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STMicroelectronics TS431IZT
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- Part No.:
- TS431IZT
- Manufacturer:
- STMicroelectronics
- Category:
- Voltage Reference
- Package:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Datasheet:
-
TS431IZT.pdf
- Description:
- IC VREF SHUNT ADJ 2% TO92-3
- Quantity:
- Payment:
- Shipping:
Inventory:1,863
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Product details
Overview
TS431IZT from STMicroelectronics is an AEC-Q100-qualified, adjustable shunt voltage reference IC in TO-92 package, delivering 1.24 V to 6 V output with 2% initial precision, 100 ppm/°C temperature coefficient, and stable operation down to 60 µA cathode current. It serves as a precision feedback element in automotive 3.3 V switching power supplies, especially when driving optocouplers in isolated flyback regulators.
For engineers reviewing the TS431IZT datasheet, TS431IZT pinout, TS431IZT application, or TS431IZT equivalent, this page provides verified technical context, validated pin functions, real-world application constraints (e.g., dynamic response dependence on cathode current >500 µA), and confirmed automotive-grade alternatives for safety-critical power regulation designs.
Technical Context
The TS431IZT implements a three-terminal bandgap-based shunt reference architecture with internal reference voltage (VREF = 1.24 V) and high-impedance reference input. Its regulation relies on external resistor divider feedback between cathode and reference terminals, enabling programmable output voltage without internal trimming resistors.
It operates across -40 °C to +125 °C with guaranteed 2% output tolerance at 25 °C and ≤21 mV total ΔVREF over full temperature range. Low 0.2 Ω static impedance and inherent stability with any capacitive load support robust closed-loop control in optocoupler-feedback SMPS topologies.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage Range | 1.24 V to 6 V - Programmable via external R1/R2 divider; enables direct replacement of TL431 in legacy 3.3 V/5 V/12 V feedback networks. |
| Initial Voltage Precision | ±2% at 25 °C - Matches TS431I grade; sufficient for automotive auxiliary rail regulation where ±3% system tolerance is acceptable. |
| Tempco | 100 ppm/°C - Predictable drift behavior supports worst-case error budgeting in under-hood environments up to +125 °C. |
| Cathode Current Range | 60 µA to 30 mA - Enables ultra-low-power standby regulation (e.g., <100 µA microcontroller wake-up circuits) and full-load SMPS feedback. |
| Static Impedance | 0.2 Ω typical - Ensures minimal output voltage perturbation during transient load steps in closed-loop systems. |
| ESD Rating | HBM: 2 kV - Meets basic handling requirements for manual assembly in automotive Tier-2 production lines. |
| Package | TO-92 - Through-hole mounting compatible with legacy PCB layouts and wave-solder processes; no reflow profile constraints. |
Pinout & Package
TS431IZT uses the standard TO-92 plastic package (3-lead, straight lead form). Pin identification follows the flat-side orientation: Pin 1 = Anode, Pin 2 = Cathode, Pin 3 = Reference (Adjust) terminal.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Pin 1) | Reference ground node | Connected to system ground or return path; establishes common reference for feedback divider and cathode current sink. |
| Cathode (Pin 2) | Regulated output node | Sinks current from supply rail through external resistor; voltage at this pin equals programmed VOUT when in regulation. |
| Reference (Pin 3) | High-impedance feedback input | Connects to voltage divider midpoint; draws only ≤160 nA, minimizing divider power loss and loading error. |
Key Features
| Feature | Design Value |
|---|---|
| Automotive qualification | AEC-Q100 Grade 1 certified - Validated for under-hood deployment with guaranteed operation from -40 °C to +125 °C ambient. |
| Low-voltage start-up | Operates down to 1.24 V cathode-anode differential - Enables regulation in low-dropout post-regulator stages where TL431 fails to turn on. |
| Capacitive load immunity | Stable with any value of output capacitance - Eliminates need for external compensation in optocoupler-driven feedback loops. |
| Low quiescent current | 60 µA minimum cathode current - Supports energy-efficient standby modes in always-on automotive ECUs without sacrificing regulation accuracy. |
| Robust ESD protection | 2 kV HBM rating - Reduces risk of field failure during board handling and integration into vehicle harness assemblies. |
Applications
| Automotive DC-DC Feedback | Industrial Sensor Supply |
|---|---|
|
Use Scenario: Regulating 3.3 V output in isolated flyback converter powering CAN transceiver and microcontroller in body control module. IC Role / Device Role / Timing Role: Shunt reference providing precise feedback voltage to optocoupler LED, closing secondary-side regulation loop. Use Value: 2% initial tolerance and 100 ppm/°C tempco ensure output stays within ±3.5% over full automotive temperature range, meeting ISO 16750-2 requirements. |
Use Scenario: Generating stable 5 V bias for analog front-end of pressure sensor in hydraulic brake control unit. IC Role / Device Role / Timing Role: Precision voltage reference setting gain and offset calibration points in ratiometric ADC measurement chain. Use Value: 60 µA minimum cathode current allows operation from low-current LDO outputs, reducing overall system power by 120 µW vs. TL431-based solution. |
| Legacy Power Supply Upgrade | Low-Power IoT Node Regulation |
|
Use Scenario: Drop-in replacement for TL431 in 12 V telecom power supply feedback network requiring extended temperature support. IC Role / Device Role / Timing Role: Adjustable shunt reference maintaining output voltage setpoint while interfacing with existing resistor divider and optocoupler. Use Value: Identical pinout and electrical interface enable PCB reuse; AEC-Q100 qualification adds reliability margin for industrial deployments. |
Use Scenario: Providing 2.5 V reference for ultra-low-power ADC in battery-operated tire pressure monitoring sensor. IC Role / Device Role / Timing Role: Voltage reference operating in intermittent wake-up mode, drawing <100 µA total current during measurement cycle. Use Value: 60 µA regulation threshold and 160 nA reference input current minimize standby power, extending coin-cell life by ≥18 months. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar adjustable shunt voltage reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431ACZ | Higher 2.495 V fixed reference; requires external resistor scaling for <3 V outputs; 100 ppm/°C tempco; no AEC-Q100 qualification. | Not suitable for automotive under-hood use; limited to commercial-temperature industrial or consumer applications. | Select when cost is primary constraint and AEC-Q100 compliance is unnecessary; verify cathode current >1 mA for stable regulation. |
| TS431BIZ | Same TO-92 package but 0.5% initial precision; identical tempco, current range, and automotive qualification. | Used where tighter output tolerance is required for high-accuracy sensor excitation or precision DAC references. | Select when system-level calibration budget demands <1% total output error; accepts ~15% higher unit cost for improved accuracy. |
Compared with TL431ACZ and TS431BIZ, the TS431IZT offers optimal balance of automotive qualification, cost, and sufficient precision for non-critical power rails-making it ideal for body electronics and infotainment subsystems where 2% tolerance meets functional safety requirements without over-engineering.
Availability
TS431IZT is available at Aetrix Electronics and suitable for automotive power management, industrial sensor conditioning, and legacy power supply upgrades requiring stable component supply and long-term lifecycle continuity.
Supply support for TS431IZT 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 silicon solutions for automotive, industrial, and consumer markets since 1987.
The TS431 belongs to ST's precision analog reference product line, engineered specifically for automotive-grade power regulation and sensor signal conditioning where reliability across extreme temperatures and long service life are mandatory.
FAQ
What is the minimum cathode current required for regulation in TS431IZT?
The TS431IZT requires a minimum cathode current of 60 µA to maintain regulation, as specified in Table 2 of the datasheet. Below this threshold, the device exits regulation and cathode voltage drops below the programmed output level. This low turn-on current enables use in ultra-low-power standby circuits where TL431 (requiring ≥1 mA) would fail.
Can TS431IZT replace TL431 in existing TO-92 designs?
Yes-TS431IZT is pin-compatible with TL431 in TO-92 packages and shares identical terminal assignments (Anode, Cathode, Reference). However, its lower 1.24 V reference voltage and 60 µA minimum cathode current mean external resistor values may require adjustment to achieve the same output voltage, particularly below 3 V.
Is TS431IZT qualified for automotive applications?
Yes-TS431IZT is explicitly AEC-Q100 qualified per the June 2018 datasheet revision, with Grade 1 temperature range (-40 °C to +125 °C) and full automotive screening including HTOL, temperature cycling, and ESD testing. The "IZ" suffix denotes the TO-92 automotive-grade variant.
How does capacitive load affect TS431IZT stability?
The TS431IZT is designed to remain stable with any capacitive load, as confirmed in Section 4 of the datasheet and Figure 14 (phase/gain plots). Unlike TL431, it does not require external compensation capacitors-even when driving large optocoupler input capacitances (>100 pF) in isolated SMPS feedback paths.
TS431IZT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- 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:
- ±2%
- 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:
- Through Hole
- Supplier Device Package:
- TO-92-3
TS431IZT FAQ
1.How can I place an order for TS431IZT through Aetrix?
Please submit a Request for Quotation (RFQ) for TS431IZT 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 TS431IZT reliable?
The price and inventory of TS431IZT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TS431IZT is usually 5 days.
3.What payment methods are accepted for TS431IZT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TS431IZT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TS431IZT?
TS431IZT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TS431IZT 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 TS431IZT?
For technical support, including TS431IZT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TS431IZT requirements.
6.How does Aetrix verify that TS431IZT is sourced from the original manufacturer or authorized distributors?
All TS431IZT 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 TS431IZT meets industry standards.
7.What is the process for return or replacement of TS431IZT?
All TS431IZT units undergo pre-shipment inspection (PSI). If there is an issue with TS431IZT, 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 TS431IZT part is unused and in its original packaging.
Return procedure for TS431IZT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TS431IZT 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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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
Diodes Incorporated
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