermal pad (pin 5), 0.95 mm pitch, 1.75 mm height, and JEDEC-standard footprint per IPC-SM-782A. Designed for reflow soldering and thermal performance optimization in high-density PCBs.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Cathode) | Output current sink | Primary current path for shunt regulation; connects to converter output node for feedback control. |
| 2 (Anode) | Ground reference | Return path for cathode current; must be low-impedance connection to system ground plane. |
| 3 (Ref) | Reference input | High-impedance node tied to resistor divider midpoint; sets regulated voltage via VOUT = VREF(1 + R1/R2). |
| 4 (NC) | No connect | Internally unconnected; must remain floating - no routing or grounding permitted. |
| 5 (Thermal Pad) | Thermal conduction | Exposed copper pad for PCB thermal relief; requires direct connection to large copper pour for >100 mW dissipation. |
Key Features
| Feature | Design Value |
|---|---|
| Trimmed bandgap reference | Delivers ±0.25% VREF accuracy at 25°C, reducing need for post-production trimming in production power supplies. |
| Sharp turn-on characteristic | Enables clean start-up behavior in isolated flyback controllers without oscillation during transient loading. |
| Low dynamic output impedance | 0.05 Ω typical maintains tight regulation under rapid load steps - critical for stable feedback in high-frequency SMPS. |
| Wide cathode current range | 100 µA–100 mA operation supports both standby-mode biasing and full-load shunt regulation in single-device design. |
| SOT-23-5 thermal pad | Exposes die substrate to PCB copper, enabling >150 mW continuous power dissipation at +125°C ambient without derating. |
Applications
| Isolated Flyback Converter Feedback | Precision Instrumentation Reference |
|---|---|
Use Scenario: Used in secondary-side feedback loop of 5–24 V isolated flyback converters to regulate output voltage without optocoupler delay. IC Role / Device Role / Timing Role: Adjustable shunt regulator providing stable reference voltage to TL431-equivalent error amplifier stage. Use Value: Enables ±1% output regulation across line/load/temperature with 0.05 Ω dynamic impedance minimizing ripple coupling into feedback path. | Use Scenario: Provides calibrated 2.5 V reference for 16-bit ADC front-end in portable test equipment. IC Role / Device Role / Timing Role: Precision voltage reference source with <0.5 ppm/°C drift, replacing discrete Zener + op-amp solutions. Use Value: Delivers 0.25% initial accuracy and <10 nA reference input current - eliminating offset errors in high-impedance sensor signal chains. |
| Battery-Powered System Supervisor | Disk Drive Spindle Motor Control |
Use Scenario: Monitors 3.3 V rail in battery-backed microcontroller systems to trigger brown-out reset below 2.9 V. IC Role / Device Role / Timing Role: Adjustable threshold detector using external resistor divider; drives comparator input directly. Use Value: Operates down to 100 µA cathode current - extends supervisor runtime in deep-sleep modes without adding quiescent current overhead. | Use Scenario: Sets precise 12 V reference for PWM-controlled spindle motor driver in 2.5-inch HDD platforms. IC Role / Device Role / Timing Role: Stable voltage reference for analog-to-digital conversion of motor back-EMF signals. Use Value: Maintains <0.1% regulation over −40°C to +85°C ambient - ensuring consistent motor speed control across environmental extremes. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar adjustable shunt regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLV431ACDBVR | 0.5% VREF accuracy, SOT-23-5, 1.24–6 V range only | Limited to ≤6 V outputs; lower accuracy reduces regulation tightness in high-voltage rails | Select when cost sensitivity outweighs need for >6 V adjustability or ±0.25% precision |
| LM4040CIM3-ADJ | Fixed 2.5 V reference (non-adjustable), SOT-23-3, 0.5% accuracy | Requires external op-amp for adjustable output; adds board area and complexity | Choose only if fixed-reference topology is acceptable and board space permits added components |
Compared with TLV431ACDBVR and LM4040CIM3-ADJ, the SC431LC5SK-1 TR uniquely combines ±0.25% accuracy, 1.24–20 V adjustability, and SOT-23-5 thermal performance - enabling single-component feedback in high-accuracy, wide-output-range power supplies without accuracy or thermal trade-offs.
Availability
SC431LC5SK-1 TR is available at Aetrix Electronics and suitable for isolated DC-DC converters, precision instrumentation references, and battery-supervised microcontroller systems requiring stable component supply with guaranteed long-term manufacturability.
Supply support for SC431LC5SK-1 TR 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
Semtech Corporation is a U.S.-based fabless semiconductor company specializing in high-performance analog and mixed-signal ICs for power management, RF, and sensing applications.
The SC431L product line was designed specifically for precision shunt regulation in space-constrained, thermally demanding power systems - targeting industrial, computing, and storage applications where accuracy, stability, and small-footprint integration are critical.
FAQ
What is the maximum cathode voltage rating for SC431LC5SK-1 TR?
The SC431LC5SK-1 TR has an absolute maximum cathode voltage rating of 20 V. This limit applies regardless of current level or ambient temperature. Exceeding 20 V risks permanent damage to the internal bandgap reference circuit. The device is rated for continuous operation up to this voltage when used within its specified cathode current range (100 µA to 100 mA) and thermal limits.
Does SC431LC5SK-1 TR require an external capacitor for stability?
No, the SC431LC5SK-1 TR does not require an external capacitor for basic stability. In fact, capacitance between 10 nF and 1 µF across its cathode-anode terminals can cause oscillation during startup at light loads. For reliable operation, use either no capacitor directly across the device (with local decoupling at the load) or ≥10 µF if placed directly across the SC431LC5SK-1 TR. This behavior is documented in Semtech's Applications Information section on stability.
How is the output voltage set on SC431LC5SK-1 TR?
The output voltage of SC431LC5SK-1 TR is set using two external resistors (R1 and R2) forming a voltage divider between cathode and reference pins. The formula is VOUT = VREF × (1 + R1/R2), where VREF = 1.24 V nominal. R2 connects from reference pin to anode (ground), and R1 connects from cathode to reference pin. Values must ensure cathode current stays within 100 µA–100 mA across all operating conditions.
What is the thermal pad (Pin 5) connection requirement for SC431LC5SK-1 TR?
Pin 5 of the SC431LC5SK-1 TR is an exposed thermal pad that must be soldered directly to a PCB copper pour for effective heat dissipation. It is not electrically connected internally - no voltage or signal should be applied. A minimum 10 mm² copper area with multiple thermal vias to inner ground planes is recommended to maintain junction temperature below +150°C at full 100 mA cathode current and +125°C ambient.
Can SC431LC5SK-1 TR replace TLV431A in existing designs?
Yes, SC431LC5SK-1 TR is a functional and pin-compatible upgrade for TLV431A in SOT-23-5 layouts. It offers tighter ±0.25% VREF accuracy versus TLV431A's ±0.5%, identical pinout and electrical interface, and extended 1.24–20 V adjustment range (vs. TLV431A's 1.24–6 V). No PCB changes are required, but verify cathode current compliance and thermal margin due to higher accuracy-driven tighter regulation.
SC431LC5SK-1 TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Semtech Corporation
- Package/Case:
- SC-74A, SOT-753
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Reference Type:
- Shunt
- Output Type:
- Adjustable
- Voltage - Output (Min/Fixed):
- 1.24V
- Voltage - Output (Max):
- 16 V
- Current - Output:
- 100 µA
- Tolerance:
- ±1%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 100 mA
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
SC431LC5SK-1 TR FAQ
1.How can I place an order for SC431LC5SK-1 TR through Aetrix?
Please submit a Request for Quotation (RFQ) for SC431LC5SK-1 TR 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 SC431LC5SK-1 TR reliable?
The price and inventory of SC431LC5SK-1 TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SC431LC5SK-1 TR is usually 5 days.
3.What payment methods are accepted for SC431LC5SK-1 TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SC431LC5SK-1 TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SC431LC5SK-1 TR?
SC431LC5SK-1 TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SC431LC5SK-1 TR 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 SC431LC5SK-1 TR?
For technical support, including SC431LC5SK-1 TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SC431LC5SK-1 TR requirements.
6.How does Aetrix verify that SC431LC5SK-1 TR is sourced from the original manufacturer or authorized distributors?
All SC431LC5SK-1 TR 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 SC431LC5SK-1 TR meets industry standards.
7.What is the process for return or replacement of SC431LC5SK-1 TR?
All SC431LC5SK-1 TR units undergo pre-shipment inspection (PSI). If there is an issue with SC431LC5SK-1 TR, 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 SC431LC5SK-1 TR part is unused and in its original packaging.
Return procedure for SC431LC5SK-1 TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SC431LC5SK-1 TR Tags
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TL431AIDBZR
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TL431BQDBZR
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AN431AN-ATRG1
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LM4040CYM3-2.5-TR
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LM4040CYM3-4.1-TR
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LM4040EIM3-2.5/NOPB
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AZ431LBNTR-G1
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LM4040D20IDBZR
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LM4041DIM3-ADJ/NOPB
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LM4040DIM3X-2.5/NOPB
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LM4040DIM3-2.5/NOPB
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AZ431LANTR-G1
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