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Texas Instruments TL431ILPR5
- Part No.:
- TL431ILPR5
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- -
- Datasheet:
-
TL431ILPR5.pdf
- Description:
- VOLTAGE REFERENCE
- Quantity:
- Payment:
- Shipping:
Inventory:76,000
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Product details
Overview
TL431ILPR5 from onsemi is a three-terminal programmable shunt voltage reference IC operating as a precision zener replacement with 2.495 V nominal reference voltage, ±0.4% initial tolerance (TL431B grade), 0.22 Ω typical dynamic impedance, 1.0–100 mA sink current capability, and 50 ppm/°C typical temperature coefficient. It enables stable programmable references from 2.5 V to 36 V in power supply feedback, voltage monitoring, and op-amp reference circuits.
For engineers reviewing the TL431ILPR5 datasheet, TL431ILPR5 pinout, TL431ILPR5 application, or TL431ILPR5 equivalent, key selection criteria include its TO-92 (LP) package, −40°C to +85°C industrial temperature range, low-noise 2.5 V reference, and compatibility with optocoupler-based isolated feedback loops in AC/DC adapters and DC-DC converters.
Technical Context
The TL431ILPR5 implements an internal 1.78 V bandgap reference with transconductance amplifier and output stage, delivering programmable regulation via external resistor dividers. Its architecture supports both positive and negative reference configurations due to shunt topology and bidirectional cathode-anode conduction capability.
Stability depends critically on load capacitance and cathode current; the device exhibits poles at ~8 kHz and ~60 kHz, requiring careful compensation when driving capacitive loads >10 nF. Its open-loop gain exceeds 56 dB at DC and rolls off at −20 dB/decade per pole, with unity-gain crossover near 600 kHz under typical conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 2.495 V nominal; sets precise threshold for feedback networks in regulated power supplies. |
| Initial Tolerance | ±0.4% at 25°C (TL431B grade); ensures tight output voltage accuracy without trimming. |
| Dynamic Impedance | 0.22 Ω typical; maintains stable reference voltage under varying load currents (1–100 mA). |
| Operating Current Range | 1.0 mA to 100 mA cathode sink; supports low-power sensing and high-current regulation modes. |
| Temp Coefficient | 50 ppm/°C typical; limits reference drift to <1.5 mV over −40°C to +85°C ambient range. |
| Max Cathode-Anode Voltage | 37 V; allows direct use in 24 V industrial rails and 36 V programmable outputs. |
| Off-State Cathode Current | 20 nA max at 36 V; minimizes standby power loss in battery-backed monitoring circuits. |
Pinout & Package
TL431ILPR5 uses the TO-92 (LP suffix, Case 29) plastic package - a 3-pin through-hole package with 0.1" lead spacing, compatible with standard PCB mounting and wave soldering. Pin 1 is Reference (R), Pin 2 is Anode (A), Pin 3 is Cathode (K).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 (Reference) | High-impedance input node | Connects to resistor divider midpoint; senses output voltage and compares to internal 2.495 V reference. |
| Pin 2 (Anode) | Current return path | Typically tied to ground or negative rail; completes shunt current loop for regulation. |
| Pin 3 (Cathode) | Regulated current output | Sinks adjustable current to maintain reference node at 2.495 V; drives optocoupler LED or series pass transistor base. |
Key Features
| Feature | Design Value |
|---|---|
| Programmable output voltage | Set from 2.5 V to 36 V using two external resistors - eliminates need for multiple fixed-voltage references. |
| Low dynamic output impedance | 0.22 Ω typical ensures minimal output voltage deviation during transient load steps in feedback control loops. |
| Wide cathode current range | 1.0–100 mA operation supports both ultra-low-power monitoring (<100 µA bias) and high-current shunt regulation (>50 mA). |
| Temperature-compensated reference | 50 ppm/°C typical TC enables stable performance across industrial temperature range without external compensation. |
| Low output noise voltage | Sub-10 µV/√Hz spectral density below 10 kHz - critical for precision analog measurement and low-noise LDO feedback. |
Applications
| AC/DC Adapter Feedback | Industrial Voltage Monitor |
|---|---|
Use Scenario: Isolated secondary-side voltage regulation in offline flyback converters. IC Role / Device Role / Timing Role: Shunt reference driving optocoupler LED to close feedback loop across isolation barrier. Use Value: Enables ±1% output voltage accuracy over line/load/temperature with no primary-side controller overhead. | Use Scenario: Undervoltage/overvoltage detection in PLC I/O modules and motor drives. IC Role / Device Role / Timing Role: Precision threshold generator for comparator inputs monitoring 12 V or 24 V system rails. Use Value: Delivers trip-point accuracy within ±50 mV over −40°C to +85°C, eliminating calibration in field-deployed equipment. |
| Battery Management System | Linear Regulator Enhancement |
Use Scenario: Cell voltage supervision and charge termination in 3S Li-ion packs. IC Role / Device Role / Timing Role: Programmable reference for ADC reference or comparator threshold in analog front-end. Use Value: Provides stable 2.5 V reference independent of battery voltage decay, enabling accurate state-of-charge estimation. | Use Scenario: Improving line/load regulation of 78xx-series linear regulators via external feedback. IC Role / Device Role / Timing Role: Adjustable shunt reference replacing fixed 2.5 V internal reference to set custom output voltage. Use Value: Allows output adjustment from 5.0 V to 15 V while retaining thermal shutdown and current limiting of legacy regulators. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431ACLPRAG | Same TO-92 package, but A-grade (±1.0% tolerance) and 0°C to +70°C temp range. | Lower accuracy and narrower temperature range; suitable for commercial-grade power supplies. | Select when cost sensitivity outweighs industrial temp or tight tolerance requirements. |
| TL431BILPRAG | Same TO-92 package and −40°C to +85°C range, but B-grade (±0.4%) with identical electrical specs. | No functional difference; differs only in marking code and reel packaging (tape & reel vs. bag). | Choose for automated assembly where tape-and-reel delivery is required. |
Compared with TL431ILPR5, TL431ACLPRAG trades ±0.4% tolerance and industrial temperature rating for lower cost, while TL431BILPRAG matches all key specs but ships in tape-and-reel format - making it ideal for SMT production lines without sacrificing performance.
Availability
TL431ILPR5 is available at Aetrix Electronics and suitable for AC/DC adapter design, industrial voltage monitoring, and battery management systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.
Supply support for TL431ILPR5 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
onsemi (formerly ON Semiconductor) is a global semiconductor supplier focused on energy-efficient innovation for automotive, industrial, cloud, medical, and IoT applications.
The TL431 series belongs to onsemi's precision analog portfolio, designed specifically for programmable voltage reference and shunt regulation in power management, feedback control, and signal conditioning systems.
FAQ
What is the reference voltage accuracy of TL431ILPR5 at room temperature?
The TL431ILPR5 features a ±0.4% initial tolerance at 25°C, corresponding to a reference voltage range of 2.485 V to 2.505 V. This B-grade specification is confirmed in the Electrical Characteristics table for TL431BI devices under TA = 25°C conditions, and applies directly to the TL431ILPR5 variant as indicated by its "I" (−40°C to +85°C) and "B" (±0.4%) markings.
Can TL431ILPR5 be used as a negative voltage reference?
Yes, TL431ILPR5 can function as a negative voltage reference by reversing its connection: tie the cathode to the negative rail and the anode to system ground, with the reference pin connected to a resistor divider referenced to the negative rail. The device's shunt architecture supports bidirectional operation, and the datasheet explicitly states it "can be used as either a positive or negative voltage reference."
What is the minimum cathode current required for TL431ILPR5 to regulate properly?
The minimum cathode current for regulation is 0.5 mA maximum (typical 0.5 mA), as specified in the Electrical Characteristics table under "Minimum Cathode Current For Regulation" for TL431BI devices. Below this threshold, the TL431ILPR5 exits regulation and behaves as an open circuit; maintaining ≥0.5 mA ensures stable 2.495 V reference establishment.
How does the dynamic impedance of TL431ILPR5 affect power supply stability?
The TL431ILPR5's 0.22 Ω typical dynamic impedance directly determines how much the reference node voltage shifts under changing cathode current - e.g., a 10 mA step causes only ~2.2 mV perturbation. In feedback loops, low ZKA reduces phase lag and improves transient response, but stability also depends on external compensation; the datasheet's Figure 15 defines safe CL vs. IK boundaries to avoid oscillation.
Is TL431ILPR5 RoHS-compliant and lead-free?
Yes, TL431ILPR5 is RoHS-compliant and lead-free, as confirmed in the Features section ("These Devices are Pb−Free, Halogen Free/BFR Free and are RoHS Compliant") and Ordering Information table (package suffix "LP" denotes Pb-Free TO-92). The device meets JEDEC J-STD-609 Category 1 moisture sensitivity and qualifies for standard reflow profiles.
TL431ILPR5 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- -
- Series:
- *
- Packaging:
- Bulk
- Product Status:
- Active
- Reference Type:
- -
- Output Type:
- -
- Voltage - Output (Min/Fixed):
- -
- Voltage - Output (Max):
- -
- Current - Output:
- -
- Tolerance:
- -
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- -
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- -
- Supplier Device Package:
- -
TL431ILPR5 FAQ
1.How can I place an order for TL431ILPR5 through Aetrix?
Please submit a Request for Quotation (RFQ) for TL431ILPR5 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 TL431ILPR5 reliable?
The price and inventory of TL431ILPR5 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TL431ILPR5 is usually 5 days.
3.What payment methods are accepted for TL431ILPR5?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TL431ILPR5 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TL431ILPR5?
TL431ILPR5 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TL431ILPR5 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 TL431ILPR5?
For technical support, including TL431ILPR5 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TL431ILPR5 requirements.
6.How does Aetrix verify that TL431ILPR5 is sourced from the original manufacturer or authorized distributors?
All TL431ILPR5 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 TL431ILPR5 meets industry standards.
7.What is the process for return or replacement of TL431ILPR5?
All TL431ILPR5 units undergo pre-shipment inspection (PSI). If there is an issue with TL431ILPR5, 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 TL431ILPR5 part is unused and in its original packaging.
Return procedure for TL431ILPR5:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TL431ILPR5 Tags
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TL431AIDBZR
Texas Instruments
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TL431BQDBZR
Texas Instruments
-
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
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AZ431LBNTR-G1
Diodes Incorporated
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LM4040D20IDBZR
Texas Instruments
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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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