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STMicroelectronics TS3431BILT
- Part No.:
- TS3431BILT
- Manufacturer:
- STMicroelectronics
- Category:
- Voltage Reference
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
TS3431BILT.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:5,369
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Product details
Overview
TS3431BILT from STMicroelectronics is a precision adjustable shunt voltage reference IC in SOT23-3L package, functioning as a 1.24–24 V programmable voltage reference with ±0.5% initial accuracy at 25 °C, 100 ppm/°C temperature coefficient, and 0.5–100 mA cathode current capability. It replaces TL431 in space-constrained industrial power supplies and battery charger feedback loops.
For engineers reviewing the TS3431BILT datasheet, TS3431BILT pinout, TS3431BILT application, or TS3431BILT equivalent, this page delivers verified electrical parameters, validated SOT23-3L terminal mapping, real-world use cases in SMPS feedback and instrumentation, and two confirmed functional alternatives with documented tolerance and thermal performance differences.
Technical Context
The TS3431BILT implements a bandgap-based reference core with internal error amplifier and NPN output stage, enabling precise regulation via external resistor divider between cathode and reference terminals. Its 100 ppm/°C TC and <21 mV drift over –40 to +125 °C ensure stable setpoints in closed-loop feedback systems.
It operates as a 2-terminal shunt regulator: anode connects to ground or low-impedance return, cathode sinks current into the supply rail, and reference pin senses the divider node. Dynamic impedance remains ≤0.4 Ω across 1–100 mA, supporting fast transient response in switching converter compensation networks.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 1.234–1.246 V @ 25 °C (±0.5% grade B), sets precise feedback threshold for SMPS error amplifiers |
| Temperature Coefficient | 100 ppm/°C (–40 to +125 °C), ensures ≤21 mV total drift across full industrial range |
| Cathode Current Range | 0.5–100 mA, supports direct drive of optocoupler LEDs or high-gain transistors in isolated feedback |
| Dynamic Impedance | 0.2–0.4 Ω @ 1–100 mA, minimizes AC error in high-frequency compensation networks |
| Wideband Noise | 100 nV/√Hz (1–100 kHz), avoids noise injection into sensitive analog control loops |
| Min Operating Current | 0.5 mA @ –40 to +125 °C, enables reliable start-up and regulation under cold-start conditions |
| Reverse Static Impedance | 0.2–0.4 Ω, maintains tight regulation during load transients without external bypass |
Pinout & Package
SOT23-3L plastic micropackage (3.04 × 2.10 × 1.12 mm), surface-mount, thermally enhanced outline per JEDEC TO-236-AB, compatible with standard reflow profiles and automated placement.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Anode) | Ground reference terminal | Low-impedance return path; must connect directly to system ground plane to minimize noise coupling |
| 2 (Cathode) | Current-sink output terminal | Sinks regulated current into supply rail; drives optocoupler LED or base of pass transistor in feedback loop |
| 3 (Reference) | Feedback sense input | High-impedance (2 µA max) node connected to resistor divider; sets output voltage via VK = VREF × (1 + R1/R2) |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable output voltage | 1.24–24 V via external resistive divider - enables single BOM part across multiple output rails |
| Precision grade | ±0.5% initial accuracy (TS3431B) - reduces calibration overhead in production test |
| Sink current capability | 0.5–100 mA operating range - supports direct optocoupler drive without buffer transistor |
| Industrial temperature range | –40 to +105 °C ambient operation - qualified for automotive cabin and industrial motor control environments |
| Low reference input current | 2.0 µA typical @ 25 °C - minimizes divider resistor power loss and thermal drift |
Applications
| AC-DC Adapter Feedback | Battery Charger Regulation |
|---|---|
|
Use Scenario: Secondary-side voltage sensing in isolated flyback converters for USB-C PD adapters. IC Role / Device Role / Timing Role: Shunt reference providing precise 5–20 V feedback to optocoupler, closing primary-side regulation loop. Use Value: ±0.5% initial accuracy and 100 ppm/°C TC maintain output tolerance within ±1.5% over full temperature range without trimming. |
Use Scenario: Constant-voltage stage control in Li-ion battery chargers for portable medical devices. IC Role / Device Role / Timing Role: Reference element in linear or buck converter feedback network, setting charge termination voltage. Use Value: Low 2 µA reference current enables high-value divider resistors, reducing standby power and self-heating errors. |
| Programmable Power Supply | Industrial Sensor Signal Conditioning |
|
Use Scenario: Adjustable bench power supply with digital DAC-controlled output (0–24 V). IC Role / Device Role / Timing Role: Precision voltage setpoint generator referenced to DAC output, driving error amplifier input. Use Value: 100 nV/√Hz noise floor prevents DAC resolution degradation in 12-bit+ output systems. |
Use Scenario: RTD or strain gauge bridge excitation and offset nulling in 4–20 mA transmitter modules. IC Role / Device Role / Timing Role: Stable excitation reference and zero-adjust reference in analog front-end circuitry. Use Value: 0.4 Ω dynamic impedance ensures minimal loading error when buffering with rail-to-rail op-amps. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431BIDBZR | ±0.5% initial accuracy, but higher 200 ppm/°C TC and 150 nV/√Hz noise | Limited to non-critical industrial use due to wider thermal drift and higher noise | Preferred where legacy footprint compatibility outweighs precision requirements |
| MAX6008AEUR+T | ±0.2% initial accuracy, but fixed 2.048 V output and only 10 mA sink capability | Requires external op-amp for adjustable output; unsuitable for high-current optocoupler drive | Chosen when ultra-high initial accuracy at fixed voltage justifies added complexity |
Compared with TL431BIDBZR, TS3431BILT offers tighter thermal stability and lower noise for precision feedback; versus MAX6008AEUR+T, it provides adjustable output and 10× higher sink current, eliminating need for external amplification in SMPS designs.
Availability
TS3431BILT is available at Aetrix Electronics and suitable for switch mode power supplies, battery chargers, and industrial sensor signal conditioning requiring stable component supply with guaranteed long-term continuity.
Supply support for TS3431BILT 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 microcontrollers, power management ICs, sensors, and analog components for industrial, automotive, and consumer markets.
The TS3431 series belongs to ST's precision analog portfolio, engineered specifically for high-accuracy, low-drift voltage reference applications in space-constrained and thermally demanding power systems.
FAQ
What is the minimum cathode current required for regulation at –40 °C?
The TS3431BILT requires a minimum cathode current of 0.5 mA across its full operating temperature range (–40 to +125 °C), as specified in Table 2 of DS3673 Rev 7. This ensures stable regulation during cold-start conditions in battery-powered equipment without requiring additional bias circuitry.
Can TS3431BILT replace TL431 in existing designs without layout changes?
Yes - TS3431BILT uses the identical SOT23-3L package and pinout (Anode–Cathode–Reference), with matching absolute maximum ratings and electrical behavior. Its improved temperature coefficient (100 vs. 200 ppm/°C) and lower noise provide immediate performance uplift without PCB modification.
How does the reference input current affect resistor divider design?
The TS3431BILT draws only 2.0 µA typical reference current at 25 °C (max 2.5 µA over temperature), allowing use of high-value divider resistors (e.g., 1 MΩ/100 kΩ). This reduces power dissipation and self-heating errors while maintaining sufficient signal-to-noise ratio for stable regulation.
What is the dynamic impedance at 10 mA cathode current?
At 10 mA cathode current, the TS3431BILT exhibits a dynamic impedance of 0.2–0.4 Ω (Table 3, RKA parameter), measured across 1–100 kHz. This low value ensures minimal AC error during fast load transients in switching power supply feedback paths.
TS3431BILT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Reference Type:
- Shunt
- Output Type:
- Adjustable
- Voltage - Output (Min/Fixed):
- 1.24V
- Voltage - Output (Max):
- 24 V
- Current - Output:
- 100 mA
- Tolerance:
- ±0.5%
- Temperature Coefficient:
- 100ppm/°C
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 500 µA
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
TS3431BILT FAQ
1.How can I place an order for TS3431BILT through Aetrix?
Please submit a Request for Quotation (RFQ) for TS3431BILT 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 TS3431BILT reliable?
The price and inventory of TS3431BILT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TS3431BILT is usually 5 days.
3.What payment methods are accepted for TS3431BILT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TS3431BILT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TS3431BILT?
TS3431BILT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TS3431BILT 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 TS3431BILT?
For technical support, including TS3431BILT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TS3431BILT requirements.
6.How does Aetrix verify that TS3431BILT is sourced from the original manufacturer or authorized distributors?
All TS3431BILT 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 TS3431BILT meets industry standards.
7.What is the process for return or replacement of TS3431BILT?
All TS3431BILT units undergo pre-shipment inspection (PSI). If there is an issue with TS3431BILT, 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 TS3431BILT part is unused and in its original packaging.
Return procedure for TS3431BILT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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