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Diodes Incorporated ZR431C
- Part No.:
- ZR431C
- Manufacturer:
- Diodes Incorporated
- Category:
- Voltage Reference
- Package:
- TO-226-3, TO-92-3 (TO-226AA)
- Datasheet:
-
ZR431C.pdf
- Description:
- IC VREF SHUNT ADJ 2% TO92
- Quantity:
- Payment:
- Shipping:
Inventory:4,249
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Product details
Overview
ZR431 from Diodes Incorporated is an adjustable precision shunt regulator in SOT23 or SOT223 packages, functioning as a programmable 2.5 V reference with ±0.5% initial tolerance, 72 ppm/°C max temperature coefficient, and 50 µA–100 mA cathode current capability. It replaces discrete Zener diodes in voltage monitoring, overvoltage protection, and switch-mode power supply feedback loops.
For engineers reviewing the ZR431 datasheet, ZR431 pinout, ZR431 application, or ZR431 equivalent, this device supports precise output voltage programming (2.5–20 V) via external resistors, delivers low dynamic impedance (≤0.75 Ω), and maintains stable regulation across –40°C to +125°C - critical for industrial power management and automotive-grade auxiliary supplies.
Technical Context
The ZR431 operates as a three-terminal shunt regulator with internal bandgap reference and error amplifier. Its reference input (VREF) is temperature-compensated, enabling stable 2.5 V operation across –40°C to +125°C, with typical deviation ≤30 mV over full range.
It sinks cathode current (IZ) from 50 µA minimum to 100 mA maximum while maintaining regulation; dynamic output impedance is ≤0.75 Ω at DC, and open-loop gain exceeds 60 dB up to 10 kHz - supporting stable closed-loop feedback in SMPS and series regulator topologies.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VREF | 2.50 V ±0.5% (tight tolerance enables accurate voltage setting without calibration) |
| Tempco | ≤72 ppm/°C (ensures <±30 mV drift over –40°C to +125°C for reliable long-term stability) |
| IZ Range | 50 µA to 100 mA (supports low-power monitoring and high-current shunt regulation) |
| RZ | ≤0.75 Ω (low dynamic impedance minimizes output voltage variation under load transients) |
| VZ Max | 20 V (allows programmable output up to 20 V using R1/R2 divider network) |
| IZ(OFF) | ≤0.1 µA at VZ = 20 V (ultra-low leakage preserves system standby efficiency) |
Pinout & Package
Available in SOT23 (3-pin, 0.009 g) and SOT223 (4-pin, pin 4 floating or tied to pin 2; 0.112 g). SOT23 is moisture-sensitivity Level 1; SOT223 is Level 3 per J-STD-020.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (K) | Current sink node | Connects to regulated rail; carries full load current plus reference current |
| Anode (A) | Ground reference | Common return path; must be low-impedance to maintain regulation accuracy |
| Reference (R) | Feedback input | Senses divided output voltage; regulates when VR = 2.5 V |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable output voltage | 2.5 V to 20 V via two external resistors - eliminates need for multiple fixed Zeners |
| Low reference input current | 0.12–1.0 µA - reduces divider power loss and improves high-impedance sensing accuracy |
| Stability with capacitive loads | Stable with ≥10 pF to 1 µF - supports direct connection to SMPS compensation networks |
| Lead-free & green compliance | Fully RoHS 3 compliant, halogen- and antimony-free - meets automotive and industrial environmental mandates |
Applications
| Shunt Regulator | Overvoltage Protection |
|---|---|
|
Use Scenario: Providing stable 5.0 V bias for analog sensor front-ends in industrial PLC modules. IC Role / Device Role / Timing Role: Shunt regulator sinking excess current to clamp rail voltage at precisely set level. Use Value: Replaces 5.1 V Zener with ±5% tolerance; achieves ±0.5% output accuracy and <±30 mV thermal drift. |
Use Scenario: Detecting >13.5 V on 12 V automotive battery rail to disable charging circuit during overvoltage events. IC Role / Device Role / Timing Role: Precision voltage threshold detector with hysteresis enabled by resistor network. Use Value: Enables trip point accuracy of ±0.06 V (0.5% of 13.5 V), reducing false triggers vs. standard Zeners. |
| SMPS Feedback Reference | Series Regulator Controller |
|
Use Scenario: Setting output voltage in isolated flyback converter with optocoupler feedback loop. IC Role / Device Role / Timing Role: Primary-side voltage reference generating error signal for optocoupler LED drive. Use Value: Low 0.75 Ω dynamic impedance ensures minimal output ripple coupling into feedback path. |
Use Scenario: Controlling pass transistor base in linear post-regulator for FPGA core supply (1.2 V @ 5 A). IC Role / Device Role / Timing Role: Adjustable reference defining regulated output via emitter-follower configuration. Use Value: Programmable 1.2 V output with <±6 mV total error (initial + temp drift), improving core voltage margin. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar adjustable shunt regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431BIDBZR | 2.495 V reference, ±0.5% tolerance, 92 ppm/°C max tempco, SOT23-3 | Higher tempco increases drift by ~20 mV over –40°C to +125°C vs. ZR431 | Prefer ZR431 where tighter thermal stability is required in wide-temperature industrial environments |
| KIA431AP | 2.5 V reference, ±2% tolerance, 100 ppm/°C max tempco, TO-92 | Loose tolerance and through-hole package limit use in space-constrained, high-accuracy designs | Acceptable only for cost-sensitive, non-critical 5 V shunt applications with relaxed accuracy |
Compared with TL431BIDBZR and KIA431AP, the ZR431 offers the lowest combined error budget (±0.5% + ≤30 mV drift) and smallest footprint (SOT23), making it optimal for compact, thermally demanding power supervision circuits.
Availability
ZR431 is available at Aetrix Electronics and suitable for industrial power supplies, automotive body control modules, and telecom DC-DC converters requiring stable component supply with guaranteed long-term continuity.
Supply support for ZR431 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 ICs, specializing in power management, signal integrity, and protection solutions for industrial, computing, and automotive markets.
The ZR431 belongs to Diodes' precision reference regulator product line, engineered specifically for high-stability, low-drift shunt regulation in space-constrained and thermally aggressive applications.
FAQ
What is the minimum cathode current required for regulation?
The ZR431 requires a minimum cathode current (IZ(MIN)) of 35 µA to maintain regulation at VREF = 2.5 V. This value is specified at full temperature range and ensures stable operation even under light-load conditions in battery-powered systems.
Can ZR431 be used with capacitive loads in feedback loops?
Yes - the ZR431 remains stable with capacitive loads from 10 pF to 1 µF, as verified in its stability boundary characterization. This allows direct integration into SMPS compensation networks without added phase compensation components.
How does the reference input current vary with temperature?
IREF ranges from 0.12 µA to 1.0 µA at 25°C and deviates by only ±0.2 µA over –40°C to +125°C. This tight drift ensures consistent resistor-divider loading and predictable output voltage accuracy across operating temperatures.
Is ZR431 qualified for automotive applications?
The base ZR431 is not AEC-Q100 qualified; however, Diodes offers automotive-grade variants (e.g., ZR431xTA with PPAP support) manufactured in IATF 16949-certified facilities. Contact Diodes or Aetrix for qualified part numbers and qualification documentation.
ZR431C Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- 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):
- 2.5V
- Voltage - Output (Max):
- 20 V
- Current - Output:
- 100 mA
- Tolerance:
- ±2%
- Temperature Coefficient:
- 55ppm/°C
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 50 µA
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-92
ZR431C FAQ
1.How can I place an order for ZR431C through Aetrix?
Please submit a Request for Quotation (RFQ) for ZR431C 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 ZR431C reliable?
The price and inventory of ZR431C are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ZR431C is usually 5 days.
3.What payment methods are accepted for ZR431C?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ZR431C transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ZR431C?
ZR431C orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ZR431C 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 ZR431C?
For technical support, including ZR431C datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ZR431C requirements.
6.How does Aetrix verify that ZR431C is sourced from the original manufacturer or authorized distributors?
All ZR431C 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 ZR431C meets industry standards.
7.What is the process for return or replacement of ZR431C?
All ZR431C units undergo pre-shipment inspection (PSI). If there is an issue with ZR431C, 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 ZR431C part is unused and in its original packaging.
Return procedure for ZR431C:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
ZR431C Tags
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TL431BQDBZR
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AN431AN-ATRG1
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AZ431LANTR-G1
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