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Texas Instruments TLVH431AQLPE3
- Part No.:
- TLVH431AQLPE3
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-226-3, TO-92-3 (TO-226AA)
- Datasheet:
-
TLVH431AQLPE3.pdf
- Description:
- IC VREF SHUNT PREC ADJ TO-92-3
- Quantity:
- Payment:
- Shipping:
Inventory:4,000
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Product details
Overview
TLVH431AQLPE3 from Texas Instruments is a low-voltage adjustable precision shunt regulator with 1.24 V reference voltage, ±1% initial tolerance at 25°C (A-grade), and operation down to 100 μA cathode current. It delivers 0.25 Ω typical dynamic impedance and supports output voltage adjustment from 1.24 V to 18 V using two external resistors. It serves as a high-accuracy, low-leakage replacement for Zener diodes in isolated flyback SMPS feedback loops.
For engineers reviewing the TLVH431AQLPE3 datasheet, TLVH431AQLPE3 pinout, TLVH431AQLPE3 application, or TLVH431AQLPE3 equivalent, key selection criteria include reference voltage accuracy over –40°C to +125°C, minimum cathode current requirement, dynamic impedance stability under load, and compatibility with optocoupler-based secondary-side regulation circuits.
Technical Context
The TLVH431AQLPE3 integrates a precision 1.24 V bandgap reference and high-gain error amplifier driving a Darlington sink output stage. Its internal architecture enables sharp turn-on behavior and stable closed-loop regulation without mandatory output capacitance-unlike many linear regulators.
It operates in two distinct functional modes: open-loop comparator mode (using internal reference for threshold detection) and closed-loop shunt regulator mode (with resistive feedback from cathode to reference pin). Both modes require ≥100 μA cathode current to maintain linear amplifier operation and specified gain.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage (VREF) | 1.24 V ±1% at 25°C - sets precise regulation point for feedback networks |
| Output Voltage Range | 1.24 V to 18 V - adjustable via external resistor divider, enabling wide supply rail coverage |
| Cathode Current Range | 100 μA to 70 mA - supports ultra-low-power monitoring and higher-current shunt regulation |
| Dynamic Impedance | 0.25 Ω typical - ensures minimal output voltage deviation under varying load current |
| Operating Temperature | –40°C to +125°C - qualified for automotive and industrial environments (Q-grade) |
| Reference Input Current | 0.1–0.5 μA - enables high-impedance feedback networks without significant error contribution |
| Thermal Stability | ±11 mV max VREF deviation over full temperature range - critical for precision analog systems |
Pinout & Package
TLVH431AQLPE3 is packaged in TO-92 (LP) format with 3 leads: Cathode (pin 1), Anode (pin 2), and Reference (pin 3). The package provides through-hole mounting, thermal resistance of 140°C/W (junction-to-ambient), and mechanical robustness for industrial assembly.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CATHODE (Pin 1) | Shunt current input/output node | Sinks regulated current; voltage at this pin defines output regulation point in closed-loop configuration |
| ANODE (Pin 2) | Common return path | Typically connected to system ground or low-side reference; forms current return path for cathode sink |
| REF (Pin 3) | Feedback input / reference sense | Compares external voltage to internal 1.24 V reference; requires ≥0.1 μA bias current for proper operation |
Key Features
| Feature | Design Value |
|---|---|
| Low-voltage operation | Starts regulation at 1.24 V - enables use in 1.8 V, 2.5 V, and 3.3 V systems where traditional 2.5 V references fail |
| Ultra-low cathode current | 100 μA minimum - reduces standby power in battery-backed or energy-harvesting applications |
| Integrated reference + amplifier | No external reference needed - simplifies design of comparators and error amplifiers in isolated supplies |
| Stable without output capacitor | Internally compensated - eliminates need for external stabilization cap in most configurations |
| Zener diode replacement | 0.02–0.1 μA off-state leakage - improves efficiency vs. standard Zeners in voltage-monitoring circuits |
Applications
| Isolated Flyback SMPS Feedback | Voltage Rail Monitoring |
|---|---|
Use Scenario: Secondary-side voltage sensing in 3.3 V isolated flyback converters using optocoupler feedback. IC Role / Device Role / Timing Role: Precision shunt regulator and error amplifier - compares sampled output voltage against 1.24 V reference and drives optocoupler LED. Use Value: Enables regulation down to ~2.7 V output (1.24 V + opto LED drop), supporting modern low-voltage rails with ±1% accuracy over –40°C to +125°C. |
Use Scenario: Real-time detection of brownout or overvoltage conditions on microcontroller I/O or sensor supply rails. IC Role / Device Role / Timing Role: Comparator with integrated reference - triggers reset or alert when rail deviates beyond set thresholds. Use Value: Eliminates external reference IC; 0.1–0.5 μA reference current minimizes loading on monitored rail, preserving measurement integrity. |
| Adjustable Linear Regulator Reference | Low-Power Data Converter Reference |
Use Scenario: Setting precise output voltage for discrete pass-transistor LDOs in industrial control modules. IC Role / Device Role / Timing Role: Adjustable voltage reference - configured with resistor divider to generate stable bias for series pass element gate/base drive. Use Value: 0.25 Ω dynamic impedance ensures <1 mV output shift per 1 mA load change, improving line/load regulation performance. |
Use Scenario: Providing stable reference voltage for 12-bit+ SAR or delta-sigma ADCs in portable instrumentation. IC Role / Device Role / Timing Role: Low-noise, low-drift reference source - directly connected to ADC REF+ pin with optional RC filtering. Use Value: ±11 mV VREF drift over temperature limits INL error to <0.5 LSB for 12-bit conversion across full industrial range. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLVH431BQLPE3 | 0.5% initial VREF tolerance (vs. 1%) and tighter tempco (±4 mV vs. ±11 mV over –40°C to +125°C) | Better suited for metrology-grade references or high-resolution DAC/ADC calibration | Select when absolute reference accuracy dominates cost and board space constraints |
| TLVH432AQLPE3 | Identical electrical specs but SOT-89-3 pinout (CATHODE–REF–ANODE) instead of TO-92's CATHODE–ANODE–REF | Requires PCB layout revision; preferred for surface-mount designs with thermal pad requirements | Choose for SMT assembly, improved thermal dissipation (52°C/W), or automated optical inspection compatibility |
Compared with TLVH431AQLPE3, TLVH431BQLPE3 offers higher baseline accuracy at the expense of wider VREF deviation spread over temperature, while TLVH432AQLPE3 trades through-hole manufacturability for surface-mount thermal and layout advantages-neither is pin-compatible without hardware changes.
Availability
TLVH431AQLPE3 is available at Aetrix Electronics and suitable for isolated power supplies, voltage supervision circuits, and precision analog references requiring stable component supply across automotive, industrial, and telecom end equipment.
Supply support for TLVH431AQLPE3 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, embedded processing, and power management technologies with over 50 years of innovation in precision analog ICs.
The TLVH431 family was designed for low-voltage, high-accuracy shunt regulation in space-constrained and thermally demanding applications-including automotive infotainment, industrial PLCs, and telecom power systems.
FAQ
What is the reference voltage tolerance of TLVH431AQLPE3 at 25°C?
The TLVH431AQLPE3 has a reference voltage tolerance of ±1% at 25°C, corresponding to a 1.24 V nominal VREF with bounds of 1.228 V to 1.252 V. This A-grade specification is confirmed in Section 5.6 of the TI SLVS555N datasheet and applies specifically to the Q-temperature grade (–40°C to +125°C) variant.
Does TLVH431AQLPE3 require an output capacitor for stability?
No, TLVH431AQLPE3 is internally compensated and remains stable without an output capacitor between cathode and anode. However, if added, capacitive load stability must be verified using TI's phase margin curves (Figures 5-15 to 5-17), as excessive capacitance can degrade phase margin depending on cathode voltage and load conditions.
What is the minimum cathode current required for regulation in TLVH431AQLPE3?
The TLVH431AQLPE3 requires a minimum cathode current of 100 μA to maintain regulation, as specified in Section 5.5 (IK(min)) of the datasheet. Operation below this level risks insufficient gain, leading to poor regulation accuracy or failure to enter active mode-especially at temperature extremes.
How does TLVH431AQLPE3 differ from TLVH432AQLPE3?
TLVH431AQLPE3 and TLVH432AQLPE3 share identical electrical specifications but differ in pinout: TLVH431AQLPE3 uses TO-92 with pin order CATHODE–ANODE–REF, while TLVH432AQLPE3 uses SOT-89-3 with CATHODE–REF–ANODE. They are not pin-compatible and require PCB redesign for substitution.
Can TLVH431AQLPE3 replace a standard Zener diode?
Yes, TLVH431AQLPE3 serves as a superior Zener diode replacement due to its 0.02–0.1 μA off-state cathode current (vs. typical Zener leakage >1 μA), ±1% reference accuracy, and sharp turn-on characteristic. It also enables adjustable output voltage via external resistors-unachievable with fixed-voltage Zeners.
TLVH431AQLPE3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA)
- Series:
- -
- Packaging:
- Bulk
- Product Status:
- Active
- Reference Type:
- Shunt
- Output Type:
- Adjustable
- Voltage - Output (Min/Fixed):
- 1.24V
- Voltage - Output (Max):
- 18 V
- Current - Output:
- 70 mA
- Tolerance:
- ±1%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 100 µA
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-92-3
TLVH431AQLPE3 FAQ
1.How can I place an order for TLVH431AQLPE3 through Aetrix?
Please submit a Request for Quotation (RFQ) for TLVH431AQLPE3 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 TLVH431AQLPE3 reliable?
The price and inventory of TLVH431AQLPE3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TLVH431AQLPE3 is usually 5 days.
3.What payment methods are accepted for TLVH431AQLPE3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TLVH431AQLPE3 transactions.
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4.How is shipping managed for TLVH431AQLPE3?
TLVH431AQLPE3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TLVH431AQLPE3 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 TLVH431AQLPE3?
For technical support, including TLVH431AQLPE3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TLVH431AQLPE3 requirements.
6.How does Aetrix verify that TLVH431AQLPE3 is sourced from the original manufacturer or authorized distributors?
All TLVH431AQLPE3 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 TLVH431AQLPE3 meets industry standards.
7.What is the process for return or replacement of TLVH431AQLPE3?
All TLVH431AQLPE3 units undergo pre-shipment inspection (PSI). If there is an issue with TLVH431AQLPE3, 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 TLVH431AQLPE3 part is unused and in its original packaging.
Return procedure for TLVH431AQLPE3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TLVH431AQLPE3 Tags
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