Datasheet TL432LI (Texas Instruments)

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TL431LI TL432LI
SLVSDQ6A – JULY 2018 – REVISED NOVEMBER 2018
TL431LI / TL432LI Programmable Shunt Regulator with Optimized Reference Current 1 Features 3 Description
• Reference Voltage Tolerance at 25°C The TL431LI device is a three-terminal adjustable 1 shunt regulator, with specified thermal stability over – 0.5% (B Grade) applicable automotive, commercial, and military – 1% (A Grade) temperature ranges. The output voltage can be set to • Minimum Typical Output Voltage: 2.495 V any value between Vref (approximately 2.495 V) and 36 V, with two external resistors. These devices have • Adjustable Output Voltage: Vref to 36 V a typical output impedance of 0.3 Ω. Active output • Operation From −40°C to +125°C (Q Temp) circuitry provides a very sharp turn-on characteristic, • Maximum Temperature Drift making these devices excellent replacements for – 10 mV (C Temp) Zener diodes in many applications, such as onboard regulation, adjustable power supplies, and switching – 17 mV (I Temp) power supplies. This device is a pin-to-pin alternative – 27 mV (Q Temp) to the industry standard TL431, with optimized Iref and • 0.3-Ω Typical Output Impedance IIdev performance. The lower Iref and IIdev values enable designers to achieve higher system accuracy • Sink-Current Capability and lower leakage current. The TL432LI device has – Imin = 1 mA (max) exactly the same functionality and electrical – I specifications as the TL431LI device, but has a KA = 15 mA (max) different pinout for the DBZ package. • Reference Input Current IREF: 0.4 μA (max) • Deviation of Reference Input Current over The TL431LI device is offered in two grades, with Temperature, I initial tolerances (at 25°C) of 0.5% and 1%, for the B I(dev): 0.3 μA (max) and A grade, respectively. In addition, low output drift
2 Applications
versus temperature ensures good stability over the entire temperature range. • Adjustable Voltage and Current Referencing The TL43xLIxQ devices are characterized for • Secondary Side Regulation in Flyback SMPS operation from –40°C to 125°C. • Zener Diode Replacement • Voltage Monitoring
Device Information(1)
• Precision Constant Current Sink/Source
PART NUMBER PACKAGE (PIN) BODY SIZE (NOM)
TL43xLI SOT-23 (3) 2.90 mm x 1.30 mm • Comparator with Integrated Reference (1) For all available packages, see the orderable addendum at the end of the data sheet.
Simplified Schematic
Input VKA IKA Vref 1 An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications, intellectual property matters and other important disclaimers. PRODUCTION DATA. Document Outline 1 Features 2 Applications 3 Description Table of Contents 4 Revision History 5 Device Comparison Table 6 Pin Configuration and Functions 7 Specifications 7.1 Absolute Maximum Ratings 7.2 ESD Ratings 7.3 Thermal Information 7.4 Recommended Operating Conditions 7.5 Electrical Characteristics 7.6 Typical Characteristics 8 Parameter Measurement Information 8.1 Temperature Coefficient 8.2 Dynamic Impedance 9 Detailed Description 9.1 Overview 9.2 Functional Block Diagram 9.3 Feature Description 9.4 Device Functional Modes 9.4.1 Open Loop (Comparator) 9.4.2 Closed Loop 10 Applications and Implementation 10.1 Application Information 10.2 Typical Applications 10.2.1 Comparator With Integrated Reference 10.2.1.1 Design Requirements 10.2.1.2 Detailed Design Procedure 10.2.1.3 Application Curve 10.2.2 Precision Constant Current Sink 10.2.2.1 Design Requirements 10.2.2.2 Detailed Design Procedure 10.2.3 Shunt Regulator/Reference 10.2.3.1 Design Requirements 10.2.3.2 Detailed Design Procedure 10.2.3.3 Application Curve 10.2.4 Isolated Flyback with Optocoupler 10.2.4.1 Design Requirements 10.3 System Examples 11 Power Supply Recommendations 12 Layout 12.1 Layout Guidelines 12.2 Layout Example 13 Device and Documentation Support 13.1 Related Links 13.2 Documentation Support 13.2.1 Device Nomenclature 13.2.2 Related Documentation 13.3 Receiving Notification of Documentation Updates 13.4 Community Resources 13.5 Trademarks 13.6 Electrostatic Discharge Caution 13.7 Glossary 14 Mechanical, Packaging, and Orderable Information