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Diodes Incorporated ZR431LF01TC
- Part No.:
- ZR431LF01TC
- Manufacturer:
- Diodes Incorporated
- Category:
- Voltage Reference
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
ZR431LF01TC.pdf
- Description:
- IC VREF SHUNT ADJ 1% SOT23
- Quantity:
- Payment:
- Shipping:
Inventory:2,547
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Product details
Overview
ZR431LF01TC from Diodes Incorporated is a three-terminal adjustable precision shunt regulator with 1% initial tolerance, 50ppm/°C max temperature coefficient, and programmable output voltage from 1.24V to 10V via external resistors; it sinks 100μA–25mA cathode current and is widely used in the feedback loop of switch-mode power supplies for 3.3V/3V low-voltage regulation.
For engineers reviewing the ZR431LF01TC datasheet, ZR431LF01TC pinout, ZR431LF01TC application, or ZR431LF01TC equivalent, key selection criteria include reference voltage accuracy (1.24V ±1%), dynamic impedance (≤2Ω), thermal stability over –40°C to +85°C, and SOT23 surface-mount compatibility in space-constrained power control designs.
Technical Context
The ZR431LF01TC implements a bandgap-based, temperature-compensated reference core with internal error amplifier and NPN pass transistor, enabling stable shunt regulation across industrial temperature range. Its reference input current remains below 0.4µA at 25°C and deviates only ±0.2µA over full temperature range.
It operates as a two-node controlled current sink: cathode voltage sets output regulation point via resistor divider, while reference pin senses feedback voltage and adjusts cathode current to maintain VREF = 1.24V. Dynamic output impedance is 0.25–2Ω, and circuit-level impedance scales with R1/R2 ratio per R′ = RZ × (1 + R1/R2).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VREF | 1.24V ±1% - precise, temperature-stable reference voltage defining regulation threshold |
| Tempco | ≤50ppm/°C - ensures ≤±4mV drift over –40°C to +85°C for stable feedback loops |
| IZ Range | 100μA to 25mA - supports low-power monitoring and higher-current shunt regulation |
| RZ | 0.25Ω to 2Ω - low dynamic impedance enables fast transient response in SMPS feedback |
| VZ Max | 10V - sets absolute upper limit for programmable output voltage configuration |
| IREF | 0.02–0.4µA - ultra-low reference pin current minimizes divider resistor loading error |
Pinout & Package
SOT23-3 surface-mount package (3.0mm × 1.4mm × 1.1mm), RoHS-compliant, halogen- and antimony-free "Green" construction.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (Pin 1) | Current sink output node | Connected to SMPS transformer secondary or supply rail; sinks regulated current to maintain VREF at reference pin |
| Anode (Pin 2) | Ground return path | Low-impedance return for cathode current; must be routed with minimal trace inductance in high-frequency SMPS |
| Reference (Pin 3) | Feedback sense input | High-impedance node sensing resistor divider voltage; deviation >±10mV triggers regulation correction |
Key Features
| Feature | Design Value |
|---|---|
| 1% initial reference tolerance | Reduces output voltage error in 3.3V/5V SMPS without post-regulation trimming |
| ≤50ppm/°C tempco | Enables ±0.5% output stability over full industrial temperature range without compensation circuitry |
| 0.25Ω typical dynamic impedance | Supports <100ns load transient recovery in isolated flyback converters with tight regulation bands |
| 100μA minimum regulation current | Allows use with high-value feedback dividers (e.g., 1MΩ/249kΩ) to minimize standby power loss |
Applications
| Switch-Mode Power Supply Feedback | Voltage Monitor & Threshold Detection |
|---|---|
Use Scenario: Primary-side feedback in isolated DC-DC converters delivering 3.3V/5V outputs. IC Role / Device Role / Timing Role: Adjustable shunt regulator providing precision reference for optocoupler-coupled error amplification. Use Value: Enables ±1% output regulation over line/load/temperature with no external op-amp or trim components. | Use Scenario: Overvoltage lockout in battery management systems protecting Li-ion cells above 4.3V. IC Role / Device Role / Timing Role: Programmable voltage threshold detector using resistor divider and comparator input biasing. Use Value: Achieves 10mV threshold resolution with <1µA quiescent current in always-on monitoring circuits. |
| Series Regulator Reference | Three-Terminal LDO Output Control |
Use Scenario: Precision reference for discrete PNP/NPN series pass transistors in linear regulators. IC Role / Device Role / Timing Role: High-accuracy, low-drift voltage setpoint driving base/gate of pass element. Use Value: Delivers <0.1% output drift vs. temperature-superior to standard zener diodes in analog instrumentation supplies. | Use Scenario: Output voltage programming of fixed-output LDOs (e.g., LM1117) via feedback injection. IC Role / Device Role / Timing Role: Adjustable reference injecting controlled current into LDO feedback node to shift output voltage. Use Value: Enables software-selectable output voltages (e.g., 1.8V/2.5V/3.3V) using single LDO and digital GPIO-controlled resistors. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar adjustable shunt regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431CDBVR | 2% initial tolerance, 92ppm/°C max tempco, higher IREF (1µA typ) | Lower accuracy and thermal stability; suitable for cost-sensitive non-critical supplies | Select when ±2% output tolerance is acceptable and board space allows SO-8 footprint |
| KIA431AP | 2.5% tolerance, 100ppm/°C tempco, 100µA min IZ | Reduced regulation margin at light loads; limited to ambient-temp-only operation | Choose only for consumer-grade applications with narrow temperature range and relaxed accuracy |
Compared with TL431CDBVR and KIA431AP, ZR431LF01TC delivers tighter 1% tolerance and lower 50ppm/°C tempco-critical for industrial SMPS requiring ±0.5% output stability across –40°C to +85°C without calibration.
Availability
ZR431LF01TC is available at Aetrix Electronics and suitable for switch-mode power supplies, voltage monitoring circuits, series regulator references, and LDO output programming requiring stable component supply with guaranteed long-term availability.
Supply support for ZR431LF01TC 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 power management, signal integrity, and protection solutions for industrial, computing, and consumer markets.
The ZR431L product line delivers precision shunt regulation with enhanced thermal stability and low-quiescent-current operation-designed specifically for feedback control in compact, high-efficiency DC-DC converters and voltage supervision systems.
FAQ
What is the minimum cathode current required for regulation?
ZR431LF01TC requires ≥100µA cathode current to maintain regulation at VREF = 1.24V. Below this threshold, output voltage deviates nonlinearly; design must ensure divider network and load draw sufficient current even at light-load conditions.
Can ZR431LF01TC replace a standard zener diode directly?
Yes-it functions as a 3-pin active zener replacement with superior performance: 1% tolerance vs. 5–10% for zeners, 50ppm/°C tempco vs. 100–500ppm/°C, and programmable voltage via resistors instead of fixed breakdown voltage.
How does the reference pin current affect resistor divider design?
IREF is 0.02–0.4µA at 25°C and varies ±0.2µA over temperature. To limit divider error to <0.1%, total divider resistance should be ≤100kΩ; higher values require error compensation or buffer amplifiers.
Is ZR431LF01TC qualified for automotive applications?
No-ZR431LF01TC is rated for industrial temperature range (–40°C to +85°C) and is not AEC-Q200 qualified. For automotive use, Diodes Incorporated offers the AEC-Q200 qualified ZR431LA series with extended temperature screening and PPAP documentation.
ZR431LF01TC 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:
- Obsolete
- Reference Type:
- Shunt
- Output Type:
- Adjustable
- Voltage - Output (Min/Fixed):
- 1.24V
- Voltage - Output (Max):
- 10 V
- Current - Output:
- 25 mA
- Tolerance:
- ±1%
- Temperature Coefficient:
- 50ppm/°C
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 100 µA
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
ZR431LF01TC FAQ
1.How can I place an order for ZR431LF01TC through Aetrix?
Please submit a Request for Quotation (RFQ) for ZR431LF01TC 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 ZR431LF01TC reliable?
The price and inventory of ZR431LF01TC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ZR431LF01TC is usually 5 days.
3.What payment methods are accepted for ZR431LF01TC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ZR431LF01TC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ZR431LF01TC?
ZR431LF01TC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ZR431LF01TC 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 ZR431LF01TC?
For technical support, including ZR431LF01TC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ZR431LF01TC requirements.
6.How does Aetrix verify that ZR431LF01TC is sourced from the original manufacturer or authorized distributors?
All ZR431LF01TC 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 ZR431LF01TC meets industry standards.
7.What is the process for return or replacement of ZR431LF01TC?
All ZR431LF01TC units undergo pre-shipment inspection (PSI). If there is an issue with ZR431LF01TC, 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 ZR431LF01TC part is unused and in its original packaging.
Return procedure for ZR431LF01TC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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