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STMicroelectronics TS431BILT
- Part No.:
- TS431BILT
- Manufacturer:
- STMicroelectronics
- Category:
- Voltage Reference
- Package:
- SC-74A, SOT-753
- Datasheet:
-
TS431BILT.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:27,812
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Product details
Overview
TS431BILT from STMicroelectronics is an AEC-Q100-qualified, adjustable shunt voltage reference IC in SOT23-5 package, delivering 0.5% initial voltage accuracy (1.24 V nominal), 100 ppm/°C temperature coefficient, and stable operation from 1.24 V to 6 V with cathode current as low as 60 µA. It serves as a precision feedback element in automotive-grade 3.3 V switching power supplies regulating optocoupler-driven isolated flyback converters.
For engineers reviewing the TS431BILT datasheet, TS431BILT pinout, TS431BILT application, or TS431BILT equivalent, key selection criteria include its 0.5% output tolerance at 25 °C, -40 °C to +125 °C automotive operating range, 0.2 Ω static impedance, and compatibility with capacitive loads without external compensation.
Technical Context
The TS431BILT implements a three-terminal bandgap-based shunt reference architecture with internal reference voltage (VREF = 1.24 V) and high-gain error amplifier. Its output voltage is set externally via two resistors (R1, R2) between cathode, anode, and reference terminals, enabling programmable regulation from 1.24 V to 6 V.
It operates with ultra-low minimum cathode current (60 µA), supports continuous cathode current up to 30 mA, and maintains stability across full temperature range (-40 °C to +125 °C) and load conditions - including direct drive of optocoupler LEDs in secondary-side feedback loops.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Initial Accuracy | ±0.5% at 25 °C - ensures tight output voltage setting for feedback loop calibration in automotive SMPS. |
| Temperature Coefficient | 100 ppm/°C - limits total output drift to ±18 mV over -40 °C to +125 °C, critical for closed-loop stability. |
| Output Voltage Range | 1.24 V to 6 V - programmable via external resistor divider, supporting common rail voltages including 3.3 V and 5 V. |
| Cathode Current Range | 60 µA to 30 mA - enables operation in ultra-low-power standby modes and full-load regulation without external biasing. |
| Static Impedance | 0.2 Ω (typ.) - provides low AC impedance for high-frequency noise rejection in feedback paths. |
| ESD Protection | HBM: 2 kV, MM: 200 V - meets automotive board-level ESD robustness requirements per AEC-Q100. |
| Operating Temperature | -40 °C to +125 °C - qualified for under-hood and infotainment system environments. |
Pinout & Package
SOT23-5 plastic micropackage (ECOPACK® compliant), 5-pin surface-mount device with exposed thermal pad (not electrically connected). Pin 1 marked by dot; pin numbering follows standard SOT23-5 convention (counterclockwise from mark).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 (Cathode) | Output current sink terminal | Connects to switched node of optocoupler LED or feedback resistor divider; carries full regulated load current. |
| Pin 2 (Anode) | Reference ground return | Common return path for reference input and cathode current; must be low-impedance connection to system ground. |
| Pin 3 (Ref) | Adjust input / reference sense | High-impedance input sensing voltage divider midpoint; sets output voltage via R1/R2 ratio. |
| Pin 4 (NC) | No connect | Internally unconnected; must remain floating or tied to Anode (Pin 2) per datasheet recommendation. |
| Pin 5 (NC) | No connect | Internally unconnected; must remain floating or tied to Anode (Pin 2) per datasheet recommendation. |
Key Features
| Feature | Design Value |
|---|---|
| Automotive qualification | AEC-Q100 Grade 1 certified (–40 °C to +125 °C), enabling use in engine control, ADAS, and body electronics. |
| Low-voltage start-up | Operates down to 1.24 V cathode-anode voltage, allowing regulation in low-input or post-regulator applications. |
| Capacitive load stability | Stable with any value of output capacitance - eliminates need for series resistance or compensation networks. |
| Ultra-low quiescent current | Reference input current ≤160 nA (max) - minimizes divider current error and improves efficiency in battery-sensitive designs. |
| High noise immunity | Equivalent input noise <250 nV/√Hz at 1 kHz - preserves signal integrity in noisy automotive power domains. |
Applications
| Automotive DC-DC Feedback | Industrial Isolated PSU |
|---|---|
Use Scenario: Secondary-side voltage regulation in 12 V to 3.3 V isolated flyback converter for automotive infotainment head unit. IC Role / Device Role / Timing Role: Adjustable shunt reference providing precise feedback to optocoupler, closing voltage loop across isolation barrier. Use Value: 0.5% accuracy and 100 ppm/°C TC ensure ±2% output regulation over full automotive temperature range without trimming. | Use Scenario: Output voltage sensing in 48 V to 24 V industrial telecom power supply with reinforced isolation. IC Role / Device Role / Timing Role: Shunt reference driving high-CTR optocoupler to maintain tight output regulation under variable line/load conditions. Use Value: 60 µA minimum cathode current enables reliable startup and regulation even during light-load burst-mode operation. |
| Low-Power Sensor Node Supply | Programmable Reference Generator |
Use Scenario: Biasing precision analog front-end in battery-powered automotive tire pressure sensor (TPMS). IC Role / Device Role / Timing Role: Low-current shunt reference generating stable 2.5 V reference for ADC and sensor excitation. Use Value: 160 nA max reference input current reduces divider power loss, extending battery life beyond 10 years. | Use Scenario: Configurable voltage reference in modular test equipment requiring multiple output levels (1.8 V, 2.5 V, 3.3 V, 5 V). IC Role / Device Role / Timing Role: Programmable shunt reference with external resistor network enabling rapid reconfiguration of reference voltage. Use Value: 1.24 V to 6 V adjustment range and 0.2 Ω output impedance support fast settling and low-noise performance across all settings. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar adjustable shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431ACDBVR | 1% initial accuracy, higher 2.5 V minimum cathode-anode voltage, 0.3 Ω typical impedance | Not AEC-Q100 qualified; limited to commercial temperature range (0 °C to +70 °C) | Select for cost-sensitive non-automotive designs where 1% tolerance and lower temp range are acceptable. |
| MAX6008AEUR+T | 0.2% initial accuracy, fixed 2.5 V output, 10 µA max quiescent current, SOT23-3 package | Fixed-output only; no external programming; lacks cathode current drive capability for optocouplers | Select when fixed 2.5 V reference with ultra-low power is required, and external voltage division is not needed. |
Compared with TL431ACDBVR and MAX6008AEUR+T, the TS431BILT uniquely combines automotive qualification, 0.5% programmable accuracy, and sufficient cathode drive (up to 30 mA) for direct optocoupler interfacing - making it the only choice for AEC-Q100-compliant isolated feedback designs requiring adjustable output.
Availability
TS431BILT is available at Aetrix Electronics and suitable for automotive power management, industrial isolated power supplies, battery-powered sensor nodes, and programmable reference generator systems requiring stable component supply across extended temperature ranges and long product lifecycles.
Supply support for TS431BILT 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, analog components, and automotive-grade semiconductors.
The TS431 belongs to ST's precision analog voltage reference product line, engineered specifically for automotive and industrial feedback applications demanding high accuracy, low-power operation, and robust thermal performance.
FAQ
What is the minimum cathode current required for regulation in TS431BILT?
The TS431BILT requires a minimum cathode current of 60 µA to maintain regulation, verified across the full -40 °C to +125 °C temperature range. This ultra-low threshold enables reliable startup and stable operation in energy-constrained applications such as automotive sleep-mode power rails and battery-backed sensor circuits.
Can TS431BILT replace TL431 in existing designs?
Yes, TS431BILT is pin-compatible with TL431 in SOT23-5 footprint when using Pins 1–3 (Cathode, Anode, Ref); however, Pins 4 and 5 are NC and must be left floating or tied to Anode. Its lower 1.24 V minimum operating voltage and 60 µA minimum cathode current improve performance in low-voltage and low-power designs, but layout review is recommended for stability with large capacitive loads.
Is TS431BILT suitable for driving optocouplers directly?
Yes - TS431BILT is explicitly optimized for optocoupler drive in isolated feedback loops, supporting cathode currents up to 30 mA. Its low 0.2 Ω output impedance and guaranteed stability with any capacitive load eliminate the need for series damping resistors, simplifying design of automotive 3.3 V flyback converters.
What does the 'B' in TS431BILT signify?
The 'B' denotes 0.5% initial output voltage accuracy at 25 °C, as specified in Table 8 of the datasheet. The 'I' indicates SOT23-5 package, 'L' denotes tape-and-reel packaging, and 'T' confirms RoHS-compliant ECOPACK® construction - collectively forming the full automotive-grade order code TS431BILT.
TS431BILT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- SC-74A, SOT-753
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Reference Type:
- Shunt
- Output Type:
- Adjustable
- Voltage - Output (Min/Fixed):
- 1.24V
- Voltage - Output (Max):
- 6 V
- Current - Output:
- 30 mA
- Tolerance:
- ±0.5%
- Temperature Coefficient:
- 100ppm/°C
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 60 µA
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
TS431BILT FAQ
1.How can I place an order for TS431BILT through Aetrix?
Please submit a Request for Quotation (RFQ) for TS431BILT 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 TS431BILT reliable?
The price and inventory of TS431BILT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TS431BILT is usually 5 days.
3.What payment methods are accepted for TS431BILT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TS431BILT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TS431BILT?
TS431BILT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TS431BILT 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 TS431BILT?
For technical support, including TS431BILT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TS431BILT requirements.
6.How does Aetrix verify that TS431BILT is sourced from the original manufacturer or authorized distributors?
All TS431BILT 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 TS431BILT meets industry standards.
7.What is the process for return or replacement of TS431BILT?
All TS431BILT units undergo pre-shipment inspection (PSI). If there is an issue with TS431BILT, 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 TS431BILT part is unused and in its original packaging.
Return procedure for TS431BILT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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