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Semtech Corporation SC431MSKQTRT
- Part No.:
- SC431MSKQTRT
- Manufacturer:
- Semtech Corporation
- Category:
- Voltage Reference
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
SC431MSKQTRT.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:2,822
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Product details
Overview
SC431MSKQTRT from Semtech is an adjustable precision shunt regulator IC used as a voltage reference and error amplifier in feedback loops of linear and switching power supplies. It delivers 2.495 V reference voltage (±0.5%), supports 130 μA to 150 mA cathode current, exhibits 0.25 Ω typical dynamic output impedance, and operates across –55°C to +125°C for military-grade power regulation.
For engineers reviewing the SC431MSKQTRT datasheet, pinout, applications, or equivalent options, key selection criteria include its 0.5% VREF tolerance over full temperature range, SOT-23-3 package compatibility, low 130 μA minimum operating current, and direct functional replacement capability for TL431-family regulators in closed-loop voltage control designs.
Technical Context
The SC431MSKQTRT implements a trimmed bandgap reference with active output circuitry enabling sharp turn-on behavior and stable regulation down to 2.5 V. Its internal architecture integrates a precision reference, error amplifier, and NPN output stage - eliminating need for external Zener diodes in feedback networks.
It functions exclusively as a 3-terminal shunt regulator: cathode, anode, and reference input. Regulation occurs by sinking variable cathode current based on reference voltage error, requiring external resistive divider to set output voltage between 2.5 V and 30 V. No enable, shutdown, or compensation pins are present.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VREF | 2.495 V ±0.5% (0.0125 V max deviation) - sets precise feedback threshold for output voltage programming |
| IZ(MIN) | 130 μA - minimum cathode current required to maintain regulation; defines lowest usable load condition |
| rZ | 0.25 Ω typical - low dynamic impedance ensures stable loop response and minimal output voltage perturbation under load transients |
| TA Range | –55°C to +125°C - enables deployment in aerospace, industrial, and automotive under-hood environments without derating |
| VZ Max | 31 V - absolute maximum cathode-to-anode voltage; limits input headroom in high-voltage regulator designs |
| PD @ 25°C | 0.37 W - thermal limit in SOT-23-3; dictates maximum power dissipation before junction overheating |
| IZ Max | 150 mA continuous - defines upper bound of shunt current handling; impacts external resistor sizing and heatsinking |
Pinout & Package
SOT-23-3 plastic surface-mount package with gull-wing leads, RoHS and WEEE compliant. Dimensions per Semtech outline drawing: 2.9 mm × 1.3 mm × 1.0 mm (L × W × H), 0.95 mm lead pitch.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (K) | Current sink output terminal | Connects to regulated output node; sinks adjustable current to maintain VREF at divider junction |
| Anode (A) | Ground return path | Reference and power return; must be low-impedance connection to system ground or power rail return |
| Reference (R) | Feedback input | Connects to resistor divider midpoint; senses output voltage and compares to internal 2.495 V reference |
Key Features
| Feature | Design Value |
|---|---|
| 0.5% VREF tolerance over –55°C to +125°C | Enables high-accuracy output voltage setting without calibration across extreme ambient conditions |
| 130 μA minimum operating current | Supports ultra-low-power regulation in standby or light-load modes without dropout or instability |
| 0.25 Ω typical dynamic output impedance | Provides tight regulation during fast load steps; reduces need for large output capacitance |
| Sharp turn-on characteristic | Ensures clean, jitter-free activation in feedback loops - critical for stable PWM controller interfaces |
| SOT-23-3 footprint compatibility | Allows drop-in replacement of TL431/TL1431 in existing layouts with no PCB redesign |
Applications
| AC-DC Adapter Feedback | Programmable Linear Regulator |
|---|---|
Use Scenario: Secondary-side voltage sensing in isolated flyback converters using optocoupler feedback. IC Role / Device Role / Timing Role: Adjustable shunt regulator providing precise 2.5 V reference to drive optocoupler LED, closing regulation loop across isolation barrier. Use Value: 0.5% VREF tolerance ensures ±1% output voltage accuracy over temperature, meeting Class II efficiency and safety standards. | Use Scenario: Output voltage adjustment in low-noise LDOs via external resistor divider. IC Role / Device Role / Timing Role: Precision shunt reference replacing Zener diode in error amplifier feedback network. Use Value: 0.25 Ω dynamic impedance minimizes load-induced output drift, improving line/load regulation to <0.01%/V. |
| Battery Charger Voltage Control | Industrial Sensor Excitation |
Use Scenario: Constant-voltage termination in multi-cell Li-ion charger circuits with discrete pass transistor. IC Role / Device Role / Timing Role: Shunt regulator setting precise charge cutoff voltage (e.g., 4.2 V/cell) via R1/R2 divider. Use Value: –55°C to +125°C operation allows reliable performance in battery packs exposed to wide environmental swings. | Use Scenario: Stable excitation voltage source for bridge-based pressure or strain sensors in process instrumentation. IC Role / Device Role / Timing Role: Low-drift voltage reference driving Wheatstone bridge, feeding instrumentation amplifier inputs. Use Value: 17 mV max VREF temp deviation over full range ensures <0.05% FS sensor output error without software compensation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar adjustable shunt regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431ACDR | 2.5 V ±1% VREF, 0.35 Ω rZ, –40°C to +125°C range | Lower accuracy and wider temp range; less suitable for military/aerospace | Preferred where cost sensitivity outweighs precision and extended temperature needs |
| AS431ASTZTR-G1 | 2.5 V ±0.5% VREF, 0.22 Ω rZ, –40°C to +125°C range | Same accuracy but narrower temp range; not rated for –55°C operation | Valid alternative when design does not require full military temperature compliance |
Compared with TL431ACDR and AS431ASTZTR-G1, the SC431MSKQTRT provides guaranteed 0.5% reference accuracy across –55°C to +125°C and lower dynamic impedance - making it uniquely suited for high-reliability, wide-temperature applications where reference stability directly impacts system safety margins.
Availability
SC431MSKQTRT is available at Aetrix Electronics and suitable for AC-DC adapters, programmable linear regulators, battery chargers, and industrial sensor excitation systems requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for SC431MSKQTRT 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 semiconductor company specializing in analog and mixed-signal ICs for power management, protection, and signal integrity.
The SC431MSKQTRT belongs to Semtech's precision voltage reference product line, engineered for high-stability shunt regulation in mission-critical power systems where accuracy, thermal robustness, and reliability are non-negotiable.
FAQ
What is the reference voltage tolerance of SC431MSKQTRT over temperature?
The SC431MSKQTRT has a reference voltage tolerance of ±0.5% over the full operating ambient temperature range of –55°C to +125°C. This corresponds to a maximum deviation of ±12.5 mV from the nominal 2.495 V reference, verified per datasheet Electrical Characteristics table (Rev. 2.0, p.3). This level of stability eliminates need for post-assembly calibration in high-reliability applications.
Can SC431MSKQTRT replace TL431 in existing designs?
Yes, SC431MSKQTRT is a direct functional and pin-compatible replacement for TL431 in SOT-23-3 layouts. It matches the same cathode-anode-reference pinout, supports identical 2.5 V to 30 V output programming, and improves upon TL431 with tighter 0.5% VREF tolerance and lower 0.25 Ω dynamic impedance. No PCB changes are required for drop-in substitution.
What is the minimum cathode current needed for SC431MSKQTRT to regulate?
The SC431MSKQTRT requires a minimum cathode current of 130 μA to maintain regulation, as specified in the Absolute Maximum Ratings and Electrical Characteristics tables. This value is guaranteed over the full –55°C to +125°C temperature range. Operating below this current may result in loss of regulation or increased output voltage drift.
Does SC431MSKQTRT support operation above 125°C ambient?
No, SC431MSKQTRT is rated for operation up to +125°C ambient temperature (TA). Its junction temperature limit is +150°C, but sustained operation beyond +125°C ambient requires derating based on package thermal resistance (θJA = 336°C/W) and power dissipation - which is not characterized or guaranteed by Semtech. Designs requiring >+125°C ambient must use alternative components.
Is SC431MSKQTRT RoHS and WEEE compliant?
Yes, SC431MSKQTRT is fully RoHS and WEEE compliant, as explicitly stated in the datasheet Features section and Ordering Information notes. It contains no lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls (PBB), or polybrominated diphenyl ethers (PBDE), meeting EU Directive 2011/65/EU and 2012/19/EU requirements.
SC431MSKQTRT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Semtech Corporation
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Reference Type:
- Shunt
- Output Type:
- Adjustable
- Voltage - Output (Min/Fixed):
- 2.495V
- Voltage - Output (Max):
- 30 V
- Current - Output:
- 130 µA
- Tolerance:
- ±0.5%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 150 mA
- Operating Temperature:
- -55°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
SC431MSKQTRT FAQ
1.How can I place an order for SC431MSKQTRT through Aetrix?
Please submit a Request for Quotation (RFQ) for SC431MSKQTRT 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 SC431MSKQTRT reliable?
The price and inventory of SC431MSKQTRT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SC431MSKQTRT is usually 5 days.
3.What payment methods are accepted for SC431MSKQTRT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SC431MSKQTRT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SC431MSKQTRT?
SC431MSKQTRT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SC431MSKQTRT 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 SC431MSKQTRT?
For technical support, including SC431MSKQTRT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SC431MSKQTRT requirements.
6.How does Aetrix verify that SC431MSKQTRT is sourced from the original manufacturer or authorized distributors?
All SC431MSKQTRT 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 SC431MSKQTRT meets industry standards.
7.What is the process for return or replacement of SC431MSKQTRT?
All SC431MSKQTRT units undergo pre-shipment inspection (PSI). If there is an issue with SC431MSKQTRT, 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 SC431MSKQTRT part is unused and in its original packaging.
Return procedure for SC431MSKQTRT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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