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Texas Instruments TLV431BIPK
- Part No.:
- TLV431BIPK
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- TO-243AA
- Datasheet:
-
TLV431BIPK.pdf
- Description:
- IC VREF SHUNT ADJ 0.5% SOT89-3
- Quantity:
- Payment:
- Shipping:
Inventory:1,455
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Product details
Overview
TLV431BIPK from Texas Instruments is a low-voltage adjustable precision shunt regulator with 0.5% reference voltage tolerance at 25°C, 1.24V nominal VREF, and operation down to 1.24V cathode-anode voltage. It delivers 0.25Ω typical dynamic impedance, 80µA typical minimum cathode current, and supports output voltage adjustment from 1.24V to 6V using two external resistors - ideal for secondary-side regulation in isolated 3.3V flyback SMPS designs.
For engineers reviewing the TLV431BIPK datasheet, TLV431BIPK pinout, TLV431BIPK application, or TLV431BIPK equivalent, key selection considerations include its SOT-89-3 package footprint (4.5mm × 4.095mm), ±11mV VREF drift over –40°C to 125°C, IK(off) < 0.1µA, and compatibility with optocoupler-based feedback loops requiring sharp turn-on and low quiescent current.
Technical Context
The TLV431BIPK implements a three-terminal shunt-regulator architecture with an internal 1.24V bandgap reference and high-gain NPN-based error amplifier driving a Darlington sink output stage. Its open-loop comparator mode enables precise voltage monitoring without external reference, while closed-loop operation with resistive feedback achieves stable voltage or current regulation.
It operates with ≥1.24V cathode-to-anode headroom and requires ≥55µA cathode current for regulation across –40°C to 125°C (TLV431BQ grade). The device is internally compensated and stable without output capacitance, though capacitive load stability boundaries are defined up to 10nF depending on VKA.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VREF @ 25°C | 1.24 V (±0.5% tolerance - enables tight-setpoint regulation in low-voltage systems) |
| VREF Drift (–40°C to 125°C) | ±11 mV (specifies TLV431BQ grade - defines worst-case setpoint shift in automotive/industrial environments) |
| Dynamic Impedance |zKA| | 0.25 Ω typical (ensures minimal output voltage variation under load transients) |
| IK(min) for Regulation | 55 µA to 100 µA (defines minimum bias current needed to maintain regulation across temperature) |
| IK(off) | < 0.1 µA (guarantees ultra-low leakage when disabled - critical for battery-backed monitoring) |
| IREF (Reference Current) | 0.1 µA to 0.5 µA (sets resistor sizing constraints for feedback network - enables high-impedance dividers) |
| Package | SOT-89-3 (4.5mm × 4.095mm - provides thermal performance RθJA = 52°C/W and PCB area efficiency vs SOT-23) |
Pinout & Package
SOT-89-3 package with exposed thermal pad (PK suffix); 3-pin configuration optimized for power dissipation in shunt-regulator applications. Pin 1 = CATHODE, Pin 2 = ANODE, Pin 3 = REF.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CATHODE (Pin 1) | Shunt current input / regulated output node | Connects to supply rail being regulated; sinks current to maintain VREF at REF pin - must be biased above ANODE by ≥1.24V |
| ANODE (Pin 2) | Common return / ground reference | Typically connected to system ground; serves as voltage reference point for both VREF and VKA measurements |
| REF (Pin 3) | Feedback input / reference threshold sense | Internally compared to 1.24V; external resistor divider connects here to set output voltage - requires ≥0.1µA bias current |
Key Features
| Feature | Design Value |
|---|---|
| Low-voltage operation | 1.24V reference enables regulation in 1.8V–3.3V systems where TL431 (2.5V) cannot function |
| Ultra-low IK(min) | 55µA minimum cathode current allows use in energy-constrained designs (e.g., always-on monitoring) |
| High-accuracy VREF | 0.5% initial tolerance (TLV431B grade) reduces calibration overhead in precision power supplies |
| Stable without output capacitor | Internal compensation eliminates need for external capacitor - simplifies layout and improves reliability |
| SOT-89 thermal performance | RθJA = 52°C/W enables 350mW+ power dissipation in standard PCB layouts - exceeds SOT-23 limits |
Applications
| Isolated Flyback SMPS Regulation | Zener Diode Replacement |
|---|---|
Use Scenario: Secondary-side voltage sensing in 3.3V isolated flyback converters using optocoupler feedback. IC Role / Device Role / Timing Role: Adjustable shunt regulator and error amplifier - compares output-derived voltage against internal 1.24V reference and drives optocoupler LED current. Use Value: Enables regulation down to ~2.7V output (1.24V + opto VF), with 0.25Ω impedance minimizing load-induced error. |
Use Scenario: Low-voltage, high-precision voltage clamping or reference generation in space-constrained PCBs. IC Role / Device Role / Timing Role: Active 3-terminal Zener replacement - provides sharp turn-on, programmable breakdown (1.24V–6V), and lower temperature drift than discrete Zeners. Use Value: 0.5% VREF tolerance and ±11mV drift over –40°C to 125°C deliver superior stability vs. 5% Zeners with >50ppm/°C drift. |
| Voltage Monitoring & Threshold Detection | Adjustable Current Sink Regulation |
Use Scenario: Undervoltage lockout (UVLO) or overvoltage detection in microcontroller power rails. IC Role / Device Role / Timing Role: Open-loop comparator with integrated reference - REF pin senses monitored voltage; CATHODE outputs logic-level signal via pull-up. Use Value: Eliminates external reference IC; 80µA typical cathode current enables direct interface with 3.3V GPIO without level-shifting. |
Use Scenario: Constant-current source for LED biasing or sensor excitation in industrial analog front-ends. IC Role / Device Role / Timing Role: Shunt-based current regulator - REF and ANODE form feedback node; cathode current mirrors setpoint defined by resistor ratio. Use Value: 0.1µA IREF enables high-value feedback resistors (>1MΩ), reducing power loss and improving noise immunity in precision current loops. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt-regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLV431BIDBVR | SOT-23-3 package (2.92mm × 2.37mm); RθJA = 206°C/W; same electrical specs and 0.5% VREF tolerance | Higher thermal resistance limits power handling; smaller footprint suits ultra-dense layouts but requires careful thermal relief | Select when board space is critical and power dissipation ≤150mW; verify copper pour for thermal management |
| TLVH431IPK | Wider VKA range (1.24V–18V); higher IK rating (80mA); same SOT-89-3 package and pinout | Supports higher-output-voltage SMPS (e.g., 12V/15V rails) and higher-current sinking - not drop-in for 6V-max designs | Choose when extending beyond 6V output or requiring >15mA cathode current; note different VREF tempco (±18mV) |
Compared with TLV431BIDBVR, TLV431BIPK offers 4× better thermal performance for sustained shunt operation; versus TLVH431IPK, it provides tighter VREF tolerance (0.5% vs 1.0%) and lower dynamic impedance (0.25Ω vs 0.35Ω) at the cost of reduced voltage headroom.
Availability
TLV431BIPK is available at Aetrix Electronics and suitable for isolated flyback SMPS regulation, precision voltage monitoring, and low-voltage Zener replacement applications requiring stable component supply and long-term industrial-grade availability.
Supply support for TLV431BIPK 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 TLV431 family was designed as a low-voltage, high-accuracy alternative to the TL431 for modern 1.8V–3.3V systems - targeting isolated power supplies, voltage supervision, and compact reference applications demanding tight tolerance and low quiescent current.
FAQ
What is the maximum cathode-to-anode voltage (VKA) rating for TLV431BIPK?
The absolute maximum VKA for TLV431BIPK is 7 V, as specified in the Absolute Maximum Ratings table. Operation beyond this voltage risks permanent damage. For reliable regulation, VKA must remain between VREF (1.24 V) and 6 V per Recommended Operating Conditions - exceeding 6 V may cause instability or parameter degradation even if below 7 V.
Does TLV431BIPK require an external output capacitor for stability?
No, TLV431BIPK is internally compensated and remains stable without an external capacitor between CATHODE and ANODE. However, if a capacitive load is added (e.g., for filtering), stability depends on value and VKA - Figure 5-19 shows phase margin vs. capacitive load, indicating safe operation up to ~10 nF at VKA = 5 V with adequate phase margin.
What is the guaranteed minimum cathode current (IK(min)) for TLV431BIPK over temperature?
TLV431BIPK guarantees IK(min) ≤ 100 µA across its full operating range of –40°C to 125°C (TLV431BQ grade). At 25°C, IK(min) is 55 µA typical. Maintaining cathode current above this threshold ensures the device remains in regulation and retains specified VREF accuracy and dynamic impedance.
Can TLV431BIPK be used as a comparator, and what are the output characteristics?
Yes, TLV431BIPK functions as an open-loop comparator with integrated 1.24V reference. In this mode, the CATHODE acts as an open-collector output: it pulls low (~1 V) when REF voltage exceeds VREF, and floats high (to external pull-up voltage) when below. Output swing and response speed depend on cathode current and overdrive - ≥100 µA IK recommended for fast transitions.
How does the SOT-89-3 package of TLV431BIPK improve thermal performance versus SOT-23 variants?
TLV431BIPK in SOT-89-3 achieves RθJA = 52°C/W, significantly lower than SOT-23-3 (206°C/W) or SOT-23-5 (206°C/W). This 4× improvement allows higher continuous power dissipation (≈350 mW vs ≈80 mW) without exceeding junction limits, making TLV431BIPK suitable for higher-current shunt applications where thermal headroom is constrained.
TLV431BIPK 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):
- 6 V
- Current - Output:
- 15 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 ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-89-3
TLV431BIPK FAQ
1.How can I place an order for TLV431BIPK through Aetrix?
Please submit a Request for Quotation (RFQ) for TLV431BIPK 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 TLV431BIPK reliable?
The price and inventory of TLV431BIPK are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TLV431BIPK is usually 5 days.
3.What payment methods are accepted for TLV431BIPK?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TLV431BIPK transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TLV431BIPK?
TLV431BIPK orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TLV431BIPK 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 TLV431BIPK?
For technical support, including TLV431BIPK datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TLV431BIPK requirements.
6.How does Aetrix verify that TLV431BIPK is sourced from the original manufacturer or authorized distributors?
All TLV431BIPK 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 TLV431BIPK meets industry standards.
7.What is the process for return or replacement of TLV431BIPK?
All TLV431BIPK units undergo pre-shipment inspection (PSI). If there is an issue with TLV431BIPK, 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 TLV431BIPK part is unused and in its original packaging.
Return procedure for TLV431BIPK:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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