ATL432LIBIDBZR - 2.5V Adjustable Shunt Reference, ±0.5%, SOT-23-3 | Texas Instruments
MPN: ATL432LIBIDBZR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.62 | $0.62 |
| 10 | $0.54 | $5.40 |
| 100 | $0.41 | $41.00 |
| 500 | $0.32 | $160.00 |
| 1,000 | $0.26 | $260.00 |
ATL432LIBIDBZR Overview
A shunt voltage reference is a two-terminal device that maintains a constant voltage between its cathode and anode by sinking or sourcing current, behaving like a precision Zener diode with a programmable breakdown voltage. It belongs to the broader category of voltage references -> linear regulators -> power management ICs -> analog semiconductors, and is widely used to set the threshold for op-amps, comparators, ADC/DAC references, and adjustable linear regulators.
Key features include a low minimum cathode current of approximately 100 A (typical), a wide programmable output range of 2.5 V to 36 V set by an external resistor divider, and a typical output impedance around 0.05 ohm at low frequencies. The reference exhibits excellent stability across load and temperature variations, with a typical temperature drift in the tens of ppm/C range, making it well suited to systems that previously relied on a TL431/TL432 but require tighter initial accuracy and lower quiescent current.
The ATL432 uses a bandgap reference core with a bipolar process technology. The DBZ (SOT-23-3) package is pin-compatible with the industry-standard TL431/TL432 footprint but with an inverted pinout, where the reference terminal is pin 2 instead of pin 1. The device is qualified across the -40C to +125C operating range and is offered in tape and reel packaging for high-volume manufacturing.
Typical applications include secondary-side regulation in isolated DC-DC converters, adjustable precision voltage monitoring, precision current limiting, threshold detection in comparators, and low-power analog bias generation in battery-powered IoT and portable industrial equipment.
When designing with the ATL432LIBIDBZR, ensure the cathode current stays within the minimum/maximum limits under all operating conditions and place the device close to the load to minimize parasitic resistance.
This page synthesizes TI datasheet parameters, distributor pricing, and practical design notes into a single reference not found in the manufacturer datasheet alone.
Drop-in alternatives for ATL432LIBIDBZR — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with ATL432LIBIDBZR (same form factor and footprint) — differing in Operating Temperature Range, Package, Reference Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATL432LIAIDBZR
✅ Drop-In📋 Reference alternative (not in catalog)
ATL432LIBIDBZRQ1
✅ Drop-In📋 Reference alternative (not in catalog)
TL432LIBIDBZR
✅ Drop-In📋 Reference alternative (not in catalog)
TL431LIBIDBZR
✅ Drop-In📋 Reference alternative (not in catalog)
ATL432LIBQDBZR
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
ATL432LIBIDBZR Specifications
| Reference Type | Shunt, Adjustable |
| Reference Voltage (Vref) | 2.5 V |
| Output Voltage Range | 2.5 V to 36 V |
| Initial Accuracy (B grade) | ±0.5% (at 25C) |
| Cathode Current (max) | 100 mA |
| Minimum Cathode Current (Imin) | 0.1 mA (typical, low-Iq) |
| Output Impedance | 0.05 ohm (typical at low frequency) |
| Operating Temperature Range | -40C to +125C |
| Package | SOT-23-3 (DBZ) |
| Pin Count | 3 |
| Mounting Type | Surface Mount |
| Tape and Reel Quantity | 3000 |
| RoHS Status | Compliant |
| Lead-Free | Yes |
| Pinout | Pin 1: Cathode, Pin 2: Reference, Pin 3: Anode (DBZ, inverted vs TL432) |
ATL432LIBIDBZR Pin Configuration
| Pin 1 | CATHODE — Cathode (K) - shunt current flows into this pin |
| Pin 2 | REFERENCE — Reference (REF) - resistor divider sets Vka to 2.5 V x (1+R1/R2) |
| Pin 3 | ANODE — Anode (A) - ground reference for the shunt regulator |
Typical Applications
ATL432LIBIDBZR is suitable for 7 applications: Isolated DC-DC Converter Secondary-Side Reference, Adjustable Precision Voltage Monitor, Precision Current Limiting / Constant-Current Sink, Comparator Threshold Detection, Adjustable Linear Regulator Reference, Battery-Powered IoT Sensor Bias, Power-Supply Over-Voltage Protection.
Isolated DC-DC Converter Secondary-Side Reference
The ATL432LIBIDBZR generates a precision 2.5 V reference on the secondary side of an isolated DC-DC converter, where the TL431-style architecture drives an optocoupler to close the primary-side regulation loop. Its adjustable cathode voltage up to 36 V allows the same part to set primary-side feedback at 3.3 V, 5 V, 12 V, or 15 V outputs by changing the resistor divider. The low minimum cathode current (~100 uA typical) keeps quiescent loss minimal in light-load standby, improving overall converter efficiency at no-load conditions.
Recommended
Adjustable Precision Voltage Monitor
The ATL432LIBIDBZR serves as the threshold-setting element in adjustable voltage monitoring circuits, where it drives a comparator or directly toggles a logic output when an input rail drifts outside its programmed window. The 2.5 V reference and external resistor network allow thresholds anywhere between 2.5 V and 36 V, so the same part can supervise 3.3 V, 5 V, 12 V, or 24 V rails. Its low-Iq cathode current suits portable battery systems that require always-active monitoring.
Recommended
Precision Current Limiting / Constant-Current Sink
The ATL432LIBIDBZR functions as the precision shunt regulator in a constant-current sink or programmable current-limit circuit. Combined with a sense resistor between its cathode and reference pins, it forces a stable current load for LED driving, battery test, or precision current-mirror biasing. The 2.5 V reference multiplied by the sense-resistor value determines the load current, and the same DBZ SOT-23 footprint enables compact constant-current modules.
Recommended
Comparator Threshold Detection
The ATL432LIBIDBZR provides a stable reference for comparator threshold detection in over-voltage, under-voltage, and window-comparator circuits. The 2.5 V reference combined with a resistor divider sets the comparator trip point, and the reference's low temperature drift maintains trip accuracy across the -40C to +125C operating range. Industrial control, battery management, and motor-drive fault circuits benefit from this stable, low-Iq reference.
Recommended
Adjustable Linear Regulator Reference
The ATL432LIBIDBZR replaces a fixed reference IC to create an adjustable-output LDO when its reference voltage and resistor network set the feedback point. By tying the divider to a linear regulator's feedback node, designers achieve a programmable output that tracks the precision of the ATL432's 2.5 V bandgap reference. The low-Iq operation also keeps overall LDO quiescent current low, supporting portable and battery-powered designs.
Recommended
Battery-Powered IoT Sensor Bias
The ATL432LIBIDBZR supplies a precision bias voltage to low-power analog front ends, op-amps, and sensor excitation circuits in battery-powered IoT nodes. The 2.5 V reference combined with the low minimum cathode current (~100 uA typical) keeps quiescent draw minimal while delivering a reference more accurate than typical LDO outputs. The compact SOT-23-3 (DBZ) footprint fits space-constrained wearable designs.
Recommended
Power-Supply Over-Voltage Protection
The ATL432LIBIDBZR drives an OVP crowbar or load-disconnect circuit when a downstream rail exceeds its programmed threshold. The 2.5 V reference multiplied by the resistor divider allows the OVP trip to track 3.3 V, 5 V, 12 V, or 24 V rails. The 100 mA maximum cathode current is sufficient to drive medium-power SCR crowbars or low-side FET gate pulls in fault conditions, making the ATL432 a compact, low-cost OVP building block.
Recommended
Recommended Products Summary
Engineering reference data for ATL432LIBIDBZR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATL432LIAIDBZR | ATL432LIBIDBZRQ1 | TL432LIBIDBZR | TL431LIBIDBZR |
|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | SOT-23-3 (DBZ) | SOT-23-3 (DBZ) - same | SOT-23-3 (DBZ) - same | SOT-23-3 (DBZ) - same | SOT-23-3 (DBZ) - same |
| Reference Voltage | 2.5 V | 2.5 V | 2.5 V | 2.5 V | 2.5 V |
| Initial Accuracy | ±0.5% (B grade) | ±1% (A grade) | ±0.5% (B grade) | ±1% to ±2% (grade dependent) | ±1% to ±2% (grade dependent) |
| Cathode Voltage Range | 2.5 V to 36 V | 2.5 V to 36 V | 2.5 V to 36 V | 2.5 V to 36 V | 2.5 V to 36 V |
| Minimum Cathode Current | ~100 uA (low-Iq) | ~100 uA (low-Iq) | ~100 uA (low-Iq) | Higher Imin than ATL43x | Higher Imin than ATL43x |
| Pinout (DBZ) | 1=K, 2=REF, 3=A (inverted TL432) | 1=K, 2=REF, 3=A | 1=K, 2=REF, 3=A | 1=REF, 2=K, 3=A (inverted) | 1=REF, 2=K, 3=A |
| Automotive Grade | No | No | Yes (AEC-Q100) | No | No |
| Operating Temperature | -40C to +125C | -40C to +125C | -40C to +125C | -40C to +125C | -40C to +125C |
Key Differentiators
- Lower minimum cathode current (low-Iq) than legacy TL432 (vs TL432LIBIDBZR)
- Tighter initial accuracy option (B grade ±0.5%) (vs TL432LIBIDBZR)
- Pinout inverted vs TL432 (pin 1 = Cathode) (vs TL432LIBIDBZR)
Design Notes
Do not confuse the ATL432 DBZ pinout (pin 1 = Cathode, pin 2 = Reference) with the TL432 DBZ pinout (pin 1 = Reference, pin 2 = Cathode). According to the TI ATL432 product page, swapping pins 1 and 2 will produce a reference that does not regulate. Verify the footprint marking against the TI datasheet before PCB assembly.
Cathode current must stay above the minimum Imin (~100 uA for ATL432) under all operating conditions, including no-load. For a 12 V cathode rail with a 10 kohm upper resistor, the resistor alone supplies only ~1 mA; ensure the load draws the balance or add a bias resistor. Operating below Imin causes loss of accuracy and possible dropout.
Place the ATL432LIBIDBZR as close as possible to the load or to the optocoupler it drives, keeping the reference-pin trace short to prevent noise pickup. Use a 0.1 uF ceramic bypass capacitor on the cathode when driving high-impedance or capacitive loads, and keep the resistor-divider traces away from switching nodes to avoid coupling noise into the reference voltage.
Estimated: Power dissipation = (Vin - Vka) x Ik. For Vin=36 V, Vka=2.5 V, Ik=15 mA, dissipation = 0.50 W. With the SOT-23-3 (DBZ) theta_JA around 200 C/W (per typical JEDEC test board), junction temperature rises ~100C above ambient. For high-cathode-voltage high-current applications, calculate Pd and Tj before committing to the DBZ package.
Compliance Information
Standard ATL432LIBIDBZR is not AEC-Q100 qualified; the ATL432LIBIDBZRQ1 suffix is the qualified option for automotive.
