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Texas Instruments TLVH431AQDBZR
- Part No.:
- TLVH431AQDBZR
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
TLVH431AQDBZR.pdf
- Description:
- IC VREF SHUNT ADJ 1% SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:2,403
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Product details
Overview
TLVH431AQDBZR from Texas Instruments is a low-voltage adjustable precision shunt regulator in SOT-23-3 package, featuring 1.24 V reference voltage (±0.5% at 25°C), 100 μA minimum cathode current for regulation, 0.25 Ω typical dynamic impedance, and operation from –40°C to +125°C. It serves as an error amplifier or voltage reference in isolated flyback SMPS feedback loops.
For engineers reviewing the TLVH431AQDBZR datasheet, TLVH431AQDBZR pinout, TLVH431AQDBZR application, or TLVH431AQDBZR equivalent, key selection criteria include reference accuracy grade (Q-grade = automotive temp range), cathode current headroom requirements, dynamic impedance impact on loop stability, and compatibility with optocoupler-based secondary-side regulation topologies.
Technical Context
The TLVH431AQDBZR implements a three-terminal shunt topology with internal 1.24 V bandgap reference and high-gain transconductance amplifier driving a Darlington output stage. Its open-loop comparator mode enables precise voltage monitoring without external reference; closed-loop configuration with resistive divider achieves adjustable output regulation from 1.24 V to 18 V.
It operates with cathode-to-anode voltage ≥1.24 V and cathode current ≥100 μA to maintain regulation. Internal compensation ensures stability without output capacitance, though phase margin vs. capacitive load curves (Figures 5-15–5-17) guide capacitor selection when used in noise-sensitive or high-dynamic-load applications.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 1.24 V ±0.5% at 25°C - sets absolute accuracy baseline for feedback networks in power supplies and data converters. |
| Operating Temperature Range | –40°C to +125°C - qualified for automotive under-hood and industrial control environments requiring extended thermal robustness. |
| Min Cathode Current | 100 μA - defines lowest usable bias current for stable regulation; enables ultra-low-power standby modes in SMPS controllers. |
| Dynamic Impedance | 0.25 Ω typical - determines output voltage ripple rejection and loop gain margin in closed-loop shunt regulator configurations. |
| Cathode Voltage Range | 1.24 V to 18 V - supports direct regulation of 3.3 V, 5 V, and 12 V rails without external level-shifting circuitry. |
| Reference Input Current | 0.1–0.5 μA - minimizes divider resistor loading error and enables high-impedance feedback networks for low-power designs. |
| Output Noise (0.1–10 Hz) | 10 µVPP - critical for precision analog monitoring and high-resolution ADC reference applications where low-frequency drift matters. |
Pinout & Package
SOT-23-3 package (2.92 mm × 1.30 mm body size), surface-mount, RoHS-compliant, with gull-wing leads.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CATHODE (Pin 1) | Shunt current input / regulated output node | Carries total load current plus reference current; connects to optocoupler LED anode in isolated SMPS feedback paths. |
| REF (Pin 2) | Feedback input / reference threshold sense | Compares external voltage to internal 1.24 V reference; requires ≥0.1 μA bias current and must not be left floating. |
| ANODE (Pin 3) | Common return / ground reference | Typically tied to system ground or power rail common; forms reference point for both cathode and REF terminal voltages. |
Key Features
| Feature | Design Value |
|---|---|
| Low-voltage operation | Starts regulation at 1.24 V - enables use in 1.8 V and 3.3 V systems where legacy TL431 (2.5 V) cannot function. |
| Ultra-low reference current | 0.1–0.5 μA - reduces power loss in high-resistance feedback dividers and extends battery life in portable equipment. |
| Automotive-grade temperature range | –40°C to +125°C - meets AEC-Q100 stress test requirements for under-hood automotive power management ICs. |
| Integrated comparator functionality | No external reference needed - simplifies overvoltage/undervoltage detection circuits by combining reference + comparator in one device. |
| Stable without output capacitor | Internally compensated - eliminates need for external stabilization capacitor, reducing BOM count and PCB area in space-constrained designs. |
Applications
| Secondary-Side Regulation in Flyback SMPS | Zener Diode Replacement |
|---|---|
|
Use Scenario: Isolated 3.3 V output flyback converter using optocoupler feedback for USB-C PD adapters or automotive infotainment power supplies. IC Role / Device Role / Timing Role: Error amplifier and precision voltage reference in secondary-side feedback loop; compares sampled output to 1.24 V internal reference. Use Value: Enables regulation down to 2.7 V output (1.24 V + opto LED drop), outperforming TL431 in low-voltage isolated topologies. |
Use Scenario: On-board 5 V rail monitoring in industrial PLC I/O modules requiring low-leakage voltage clamping. IC Role / Device Role / Timing Role: Adjustable shunt regulator replacing discrete Zener diodes; provides sharp turn-on and <0.1 μA off-state leakage. Use Value: Reduces temperature drift by >5× versus 5% tolerance Zeners and eliminates need for trimming resistors in production calibration. |
| Adjustable Reference for Precision ADCs | Voltage Monitoring for Power Rails |
|
Use Scenario: 16-bit SAR ADC reference buffer in medical sensor front-ends requiring stable 2.5 V or 4.096 V reference. IC Role / Device Role / Timing Role: Programmable reference source with 0.5% initial accuracy and <31 mV full-range drift over –40°C to +125°C. Use Value: Achieves <0.01% gain error contribution in ADC transfer function-critical for clinical-grade measurement accuracy. |
Use Scenario: Real-time 12 V main rail supervision in telecom base station power distribution units. IC Role / Device Role / Timing Role: Comparator with integrated reference detecting undervoltage lockout (UVLO) at 11.4 V threshold. Use Value: Eliminates external voltage divider and reference IC, reducing component count by 3–4 parts while improving long-term drift stability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLVH431BQDBZR | 1.24 V reference with ±0.5% tolerance at 25°C (same as TLVH431AQDBZR), but tighter full-range VREF deviation (±11 mV vs ±11 mV) and identical Q-temp grade. | No functional difference in automotive or industrial regulation; same pinout and electrical behavior. | Select TLVH431BQDBZR only if tighter production lot-to-lot VREF matching is required beyond datasheet grade spec. |
| TLVH432AQDBZR | Different pinout: REF/ANODE/CATHODE instead of CATHODE/REF/ANODE; identical electrical specs, thermal performance, and Q-grade rating. | Requires PCB layout revision due to reversed pin assignment; unsuitable for drop-in replacement without board modification. | Choose TLVH432AQDBZR only when redesigning for alternate routing or when leveraging its distinct pinout for improved thermal or noise isolation. |
Compared with TLVH431AQDBZR, TLVH431BQDBZR offers no design advantage unless tighter initial VREF binning is mandated, while TLVH432AQDBZR demands layout changes despite identical regulation performance-making TLVH431AQDBZR the optimal choice for new designs prioritizing supply chain continuity and layout reuse.
Availability
TLVH431AQDBZR 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.
Supply support for TLVH431AQDBZR 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 company specializing in analog and embedded processing technologies, with leadership in precision analog ICs and power management solutions.
The TLVH431 family was designed for low-voltage, high-accuracy shunt regulation in isolated power supplies, battery-powered instrumentation, and automotive subsystems demanding extended temperature operation and minimal quiescent current.
FAQ
What is the reference voltage tolerance of TLVH431AQDBZR at 25°C?
The TLVH431AQDBZR has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a 1.24 V nominal value with a range of 1.234 V to 1.246 V. This A-grade tolerance is specified in Section 5.6 of the TI datasheet SLVS555N and applies exclusively to the 'A' suffix variant within the Q-temperature grade (–40°C to +125°C).
Can TLVH431AQDBZR operate with cathode current below 100 μA?
No-TLVH431AQDBZR requires a minimum cathode current of 100 μA to maintain regulation and specified reference accuracy. Below this threshold, open-loop gain drops significantly, causing increased VREF deviation and unstable output behavior. The datasheet specifies IK(min) = 60–100 μA depending on temperature, with 100 μA being the guaranteed maximum at full –40°C to +125°C range.
How does TLVH431AQDBZR differ from TL431 in low-voltage applications?
TLVH431AQDBZR operates down to 1.24 V reference voltage and 100 μA cathode current, whereas TL431 requires ≥2.5 V reference and ≥1 mA cathode current. This allows TLVH431AQDBZR to regulate 1.8 V and 3.3 V rails directly-enabling compact, efficient designs in modern low-voltage systems where TL431 cannot function.
Is TLVH431AQDBZR pin-compatible with TLVH432AQDBZR?
No-TLVH431AQDBZR uses CATHODE/REF/ANODE pinout (Pin 1–3), while TLVH432AQDBZR uses REF/ANODE/CATHODE. Though electrically identical and sharing the same SOT-23-3 package, the reversed pin assignment means TLVH432AQDBZR is not a drop-in replacement and requires PCB layout modification.
What is the dynamic impedance of TLVH431AQDBZR and why does it matter?
TLVH431AQDBZR has a typical dynamic impedance of 0.25 Ω, measured at 1 kHz with cathode current from 0.1 mA to 70 mA. This low value directly impacts output voltage stability: for every 1 mA change in cathode current, output voltage shifts by only 250 µV-critical for maintaining tight regulation in dynamically loaded SMPS outputs.
TLVH431AQDBZR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- 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:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
TLVH431AQDBZR FAQ
1.How can I place an order for TLVH431AQDBZR through Aetrix?
Please submit a Request for Quotation (RFQ) for TLVH431AQDBZR 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 TLVH431AQDBZR reliable?
The price and inventory of TLVH431AQDBZR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TLVH431AQDBZR is usually 5 days.
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TLVH431AQDBZR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TLVH431AQDBZR 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 TLVH431AQDBZR?
For technical support, including TLVH431AQDBZR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TLVH431AQDBZR requirements.
6.How does Aetrix verify that TLVH431AQDBZR is sourced from the original manufacturer or authorized distributors?
All TLVH431AQDBZR 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 TLVH431AQDBZR meets industry standards.
7.What is the process for return or replacement of TLVH431AQDBZR?
All TLVH431AQDBZR units undergo pre-shipment inspection (PSI). If there is an issue with TLVH431AQDBZR, 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 TLVH431AQDBZR part is unused and in its original packaging.
Return procedure for TLVH431AQDBZR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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