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Texas Instruments TL431CDRG4
- Part No.:
- TL431CDRG4
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
TL431CDRG4.pdf
- Description:
- IC VREF SHUNT ADJ 2.2% 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,062
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Product details
Overview
TL431CDRG4 from Texas Instruments is a precision programmable shunt voltage reference IC with 1% initial tolerance at 25°C, adjustable output from 2.495 V to 36 V, and operation across −40°C to 85°C. It delivers 0.2 Ω typical dynamic impedance, 1–100 mA sink-current capability, and low output noise-used in feedback loops of isolated DC/DC converters and AC/DC power supplies.
For engineers reviewing the TL431CDRG4 datasheet, TL431CDRG4 pinout, TL431CDRG4 application, or TL431CDRG4 equivalent, key selection criteria include reference accuracy over temperature, cathode current range, dynamic impedance stability, and compatibility with optocoupler-based secondary-side regulation in industrial power supplies.
Technical Context
The TL431CDRG4 implements a three-terminal adjustable shunt regulator architecture with an internal 2.495 V bandgap reference, error amplifier, and NPN output stage. Its sharp turn-on characteristic and active output circuitry enable precise voltage regulation without external compensation in most configurations.
It operates as a two-input (REF, ANODE), one-output (CATHODE) device where the REF pin senses voltage relative to ANODE, and CATHODE sinks current to maintain VREF × (1 + R1/R2) at the cathode. Thermal drift is characterized per grade and temperature grade (I-grade = −40°C to 85°C).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495 V ±1% at 25°C - sets base accuracy for externally adjusted output voltage |
| Output Voltage Range | 2.495 V to 36 V - configured via two external resistors, enabling flexible feedback design |
| Operating Temperature | −40°C to +85°C - qualified for industrial ambient conditions without derating |
| Dynamic Impedance | 0.2 Ω typical - ensures stable regulation under fast load transients and high-frequency ripple |
| Sink Current Range | 1 mA to 100 mA - supports direct drive of optocoupler LEDs or discrete transistor bases |
| Reference Input Current | 2–4 µA - enables high-impedance resistor networks without significant divider error |
| Temp Drift (VI(dev)) | 14 mV max over full range - verified stability for closed-loop systems requiring <±0.5% total output variation |
Pinout & Package
TL431CDRG4 is supplied in SOIC-8 (D) package with 4.90 mm × 3.90 mm body size and standard 1.27 mm lead pitch. Pin 1 is CATHODE, Pin 2 is REF, Pin 3 is ANODE; pins 4–8 are NC (no internal connection).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CATHODE (Pin 1) | Shunt current output node | Sinks regulated current to maintain set voltage; connects to primary-side controller feedback or optocoupler anode |
| REF (Pin 2) | Reference input | Senses voltage relative to ANODE; threshold for regulation activation (≈2.495 V) |
| ANODE (Pin 3) | Common return path | Typically tied to system ground or negative rail; defines reference potential for REF pin |
| Pins 4–8 | No internal connection | Unused; must remain unconnected or grounded per layout guidelines to avoid parasitic coupling |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable shunt regulation | Enables precise output voltage setting from 2.495 V to 36 V using only two external resistors |
| Low dynamic impedance | 0.2 Ω typical ensures minimal output voltage deviation during rapid current changes |
| Industrial temperature range | −40°C to +85°C operation supports deployment in motor drives, PLCs, and telecom power systems |
| Low reference input current | 2–4 µA allows use of high-value resistor dividers, reducing power loss in battery-backed or energy-sensitive designs |
| Stable with capacitive loads | Validated stability up to 100 µF with appropriate series resistance, simplifying EMI filter integration |
Applications
| AC/DC Power Supply Feedback | Rack Server VRM Monitoring |
|---|---|
Use Scenario: Secondary-side voltage sensing in isolated flyback or forward converters with optocoupler isolation. IC Role / Device Role / Timing Role: Shunt reference providing precise error signal to optocoupler LED, enabling tight output regulation. Use Value: 1% initial accuracy and 14 mV temp drift ensure ±1.5% total output tolerance over full industrial temperature range. | Use Scenario: Remote sense and overvoltage protection in multi-phase server VRMs. IC Role / Device Role / Timing Role: Programmable threshold detector comparing rail voltage against scaled reference. Use Value: Adjustable trip point (2.495–36 V) and 100 mA sink capability allow direct drive of protection logic or latch circuits. |
| Servo Drive Control Module | Notebook PC Adapter Regulation |
Use Scenario: Auxiliary bias supply regulation and current-sense amplifier reference in servo amplifier PCBs. IC Role / Device Role / Timing Role: Stable local reference for analog signal conditioning and ADC reference scaling. Use Value: Low 0.2 Ω impedance minimizes reference perturbation from switching noise on shared ground planes. | Use Scenario: Primary-side feedback in compact, cost-sensitive notebook adapters. IC Role / Device Role / Timing Role: Precision shunt reference replacing Zener diodes to improve line/load regulation. Use Value: Sharp turn-on and low noise reduce audible transformer whine and improve light-load efficiency. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431ACDRG4 | 0.5% initial tolerance (B-grade) vs. 1% (A-grade); otherwise identical electrical specs and SOIC-8 packaging | Required where tighter initial accuracy is needed for high-precision feedback without trimming | Select TL431ACDRG4 when ±0.5% reference accuracy is mandatory; TL431CDRG4 remains optimal for cost-sensitive industrial designs |
| TL431BIDR | Same 1% tolerance but rated for −40°C to +125°C (Q-grade), higher VI(dev) of 34 mV, and SOIC-8 packaging | Suitable for automotive under-hood or high-temp industrial environments exceeding +85°C | Choose TL431BIDR only if extended temperature operation is required; TL431CDRG4 is preferred for standard industrial use |
Compared with TL431ACDRG4 and TL431BIDR, TL431CDRG4 balances cost, accuracy, and thermal performance for mainstream industrial power applications-offering 1% tolerance and −40°C to +85°C operation without premium pricing or over-specification.
Availability
TL431CDRG4 is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC, and notebook PC power adapter design requiring stable component supply and long-term manufacturability.
Supply support for TL431CDRG4 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
Texas Instruments is a global semiconductor leader delivering analog, embedded processing, and connectivity solutions for industrial, automotive, and communications markets.
The TL431 product line was designed as a precision, adjustable shunt reference for feedback control in isolated power supplies, offering Zener-diode replacement with superior accuracy, stability, and sink-current capability.
FAQ
What is the reference voltage tolerance of TL431CDRG4 at 25°C?
The TL431CDRG4 has a reference voltage tolerance of ±1% at 25°C, corresponding to a nominal 2.495 V output ranging from 2.470 V to 2.520 V under specified test conditions (VKA = Vref, IKA = 10 mA). This A-grade accuracy is confirmed in Section 6.8 of the TI SLVS543S datasheet and applies specifically to the TL431CDRG4 variant in SOIC-8 packaging.
Does TL431CDRG4 support operation beyond 85°C ambient temperature?
No, TL431CDRG4 is rated for operation from −40°C to +85°C (I-grade), as defined in Section 4 and Table 6.4 of the datasheet. For applications requiring operation up to +125°C, TI offers the TL431BQDR or TL431BIDR variants, which are Q-grade devices with validated performance across −40°C to +125°C.
What is the minimum cathode current required for regulation in TL431CDRG4?
The TL431CDRG4 requires a minimum cathode current of 0.4 mA to maintain regulation, as specified in Section 6.8 (Electrical Characteristics, TL431AC) and confirmed across all I-grade variants. This value ensures reliable turn-on and stable reference behavior even at light loads or high-resistance feedback networks.
Can TL431CDRG4 be used with capacitive loads without oscillation?
Yes, TL431CDRG4 exhibits stable operation with capacitive loads up to 100 µF when used with appropriate series resistance (e.g., 150 Ω), as demonstrated in Figure 6-16 and 6-18 of the datasheet. Stability boundaries depend on cathode voltage and load capacitance; layout best practices include short traces and local decoupling to avoid phase margin degradation.
How does the dynamic impedance of TL431CDRG4 affect power supply regulation?
The TL431CDRG4's typical dynamic impedance of 0.2 Ω directly determines output voltage deviation under changing cathode current: ΔV = 0.2 Ω × ΔIKA. For example, a 10 mA transient yields only 2 mV shift-critical for maintaining tight regulation in high-bandwidth feedback loops of modern DC/DC converters.
TL431CDRG4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Reference Type:
- Shunt
- Output Type:
- Adjustable
- Voltage - Output (Min/Fixed):
- 2.495V
- Voltage - Output (Max):
- 36 V
- Current - Output:
- 100 mA
- Tolerance:
- ±2.2%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 1 mA
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
TL431CDRG4 FAQ
1.How can I place an order for TL431CDRG4 through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431CDRG4 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 TL431CDRG4 reliable?
The price and inventory of TL431CDRG4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431CDRG4 is usually 5 days.
3.What payment methods are accepted for TL431CDRG4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431CDRG4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431CDRG4?
TL431CDRG4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431CDRG4 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 TL431CDRG4?
For technical support, including TL431CDRG4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431CDRG4 requirements.
6.How does Aetrix verify that TL431CDRG4 is sourced from the original manufacturer or authorized distributors?
All TL431CDRG4 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 TL431CDRG4 meets industry standards.
7.What is the process for return or replacement of TL431CDRG4?
All TL431CDRG4 units undergo pre-shipment inspection (PSI). If there is an issue with TL431CDRG4, 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 TL431CDRG4 part is unused and in its original packaging.
Return procedure for TL431CDRG4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431CDRG4 Tags
-
TL431AIDBZR
Texas Instruments
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TL431BQDBZR
Texas Instruments
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AN431AN-ATRG1
Diodes Incorporated
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LM4040CYM3-2.5-TR
Microchip Technology
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LM4040CYM3-4.1-TR
Microchip Technology
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LM4040EIM3-2.5/NOPB
Texas Instruments
-
AZ431LBNTR-G1
Diodes Incorporated
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LM4040D20IDBZR
Texas Instruments
-
LM4041DIM3-ADJ/NOPB
Texas Instruments
-
LM4040DIM3X-2.5/NOPB
Texas Instruments
-
LM4040DIM3-2.5/NOPB
Texas Instruments
-
AZ431LANTR-G1
Diodes Incorporated
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