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Texas Instruments TLVH431QLPR
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- Part No.:
- TLVH431QLPR
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Datasheet:
-
TLVH431QLPR.pdf
- Description:
- IC VREF SHUNT ADJ 1.5% TO92-3
- Quantity:
- Payment:
- Shipping:
Inventory:2,000
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Product details
Overview
TLVH431QLPR from Texas Instruments is a low-voltage adjustable precision shunt regulator with 1.24 V reference voltage, ±0.5% initial tolerance (B-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 TLVH431QLPR datasheet, TLVH431QLPR pinout, TLVH431QLPR application, or TLVH431QLPR equivalent, key selection criteria include reference voltage accuracy over –40°C to +125°C, minimum cathode current requirement (100 µA), dynamic impedance (0.25 Ω), thermal stability (±31 mV over full temperature range for Q-grade), and compatibility with optocoupler-based secondary-side regulation in 3.3 V systems.
Technical Context
The TLVH431QLPR implements a bandgap-referenced error amplifier with Darlington sink output stage, enabling precise shunt regulation without external compensation. Its internal 1.24 V reference is trimmed at wafer test to achieve ±0.5% tolerance at 25°C and maintains stability across –40°C to +125°C industrial-automotive temperature range.
It operates in two distinct functional modes: open-loop comparator mode (with integrated reference) for voltage monitoring, and closed-loop shunt regulator mode (with resistive feedback from cathode to REF) for adjustable voltage regulation. The device requires ≥100 µA cathode current to enter linear regulation and exhibits sharp turn-on characteristics due to active output circuitry.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage (VREF) | 1.24 V nominal, ±0.5% at 25°C - enables accurate low-voltage setpoints starting at 1.24 V |
| Output Voltage Range | 1.24 V to 18 V - adjustable via two external resistors, supporting wide-range power rail regulation |
| Cathode Current Range | 100 µA to 70 mA - ultra-low minimum current allows operation in energy-constrained feedback paths |
| Dynamic Impedance | 0.25 Ω typical - ensures tight regulation under load transients and low-output-impedance behavior |
| Temperature Range | –40°C to +125°C - qualified for automotive and industrial environments without derating |
| VREF Deviation | ±31 mV over full temperature range (Q-grade) - translates to ±25 ppm/°C average TC for stable reference |
| Reference Input Current | 0.1–0.5 µA - negligible loading on feedback divider, preserving accuracy in high-impedance networks |
Pinout & Package
TLVH431QLPR is packaged in TO-92 (LP) format: 4.30 mm × 4.30 mm body, 3-pin through-hole package with axial lead configuration. Pin 1 = CATHODE, Pin 2 = ANODE, Pin 3 = REF.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CATHODE (Pin 1) | Shunt current input / output node | Primary current path; sinks regulated current when REF voltage exceeds 1.24 V; connects to SMPS output or optocoupler LED anode |
| ANODE (Pin 2) | Common return / ground reference | Low-impedance return path for cathode current and reference bias; must be connected to system ground or lowest potential node |
| REF (Pin 3) | Feedback input / reference threshold | Senses external voltage divider; device regulates when voltage at this pin equals 1.24 V; draws only 0.1–0.5 µA |
Key Features
| Feature | Design Value |
|---|---|
| Low-voltage operation | Starts regulation at 1.24 V cathode-to-anode voltage - enables use in 1.8 V, 2.5 V, and 3.3 V systems where TL431 cannot function |
| B-grade precision | ±0.5% VREF tolerance at 25°C - reduces calibration overhead in precision power supplies and data converter references |
| Ultra-low IK(min) | 100 µA minimum cathode current - permits operation with high-value feedback resistors, minimizing standby power in isolated converters |
| Internal compensation | Stable without output capacitor - eliminates need for external stabilization components in most shunt regulator configurations |
| Wide temperature specification | –40°C to +125°C operation with guaranteed parameters - supports under-hood automotive and industrial control applications |
Applications
| Adjustable Voltage Reference for Data Converters | Secondary-Side Regulation in Flyback SMPS |
|---|---|
|
Use Scenario: Providing stable, low-drift reference voltage to SAR or delta-sigma ADCs in battery-powered instrumentation. IC Role / Device Role / Timing Role: Precision shunt reference supplying VREF input to analog front-end; replaces discrete Zener + op-amp solutions. Use Value: ±0.5% initial accuracy and ±31 mV drift over –40°C to +125°C ensure <0.01% measurement error contribution across operating conditions. |
Use Scenario: Regulating 3.3 V output in isolated flyback converters using optocoupler feedback to primary-side controller. IC Role / Device Role / Timing Role: Secondary-side error amplifier and voltage reference; compares output-derived voltage against 1.24 V and drives optocoupler LED. Use Value: 100 µA IK(min) enables reliable startup and light-load regulation; 0.25 Ω dynamic impedance improves transient response vs. Zener alternatives. |
| Zener Diode Replacement | Power Rail Voltage Monitoring |
|
Use Scenario: Replacing 1.2–2.4 V Zener diodes in on-board LDO pre-regulation or bias networks. IC Role / Device Role / Timing Role: Adjustable shunt regulator clamping voltage at user-defined level; configured as 2-terminal device with REF tied to cathode. Use Value: 0.1–0.5 µA reference current minimizes leakage error; sharp turn-on characteristic avoids soft-clamping behavior seen in low-voltage Zeners. |
Use Scenario: Monitoring 5 V or 12 V supply rails for undervoltage lockout (UVLO) or brownout detection in microcontroller systems. IC Role / Device Role / Timing Role: Comparator with integrated 1.24 V reference; REF pin biased by resistor divider, cathode pulled to logic-high or open-drain output. Use Value: Eliminates need for external reference IC; ±0.5% VREF tolerance enables accurate 1% UVLO thresholds without trimming. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLVH431CLPR | ±1.5% VREF tolerance at 25°C (standard grade); same pinout, package, and electrical specs otherwise | Lower accuracy acceptable in cost-sensitive non-critical rails; higher VREF deviation (±42 mV over –40°C to +70°C) | Select TLVH431CLPR when ±1.5% initial tolerance suffices and B-grade precision is not required for system accuracy budget. |
| TLVH432QLPR | Identical electrical specs but SOT-89-3 package (Pin 1=CATHODE, Pin 2=REF, Pin 3=ANODE); different pinout than TLVH431QLPR | Surface-mount alternative for space-constrained PCBs; requires layout revision due to reversed REF/ANODE pin assignment | Choose TLVH432QLPR only when SOT-89 footprint is preferred and board layout can accommodate pinout change. |
Compared with TLVH431CLPR, TLVH431QLPR provides tighter reference accuracy critical for high-resolution ADC references and low-tolerance SMPS outputs; compared with TLVH432QLPR, it offers identical performance in TO-92 through-hole packaging-ideal for prototyping, repair, and legacy through-hole designs requiring no PCB redesign.
Availability
TLVH431QLPR is available at Aetrix Electronics and suitable for industrial power supplies, automotive body electronics, and precision analog instrumentation requiring stable component supply with long-term lifecycle support.
Supply support for TLVH431QLPR 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 delivering analog, embedded processing, and connectivity solutions for industrial, automotive, and communications markets.
The TLVH431 family was designed specifically for low-voltage, high-accuracy shunt regulation in isolated power supplies and precision reference applications-addressing limitations of legacy TL431 in sub-2.5 V systems.
FAQ
What is the reference voltage tolerance of TLVH431QLPR at 25°C?
The TLVH431QLPR features a ±0.5% reference voltage tolerance at 25°C, corresponding to a 1.24 V nominal VREF with a range of 1.234 V to 1.246 V. This B-grade precision is specified in Section 5.7 of the TI datasheet SLVS555N and applies across all operating conditions at room temperature. TLVH431QLPR maintains this accuracy without external trimming or calibration.
Can TLVH431QLPR operate with cathode current below 100 µA?
No-TLVH431QLPR requires a minimum cathode current of 100 µA to maintain regulation and ensure proper amplifier biasing. Below this threshold, gain drops significantly and the device exits linear operation, leading to inaccurate or unstable output. This IK(min) value is guaranteed over –40°C to +125°C and is documented in Sections 5.5–5.7 of the TLVH431 datasheet.
What package type does TLVH431QLPR use?
TLVH431QLPR uses the TO-92 (LP) package: a 3-pin through-hole plastic case measuring 4.30 mm × 4.30 mm with axial leads. Pin 1 is CATHODE, Pin 2 is ANODE, and Pin 3 is REF. This package is explicitly listed in the "Device Information" table of the TI datasheet SLVS555N and is distinct from SOT-23, SC70, or SOT-89 variants.
How does TLVH431QLPR differ from TL431 in low-voltage applications?
TLVH431QLPR operates down to 1.24 V reference voltage and 100 µA cathode current, whereas TL431 requires ≥2.5 V VREF and ≥1 mA IK(min). This makes TLVH431QLPR suitable for 1.8 V, 2.5 V, and 3.3 V systems where TL431 cannot regulate. Both share functional equivalence as adjustable shunt regulators, but TLVH431QLPR extends usable voltage headroom significantly.
Is TLVH431QLPR compatible with optocoupler-based feedback in flyback converters?
Yes-TLVH431QLPR is widely deployed in isolated flyback SMPS for secondary-side regulation. Its 100 µA IK(min), 1.24 V VREF, and low dynamic impedance (0.25 Ω) enable stable feedback loop operation with common optocouplers like PC817 or SFH615A. TI Application Report SLUA671 confirms TLVH431QLPR as a direct drop-in replacement for TL431 in such topologies.
TLVH431QLPR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Series:
- -
- Packaging:
- Cut Tape (CT)
- 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:
- ±1.5%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 100 µA
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-92-3
TLVH431QLPR FAQ
1.How can I place an order for TLVH431QLPR through Aetrix?
Please submit a Request for Quotation (RFQ) for TLVH431QLPR 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 TLVH431QLPR reliable?
The price and inventory of TLVH431QLPR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TLVH431QLPR is usually 5 days.
3.What payment methods are accepted for TLVH431QLPR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TLVH431QLPR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TLVH431QLPR?
TLVH431QLPR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TLVH431QLPR 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 TLVH431QLPR?
For technical support, including TLVH431QLPR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TLVH431QLPR requirements.
6.How does Aetrix verify that TLVH431QLPR is sourced from the original manufacturer or authorized distributors?
All TLVH431QLPR 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 TLVH431QLPR meets industry standards.
7.What is the process for return or replacement of TLVH431QLPR?
All TLVH431QLPR units undergo pre-shipment inspection (PSI). If there is an issue with TLVH431QLPR, 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 TLVH431QLPR part is unused and in its original packaging.
Return procedure for TLVH431QLPR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TLVH431QLPR Tags
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