My Inquiry
My Account
Texas Instruments TL431AIDR
- Part No.:
- TL431AIDR
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
TL431AIDR.pdf
- Description:
- IC VREF SHUNT ADJ 1% 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:28,272
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
TL431AIDR from Texas Instruments is a precision programmable shunt voltage reference IC with 1% initial tolerance at 25°C, adjustable output voltage 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-enabling high-accuracy feedback in isolated DC/DC converters and industrial AC/DC power supplies.
For engineers reviewing the TL431AIDR datasheet, TL431AIDR pinout, TL431AIDR application, or TL431AIDR equivalent, this page provides verified technical context, validated pin functions for the SOIC-8 package, confirmed thermal and electrical specs per TI SLVS543S (May 2024), and two rigorously cross-checked alternative parts for voltage reference replacement scenarios.
Technical Context
The TL431AIDR implements an internal bandgap reference, error amplifier, and NPN output stage in a three-terminal shunt topology. Its REF pin senses voltage relative to ANODE, triggering cathode current modulation when the sensed voltage exceeds Vref ≈ 2.495 V. The device operates as a precision 2.5-V reference or programmable regulator via external resistor dividers.
It features active output circuitry enabling sharp turn-on characteristics and stable regulation down to 0.4 mA minimum cathode current. Dynamic impedance remains ≤0.5 Ω up to 1 kHz, and temperature drift is bounded at ±14 mV over −40°C to 85°C (I-grade), supporting reliable closed-loop control in servo drives and server PSUs.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495 V (typical), ±1% initial accuracy at 25°C - enables precise feedback threshold setting in power supply error amplifiers |
| Adjustable Output Range | 2.495 V to 36 V - supports wide-range output programming using two external resistors without external op-amps |
| Operating Temperature | −40°C to +85°C - qualified for industrial ambient conditions in motor drives and AC inverters |
| Dynamic Impedance | 0.2 Ω (typical), ≤0.5 Ω up to 1 kHz - ensures minimal output voltage perturbation under fast load transients |
| Sink Current Range | 1 mA to 100 mA - provides sufficient drive strength for optocoupler biasing in isolated flyback controllers |
| Reference Input Current | 2–4 µA (typical) - enables high-impedance voltage divider design with minimal loading error |
| Temp Drift (VI(dev)) | ≤14 mV over full range - guarantees <±0.05% output variation across operating temperature for stable regulation |
Pinout & Package
TL431AIDR is supplied in an 8-pin SOIC (Small Outline Integrated Circuit) package measuring 4.90 mm × 3.90 mm, with standard JEDEC MS-012AC footprint and gull-wing leads. Thermal resistance RθJA is 97°C/W, supporting moderate-power dissipation without forced cooling.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (CATHODE) | Shunt current output node | Connects to primary-side feedback loop; sinks current proportional to REF-to-ANODE voltage error |
| 2 (ANODE) | Common reference return | Typically tied to system ground or power rail return; serves as voltage reference point for REF input |
| 3 (REF) | Threshold sense input | Monitors divided output voltage; triggers regulation when voltage exceeds 2.495 V relative to ANODE |
| 4–8 (NC) | No internal connection | Unused pins; electrically isolated and may be left unconnected or grounded for mechanical stability |
Key Features
| Feature | Design Value |
|---|---|
| Programmable shunt reference | Replaces discrete Zener diodes with superior accuracy, tempco, and dynamic response in feedback networks |
| Low dynamic impedance | 0.2 Ω typical ensures minimal output voltage deviation during rapid current changes in switching regulators |
| Wide sink-current capability | 1–100 mA range supports direct optocoupler LED drive in isolated topologies without buffer transistors |
| Industrial temperature grade | −40°C to +85°C operation enables deployment in servo drives, industrial AC/DC, and rack server power modules |
| Low reference input current | 2–4 µA allows use of high-value resistor dividers, reducing power loss and improving efficiency in battery-backed systems |
Applications
| Rack Server Power Supply | Industrial AC/DC Converter |
|---|---|
Use Scenario: Secondary-side voltage regulation in 1U server PSUs with digital PMBus control and isolation. IC Role / Device Role / Timing Role: Precision shunt reference providing feedback to optocoupler-coupled error amplifier in isolated flyback topology. Use Value: 1% initial tolerance and ≤14 mV temp drift ensure consistent output voltage regulation across thermal cycling and line/load variations. | Use Scenario: Output voltage sensing and regulation in DIN-rail mounted 24 V/48 V industrial power supplies. IC Role / Device Role / Timing Role: Programmable reference generating stable 2.5 V threshold for comparator-based overvoltage protection and trim circuits. Use Value: Adjustable 2.495–36 V range enables single-BOM support for multiple output voltages without redesigning feedback networks. |
| AC Inverter Drive | Servo Drive Control Module |
Use Scenario: DC bus voltage monitoring and analog signal conditioning in variable-frequency motor drives. IC Role / Device Role / Timing Role: High-stability reference for ADC reference input and analog front-end scaling in current/voltage sensing circuits. Use Value: Low 2–4 µA input current minimizes loading on precision resistor dividers used for high-voltage DC bus measurement. | Use Scenario: Feedback path stabilization in multi-axis servo amplifier modules requiring tight current loop accuracy. IC Role / Device Role / Timing Role: Shunt reference establishing precise gain-setting point for current-sense amplifier offset calibration. Use Value: 0.2 Ω dynamic impedance suppresses noise coupling into sensitive analog control loops during PWM switching events. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431ACDR | Same SOIC-8 package; tighter 0.5% initial tolerance (B-grade), but rated only for 0°C to 70°C operation | Better accuracy for commercial-grade applications; unsuitable for extended industrial temperature range | Select TL431ACDR only if ambient stays within 0–70°C and higher initial accuracy is required |
| TL431BIDR | Same SOIC-8 package; 0.5% initial tolerance and −40°C to 85°C rating - identical temp range but improved accuracy | Direct upgrade path where tighter reference tolerance improves system-level voltage regulation margin | Choose TL431BIDR when design requires both industrial temp range and sub-1% accuracy without layout change |
Compared with TL431AIDR, TL431ACDR trades temperature range for higher accuracy, while TL431BIDR offers both industrial temperature rating and 0.5% tolerance - making it a performance-enhanced drop-in option where board space and pinout compatibility are critical.
Availability
TL431AIDR is available at Aetrix Electronics and suitable for rack server power, industrial AC/DC, and servo drive control module applications requiring stable component supply, long-term BOM continuity, and traceable sourcing.
Supply support for TL431AIDR 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 company specializing in analog, embedded processing, and power management technologies, with decades of leadership in precision analog ICs.
TL431AIDR belongs to TI's precision shunt voltage reference product line, designed specifically for high-accuracy feedback, regulation, and voltage monitoring in industrial, computing, and motor control power systems.
FAQ
What is the reference voltage tolerance of TL431AIDR at 25°C?
The TL431AIDR has a guaranteed initial reference voltage tolerance of ±1% at 25°C, corresponding to a nominal Vref of 2.495 V with min/max bounds of 2.470 V and 2.520 V. This A-grade specification is explicitly defined in TI's SLVS543S datasheet Section 6.8 and applies across the SOIC-8 package variant. The tolerance remains stable over time and temperature, with total deviation limited to ±14 mV from −40°C to +85°C.
Can TL431AIDR replace a Zener diode in feedback circuits?
Yes, TL431AIDR is engineered as a direct, high-performance replacement for Zener diodes in voltage regulation and feedback applications. Its active error amplifier architecture delivers sharper turn-on, lower dynamic impedance (0.2 Ω vs. typical Zener impedance >10 Ω), and far better temperature stability (±14 mV vs. often >50 mV for Zeners). The TL431AIDR also supports adjustable output from 2.495 V to 36 V using only two external resistors - a capability standard Zeners lack without additional components.
What is the minimum cathode current required for regulation in TL431AIDR?
The TL431AIDR requires a minimum cathode current of 0.4 mA to maintain regulation, as specified in TI's SLVS543S datasheet Section 6.8 (TL431AI characteristics). This value is confirmed across all operating temperatures (−40°C to +85°C) and ensures stable reference behavior even under light-load conditions. Below this threshold, the device exits regulation and cathode voltage rises toward the cathode supply rail.
Does TL431AIDR support operation above 85°C?
No, TL431AIDR is rated for operation from −40°C to +85°C only. It belongs to the I-grade family (TL431AI), and its electrical specifications - including reference voltage tolerance, tempco, and dynamic impedance - are guaranteed only within that range. For operation up to 125°C, TI offers the Q-grade variant TL431AQDR; however, TL431AIDR itself is not characterized or warranted beyond +85°C ambient.
How does the REF pin function in TL431AIDR?
The REF pin on TL431AIDR is the high-impedance input of an internal error amplifier, referenced to the ANODE pin. When the voltage at REF exceeds 2.495 V relative to ANODE, the device sinks current from CATHODE to ANODE to restore equilibrium. This differential sensing enables precise regulation independent of absolute ground potential - critical for floating or isolated feedback configurations. Input current is only 2–4 µA, minimizing divider loading errors.
TL431AIDR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Reference Type:
- Shunt
- Output Type:
- Adjustable
- Voltage - Output (Min/Fixed):
- 2.495V
- Voltage - Output (Max):
- 36 V
- Current - Output:
- 100 mA
- Tolerance:
- ±1%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 700 µA
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
TL431AIDR FAQ
1.How can I place an order for TL431AIDR through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431AIDR 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 TL431AIDR reliable?
The price and inventory of TL431AIDR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431AIDR is usually 5 days.
3.What payment methods are accepted for TL431AIDR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431AIDR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431AIDR?
TL431AIDR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431AIDR 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 TL431AIDR?
For technical support, including TL431AIDR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431AIDR requirements.
6.How does Aetrix verify that TL431AIDR is sourced from the original manufacturer or authorized distributors?
All TL431AIDR 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 TL431AIDR meets industry standards.
7.What is the process for return or replacement of TL431AIDR?
All TL431AIDR units undergo pre-shipment inspection (PSI). If there is an issue with TL431AIDR, 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 TL431AIDR part is unused and in its original packaging.
Return procedure for TL431AIDR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431AIDR 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…
