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Texas Instruments TLVH431AQLPRE3
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- Part No.:
- TLVH431AQLPRE3
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Datasheet:
-
TLVH431AQLPRE3.pdf
- Description:
- IC VREF SHUNT ADJ 1% TO92-3
- Quantity:
- Payment:
- Shipping:
Inventory:4,287
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Product details
Overview
TLVH431AQLPRE3 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 1.24 V cathode-anode voltage. It delivers stable regulation across –40°C to +125°C, supports 100 μA–70 mA cathode current, and provides 0.25 Ω typical dynamic impedance-enabling accurate secondary-side feedback in isolated 3.3 V flyback SMPS designs.
For engineers reviewing the TLVH431AQLPRE3 datasheet, TLVH431AQLPRE3 pinout, TLVH431AQLPRE3 application, or TLVH431AQLPRE3 equivalent, this device serves as a low-leakage, high-stability replacement for Zener diodes and as an integrated-reference comparator in power rail monitoring, data converter references, and optocoupler-coupled feedback loops where sub-2.5 V reference capability is required.
Technical Context
The TLVH431AQLPRE3 implements a bandgap-referenced error amplifier with Darlington output stage, enabling precise shunt regulation via external resistor divider between cathode and reference pins. Its internal 1.24 V reference is thermally stabilized across –40°C to +125°C, with <31 mV total VREF deviation over full temperature range (Q-grade) and <0.5 μA reference input current.
It operates in two functional modes: open-loop comparator mode (with reference pin tied to monitored voltage) and closed-loop shunt regulator mode (with resistive feedback from cathode to reference). Unlike standard linear regulators, it requires no external compensation capacitor for stability under typical loads due to internal frequency compensation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage (VREF) | 1.24 V ±1% at 25°C - sets minimum programmable output voltage and defines accuracy baseline for all regulated outputs. |
| Operating Cathode-Anode Voltage (VKA) | 1.24 V to 18 V - enables regulation of low-voltage rails (e.g., 3.3 V, 2.5 V) unreachable by TL431-class devices. |
| Cathode Current Range | 100 μA to 70 mA - supports ultra-low-power monitoring and high-current shunt regulation without external boost. |
| Dynamic Impedance (|zKA|) | 0.25 Ω typical - ensures tight output voltage regulation under load transients and minimizes output ripple. |
| Temperature Range | –40°C to +125°C - qualified for automotive under-hood and industrial control applications requiring extended thermal robustness. |
| Reference Input Current (Iref) | 0.1–0.5 μA - reduces divider resistor power loss and improves accuracy in high-impedance feedback networks. |
| Output Voltage Adjustment | VO = VREF × (1 + R1/R2) + Iref × R1 - allows precise setting of any output between 1.24 V and 18 V using two external resistors. |
Pinout & Package
SOT-23-3 (DBZ) package: 2.92 mm × 1.30 mm body, 3-pin surface-mount, RoHS-compliant, tape-and-reel packaging.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1: CATHODE | Shunt current sink node | Primary current path for regulation; connects to output rail or optocoupler LED anode in isolated SMPS feedback. |
| Pin 2: REF | Reference input terminal | Senses divided output voltage; must be biased with ≥0.1 μA and not left floating to maintain amplifier bias. |
| Pin 3: ANODE | Common return / ground reference | Connects to system ground or negative rail; serves as voltage reference point for both VREF and VKA measurements. |
Key Features
| Feature | Design Value |
|---|---|
| Low-voltage operation | Starts regulating at 1.24 V cathode-anode differential-enables use in 1.8 V, 2.5 V, and 3.3 V systems where TL431 fails. |
| Ultra-low reference input current | 0.1–0.5 μA maximum-permits use of MΩ-range feedback resistors without degrading accuracy or increasing self-heating. |
| High-temperature grade | Qualified from –40°C to +125°C (Q-grade)-supports automotive engine control units and industrial motor drives. |
| Integrated comparator functionality | No external reference needed-internal 1.24 V threshold enables direct voltage monitoring and fault detection circuits. |
| Stable without output capacitor | Internally compensated-eliminates need for stability-tuning capacitor in most shunt regulator configurations. |
Applications
| Adjustable Voltage Reference for Data Converters | Secondary-Side Regulation in Flyback SMPS |
|---|---|
Use Scenario: Precision ADC/DAC reference in battery-powered IoT sensor nodes requiring low quiescent current and stable 1.24–5 V reference. IC Role / Device Role / Timing Role: Adjustable shunt reference providing stable VREF to converter analog front-end; replaces discrete Zener + op-amp solutions. Use Value: 1% initial tolerance and <31 mV VREF drift over –40°C to +125°C ensure consistent conversion accuracy across environmental conditions. |
Use Scenario: Isolated feedback path in 3.3 V AC/DC flyback converters using optocoupler coupling to primary-side controller. IC Role / Device Role / Timing Role: Error amplifier and voltage reference on secondary side; compares scaled output voltage and drives optocoupler LED current. Use Value: 100 μA minimum cathode current enables regulation at light loads; 0.25 Ω dynamic impedance maintains tight output regulation during transient steps. |
| Zener Diode Replacement | Voltage Monitoring for Power Rails |
Use Scenario: On-board 1.8 V or 2.5 V rail stabilization in FPGA or microcontroller power domains where space and leakage are critical. IC Role / Device Role / Timing Role: Low-leakage shunt regulator clamping excess voltage; replaces 1N47xx Zeners with superior tempco and tighter tolerance. Use Value: IK(off) ≤ 0.1 μA at 18 V reverse bias reduces standby power loss; 1.24 V reference enables lower-clamp thresholds than standard Zeners. |
Use Scenario: Real-time monitoring of 5 V, 3.3 V, or 1.2 V supply rails in telecom line cards or server motherboards for brownout detection. IC Role / Device Role / Timing Role: Comparator with built-in reference; triggers reset or alert when rail drops below programmed threshold. Use Value: Open-loop configuration achieves fast response (<1 μs typical); 0.5 μA Iref minimizes loading on monitored rail. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLVH431BQDBZR | 0.5% initial VREF tolerance (B-grade) vs. 1% (A-grade); otherwise identical electrical specs and pinout. | Better accuracy-critical references (e.g., high-resolution DACs); same thermal and current ratings. | Select when ±0.5% reference accuracy at 25°C is mandatory; higher cost, same PCB layout. |
| TLV431ACDBVR | Lower max cathode voltage (6 V vs. 18 V); 1.24 V reference, 1% tolerance, SOT-23-3 package. | Not suitable for >6 V output regulation or high-VKA flyback topologies; limited headroom in 12 V systems. | Choose only for low-voltage-only applications (<6 V) where smaller footprint or lower cost outweighs voltage range limitation. |
Compared with TLVH431BQDBZR, TLVH431AQLPRE3 trades 0.5% initial accuracy for lower unit cost while retaining full 18 V cathode capability and Q-grade temperature range; versus TLV431ACDBVR, it adds 3× higher voltage headroom and maintains compatibility with existing 3.3 V–12 V isolated SMPS designs.
Availability
TLVH431AQLPRE3 is available at Aetrix Electronics and suitable for automotive power management, industrial SMPS feedback, and precision analog reference applications requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for TLVH431AQLPRE3 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 devices in modern 3.3 V and lower systems.
FAQ
What is the reference voltage tolerance of TLVH431AQLPRE3 at 25°C?
The TLVH431AQLPRE3 has a reference voltage tolerance of ±1% at 25°C, corresponding to a 1.24 V nominal VREF ranging from 1.228 V to 1.252 V. This A-grade specification is confirmed in Section 5.6 of the official TI datasheet SLVS555N and applies specifically to the Q-temperature grade variant TLVH431AQLPRE3.
Can TLVH431AQLPRE3 operate with cathode-anode voltage below 2.5 V?
Yes, TLVH431AQLPRE3 is explicitly designed for low-voltage operation starting at 1.24 V cathode-anode differential-unlike TL431 which requires ≥2.5 V. This enables direct use in 1.8 V, 2.5 V, and 3.3 V systems, including secondary-side regulation in flyback converters where output voltage headroom is constrained.
What is the minimum cathode current required for regulation in TLVH431AQLPRE3?
The TLVH431AQLPRE3 requires a minimum cathode current of 100 μA to maintain regulation, as specified in Section 5.5 of the datasheet. This value is valid across the full –40°C to +125°C operating range and is critical for stable operation in light-load or high-resistance feedback configurations.
Does TLVH431AQLPRE3 require an external compensation capacitor?
No, TLVH431AQLPRE3 is internally compensated and remains stable without an external output capacitor between cathode and anode under typical operating conditions. However, if a capacitive load is added, Figures 5-15 through 5-17 in the datasheet provide phase margin guidance for selecting appropriate capacitance values to maintain stability.
How does the pinout of TLVH431AQLPRE3 differ from TLVH432 variants?
TLVH431AQLPRE3 uses the DBZ SOT-23-3 package with pinout: Pin 1 = CATHODE, Pin 2 = REF, Pin 3 = ANODE. TLVH432 variants use inverted pinout (Pin 1 = REF, Pin 2 = ANODE, Pin 3 = CATHODE) in the same package-making them non-pin-compatible despite functional equivalence. Substitution requires PCB layout revision.
TLVH431AQLPRE3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- 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:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-92-3
TLVH431AQLPRE3 FAQ
1.How can I place an order for TLVH431AQLPRE3 through Aetrix?
Please submit a Request for Quotation (RFQ) for TLVH431AQLPRE3 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 TLVH431AQLPRE3 reliable?
The price and inventory of TLVH431AQLPRE3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TLVH431AQLPRE3 is usually 5 days.
3.What payment methods are accepted for TLVH431AQLPRE3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TLVH431AQLPRE3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TLVH431AQLPRE3?
TLVH431AQLPRE3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TLVH431AQLPRE3 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 TLVH431AQLPRE3?
For technical support, including TLVH431AQLPRE3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TLVH431AQLPRE3 requirements.
6.How does Aetrix verify that TLVH431AQLPRE3 is sourced from the original manufacturer or authorized distributors?
All TLVH431AQLPRE3 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 TLVH431AQLPRE3 meets industry standards.
7.What is the process for return or replacement of TLVH431AQLPRE3?
All TLVH431AQLPRE3 units undergo pre-shipment inspection (PSI). If there is an issue with TLVH431AQLPRE3, 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 TLVH431AQLPRE3 part is unused and in its original packaging.
Return procedure for TLVH431AQLPRE3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TLVH431AQLPRE3 Tags
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