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STMicroelectronics TS431IZ
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- Part No.:
- TS431IZ
- Manufacturer:
- STMicroelectronics
- Category:
- Voltage Reference
- Package:
- TO-226-3, TO-92-3 (TO-226AA)
- Datasheet:
-
TS431IZ.pdf
- Description:
- IC VREF SHUNT ADJ 2% TO92-3
- Quantity:
- Payment:
- Shipping:
Inventory:1,676
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Product details
Overview
TS431IZ from STMicroelectronics is an AEC-Q100-qualified, adjustable three-terminal shunt voltage reference IC in TO92 plastic package, delivering 1.24–6 V output with 2% initial precision, 100 ppm/°C temperature coefficient, and stable operation down to 60 µA cathode current. It replaces TL431 in automotive 3.3 V flyback power supply feedback loops where low-voltage startup and optocoupler drive are critical.
For engineers reviewing the TS431IZ datasheet, TS431IZ pinout, TS431IZ application, or TS431IZ equivalent, this page delivers verified electrical specs, TO92 terminal mapping, automotive-grade thermal performance (−40 °C to +125 °C), and direct alternatives for shunt reference design-in across industrial and automotive power systems.
Technical Context
The TS431IZ operates as a precision two-input comparator with internal 1.24 V bandgap reference, comparing cathode-to-anode voltage against Vref via external resistor divider. Its reference input current (70–160 nA typ.) enables high-impedance feedback networks without loading error.
It achieves 0.2 Ω static impedance and remains stable with any capacitive load-critical for isolated DC-DC converters using optocouplers. The device's −40 °C to +125 °C operating range and AEC-Q100 qualification confirm its suitability for under-hood automotive power regulation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage Range | 1.24 V to 6 V - set externally via R1/R2; enables flexible feedback for 3.3 V, 5 V, or 12 V SMPS outputs |
| Initial Voltage Precision | ±2% - specified at 25 °C; supports cost-sensitive automotive auxiliary rail regulation without trimming |
| Tempco | 100 ppm/°C - ensures ≤18 mV drift over −40 °C to +125 °C; meets ASIL-B functional safety margin for voltage sensing |
| Cathode Current Range | 60 µA to 30 mA - allows operation in ultra-low-power standby modes and full-load regulation without external biasing |
| Static Impedance | 0.2 Ω typ. - provides tight regulation under dynamic load steps; reduces output ripple in closed-loop feedback |
| ESD Rating | HBM: 2 kV - sufficient for handling in automotive assembly lines without special ESD controls |
Pinout & Package
TS431IZ uses the standard TO92 plastic through-hole package (3-pin, straight lead configuration). Pin 1 = Anode, Pin 2 = Cathode, Pin 3 = Reference (Ref) - confirmed per Figure 1 and Table 6 in ST DocID5558 Rev 12.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Pin 1) | Reference ground node | Connected to system GND or isolated secondary ground; sets return path for reference current Iref |
| Cathode (Pin 2) | Regulated output node | Drives optocoupler LED or error amplifier; sinks current proportional to output overvoltage |
| Reference (Pin 3) | Feedback sense input | High-impedance (≤160 nA) input tied to resistor divider midpoint; determines regulated voltage threshold |
Key Features
| Feature | Design Value |
|---|---|
| Low-voltage operation | Starts regulation at 1.24 V - enables use in 3.3 V and lower-output flyback converters where TL431 fails to start |
| Wide cathode current range | 60 µA–30 mA - eliminates need for external bias resistors in both standby and full-load conditions |
| Capacitive load stability | Stable with any Cload - removes need for series damping resistors in optocoupler circuits, simplifying layout |
| AEC-Q100 qualification | Qualified for automotive grade - validated for reliability in engine control units, body electronics, and ADAS power rails |
Applications
| Automotive DC-DC Feedback | Industrial SMPS Regulation |
|---|---|
|
Use Scenario: Regulating 3.3 V output in isolated flyback converter for automotive infotainment MCU supply. IC Role / Device Role / Timing Role: Shunt reference providing precise feedback to optocoupler, closing voltage loop across isolation barrier. Use Value: Enables reliable startup at cold cranking (6.5 V battery) and maintains ±2% output accuracy over full automotive temperature range. |
Use Scenario: Voltage reference in 24 V to 5 V offline SMPS for PLC I/O modules. IC Role / Device Role / Timing Role: Adjustable shunt reference setting output voltage via resistor divider; replaces fixed references for BOM flexibility. Use Value: 60 µA minimum cathode current allows direct optocoupler drive without auxiliary bias winding, reducing transformer complexity. |
| Low-Power Sensor Biasing | Programmable Threshold Detection |
|
Use Scenario: Providing stable 2.5 V bias for analog sensor signal conditioning in battery-powered telematics units. IC Role / Device Role / Timing Role: Low-quiescent-current voltage reference sourcing precision bias for op-amp front-end stages. Use Value: 70 nA typical reference input current minimizes divider loading error, preserving ADC accuracy in low-power sleep modes. |
Use Scenario: Configurable overvoltage protection threshold in 12 V automotive accessory power module. IC Role / Device Role / Timing Role: Adjustable comparator reference enabling user-selectable trip points (e.g., 13.2 V or 14.4 V) via potentiometer. Use Value: 100 ppm/°C tempco ensures trip point drift stays within ±150 mV over −40 °C to +125 °C, meeting ISO 16750-2 requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431ACZ | Higher 2.495 V fixed reference; requires external resistor network to adjust below 2.5 V; 100 ppm/°C tempco; no AEC-Q100 qualification | Not qualified for automotive; limited to industrial/commercial ambient (0 °C to +70 °C) | Select when cost is primary and automotive qualification is unnecessary; avoid where cold-start regulation <2.5 V is required |
| MAX6008AEUR+T | Fixed 1.25 V output; SOT23-3 package; 0.1% initial accuracy; 30 ppm/°C tempco; 1 µA max quiescent current | Lacks adjustability; unsuitable for variable-output or optocoupler-driven feedback loops | Choose only for ultra-low-power, fixed-voltage biasing where precision > accuracy and size > flexibility |
Compared with TL431ACZ and MAX6008AEUR+T, TS431IZ uniquely combines automotive qualification, 1.24 V startup, external adjustability, and TO92 through-hole compatibility-making it the only drop-in solution for legacy automotive power designs requiring mechanical robustness and wide-cathode-current operation.
Availability
TS431IZ is available at Aetrix Electronics and suitable for automotive power supplies, industrial SMPS feedback circuits, and programmable voltage monitoring systems requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for TS431IZ 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 ICs, sensors, and analog components for automotive, industrial, and consumer markets.
The TS431IZ belongs to ST's precision analog voltage reference product line, engineered specifically for automotive-grade feedback regulation in isolated DC-DC converters and robust industrial power management systems.
FAQ
What is the maximum cathode current rating for TS431IZ?
The absolute maximum continuous cathode current is +40 mA per Table 1, but the recommended operating range is 60 µA to 30 mA. Exceeding 30 mA risks exceeding the TO92 package's 625 mW power dissipation limit at elevated temperatures, especially above 85 °C ambient.
Can TS431IZ replace TL431 in existing TO92-based designs?
Yes-TS431IZ shares identical TO92 pinout (Anode–Cathode–Ref), same footprint, and broader operating range (1.24 V vs. 2.495 V min). It improves cold-start capability and reduces external biasing needs, but requires verifying resistor divider values to maintain target output voltage.
Is TS431IZ qualified for ASIL-B automotive applications?
TS431IZ is AEC-Q100 qualified (Grade 1: −40 °C to +125 °C), which satisfies hardware-level requirements for ASIL-B systems. However, functional safety compliance depends on system-level implementation-including fault detection, redundancy, and diagnostic coverage-not solely on component qualification.
Does TS431IZ require an external capacitor for stability?
No-TS431IZ is designed to remain stable with any capacitive load, including direct connection to optocoupler LEDs or large bulk capacitors. This eliminates the need for series damping resistors or compensation networks required by many competing shunt references.
TS431IZ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA)
- Series:
- -
- Packaging:
- Bulk
- Product Status:
- Obsolete
- 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
TS431IZ FAQ
1.How can I place an order for TS431IZ through Aetrix?
Please submit a Request for Quotation (RFQ) for TS431IZ 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 TS431IZ reliable?
The price and inventory of TS431IZ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TS431IZ is usually 5 days.
3.What payment methods are accepted for TS431IZ?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TS431IZ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TS431IZ?
TS431IZ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TS431IZ 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 TS431IZ?
For technical support, including TS431IZ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TS431IZ requirements.
6.How does Aetrix verify that TS431IZ is sourced from the original manufacturer or authorized distributors?
All TS431IZ 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 TS431IZ meets industry standards.
7.What is the process for return or replacement of TS431IZ?
All TS431IZ units undergo pre-shipment inspection (PSI). If there is an issue with TS431IZ, 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 TS431IZ part is unused and in its original packaging.
Return procedure for TS431IZ:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TS431IZ Tags
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