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Diodes Incorporated ZTL431AQFTA
- Part No.:
- ZTL431AQFTA
- Manufacturer:
- Diodes Incorporated
- Category:
- Voltage Reference
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
ZTL431AQFTA.pdf
- Description:
- IC VREF SHUNT 2.5V SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:1,281
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Product details
Overview
ZTL431AQFTA from Diodes Incorporated is an automotive-grade adjustable precision shunt regulator in SOT23 package, featuring 1% initial reference voltage tolerance (2.5 V ±25 mV), -40°C to +125°C operating range, 0.2 Ω typical dynamic output impedance, and 1–100 mA sink current capability. It functions as a programmable voltage reference in feedback loops of isolated DC-DC converters and linear regulators.
For engineers reviewing the ZTL431AQFTA datasheet, ZTL431AQFTA pinout, ZTL431AQFTA application, or ZTL431AQFTA equivalent, this device supports AEC-Q100-compliant designs requiring stable 2.5 V reference with low temperature drift, high sink current headroom, and robust ESD immunity (2 kV HBM) in space-constrained automotive power systems.
Technical Context
The ZTL431AQFTA 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 pins. Its architecture delivers stable operation up to 20 V cathode-anode voltage with minimal load regulation error.
It operates across full automotive ambient range (-40°C to +125°C) with ≤34 mV reference deviation over that span and exhibits <2.7 mV/V cathode voltage sensitivity-critical for maintaining accuracy under varying input conditions in battery-supplied systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage (VREF) | 2.5 V ±25 mV at +25°C - sets minimum programmable output voltage in shunt regulator circuits |
| Cathode Voltage Range (VKA) | 2.5 V to 20 V - defines usable input voltage window for regulation without breakdown |
| Sink Current Range (IKA) | 1 mA to 100 mA - supports high-side feedback current drive for optocoupler-based isolation |
| Dynamic Output Impedance (RZ) | 0.2 Ω typical - ensures minimal output voltage shift under fast load transients |
| Temp. Range (TA) | -40°C to +125°C - validated for under-hood automotive environments per AEC-Q100 Grade 1 |
| ESD Rating (HBM) | 2 kV - meets automotive board-level ESD robustness requirements |
| Package | SOT23 - 3-pin surface-mount footprint compatible with standard reflow profiles and automated assembly |
Pinout & Package
SOT23-3 package with gull-wing leads, 0.915 mm nominal lead pitch, 2.40 mm × 1.30 mm body size, and matte tin-plated terminals compliant with J-STD-020 Level 1 moisture sensitivity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Pin 1) | Reference ground node | Common return path for reference input current and cathode sink current; must connect to system ground or lowest potential point in feedback network |
| Cathode (Pin 2) | Regulated output node | Source of regulated current into external load or optocoupler LED; voltage here is set by R1/R2 divider |
| Reference (Pin 3) | Feedback sense input | High-impedance input monitoring voltage divider output; triggers regulation when ≥2.5 V applied |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q100 qualified | Validated for automotive applications including engine control, body electronics, and ADAS power supplies |
| 0.5% B-grade option available | ZTL431BQFTA offers tighter 2.5 V ±12.5 mV tolerance for high-accuracy feedback paths |
| Stable with ≥4.7 nF anode-cathode capacitance | Enables reliable operation with common ceramic decoupling caps without oscillation risk |
| Green, RoHS 3 & halogen-free | Meets EU Directive 2015/863/EU with <900 ppm Br/Cl and <1000 ppm Sb compounds |
| IATF 16949 manufacturing | Produced in certified facilities with PPAP documentation support for OEM supply chains |
Applications
| Isolated DC-DC Feedback | Automotive Linear Regulator |
|---|---|
|
Use Scenario: Secondary-side voltage sensing in flyback converters powering infotainment ECUs. IC Role / Device Role / Timing Role: Adjustable shunt reference providing optocoupler LED drive current proportional to output voltage deviation. Use Value: Enables tight ±1% output regulation across -40°C to +125°C while maintaining stability with typical 4.7 nF compensation cap. |
Use Scenario: Precision voltage reference for LDOs supplying radar sensor analog front-ends. IC Role / Device Role / Timing Role: Programmable 2.5 V reference setting LDO feedback threshold with minimal thermal drift. Use Value: Delivers ≤34 mV VREF deviation over full temperature range, ensuring consistent LDO output despite under-hood thermal cycling. |
| Overvoltage Protection Circuit | Improved Zener Replacement |
|
Use Scenario: Monitoring 12 V battery rail for overvoltage events in telematics gateways. IC Role / Device Role / Timing Role: Shunt regulator triggering MOSFET gate driver when VKA exceeds 15.5 V (set via R1/R2). Use Value: Provides sharp turn-on at precisely defined threshold with 100 mA sink capacity to rapidly clamp fault currents. |
Use Scenario: Replacing 2.5 V zener diodes in instrument cluster backlight drivers. IC Role / Device Role / Timing Role: Low-impedance, temperature-stable reference replacing passive zener with poor regulation and wide tolerance. Use Value: Reduces reference drift from ±5% (zener) to ±1%, improving LED current consistency across temperature and lifetime. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar adjustable shunt regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431ACDBVR | Non-automotive grade; 0°C to +70°C rating; no AEC-Q100 qualification; 2% VREF tolerance | Limited to commercial/industrial power supplies without automotive environmental or reliability requirements | Select only for cost-sensitive non-automotive designs where extended temperature and qualification are unnecessary |
| ZTL432AQFTA | Same electrical specs but SOT23 pinout differs: Anode = Pin 1, Cathode = Pin 3, Ref = Pin 2 | Requires PCB layout revision due to swapped cathode/reference pins; not drop-in compatible | Choose only when redesigning for improved thermal performance or legacy board compatibility with TL432 footprint |
Compared with TL431ACDBVR, ZTL431AQFTA adds AEC-Q100 compliance, wider temperature range, and tighter tolerance-essential for automotive safety-critical rails. Versus ZTL432AQFTA, it retains standard TL431 pinout, avoiding layout changes while delivering identical regulation performance.
Availability
ZTL431AQFTA is available at Aetrix Electronics and suitable for automotive power management, isolated feedback networks, and precision voltage reference applications requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for ZTL431AQFTA 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
Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability components for automotive, industrial, and computing markets.
ZTL431AQFTA belongs to Diodes' automotive-qualified shunt regulator product line, designed specifically to replace legacy TL431/TL432 in AEC-Q100-compliant systems demanding enhanced temperature stability and process control.
FAQ
What is the maximum cathode-to-anode voltage the ZTL431AQFTA can withstand?
The ZTL431AQFTA has an absolute maximum cathode voltage (VKA) rating of 20 V relative to the anode. Operation beyond this voltage risks permanent damage. In normal regulation, VKA must remain ≥VREF (2.5 V) and ≤20 V, with recommended operating range spanning 2.5 V to 18 V for margin.
Can ZTL431AQFTA be used without external resistors?
No. The ZTL431AQFTA requires two external resistors (R1 and R2) forming a voltage divider between cathode and reference pins to set the output voltage. With only the reference pin connected and no divider, the device cannot regulate-it will remain off unless VREF ≥2.5 V is externally applied.
How does the ZTL431AQFTA differ from standard TL431 in automotive use?
ZTL431AQFTA is fully AEC-Q100 qualified, manufactured in IATF 16949 facilities, and specified from -40°C to +125°C with tighter initial tolerance (1%) and lower reference drift (≤34 mV). Standard TL431 lacks automotive qualification, has wider temp range limits, and typically offers only 2% tolerance.
What capacitor value is required between anode and cathode for stability?
A minimum 4.7 nF ceramic capacitor is recommended between anode and cathode to ensure stability across all operating conditions. This value suppresses instability observed in the 100 pF–10 nF range per the datasheet's stability boundary graph, preventing oscillation during transient load steps.
ZTL431AQFTA Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- 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):
- 2.5V
- Voltage - Output (Max):
- 20 V
- Current - Output:
- 100 mA
- Tolerance:
- ±1%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 600 µA
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
ZTL431AQFTA FAQ
1.How can I place an order for ZTL431AQFTA through Aetrix?
Please submit a Request for Quotation (RFQ) for ZTL431AQFTA 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 ZTL431AQFTA reliable?
The price and inventory of ZTL431AQFTA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ZTL431AQFTA is usually 5 days.
3.What payment methods are accepted for ZTL431AQFTA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ZTL431AQFTA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ZTL431AQFTA?
ZTL431AQFTA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ZTL431AQFTA 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 ZTL431AQFTA?
For technical support, including ZTL431AQFTA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ZTL431AQFTA requirements.
6.How does Aetrix verify that ZTL431AQFTA is sourced from the original manufacturer or authorized distributors?
All ZTL431AQFTA 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 ZTL431AQFTA meets industry standards.
7.What is the process for return or replacement of ZTL431AQFTA?
All ZTL431AQFTA units undergo pre-shipment inspection (PSI). If there is an issue with ZTL431AQFTA, 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 ZTL431AQFTA part is unused and in its original packaging.
Return procedure for ZTL431AQFTA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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