My Inquiry
My Account
Texas Instruments TLVH431BQPK
- Part No.:
- TLVH431BQPK
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-243AA
- Datasheet:
-
TLVH431BQPK.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% SOT89-3
- Quantity:
- Payment:
- Shipping:
Inventory:1,988
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
TLVH431BQPK from Texas Instruments is a low-voltage adjustable precision shunt regulator in SOT-89-3 package, featuring 1.24 V reference voltage (±0.5% at 25°C), operation down to 1.24 V cathode-anode voltage, and 100 μA minimum cathode current for regulation - used as secondary-side voltage reference in isolated 3.3 V flyback SMPS designs.
For engineers reviewing the TLVH431BQPK datasheet, TLVH431BQPK pinout, TLVH431BQPK application, or TLVH431BQPK equivalent, key selection criteria include reference accuracy over –40°C to +125°C, dynamic impedance of 0.25 Ω, ultra-low reference terminal current (0.1–0.5 μA), and compatibility with optocoupler-based feedback loops requiring stable low-voltage regulation.
Technical Context
The TLVH431BQPK 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, enabling adjustable output voltage from 1.24 V to 18 V via two external resistors.
Unlike the TL431, it operates at lower headroom (down to 1.24 V), supports wider cathode current range (100 μA–70 mA), and achieves 0.25 Ω typical dynamic impedance without external compensation. It functions in both open-loop comparator mode (integrated reference) and closed-loop shunt regulation mode, with thermal stability specified across –40°C to +125°C (Q-grade).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage (VREF) | 1.24 V ±0.5% at 25°C - sets precise threshold for feedback networks in isolated power supplies. |
| Operating Cathode-Anode Voltage Range | 1.24 V to 18 V - enables regulation of low-voltage rails (e.g., 3.3 V, 5 V) and higher outputs without external level-shifting. |
| Min Cathode Current (IK(min)) | 100 μA - allows stable regulation in ultra-low-power applications where TL431 would fail to turn on. |
| Dynamic Impedance (|zKA|) | 0.25 Ω typical - ensures tight output voltage regulation under load transients in feedback loops. |
| Reference Terminal Current (Iref) | 0.1–0.5 μA - minimizes resistor-divider loading error and enables high-impedance sensing in battery-powered systems. |
| Temperature Range | –40°C to +125°C (Q-grade) - qualified for automotive under-hood and industrial control environments. |
| ESD Rating (HBM) | ±2000 V - meets standard handling requirements for automated assembly without special ESD controls. |
Pinout & Package
SOT-89-3 package (4.50 mm × 2.50 mm body size) with gull-wing leads; thermally enhanced tab connected to ANODE for PCB heat dissipation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1: CATHODE | Shunt current input / regulated output node | Accepts up to 70 mA sink current; connects to optocoupler LED anode or feedback divider top node in SMPS designs. |
| 2: ANODE | Common return / ground reference | Must be connected to system ground or lowest potential point; thermal tab ties to this pin for improved power dissipation. |
| 3: REF | Feedback input / reference threshold sense | Compares external voltage to internal 1.24 V bandgap; requires ≥0.1 μA bias current and must not float. |
Key Features
| Feature | Design Value |
|---|---|
| Low-voltage operation | Starts regulating at 1.24 V cathode-anode differential - enables use in 3.3 V and lower isolated supplies where TL431 cannot function. |
| 0.5% initial reference tolerance (B-grade) | Reduces output voltage error budget in precision feedback paths, minimizing need for post-production trimming. |
| 0.25 Ω dynamic impedance | Delivers <1 mV output deviation under 10 mA load step - critical for maintaining cross-regulation in multi-output flyback converters. |
| Stable without output capacitor | Internally compensated design eliminates mandatory cathode-to-anode capacitor, simplifying layout and reducing BOM count. |
| Ultra-low Iref (0.1–0.5 μA) | Permits use of >1 MΩ feedback dividers - lowers standby power and improves noise immunity in high-impedance monitoring circuits. |
Applications
| Secondary-Side Regulation in Isolated Flyback SMPS | Zener Diode Replacement in Low-Leakage Circuits |
|---|---|
|
Use Scenario: Regulating 3.3 V output in AC/DC adapter with optocoupler-coupled feedback loop. IC Role / Device Role / Timing Role: Precision shunt reference and error amplifier - compares sampled output voltage to 1.24 V internal reference and adjusts optocoupler LED current to maintain regulation. Use Value: Enables stable 3.3 V output with <±1% total error over line, load, and temperature - replacing TL431 where 2.5 V minimum headroom is unavailable. |
Use Scenario: Providing accurate 2.5 V bias voltage for analog sensor interface in battery-powered IoT node. IC Role / Device Role / Timing Role: Adjustable shunt reference - configured as 2.5 V Zener replacement using R1/R2 divider, sinking only leakage current when inactive. Use Value: Delivers 10× lower off-state cathode current (0.02–0.1 μA) vs. standard Zeners, extending battery life by reducing quiescent drain. |
| Voltage Monitoring for Power Rails | Comparator with Integrated Reference |
|
Use Scenario: Detecting undervoltage condition on 5 V microcontroller supply rail in automotive infotainment system. IC Role / Device Role / Timing Role: Threshold detector - REF pin tied to divided 5 V rail; CATHODE pulled high; ANODE grounded; output toggles at 4.75 V trip point. Use Value: Eliminates need for external reference IC and comparator - single-device solution with guaranteed 0.5% trip accuracy over –40°C to +125°C. |
Use Scenario: Implementing window comparator for Li-ion cell voltage supervision in portable medical device. IC Role / Device Role / Timing Role: Precision comparator - uses internal 1.24 V reference to compare scaled cell voltage; drives enable signal when within 3.0–4.2 V range. Use Value: Reduces component count and layout area vs. discrete op-amp + reference; maintains <10 mV hysteresis control via external resistor network. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt reference applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLVH431BQDBZ | SOT-23-3 package (2.92 mm × 1.30 mm); same electrical specs and Q-grade temp range. | Smaller footprint but lower thermal performance (RθJA = 206°C/W vs. 52°C/W for PK); unsuitable for >30 mA continuous dissipation. | Select TLVH431BQDBZ only when board space is constrained and power dissipation remains below 150 mW. |
| TLVH432BQPK | Identical SOT-89-3 package but reversed pinout: Pin 1 = REF, Pin 2 = ANODE, Pin 3 = CATHODE. | Requires PCB layout revision; incompatible with TLVH431BQPK footprint without trace modification. | Choose TLVH432BQPK only when redesigning for alternate routing or when leveraging its distinct pin assignment for specific layout optimization. |
Compared with TLVH431BQPK, TLVH431BQDBZ trades thermal capability for compactness, while TLVH432BQPK offers identical performance in a non-pin-compatible variant - making TLVH431BQPK the optimal choice for thermally demanding, drop-in-replacement scenarios in existing SOT-89 layouts.
Availability
TLVH431BQPK is available at Aetrix Electronics and suitable for isolated flyback SMPS designs, precision voltage monitoring systems, and low-leakage Zener replacement applications requiring stable component supply across automotive, industrial, and medical end equipment.
Supply support for TLVH431BQPK 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 specifically for low-voltage, high-accuracy shunt regulation in isolated power supplies and precision monitoring - addressing limitations of legacy TL431 in 3.3 V and sub-3 V systems.
FAQ
What is the reference voltage tolerance of TLVH431BQPK at 25°C?
The TLVH431BQPK has a reference voltage tolerance of ±0.5% at 25°C, corresponding to a 1.24 V nominal value with min/max bounds of 1.234 V and 1.246 V. This B-grade accuracy is confirmed in Section 5.7 of the TI datasheet SLVS555N and applies specifically to the TLVH431BQPK variant across its full operating temperature range.
Can TLVH431BQPK operate with cathode voltage below 2.5 V?
Yes, TLVH431BQPK is explicitly rated for operation down to 1.24 V cathode-to-anode voltage - significantly lower than the 2.5 V minimum required by TL431. This enables direct use in 3.3 V and 2.5 V isolated feedback circuits without additional biasing, as verified in the "Low-voltage operation" feature and Figure 6-1 test circuit.
What is the maximum continuous cathode current rating for TLVH431BQPK?
The TLVH431BQPK supports up to 70 mA continuous cathode current, as specified in Section 5.3 (Recommended Operating Conditions) and validated in thermal data showing RθJA = 52°C/W for the SOT-89 package. At 70 mA and 5 V cathode-anode differential, power dissipation reaches 350 mW - requiring appropriate PCB copper area for thermal management.
Does TLVH431BQPK require an output capacitor for stability?
No, TLVH431BQPK is internally compensated and stable without an output capacitor between CATHODE and ANODE, per Section 7.3. However, if a capacitor is added for noise filtering, Figures 5-15 through 5-17 provide phase-margin guidance versus capacitive load - confirming stability up to 10 nF at 1.25 V cathode voltage.
How does the pinout of TLVH431BQPK differ from TLVH432BQPK?
TLVH431BQPK uses Pin 1 = CATHODE, Pin 2 = ANODE, Pin 3 = REF; TLVH432BQPK reverses this to Pin 1 = REF, Pin 2 = ANODE, Pin 3 = CATHODE (Figure 4-6 vs. Figure 4-7). This difference is documented in the Pin Functions table and makes them non-pin-compatible despite identical package and electrical specs.
TLVH431BQPK Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- TO-243AA
- 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:
- ±0.5%
- 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-89-3
TLVH431BQPK FAQ
1.How can I place an order for TLVH431BQPK through Aetrix?
Please submit a Request for Quotation (RFQ) for TLVH431BQPK 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 TLVH431BQPK reliable?
The price and inventory of TLVH431BQPK are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TLVH431BQPK is usually 5 days.
3.What payment methods are accepted for TLVH431BQPK?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TLVH431BQPK transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TLVH431BQPK?
TLVH431BQPK orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TLVH431BQPK 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 TLVH431BQPK?
For technical support, including TLVH431BQPK datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TLVH431BQPK requirements.
6.How does Aetrix verify that TLVH431BQPK is sourced from the original manufacturer or authorized distributors?
All TLVH431BQPK 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 TLVH431BQPK meets industry standards.
7.What is the process for return or replacement of TLVH431BQPK?
All TLVH431BQPK units undergo pre-shipment inspection (PSI). If there is an issue with TLVH431BQPK, 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 TLVH431BQPK part is unused and in its original packaging.
Return procedure for TLVH431BQPK:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TLVH431BQPK Tags
-
TL431AIDBZR
Texas Instruments
-
TL431BQDBZR
Texas Instruments
-
AN431AN-ATRG1
Diodes Incorporated
-
LM4040CYM3-2.5-TR
Microchip Technology
-
LM4040CYM3-4.1-TR
Microchip Technology
-
LM4040EIM3-2.5/NOPB
Texas Instruments
-
AZ431LBNTR-G1
Diodes Incorporated
-
LM4040D20IDBZR
Texas Instruments
-
LM4041DIM3-ADJ/NOPB
Texas Instruments
-
LM4040DIM3X-2.5/NOPB
Texas Instruments
-
LM4040DIM3-2.5/NOPB
Texas Instruments
-
AZ431LANTR-G1
Diodes Incorporated
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
