My Inquiry
My Account
Texas Instruments TL1431QDR
- Part No.:
- TL1431QDR
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
TL1431QDR.pdf
- Description:
- IC VREF SHUNT ADJ 0.4% 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,575
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
TL1431QDR from Texas Instruments is a precision programmable shunt voltage reference IC with 0.4% initial voltage tolerance, 0.2Ω typical output impedance, and fast 500ns turn-on time. It operates as an adjustable error amplifier or Zener replacement in secondary-side regulation of automotive-grade flyback SMPSs, delivering stable 2.5V–36V output via two external resistors.
For engineers reviewing the TL1431QDR datasheet, TL1431QDR pinout, TL1431QDR application, or TL1431QDR equivalent, this page provides verified thermal stability (–40°C to 125°C), cathode current range (1–100mA), reference input voltage (2.49–2.51V at 25°C), output impedance (0.2Ω typ), and SOIC-8 package mapping - all confirmed for the TL1431QDR variant.
Technical Context
The TL1431QDR integrates a precision 2.5V bandgap reference and high-gain transconductance amplifier in a single SOIC-8 package. Its internal Darlington output stage enables 100mA sink capability while maintaining 0.2Ω dynamic impedance below 1kHz. The device functions in open-loop comparator mode or closed-loop shunt regulation, with feedback applied between CATHODE and REF pins.
Thermal characterization is specified across –40°C to 125°C, with VI(ref) deviation ≤55mV and II(ref) deviation ≤2µA over full temperature range. Stability is guaranteed without external capacitance, though Figure 5-12 defines safe CL vs IKA operating boundaries for capacitive loads up to 100µF.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.49–2.51 V at 25°C; sets precise regulation point for feedback networks |
| Initial Tolerance | ±0.4% at 25°C; enables <±10mV absolute error in 2.5V reference designs |
| Output Impedance | 0.2 Ω typical (≤0.4Ω max); ensures <40mV load regulation error at 200mA step change |
| Cathode Current Range | 1–100 mA; supports robust shunt regulation across wide load conditions |
| Operating Temperature | –40°C to +125°C; qualified for under-hood automotive power supply monitoring |
| Turn-on Time | 500 ns; enables fast transient response in overvoltage clamp and protection circuits |
| Reference Input Current | 1.5–2.5 µA at 25°C; permits high-impedance resistor dividers (e.g., 1MΩ/100kΩ) |
Pinout & Package
TL1431QDR is housed in an 8-pin SOIC (D) package measuring 3.90mm × 4.90mm, with ANODE pins internally bonded and thermally optimized for PCB heat dissipation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CATHODE (Pin 1) | Shunt current output / voltage sensing node | Sinks regulated current to maintain programmed VKA; connects to SMPS output or feedback divider midpoint |
| ANODE (Pins 2,3,6,7) | Common return / ground reference | All four pins tied internally; must be connected to system ground or low-impedance return path |
| REF (Pin 8) | Reference input / error amplifier inverting input | Compares external voltage against internal 2.5V reference; requires ≥5µA bias current for proper operation |
| NC (Pins 4,5) | No internal connection | Not bonded; must remain unconnected per TI design guidelines |
Key Features
| Feature | Design Value |
|---|---|
| Automotive temperature grade | Qualified from –40°C to +125°C per AEC-Q100; supports engine control and ADAS power rails |
| Low-output-impedance regulation | 0.2Ω typical impedance enables <10mV line/load regulation error in 5V/12V SMPS feedback loops |
| Fast turn-on response | 500ns propagation delay allows use in overvoltage protection circuits with <1µs reaction time |
| Zener diode replacement | Adjustable 2.5–36V output replaces discrete Zener+resistor networks, reducing BOM count and layout area |
| Internal compensation | Stable without external capacitor; eliminates risk of oscillation in space-constrained automotive modules |
Applications
| Secondary-Side Flyback Regulation | Voltage Monitoring & Clamp |
|---|---|
|
Use Scenario: Isolated DC-DC converter in automotive infotainment power supply, where primary-side regulation lacks precision. IC Role / Device Role / Timing Role: Shunt regulator error amplifier referenced to secondary-side output, feeding optocoupler feedback to primary controller. Use Value: Enables ±1% output voltage accuracy over temperature and line, replacing less-stable TL431 variants with tighter automotive qualification. |
Use Scenario: Overvoltage protection circuit on 24V battery rail in vehicle body control module. IC Role / Device Role / Timing Role: Precision voltage clamp triggered at 28.5V, sinking excess current to prevent downstream IC damage. Use Value: 500ns turn-on ensures clamping within first switching cycle of transient events; 0.4% tolerance avoids nuisance tripping. |
| Adjustable Current Reference | Comparator with Integrated Reference |
|
Use Scenario: Programmable LED driver current setting in adaptive headlight system. IC Role / Device Role / Timing Role: Two-resistor-configured shunt reference generating precise 100mV sense voltage for current-sense amplifier. Use Value: 0.2Ω output impedance minimizes current-sense error drift across 10:1 dimming range; automotive temp range ensures reliability. |
Use Scenario: Battery cell voltage monitoring in 12S Li-ion pack for EV battery management system. IC Role / Device Role / Timing Role: Open-loop comparator comparing cell voltage against internal 2.5V reference, triggering fault signal at 4.25V. Use Value: Eliminates need for external reference IC; 2.5V threshold accuracy ±10mV ensures cell-level overvoltage detection within safety limits. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431BIDR | Commercial-grade (0°C to 70°C); 0.5% initial tolerance; same SOIC-8 pinout | Lacks automotive qualification; unsuitable for under-hood use or AEC-Q100-compliant designs | Select only for cost-sensitive non-automotive applications where extended temperature is not required |
| TL1431CDBVR | Commercial-grade (0°C to 70°C); identical electrical specs but lower thermal rating | Cannot operate in engine bay or powertrain environments requiring –40°C startup or 125°C ambient | Use when full automotive qualification is unnecessary and board-level thermal management is controlled |
Compared with TL1431QDR, TL431BIDR and TL1431CDBVR offer identical functionality and pinout but lack the –40°C to 125°C qualification, making TL1431QDR the sole choice for automotive power supply feedback, battery monitoring, and other safety-critical thermal environments.
Availability
TL1431QDR is available at Aetrix Electronics and suitable for automotive power supplies, battery management systems, and industrial SMPS designs requiring stable component supply with guaranteed long-term availability and traceable sourcing.
Supply support for TL1431QDR 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 specializing in analog and embedded processing technologies, with decades of expertise in precision reference and power management ICs.
The TL1431 product line delivers automotive-qualified, programmable shunt references designed specifically for secondary-side regulation, voltage monitoring, and comparator applications in harsh-temperature environments.
FAQ
What is the maximum cathode voltage rating for TL1431QDR?
The absolute maximum cathode voltage (VKA) for TL1431QDR is 37 V, with recommended operating range up to 36 V relative to ANODE. Exceeding 37 V risks permanent damage. This rating is validated across the full –40°C to 125°C temperature range and applies specifically to the TL1431QDR variant per TI SLVS062O datasheet Section 5.1.
Does TL1431QDR require an external capacitor for stability?
No, TL1431QDR is internally compensated and remains stable without any external capacitor between CATHODE and ANODE. However, if a capacitive load is present downstream (e.g., from connected ICs), designers must consult Figure 5-12 in the TL1431QDR datasheet to ensure CL and IKA values fall within the stable region - particularly critical in automotive applications where load capacitance may vary.
What is the minimum cathode current needed for regulation in TL1431QDR?
The minimum cathode current (Imin) required for regulation in TL1431QDR is 0.45 mA at 25°C, with a maximum of 1 mA across –40°C to 125°C. Below this threshold, the device exits regulation and cannot maintain the programmed output voltage. This value is measured with VKA = VI(ref) and is specified in Section 5.6 of the TL1431QDR datasheet.
How does the reference input current (II(ref)) of TL1431QDR affect resistor divider design?
TL1431QDR exhibits 1.5–2.5 µA reference input current at 25°C, rising to ≤4 µA over –40°C to 125°C. This current flows into the REF pin and must be supplied by the upper resistor (R1) in the feedback divider. To limit error, R1 should be sized so that II(ref) contributes <0.1% of total divider current - e.g., using R1 = 100 kΩ and R2 = 10 kΩ yields ~100 µA divider current, keeping II(ref) impact below 4%.
Is TL1431QDR pin-compatible with standard TL431 variants?
Yes, TL1431QDR uses the same SOIC-8 (D) package and identical pin configuration (CATHODE–ANODE–REF layout) as TL431BIDR and TL1431CDBVR. However, TL1431QDR adds automotive qualification (–40°C to 125°C), tighter initial tolerance (0.4% vs 0.5%), and enhanced ESD ratings (±2000 V HBM), making it a direct drop-in replacement where extended temperature and reliability are required.
TL1431QDR 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):
- 2.5V
- 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:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
TL1431QDR FAQ
1.How can I place an order for TL1431QDR through Aetrix?
Please submit a Request for Quotation (RFQ) for TL1431QDR 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 TL1431QDR reliable?
The price and inventory of TL1431QDR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL1431QDR is usually 5 days.
3.What payment methods are accepted for TL1431QDR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL1431QDR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL1431QDR?
TL1431QDR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL1431QDR 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 TL1431QDR?
For technical support, including TL1431QDR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL1431QDR requirements.
6.How does Aetrix verify that TL1431QDR is sourced from the original manufacturer or authorized distributors?
All TL1431QDR 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 TL1431QDR meets industry standards.
7.What is the process for return or replacement of TL1431QDR?
All TL1431QDR units undergo pre-shipment inspection (PSI). If there is an issue with TL1431QDR, 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 TL1431QDR part is unused and in its original packaging.
Return procedure for TL1431QDR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL1431QDR 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…
