My Inquiry
My Account
Texas Instruments TL1431CDRG4
- Part No.:
- TL1431CDRG4
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
TL1431CDRG4.pdf
- Description:
- IC VREF SHUNT ADJ 0.4% 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,361
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
TL1431CDRG4 from Texas Instruments is a precision programmable shunt voltage reference IC with 0.4% initial voltage tolerance, 0.2Ω typical output impedance, and adjustable output voltage from 2.5V to 36V via two external resistors. It operates as a Zener diode replacement in secondary-side regulation of flyback SMPSs and provides stable reference for voltage monitoring and comparator circuits.
For engineers reviewing the TL1431CDRG4 datasheet, TL1431CDRG4 pinout, TL1431CDRG4 application, or TL1431CDRG4 equivalent, this page delivers verified electrical specs, SOIC-8 package mapping, thermal performance data, functional mode distinctions (open-loop comparator vs. closed-loop regulator), and validated alternative parts for commercial-temperature designs.
Technical Context
The TL1431CDRG4 integrates a 2.5V bandgap reference and high-gain transconductance amplifier driving an internal Darlington sink stage, enabling precise cathode voltage regulation via REF–CATHODE feedback. Its open-loop operation supports comparator use with integrated reference; closed-loop configuration enables adjustable shunt regulation with <500ns turnon.
It requires ≥1mA cathode current (IKA) for regulation and ≥5µA reference input current (II(ref)) to bias the internal NPN. Thermal stability is specified over 0°C to 70°C (commercial grade), with VI(ref) deviation ≤20mV and temperature coefficient ≤80ppm/°C across the range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage (VI(ref)) | 2.500V ±10mV at 25°C; sets regulated output threshold in feedback networks |
| Initial Tolerance | ±0.4% at 25°C; ensures ≤10mV absolute error before trimming or temperature drift |
| Output Impedance (|zKA|) | 0.2Ω typical (≤0.4Ω max); minimizes load-induced voltage shift under 1–100mA cathode current |
| Cathode Voltage Range | 2.5V to 36V; supports wide-range adjustable regulation without external series pass devices |
| Min Cathode Current (Imin) | 0.45–1.0mA; minimum sink current required to maintain regulation and amplifier linearity |
| Turnon Time | 500ns typical; enables fast transient response in clamping and protection circuits |
| Reference Input Current | 1.5–2.5µA at 25°C; low bias current reduces resistor-divider power loss and accuracy error |
Pinout & Package
TL1431CDRG4 is packaged in an 8-pin SOIC (D package), 3.90mm × 4.90mm body size, with ANODE pins internally bonded together for low-inductance ground return.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CATHODE (Pin 1) | I/O sink node | Primary current path: sinks 1–100mA to regulate voltage; connects to output node in shunt configurations |
| ANODE (Pins 2,3,6,7) | Ground reference | Internally shorted pins; must be connected to system ground or return path for stable reference bias |
| REF (Pin 8) | Feedback input | Senses voltage divider midpoint; forces CATHODE to 2.5V × (1 + R1/R2) when properly biased |
| NC (Pins 4,5) | No connection | Unbonded die pads; must remain unconnected per TI design guidelines to avoid parasitic coupling |
Key Features
| Feature | Design Value |
|---|---|
| Zener diode replacement capability | Enables adjustable 2.5–36V shunt regulation without discrete Zener selection or thermal drift compensation |
| Internal Darlington sink stage | Supports up to 100mA cathode current while maintaining low output impedance and sharp turnon |
| Stability without output capacitor | Internally compensated for unity-gain stability; eliminates need for cathode–anode bypass cap in most applications |
| Integrated reference + amplifier | Combines precision 2.5V reference and high-gain op-amp in one die-reduces BOM count vs. discrete solutions |
| Fast comparator mode | Operates as rail-to-rail comparator with built-in 2.5V threshold; eliminates external reference in level-detection circuits |
Applications
| Secondary-Side SMPS Regulation | Zener Diode Replacement |
|---|---|
|
Use Scenario: Isolated flyback converter where primary-side controller receives feedback via optocoupler from secondary-side voltage sense. IC Role / Device Role / Timing Role: TL1431CDRG4 acts as precision shunt regulator on secondary side, generating stable reference for optocoupler LED drive. Use Value: Enables ±1% output voltage regulation across line/load/temperature without magnetic feedback components or trimming. |
Use Scenario: Low-cost voltage clamp or reference in linear regulators, battery chargers, and overvoltage protectors. IC Role / Device Role / Timing Role: TL1431CDRG4 replaces discrete Zener diodes by providing programmable, temperature-stable breakdown voltage. Use Value: Eliminates Zener tolerance stacking and thermal coefficient mismatch; improves long-term stability by >5× vs. 5% Zeners. |
| Voltage Monitoring | Comparator with Integrated Reference |
|
Use Scenario: System-level supervision of 5V, 12V, or 24V rails in industrial PLCs or telecom power modules. IC Role / Device Role / Timing Role: TL1431CDRG4 compares monitored rail against scaled-down reference using external resistors. Use Value: Delivers accurate trip point (e.g., 11.4V ±0.05V) without external reference IC or precision resistor network. |
Use Scenario: Threshold detection for battery low-voltage warning, reset generation, or fault flag assertion. IC Role / Device Role / Timing Role: TL1431CDRG4 operates open-loop as comparator with internal 2.5V reference and rail-to-rail output swing. Use Value: Reduces component count by integrating reference and comparator; achieves <1µs propagation delay with no external biasing. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar programmable shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431ACDR | Same SOIC-8 package; 1% initial tolerance (vs. TL1431CDRG4's 0.4%); wider VI(ref) min/max (2.495V/2.505V) | Lower accuracy grade suitable for cost-sensitive non-critical references; identical pinout and bias requirements | Select TL431ACDR only if ±1% output tolerance is acceptable and thermal drift budget allows higher VI(dev) |
| TLVH431IDBVR | Low-voltage variant (1.24V reference); SOT-23-5 package; 0.5% initial tolerance; max cathode voltage 18V (vs. 36V) | Not drop-in compatible: different pinout, lower voltage rating, and reduced sink current (80mA vs. 100mA) | Choose TLVH431IDBVR only for sub-18V systems requiring smaller footprint and lower reference voltage-not for direct TL1431CDRG4 replacement |
Compared with TL431ACDR and TLVH431IDBVR, TL1431CDRG4 offers superior initial accuracy (0.4% vs. 1% or 0.5%) and higher cathode voltage capability (36V vs. 36V or 18V), making it optimal for precision secondary-side regulation and high-voltage monitoring where tight tolerance and extended range are critical.
Availability
TL1431CDRG4 is available at Aetrix Electronics and suitable for industrial power supplies, telecom DC-DC converters, and automotive body-control modules requiring stable component supply with commercial-temperature qualification (0°C to 70°C).
Supply support for TL1431CDRG4 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 designing analog ICs, embedded processors, and connectivity solutions for industrial, automotive, and communications markets.
The TL1431 family was engineered as a precision, programmable shunt reference targeting cost-effective, high-accuracy voltage regulation and monitoring in commercial-grade power management systems.
FAQ
What is the operating temperature range for TL1431CDRG4?
The TL1431CDRG4 is characterized for operation from 0°C to 70°C (commercial temperature range). Its electrical specifications-including reference voltage deviation (≤20mV), output impedance (0.2Ω typical), and cathode current capability (1–100mA)-are guaranteed within this range. Operation outside this range is not supported per TI's datasheet SLVS062O.
Can TL1431CDRG4 replace a Zener diode directly?
Yes, TL1431CDRG4 can directly replace Zener diodes in shunt regulation applications. Unlike passive Zeners, it provides programmable output (2.5V–36V) via two external resistors, 0.4% initial tolerance, and 0.2Ω dynamic impedance-delivering significantly better accuracy, thermal stability, and load regulation than discrete Zener solutions.
What is the minimum cathode current required for regulation in TL1431CDRG4?
The TL1431CDRG4 requires a minimum cathode current (Imin) of 0.45mA to 1.0mA (depending on temperature and conditions) to maintain regulation. Below this threshold, the internal amplifier exits linear region and regulation fails. This value is specified in Section 5.5 of the TI datasheet and must be ensured via external biasing or load current.
Does TL1431CDRG4 require an output capacitor for stability?
No, TL1431CDRG4 is internally compensated and stable without an output capacitor between CATHODE and ANODE. However, if downstream circuitry presents capacitive loading (e.g., optocoupler input), designers must consult Figure 5-12 (stability boundary chart) to select CL values that avoid oscillation-TI confirms stability up to 1nF with proper layout.
How does the REF pin function in TL1431CDRG4?
The REF pin on TL1431CDRG4 is the high-impedance input to the internal error amplifier. When connected to a resistive divider between CATHODE and ANODE, it forces the CATHODE voltage to 2.5V × (1 + R1/R2). It requires ≥5µA bias current (II(ref)) to operate-leaving it floating or connecting it to high-impedance nodes will disable regulation.
TL1431CDRG4 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):
- 2.5V
- Voltage - Output (Max):
- 36 V
- Current - Output:
- 100 mA
- Tolerance:
- ±0.4%
- 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
TL1431CDRG4 FAQ
1.How can I place an order for TL1431CDRG4 through Aetrix?
Please submit a Request for Quotation (RFQ) for TL1431CDRG4 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 TL1431CDRG4 reliable?
The price and inventory of TL1431CDRG4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL1431CDRG4 is usually 5 days.
3.What payment methods are accepted for TL1431CDRG4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL1431CDRG4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL1431CDRG4?
TL1431CDRG4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL1431CDRG4 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 TL1431CDRG4?
For technical support, including TL1431CDRG4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL1431CDRG4 requirements.
6.How does Aetrix verify that TL1431CDRG4 is sourced from the original manufacturer or authorized distributors?
All TL1431CDRG4 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 TL1431CDRG4 meets industry standards.
7.What is the process for return or replacement of TL1431CDRG4?
All TL1431CDRG4 units undergo pre-shipment inspection (PSI). If there is an issue with TL1431CDRG4, 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 TL1431CDRG4 part is unused and in its original packaging.
Return procedure for TL1431CDRG4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL1431CDRG4 Tags
-
TL431AIDBZR
Texas Instruments
-
TL431BQDBZR
Texas Instruments
-
AN431AN-ATRG1
Diodes Incorporated
-
LM4040CYM3-2.5-TR
Microchip Technology
-
LM4040CYM3-4.1-TR
Microchip Technology
-
LM4040EIM3-2.5/NOPB
Texas Instruments
-
AZ431LBNTR-G1
Diodes Incorporated
-
LM4040D20IDBZR
Texas Instruments
-
LM4041DIM3-ADJ/NOPB
Texas Instruments
-
LM4040DIM3X-2.5/NOPB
Texas Instruments
-
LM4040DIM3-2.5/NOPB
Texas Instruments
-
AZ431LANTR-G1
Diodes Incorporated
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
