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STMicroelectronics TL431AIZ-AP
- Part No.:
- TL431AIZ-AP
- Manufacturer:
- STMicroelectronics
- Category:
- Voltage Reference
- Package:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Datasheet:
-
TL431AIZ-AP.pdf
- Description:
- IC VREF SHUNT ADJ 1% TO92-3
- Quantity:
- Payment:
- Shipping:
Inventory:5,937
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Product details
Overview
TL431AIZ-AP from STMicroelectronics is an AEC-Q100 qualified adjustable shunt voltage reference in TO-92 package, delivering 2.5–36 V output via two external resistors, ±1% initial voltage accuracy, 0.22 Ω typical dynamic impedance, and operation across –40 °C to +125 °C for automotive power supply feedback loops.
For engineers reviewing the TL431AIZ-AP datasheet, TL431AIZ-AP pinout, TL431AIZ-AP application, or TL431AIZ-AP equivalent, key selection criteria include automotive temperature range compliance, sink current capability (1–100 mA), low dynamic impedance, and TO-92 mechanical compatibility with legacy board layouts.
Technical Context
The TL431AIZ-AP implements a precision bandgap reference with internal error amplifier and NPN transistor output stage, configured as a 3-terminal shunt regulator. Its reference input (REF) compares against an internal 2.495 V nominal threshold, controlling cathode-to-anode conduction to maintain set output voltage.
It operates in closed-loop feedback configurations where cathode connects to supply rail and anode to ground or return path, enabling precise voltage regulation without series pass elements. Temperature stability is achieved via curvature-compensated bandgap design, validated over –40 °C to +125 °C with ≤30 mV total ΔVref deviation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495 V nominal (±1% tolerance); sets minimum programmable output at 2.5 V with external resistor divider. |
| Output Voltage Range | 2.5 V to 36 V; determined by R1/R2 ratio per VOUT = VREF(1 + R1/R2), enabling flexible feedback point selection. |
| Sink Current Range | 1 mA to 100 mA; supports direct regulation of medium-power supplies without external boost transistors. |
| Dynamic Impedance | 0.22 Ω typical; ensures <10 mV output variation under 10 mA load step, critical for stable feedback in switching converters. |
| Temperature Range | –40 °C to +125 °C; qualified per AEC-Q100 Grade 1, suitable for under-hood automotive ECUs and industrial controllers. |
| Voltage Deviation | ≤30 mV over full temperature range; guarantees ≤0.85% output drift in battery management or motor control reference circuits. |
| Reference Input Current | ≤4 µA typical; minimizes resistor-divider power loss and enables high-impedance programming (e.g., 1 MΩ top resistor). |
Pinout & Package
TL431AIZ-AP uses TO-92 plastic package (bulk packing), with 3 leads arranged in straight-line configuration. Pin 1 = Anode, Pin 2 = Cathode, Pin 3 = Reference (REF). Mechanical dimensions: max height 4.7 mm, lead pitch 12.7 mm, body diameter 4.0 mm.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Pin 1) | Current return path | Connected to system ground or low-side return; carries full cathode current minus reference input current. |
| Cathode (Pin 2) | Regulated output node | Connects to positive supply rail; sinks current to maintain programmed voltage at REF node. |
| Reference (Pin 3) | Precision voltage sense input | High-impedance input tied to resistor divider midpoint; triggers regulation when voltage exceeds 2.495 V. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q100 qualification | Grade 1 stress testing completed (–40 °C to +125 °C), enabling use in automotive powertrain and ADAS modules. |
| Adjustable output via 2-resistor network | Eliminates need for multiple fixed-voltage references; one BOM item covers 2.5–36 V range with <0.5% setting resolution. |
| Low dynamic impedance (0.22 Ω) | Enables stable loop compensation in flyback and forward converters without additional output capacitance. |
| Wide sink current range (1–100 mA) | Supports direct driving of optocoupler LEDs in isolated SMPS feedback paths up to 20 mA without buffer stages. |
| Minimal reference input current (≤4 µA) | Permits high-value resistor dividers (>1 MΩ), reducing quiescent power in always-on battery monitoring circuits. |
Applications
| Automotive Power Supply | Industrial SMPS Feedback |
|---|---|
|
Use Scenario: Regulating 12 V battery-derived rails in engine control units (ECUs) with wide ambient temperature swings. IC Role / Device Role / Timing Role: Shunt reference in optocoupler-coupled secondary-side feedback loop of isolated DC/DC converter. Use Value: Maintains ±1.2% output accuracy over –40 °C to +125 °C, eliminating need for external temperature compensation circuitry. |
Use Scenario: Setting precise 5 V or 3.3 V outputs in factory automation PLC power modules. IC Role / Device Role / Timing Role: Adjustable voltage reference for TL431-based error amplifier in non-isolated buck converter feedback network. Use Value: Enables single-footprint design across multiple output voltages using only resistor changes-reducing inventory and layout variants. |
| Programmable Overvoltage Protection | Battery Management Reference |
|
Use Scenario: Detecting overvoltage conditions (>15 V) on 12 V vehicle systems to trigger shutdown logic. IC Role / Device Role / Timing Role: Precision comparator input reference for discrete MOSFET-based crowbar circuit. Use Value: Delivers 30 mV max voltage drift over temperature, ensuring consistent trip point without calibration across production lots. |
Use Scenario: Providing stable reference for ADC measurement of Li-ion cell voltage in automotive BMS modules. IC Role / Device Role / Timing Role: Low-drift, low-power reference source for SAR ADC biasing in always-on monitoring circuitry. Use Value: 4 µA max IREF enables >10-year battery life in backup-supplied monitoring nodes with 10 kΩ divider. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar adjustable shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431CZ-AP | Commercial grade (0 °C to +70 °C), ±2% initial accuracy, same TO-92 package and pinout. | Not qualified for automotive or extended-temperature industrial use; limited to consumer-grade power supplies. | Select when cost sensitivity outweighs temperature range and AEC-Q100 requirements. |
| TL432AIZ-AP | Identical specs but includes integrated thermal shutdown; otherwise pin-compatible and functionally equivalent. | Preferred in high-reliability automotive applications where overtemperature latch-up protection is mandated. | Choose when system-level safety standards require automatic fault shutdown above 150 °C junction temperature. |
Compared with TL431CZ-AP, TL431AIZ-AP adds AEC-Q100 qualification and tighter accuracy for automotive use; compared with TL432AIZ-AP, it lacks thermal shutdown but offers lower cost and identical regulation performance in non-fail-safe designs.
Availability
TL431AIZ-AP is available at Aetrix Electronics and suitable for automotive power supply design, industrial SMPS feedback networks, programmable overvoltage protection circuits, and battery management reference applications requiring stable component supply across extended temperature ranges.
Supply support for TL431AIZ-AP 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 analog, microcontroller, power, and sensor solutions for automotive, industrial, and consumer markets.
The TL431 product line delivers precision programmable shunt references optimized for feedback stability, temperature resilience, and footprint efficiency in power conversion and voltage monitoring systems.
FAQ
What is the maximum cathode-to-anode voltage rating for TL431AIZ-AP?
The absolute maximum cathode-to-anode voltage (VKA) is 37 V. Operation beyond this risks permanent damage. For reliable 36 V output designs, derating to ≤34 V is recommended to ensure margin against transients and ripple peaks in automotive environments.
Can TL431AIZ-AP replace TL431ACZ-AP in existing designs?
Yes - TL431AIZ-AP and TL431ACZ-AP share identical TO-92 packaging, pinout, electrical specifications, and ±1% accuracy. The "I" suffix denotes the automotive temperature grade (–40 °C to +125 °C), while "AC" indicates commercial-grade accuracy labeling; both meet the same performance envelope.
Does TL431AIZ-AP require an external capacitor for stability?
No external capacitor is required for basic regulation, but a 1 nF ceramic capacitor from REF to ANODE is recommended for high-frequency noise immunity. For capacitive loads >100 nF on the cathode, a 1–10 Ω series resistor between cathode and load improves phase margin per Figure 21 in the datasheet.
How does the reference input current affect resistor divider design?
With IREF ≤ 4 µA typical, a 10 kΩ–100 kΩ divider yields negligible error (<0.04%). For ultra-low-power applications, 1 MΩ dividers increase error to ~0.4%, but remain acceptable for 1% overall system accuracy when combined with ±1% VREF tolerance.
TL431AIZ-AP Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Series:
- -
- Packaging:
- Cut Tape (CT)
- Product Status:
- Active
- Reference Type:
- Shunt
- Output Type:
- Adjustable
- Voltage - Output (Min/Fixed):
- 2.495V
- Voltage - Output (Max):
- 36 V
- Current - Output:
- 100 mA
- Tolerance:
- ±1%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 700 µA
- Operating Temperature:
- -40°C ~ 105°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-92-3
TL431AIZ-AP FAQ
1.How can I place an order for TL431AIZ-AP through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431AIZ-AP 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 TL431AIZ-AP reliable?
The price and inventory of TL431AIZ-AP are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431AIZ-AP is usually 5 days.
3.What payment methods are accepted for TL431AIZ-AP?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431AIZ-AP transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431AIZ-AP?
TL431AIZ-AP orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431AIZ-AP 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 TL431AIZ-AP?
For technical support, including TL431AIZ-AP datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431AIZ-AP requirements.
6.How does Aetrix verify that TL431AIZ-AP is sourced from the original manufacturer or authorized distributors?
All TL431AIZ-AP 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 TL431AIZ-AP meets industry standards.
7.What is the process for return or replacement of TL431AIZ-AP?
All TL431AIZ-AP units undergo pre-shipment inspection (PSI). If there is an issue with TL431AIZ-AP, 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 TL431AIZ-AP part is unused and in its original packaging.
Return procedure for TL431AIZ-AP:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431AIZ-AP Tags
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AZ431LANTR-G1
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