My Inquiry
My Account
Texas Instruments TLVH431ACPK
- Part No.:
- TLVH431ACPK
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-243AA
- Datasheet:
-
TLVH431ACPK.pdf
- Description:
- IC VREF SHUNT ADJ 1% SOT89-3
- Quantity:
- Payment:
- Shipping:
Inventory:965
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
TLVH431ACPK from Texas Instruments is a low-voltage adjustable precision shunt regulator in SOT-89-3 package, delivering 1.24 V reference voltage with ±1% initial tolerance at 25°C, 0.25 Ω typical dynamic impedance, and operation from 1.24 V to 18 V cathode voltage across –40°C to +125°C. It serves as an ultra-low-leakage Zener replacement and error amplifier in isolated flyback SMPS feedback loops.
For engineers reviewing the TLVH431ACPK datasheet, TLVH431ACPK pinout, TLVH431ACPK application, or TLVH431ACPK equivalent, key selection criteria include cathode current range (100 μA–70 mA), thermal stability over industrial/automotive temperature ranges, output impedance impact on regulation accuracy, and compatibility with optocoupler-based secondary-side control architectures.
Technical Context
The TLVH431ACPK 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 compared against the REF pin voltage, driving cathode current to maintain regulation when feedback is applied via external resistors.
It operates in two distinct functional modes: open-loop comparator mode (for voltage monitoring) and closed-loop shunt regulator mode (for adjustable voltage references). The device achieves sharp turn-on characteristics and stable performance down to 100 μA cathode current, making it suitable for low-power and high-accuracy applications where traditional TL431 devices cannot operate.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference Voltage | 1.24 V ±1% at 25°C - sets minimum adjustable output voltage and defines feedback divider ratio accuracy |
| Cathode Voltage Range | 1.24 V to 18 V - enables regulation of 3.3 V, 5 V, and 12 V rails using standard resistor networks |
| Cathode Current Range | 100 μA to 70 mA - supports ultra-low-power monitoring and high-current shunt regulation without external boost |
| Dynamic Impedance | 0.25 Ω typical - ensures <1 mV output deviation per 1 mA load change, critical for tight regulation |
| Operating Temperature | –40°C to +125°C - qualified for automotive under-hood and industrial control environments |
| Reference Input Current | 0.1–0.5 μA - minimizes divider resistor power loss and improves high-impedance feedback network accuracy |
| Output Voltage Drift | ±11 mV over full temperature range (TLVH431AQ grade) - corresponds to ~92 ppm/°C average TC for stable long-term performance |
Pinout & Package
SOT-89-3 package: 4.50 mm × 2.50 mm body, 1.8 mm height, surface-mount, thermally enhanced tab (cathode-connected).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1: CATHODE | Shunt current input/output node | Primary current path; connects to regulated rail or optocoupler LED anode; tab is electrically connected to this pin |
| 2: ANODE | Common reference and return path | Typically tied to system ground or negative rail; establishes voltage reference point for REF and cathode operation |
| 3: REF | Feedback input / reference threshold sense | Compares external voltage to internal 1.24 V reference; requires ≥0.1 μA bias current; must not be left floating |
Key Features
| Feature | Design Value |
|---|---|
| Low-voltage operation | Starts regulating at 1.24 V cathode-to-anode - enables use in 1.8 V, 2.5 V, and 3.3 V systems where TL431 fails |
| Ultra-low reference current | 0.1–0.5 μA at REF pin - allows >1 MΩ feedback dividers, reducing power loss and noise sensitivity |
| High-accuracy grade | ±1% initial tolerance (A grade) - eliminates need for post-production trimming in cost-sensitive power supplies |
| Thermal stability | ±11 mV drift over –40°C to +125°C - maintains regulation accuracy in engine control units and motor drives |
| Stable without output capacitor | Internally compensated - removes risk of instability from PCB layout parasitics or capacitor aging in field-deployed equipment |
Applications
| Secondary-Side Flyback Regulation | Zener Diode Replacement |
|---|---|
|
Use Scenario: Isolated 3.3 V output in AC/DC adapter with optocoupler feedback. IC Role / Device Role / Timing Role: Adjustable shunt regulator and error amplifier - compares sampled output voltage to internal 1.24 V reference and sinks cathode current to modulate optocoupler LED drive. Use Value: Enables regulation down to 2.7 V output (1.24 V + opto VF), 30% lower than TL431-based designs, while maintaining ±1% output accuracy over temperature. |
Use Scenario: Precision 5 V rail monitor in programmable logic controller I/O module. IC Role / Device Role / Timing Role: Low-leakage voltage clamp - replaces 5.1 V Zener diode with 10× lower IREF and 4× lower dynamic impedance. Use Value: Reduces standby current by 2.5 μA per channel and improves voltage threshold repeatability by ±10 mV versus discrete Zener solutions. |
| Adjustable Data Converter Reference | Voltage Monitoring for Power Rails |
|
Use Scenario: Programmable gain stage for 16-bit SAR ADC in test equipment. IC Role / Device Role / Timing Role: Adjustable precision reference - sets ADC full-scale voltage via R1/R2 divider; REF pin directly interfaces with ADC reference input. Use Value: Achieves 0.006% linearity contribution from reference drift (±11 mV / 18 V) and supports 10 ppm/°C effective TC with matched resistors. |
Use Scenario: Undervoltage lockout (UVLO) detection on 12 V automotive subsystem rail. IC Role / Device Role / Timing Role: Comparator with integrated reference - REF pin biased to 9 V via resistor divider; cathode pulled high to trigger fault signal when rail drops below threshold. Use Value: Eliminates external reference IC and reduces BOM count by one component while maintaining ±1.5% trip-point accuracy over temperature. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLVH431ACPW | SOT-23-3 package (2.92 mm × 1.30 mm); same electrical specs and A-grade tolerance | Higher thermal resistance (206 °C/W vs 52 °C/W) limits power dissipation in high-current regulation | Select when board space is constrained and thermal load ≤150 mW; avoid for >20 mA continuous cathode current |
| TLVH431BPK | Same SOT-89-3 package but 0.5% initial tolerance (B grade); otherwise identical operating conditions | Lower reference drift (±4 mV over temp) supports metrology-grade references and high-precision DACs | Select when absolute reference accuracy is prioritized over cost; adds ~12% unit price premium for ±0.5% guarantee |
Compared with TLVH431ACPW, TLVH431ACPK delivers 4× better thermal performance for sustained 50–70 mA cathode loads, while TLVH431BPK trades 0.5% tighter initial tolerance for higher cost-making TLVH431ACPK the optimal balance of accuracy, thermal capability, and value for industrial power supply designs.
Availability
TLVH431ACPK is available at Aetrix Electronics and suitable for industrial power supplies, automotive body electronics, and test & measurement equipment requiring stable component supply across extended temperature ranges and multi-year production cycles.
Supply support for TLVH431ACPK 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 specializing in analog, embedded processing, and power management technologies, with decades of expertise in precision voltage references and power control ICs.
The TLVH431 family was designed specifically for low-voltage, high-accuracy shunt regulation in isolated power supplies and sensing applications-addressing limitations of legacy TL431 devices in modern 3.3 V and battery-powered systems.
FAQ
What is the minimum cathode current required for regulation in TLVH431ACPK?
The TLVH431ACPK requires a minimum cathode current of 100 μA to maintain regulation across its full operating temperature range (–40°C to +125°C). This value is specified as IK(min) in the electrical characteristics table and is critical for ensuring sufficient open-loop gain in feedback configurations. Below this threshold, the device may exhibit reduced accuracy or fail to regulate. TLVH431ACPK achieves this low requirement through optimized Darlington output stage design, enabling reliable operation in ultra-low-power applications where TL431 would drop out.
How does the SOT-89 package of TLVH431ACPK improve thermal performance compared to SOT-23 variants?
The TLVH431ACPK in SOT-89-3 offers a junction-to-ambient thermal resistance (RθJA) of 52 °C/W, significantly lower than the 206 °C/W of the SOT-23-3 (TLVH431ACPW) variant. This 75% improvement stems from the larger copper tab area and enhanced thermal path to the PCB, allowing TLVH431ACPK to dissipate up to 450 mW continuously at +85°C ambient-nearly 3× more than the SOT-23 version. This makes TLVH431ACPK suitable for higher-current shunt regulation without derating.
Can TLVH431ACPK be used as a standalone comparator without external resistors?
Yes, TLVH431ACPK can operate in open-loop comparator mode with no external feedback resistors. When supplied with ≥100 μA cathode current and a valid reference voltage applied to the REF pin, it compares that voltage to its internal 1.24 V bandgap reference and drives the cathode to sink current accordingly. This configuration is commonly used for voltage monitoring and undervoltage lockout. However, the REF pin must never be left floating-it requires a defined DC path to ensure proper NPN base biasing, as confirmed in Section 7.3 of the TI datasheet for TLVH431ACPK.
What is the significance of the 'A' suffix in TLVH431ACPK?
The 'A' in TLVH431ACPK denotes the 1% initial reference voltage tolerance grade at 25°C, distinguishing it from the standard (1.5%) and B-grade (0.5%) variants. This grading is verified during final test and applies specifically to the 1.24 V nominal VREF parameter. The 'C' indicates commercial temperature range qualification (0°C to 70°C), though the full part is also characterized for –40°C to +125°C operation per the Q-grade specification. The 'PK' suffix explicitly identifies the SOT-89-3 package variant.
Does TLVH431ACPK require an output capacitor for stability in shunt regulator applications?
No, TLVH431ACPK is internally compensated and remains stable without an output capacitor between cathode and anode-a key advantage over many linear regulators. This eliminates capacitor-related failure modes (aging, ESR drift) and simplifies layout. However, if an output capacitor is added for filtering, Figures 5-15 through 5-17 in the TI datasheet provide phase-margin guidance for selecting values up to 10 nF depending on cathode voltage and load conditions. Stability is maintained across all recommended operating conditions without external compensation components.
TLVH431ACPK 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:
- ±1%
- Temperature Coefficient:
- -
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 100 µA
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-89-3
TLVH431ACPK FAQ
1.How can I place an order for TLVH431ACPK through Aetrix?
Please submit a Request for Quotation (RFQ) for TLVH431ACPK 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 TLVH431ACPK reliable?
The price and inventory of TLVH431ACPK are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TLVH431ACPK is usually 5 days.
3.What payment methods are accepted for TLVH431ACPK?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TLVH431ACPK transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TLVH431ACPK?
TLVH431ACPK orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TLVH431ACPK 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 TLVH431ACPK?
For technical support, including TLVH431ACPK datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TLVH431ACPK requirements.
6.How does Aetrix verify that TLVH431ACPK is sourced from the original manufacturer or authorized distributors?
All TLVH431ACPK 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 TLVH431ACPK meets industry standards.
7.What is the process for return or replacement of TLVH431ACPK?
All TLVH431ACPK units undergo pre-shipment inspection (PSI). If there is an issue with TLVH431ACPK, 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 TLVH431ACPK part is unused and in its original packaging.
Return procedure for TLVH431ACPK:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
TLVH431ACPK 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…
