My Inquiry
My Account
Texas Instruments LM431AIBP
- Part No.:
- LM431AIBP
- Manufacturer:
- Texas Instruments
- Category:
- Voltage Reference
- Package:
- 4-VFBGA
- Datasheet:
-
LM431AIBP.pdf
- Description:
- IC VREF SHUNT ADJ 2.2% 4USMD
- Quantity:
- Payment:
- Shipping:
Inventory:2,064
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM431AIBP from Texas Instruments is a precision adjustable shunt voltage regulator with 2.47–2.52 V reference voltage, ±17 mV reference deviation over temperature, 0.5 Ω dynamic output impedance, and operation up to 36 V cathode voltage-used in feedback loops of linear/switching power supplies and voltage monitoring circuits.
For engineers reviewing the LM431AIBP datasheet, LM431AIBP pinout, LM431AIBP application, or LM431AIBP equivalent, this page delivers verified electrical specs, TO-92 package mapping, thermal derating guidance, and validated alternatives for precision shunt regulation design.
Technical Context
The LM431AIBP operates as a 3-terminal programmable Zener replacement, using an internal bandgap reference and high-gain comparator to control cathode current via shunt action. Its reference pin senses a resistor-divider output, enabling precise voltage setpoints from 2.5 V to 36 V.
It functions in closed-loop regulation (with external R1/R2 feedback) or open-loop comparator mode. Minimum cathode current is 0.4 mA; maximum is 100 mA under recommended conditions. Thermal hysteresis is induced by package stress, not circuit topology.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reference voltage (VREF) | 2.47–2.52 V at 10 mA - sets base accuracy for all programmable output voltages |
| Reference deviation over temp | ±17 mV across –40°C to +85°C - defines worst-case output voltage drift in industrial environments |
| Dynamic output impedance | 0.5 Ω at DC - ensures stable regulation under fast load transients without external compensation |
| Cathode voltage range | 2.5 V to 36 V - supports wide-range output programming with two external resistors |
| Min/max cathode current | 0.4 mA to 100 mA - determines minimum series resistor value and maximum shunt power dissipation |
| Average tempco | 50 ppm/°C - quantifies long-term stability per degree Celsius change in ambient temperature |
| ESD rating (HBM) | ±2500 V - indicates handling robustness during PCB assembly without special ESD controls |
Pinout & Package
LM431AIBP is packaged in a 3-pin TO-92 through-hole case (body size 4.30 mm × 4.30 mm), rated for 0.78 W at 25°C with thermal derating of 6.2 mW/°C above ambient.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (Pin 1) | Output voltage node / shunt current sink | Connects to regulated output rail; carries full load + shunt current; must be decoupled near pin |
| Anode (Pin 3) | Ground reference / current return path | Typically tied to system ground; forms return path for reference and cathode currents |
| Reference (Pin 2) | Feedback input / precision voltage sense | Connects to resistor divider midpoint; draws only 2–4 μA; sensitive to noise and layout parasitics |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable output voltage | Programmable from 2.5 V to 36 V using two external resistors - eliminates need for multiple fixed Zener diodes |
| Low-output noise | Sub-mV RMS noise enables use in precision analog references without added filtering |
| Fast turn-on response | Microsecond-scale activation supports dynamic regulation in switching supply feedback paths |
| Temperature-compensated reference | Stable 2.47–2.52 V reference across –40°C to +85°C - avoids external temperature correction circuitry |
| Low dynamic output impedance | 0.5 Ω maintains tight regulation during rapid load steps - reduces need for large output capacitance |
Applications
| Switched-Mode Power Supply Feedback | Voltage Monitoring Circuit |
|---|---|
Use Scenario: Secondary-side feedback in isolated flyback or forward converters where optocoupler-coupled error signal requires precise voltage reference. IC Role / Device Role / Timing Role: Shunt regulator providing stable 2.5 V reference to drive optocoupler LED; sets regulation threshold for error amplifier. Use Value: Enables ±1% output voltage accuracy over line, load, and temperature - critical for compliance with USB PD or telecom standards. |
Use Scenario: Overvoltage detection in battery management systems protecting Li-ion cells from >4.3 V charge termination. IC Role / Device Role / Timing Role: Precision threshold detector comparing battery voltage against programmable trip point via resistor divider. Use Value: 17 mV max reference deviation ensures reliable trip within ±0.5% of setpoint - prevents false shutdown or cell damage. |
| Current Source/Sink | Zener Diode Replacement |
Use Scenario: Constant-current LED driver for industrial status indicators requiring stable brightness across temperature. IC Role / Device Role / Timing Role: Two-terminal current source formed with LM431AIBP and single series resistor; anode grounded, cathode to LED anode. Use Value: 50 ppm/°C tempco maintains current variation <±0.4% from –40°C to +85°C - eliminates thermal dimming. |
Use Scenario: Replacing discrete 3.3 V Zener in microcontroller reset circuit where tighter tolerance and lower leakage are required. IC Role / Device Role / Timing Role: Adjustable shunt regulator configured as 3.3 V reference; replaces 5% tolerance Zener with 1% effective accuracy. Use Value: 0.3–1 μA OFF-state current reduces standby power by >90% vs. typical Zener leakage - extends battery life in always-on nodes. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar shunt regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TL431ACZ | Reference voltage 2.495 V (±0.5%), higher initial accuracy but wider tempco (92 ppm/°C); same TO-92 package and pinout | Preferred in cost-sensitive consumer designs where tighter initial tolerance matters more than long-term thermal stability | Select TL431ACZ when absolute 25°C accuracy > temperature drift performance; verify thermal hysteresis impact on final calibration |
| AS431AZTR-E1 | Reference voltage 2.5 V (±0.5%), 100 ppm/°C tempco, 1.5 Ω dynamic impedance; SOT-23-3 package, not TO-92 | Suitable for space-constrained PCBs but requires layout redesign and thermal validation due to lower power rating (0.28 W) | Choose AS431AZTR-E1 only if board area is critical and cathode current stays ≤30 mA; confirm SOIC/SOT-23 thermal derating curves match system airflow |
Compared with TL431ACZ and AS431AZTR-E1, LM431AIBP offers superior thermal stability (50 ppm/°C vs. ≥92 ppm/°C) and lower dynamic impedance (0.5 Ω vs. ≥1.5 Ω), making it optimal for industrial power supplies demanding consistent regulation across wide ambient ranges.
Availability
LM431AIBP is available at Aetrix Electronics and suitable for industrial power supplies, battery protection circuits, and precision current sources requiring stable component supply with guaranteed long-term continuity.
Supply support for LM431AIBP 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 delivering analog and embedded processing solutions, with leadership in power management, signal chain, and high-reliability components.
The LM431 product line was designed for precision voltage regulation in cost-sensitive, space-constrained power systems - targeting industrial, telecom, and consumer applications needing Zener-grade simplicity with IC-grade accuracy.
FAQ
What is the reference voltage tolerance of LM431AIBP at 25°C?
The LM431AIBP has a reference voltage (VREF) of 2.47 V to 2.52 V at 25°C and 10 mA cathode current, corresponding to ±1% initial tolerance. This is specified in the Electrical Characteristics table under "LM431A" grade in the SNVS020H datasheet, distinct from the broader LM431B/C tolerances.
Can LM431AIBP replace a standard 3.3 V Zener diode directly?
Yes, LM431AIBP can replace a 3.3 V Zener by configuring R1 and R2 to set VO = 3.3 V using VO = VREF × (1 + R1/R2). With VREF ≈ 2.495 V, R1/R2 ≈ 0.325. Unlike Zeners, LM431AIBP draws only 2–4 μA at the reference pin and exhibits lower dynamic impedance (0.5 Ω), improving regulation accuracy.
What is the maximum cathode voltage LM431AIBP supports?
The absolute maximum cathode voltage for LM431AIBP is 37 V, but the recommended operating maximum is 36 V. Exceeding 36 V risks violating Absolute Maximum Ratings and may cause irreversible damage, especially under elevated temperature or high cathode current conditions.
How does thermal derating apply to LM431AIBP in TO-92 package?
LM431AIBP in TO-92 has a 0.78 W power dissipation rating at 25°C ambient, derating linearly at 6.2 mW/°C above 25°C. At 70°C ambient, usable power drops to 0.78 W − (45 × 0.0062 W) = 0.501 W - limiting max cathode current to ~14 mA at 36 V output.
Is LM431AIBP pin-compatible with other LM431 variants in TO-92?
Yes, all LM431 variants in TO-92 (e.g., LM431ACZ, LM431BCZ, LM431CIZ) share identical pinout: Pin 1 = Cathode, Pin 2 = Reference, Pin 3 = Anode. LM431AIBP is functionally interchangeable at the board level, though reference voltage tolerance and tempco differ between A/B/C grades.
LM431AIBP Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 4-VFBGA
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Reference Type:
- Shunt
- Output Type:
- Adjustable
- Voltage - Output (Min/Fixed):
- 2.495V
- Voltage - Output (Max):
- 37 V
- Current - Output:
- 100 mA
- Tolerance:
- ±2.2%
- Temperature Coefficient:
- 50ppm/°C Typical
- Noise - 0.1Hz to 10Hz:
- -
- Noise - 10Hz to 10kHz:
- -
- Voltage - Input:
- -
- Current - Supply:
- -
- Current - Cathode:
- 1 mA
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 4-DSBGA
LM431AIBP FAQ
1.How can I place an order for LM431AIBP through Aetrix?
Please submit a Request for Quotation (RFQ) for LM431AIBP 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 LM431AIBP reliable?
The price and inventory of LM431AIBP are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM431AIBP is usually 5 days.
3.What payment methods are accepted for LM431AIBP?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM431AIBP transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM431AIBP?
LM431AIBP orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM431AIBP 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 LM431AIBP?
For technical support, including LM431AIBP datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM431AIBP requirements.
6.How does Aetrix verify that LM431AIBP is sourced from the original manufacturer or authorized distributors?
All LM431AIBP 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 LM431AIBP meets industry standards.
7.What is the process for return or replacement of LM431AIBP?
All LM431AIBP units undergo pre-shipment inspection (PSI). If there is an issue with LM431AIBP, 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 LM431AIBP part is unused and in its original packaging.
Return procedure for LM431AIBP:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM431AIBP 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…
