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Texas Instruments TLVH431QDBZR
- Part No.:
- TLVH431QDBZR
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
TLVH431QDBZR.pdf
- Description:
- IC VREF SHUNT ADJ 1.5% SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:6,914
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Product details
Overview
TLVH431QDBZR 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 TLVH431QDBZR datasheet, TLVH431QDBZR pinout, TLVH431QDBZR application, or TLVH431QDBZR equivalent, key selection criteria include its Q-grade (–40°C to +125°C) thermal stability, SOT-23-3 package compatibility, 1.24 V reference accuracy, and suitability for secondary-side regulation in 3.3 V isolated power supplies.
Technical Context
The TLVH431QDBZR implements a precision bandgap reference and high-gain transconductance amplifier in a 3-terminal shunt topology. Its internal architecture forces the REF pin to 1.24 V when sufficient cathode current (≥100 μA) flows and feedback is applied between CATHODE and REF terminals.
In open-loop mode, it functions as a comparator with integrated reference; in closed-loop configuration, it acts as an error amplifier for voltage regulation. The device is internally compensated and stable without external output capacitance, though phase margin vs. capacitive load is characterized up to 100 nF.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage (VREF) | 1.24 V nominal at 25°C; ±0.5% tolerance for B-grade ensures tight initial setpoint for precision feedback circuits. |
| Operating Temperature Range | –40°C to +125°C (Q-grade); enables use in automotive under-hood and industrial control environments. |
| Cathode Current Range | 100 μA to 70 mA; ultra-low minimum current allows regulation in low-power standby modes and energy-efficient designs. |
| Dynamic Impedance | 0.25 Ω typical; provides sharp regulation and minimal output voltage deviation under load transients. |
| Output Voltage Range | Adjustable from 1.24 V to 18 V via two external resistors; supports wide-range supply monitoring and programmable references. |
| Reference Input Current | 0.1–0.5 μA; extremely low bias current minimizes resistor-divider loading errors and improves accuracy. |
| VREF Tempco (ΔVREF/ΔT) | 11–31 mV over full range (Q-grade); translates to ~24 ppm/°C max drift, suitable for stable long-term regulation. |
Pinout & Package
SOT-23-3 package (DBZ): 2.92 mm × 1.30 mm body, 3-pin surface-mount outline with gull-wing leads.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - CATHODE | Shunt current input / output node | Primary current path; sinks regulated current to maintain REF at 1.24 V; connects to optocoupler LED anode in isolated SMPS. |
| 2 - ANODE | Common return / ground reference | Low-impedance common terminal; must be connected to system ground or power rail return; defines voltage reference point for VKA. |
| 3 - REF | Feedback input / reference threshold | Senses external divider voltage; device regulates CATHODE-to-ANODE voltage until REF = 1.24 V; requires ≥0.1 μA bias current. |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low reference voltage | 1.24 V enables regulation in sub-3.3 V systems where standard 2.5 V references fail. |
| B-grade precision | ±0.5% VREF tolerance at 25°C reduces calibration overhead in high-accuracy power supplies. |
| Q-grade extended temperature | –40°C to +125°C operation supports automotive and industrial applications without derating. |
| Sub-100 μA regulation threshold | 100 μA IK(min) allows stable regulation during deep sleep or low-load conditions in battery-powered devices. |
| Internal compensation | No external capacitor required for stability; simplifies layout and reduces BOM count in space-constrained designs. |
Applications
| Isolated Flyback SMPS Feedback | Zener Diode Replacement |
|---|---|
|
Use Scenario: Secondary-side voltage sensing in 3.3 V isolated flyback converters using optocoupler feedback. IC Role / Device Role / Timing Role: Adjustable shunt regulator and error amplifier; sets precise output voltage by controlling optocoupler LED current. Use Value: Enables regulation down to 2.7 V output (1.24 V + 1.4 V LED drop); eliminates need for external op-amp and reference IC. |
Use Scenario: On-board voltage clamping and rail monitoring in microcontroller-based systems. IC Role / Device Role / Timing Role: Precision shunt reference with active regulation; replaces passive Zener diodes in 1.8 V–5 V rails. Use Value: Reduces leakage current by >90% versus 1N47xx Zeners; improves accuracy and thermal stability across temperature. |
| Comparator with Integrated Reference | ADC Reference Buffer |
|
Use Scenario: Threshold detection for battery voltage monitoring or power-good signaling in portable electronics. IC Role / Device Role / Timing Role: Open-loop comparator with built-in 1.24 V reference; compares analog input against fixed threshold. Use Value: Eliminates external reference IC and reduces component count; achieves <10 μs response time with sharp turn-on. |
Use Scenario: Stable reference source for SAR and delta-sigma ADCs in data acquisition modules. IC Role / Device Role / Timing Role: Low-noise, low-drift voltage reference; supplies clean, regulated voltage to ADC REF+ pin. Use Value: 0.25 Ω output impedance and <0.5 μA input current minimize code-dependent reference errors and improve ENOB. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLVH431BDBZR | Same SOT-23-3 package and Q-grade temp range, but B-grade (±0.5%) matches TLVH431QDBZR's tolerance; identical electrical specs. | No functional difference; direct substitution in all TLVH431QDBZR designs requiring same precision and temperature rating. | Select TLVH431BDBZR only if part marking or internal documentation requires explicit 'B' suffix; otherwise TLVH431QDBZR is functionally identical. |
| TLVH432QDBZR | Different pinout: REF and ANODE swapped (pin 1=REF, pin 2=ANODE, pin 3=CATHODE); same electrical performance and Q-grade rating. | Requires PCB layout change; not pin-compatible; used where alternate routing or thermal relief favors reversed pin assignment. | Choose TLVH432QDBZR only when board layout constraints favor its pin arrangement; verify schematic connectivity before substitution. |
Compared with TLVH431QDBZR, TLVH431BDBZR offers identical performance and drop-in compatibility, while TLVH432QDBZR provides identical regulation capability but demands pinout-aware redesign due to swapped REF/ANODE terminals.
Availability
TLVH431QDBZR is available at Aetrix Electronics and suitable for isolated power supplies, battery management systems, precision instrumentation, and automotive control modules requiring stable component supply across extended temperature ranges.
Supply support for TLVH431QDBZR 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, embedded processing, and power management technologies, with decades of leadership in precision reference and power IC design.
The TLVH431 family was designed specifically for low-voltage, high-accuracy shunt regulation in isolated and non-isolated power conversion, replacing Zener diodes with superior thermal stability and lower leakage.
FAQ
What is the reference voltage tolerance of TLVH431QDBZR at 25°C?
The TLVH431QDBZR has a ±0.5% reference voltage tolerance at 25°C, corresponding to the B-grade specification. This means its VREF falls within 1.234 V to 1.246 V under nominal conditions, enabling high-accuracy feedback in precision power supplies and measurement circuits. TLVH431QDBZR maintains this grade across its full –40°C to +125°C operating range.
Does TLVH431QDBZR require an external output capacitor for stability?
No, TLVH431QDBZR is internally compensated and remains stable without an external capacitor between CATHODE and ANODE. However, if a capacitive load is added-such as for noise filtering-the device's phase margin must be verified per Figures 5-15 to 5-17 in the datasheet. TLVH431QDBZR supports up to 100 nF while maintaining ≥45° phase margin depending on cathode voltage and current.
Can TLVH431QDBZR replace a standard TL431 in existing designs?
TLVH431QDBZR can replace TL431 only with circuit modifications: its 1.24 V reference is half that of TL431's 2.5 V, requiring resistor-divider recalculations. Also, TLVH431QDBZR operates down to 100 μA cathode current versus TL431's 1 mA minimum, enabling lower-power operation. Pinout is identical in SOT-23-3, but TLVH431QDBZR must not be used as a direct drop-in without verifying biasing and gain margins.
What is the minimum cathode current needed for regulation in TLVH431QDBZR?
The minimum cathode current for regulation in TLVH431QDBZR is 100 μA at 25°C, rising to 120 μA at +125°C per datasheet Figure 5-5. Below this threshold, the internal amplifier exits linear region and regulation degrades. Designers must ensure the external circuit supplies ≥100 μA continuously-even during light-load or standby-to maintain TLVH431QDBZR's 1.24 V reference accuracy.
How does the TLVH431QDBZR pinout differ from TLVH432QDBZR?
TLVH431QDBZR uses pin 1=CATHODE, pin 2=ANODE, pin 3=REF in SOT-23-3. TLVH432QDBZR swaps ANODE and REF: pin 1=REF, pin 2=ANODE, pin 3=CATHODE. This reversal affects PCB layout and schematic connectivity. TLVH431QDBZR and TLVH432QDBZR share identical electrical specs and Q-grade rating, but TLVH432QDBZR is not pin-compatible with TLVH431QDBZR without board revision.
TLVH431QDBZR 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:
- ±1.5%
- 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:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
TLVH431QDBZR FAQ
1.How can I place an order for TLVH431QDBZR through Aetrix?
Please submit a Request for Quotation (RFQ) for TLVH431QDBZR 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 TLVH431QDBZR reliable?
The price and inventory of TLVH431QDBZR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TLVH431QDBZR is usually 5 days.
3.What payment methods are accepted for TLVH431QDBZR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TLVH431QDBZR transactions.
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4.How is shipping managed for TLVH431QDBZR?
TLVH431QDBZR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TLVH431QDBZR 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 TLVH431QDBZR?
For technical support, including TLVH431QDBZR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TLVH431QDBZR requirements.
6.How does Aetrix verify that TLVH431QDBZR is sourced from the original manufacturer or authorized distributors?
All TLVH431QDBZR 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 TLVH431QDBZR meets industry standards.
7.What is the process for return or replacement of TLVH431QDBZR?
All TLVH431QDBZR units undergo pre-shipment inspection (PSI). If there is an issue with TLVH431QDBZR, 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 TLVH431QDBZR part is unused and in its original packaging.
Return procedure for TLVH431QDBZR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TLVH431QDBZR Tags
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