TL432AIL3T - 2.495-36V Adj Shunt V-Ref, 1%, SOT-23-3 | STMicroelectronics
부품 번호: TL432AIL3T ✓ 활성| 수량 | 단가 | 합계 |
|---|---|---|
| 1 | $0.42 | $0.42 |
| 10 | $0.36 | $3.60 |
| 100 | $0.28 | $28.00 |
| 500 | $0.22 | $110.00 |
| 1,000 | $0.18 | $180.00 |
| 3,000 | $0.14 | $420.00 |
TL432AIL3T 개요
A shunt voltage reference is a two-terminal device that behaves like a programmable Zener diode: when biased with a current source above its minimum cathode current (typically 1 mA), it holds its cathode voltage at a precise reference value. The TL432 extends the classic TL431 family with a reverse pinout (cathode-anode-reference on pins 1-2-3 instead of reference-anode-cathode), enabling simpler PCB routing in many polarity-sensitive designs. The TL432 belongs to the broader class of linear voltage references - subcategory of power management ICs - sitting alongside series and shunt regulators.
Key features include guaranteed temperature stability across the full automotive range, 100 mA continuous sink current capability, low typical output impedance of 0.22 ohm, and a sharp turn-on characteristic that makes it usable as a voltage comparator or error amplifier. The 1% voltage precision grade (A suffix) suits precision analog circuits, while the lower-cost B and C grades offer 1% and 2% tolerance for cost-optimized designs.
The TL432 uses a buried-Zener bandgap architecture with on-chip temperature compensation. Output voltage is programmed by an external resistor divider: VOUT = VREF * (1 + R1/R2), where VREF = 2.495 V. The same die is offered in the TL431 family with mirrored pinout, allowing engineers to standardize on one footprint design.
Typical applications include adjustable voltage regulators, switching power supply feedback loops, precision current sources, ADC/DAC reference rails, and automotive ECU voltage monitoring. The wide 2.495 V to 36 V output range and automotive temperature grade make it suitable for 12 V/24 V automotive subsystems and industrial 24 V bus systems.
When designing with the TL432, always ensure cathode current stays between 1 mA (minimum) and 100 mA (maximum), and add a 0.1 uF bypass capacitor across the reference node when used in noisy switching environments. The SOT-23-3 package has a thermal resistance around 250 C/W, so continuous dissipation above 50 mW requires thermal analysis.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone.
드롭인 대체품: TL432AIL3T — 동일 패키지, 핀 호환. PCB 재작업이 필요한 다른 패키지 부품은 제외됩니다.
이 시리즈의 변형
다음과 드롭인 호환되는 동일 시리즈 모델: TL432AIL3T (동일 폼 팩터 및 풋프린트) — 차이점: MSL Level, Package.
빠른 비교 도구 — 나란히 비교할 대체 부품을 선택하십시오:
TL432BIL3T
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
TL432CIL3T
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
TL432AIL3T 사양
| Product Type | Adjustable Shunt Voltage Reference |
| Reference Voltage (Vref) | 2.495 V |
| 출력 전압 범위 | 2.495 V to 36 V |
| Initial Accuracy | 1% (A grade) |
| Cathode Current Range (Ik) | 1 mA to 100 mA |
| Typical Output Impedance | 0.22 ohm |
| 동작 온도 범위 | -40 C to +125 C (automotive) |
| 패키지 | SOT-23-3 (L3T) |
| 실장 유형 | Surface Mount |
| MSL 레벨 | 1 (unlimited) |
| Pinout Orientation | Reverse (Cathode-Anode-Ref) vs TL431 |
| RoHS 상태 | Compliant |
| Lead-Free | Yes |
| Automotive Grade | Yes (-40 C to +125 C) |
| Reference Family | TL432 (TL431 reverse pinout family) |
TL432AIL3T 핀 구성
| 핀 1 | K (Cathode) — Cathode - current sinks to ground via external bias resistor |
| 핀 2 | A (Anode) — Anode - typically connected to ground |
| 핀 3 | Ref — Reference - external resistor divider sets VOUT |
일반적인 애플리케이션
TL432AIL3T 적합 용도: 6 애플리케이션s: Adjustable Voltage Regulator Reference, Switching Power Supply Feedback, Automotive ECU Voltage Monitoring, ADC/DAC Precision Reference Rail, Constant Current Source / Sink, Comparator and Threshold Detector.
Adjustable Voltage Regulator Reference
The TL432AIL3T serves as the precision feedback reference for adjustable linear regulators and switching converters, holding VOUT at any value from 2.495 V to 36 V via an external resistor divider. With 1% initial accuracy and 0.22 ohm typical output impedance, it provides stable reference for DC-DC converter feedback loops. A 10 nF capacitor on the reference pin improves noise rejection, and the 100 mA cathode current capability allows direct biasing from a 12 V or 24 V supply through a single bias resistor. The SOT-23-3 footprint occupies less than 6 mm^2 of PCB area, making it ideal for compact POL (point-of-load) designs in industrial 24 V bus systems.
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Switching Power Supply Feedback
In isolated and non-isolated switching power supplies, the TL432AIL3T forms the error amplifier reference in the secondary-side feedback path. The opto-isolated feedback loop uses the TL432 to compare the divided output voltage against its 2.495 V reference; the error current drives the optocoupler LED back to the primary-side PWM controller. With 1% voltage tolerance, output regulation accuracy of +/-1.5% is achievable across load and line variations. The wide cathode current range (1 mA to 100 mA) accommodates light-load to full-load feedback currents, while the -40 C to +125 C automotive temperature range ensures stable operation in harsh environments.
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Automotive ECU Voltage Monitoring
The TL432AIL3T's automotive-grade temperature range (-40 C to +125 C) and 36 V maximum cathode voltage make it well suited to monitor 12 V and 24 V automotive battery rails. Configured as a comparator with VREF = 2.495 V and a resistor divider scaling the battery voltage down, it generates a logic-level fault signal when the rail falls outside safe limits (e.g., undervoltage or overvoltage detection for ECU reset). The 100 mA sink current can drive small relay coils or MOSFET gates directly, eliminating an extra driver stage. This compact SOT-23-3 voltage supervisor outperforms discrete Zener+transistor solutions in accuracy, temperature stability, and PCB footprint.
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ADC/DAC Precision Reference Rail
Precision analog-to-digital and digital-to-analog converters require low-drift, low-impedance reference voltages to achieve their rated linearity and noise performance. The TL432AIL3T's 0.22 ohm typical output impedance provides tight load regulation for SAR ADCs and sigma-delta ADCs drawing milliamps of reference current, while its 1% initial accuracy translates to a known, repeatable reference at 25 C. With a single external resistor divider, the user can scale the internal 2.495 V reference up to the ADC's required VREF (commonly 2.5 V, 3.3 V, 4.096 V, or 5.0 V). Add a 10 uF tantalum or ceramic bypass capacitor on the reference pin to absorb transient reference current demands during ADC conversions.
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Constant Current Source / Sink
The TL432AIL3T combined with a single external pass transistor forms a programmable constant current sink or source. The TL432 monitors the voltage across a sense resistor in series with the load, comparing it to the 2.495 V reference; when the load current exceeds the programmed setpoint, the TL432 shunts base drive away from the pass transistor, regulating the current. Typical accuracy is +/-2% to +/-5% depending on sense resistor tolerance and transistor beta. Common uses include LED drivers (constant brightness regardless of supply voltage), battery chargers (constant current phase), and 4-20 mA industrial current loop transmitters where the loop current must be tightly controlled.
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Comparator and Threshold Detector
The TL432AIL3T's sharp turn-on characteristic and 1 mA minimum cathode current allow it to be used as a low-cost analog comparator. The reference pin connects to the threshold divider (e.g., VREF x (1+R1/R2)), while the cathode pin monitors the input signal; when the input exceeds the threshold, the cathode saturates low, and vice versa. Typical response time is 1 us to 5 us, suitable for non-critical comparator applications such as battery low-voltage alarms, window comparators, and Schmitt trigger circuits. Compared to a dedicated comparator IC, the TL432 is cheaper and smaller, though slower and with less precise output swing. It excels in cost-sensitive designs where precision is moderate.
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추천 제품 요약
엔지니어링 참조 데이터: TL432AIL3T — 비교, 설계 지침 및 규정 준수 정보.
선택 가이드
대체품과의 비교
| 파라미터 | 이 제품 | TL432BIL3T | TL432CIL3T | TL431AIL3T |
|---|---|---|---|---|
| Package | SOT-23-3 (L3T) | SOT-23-3 (L3T) - same | SOT-23-3 (L3T) - same | SOT-23-3 - same outline, reversed pinout |
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics |
| Initial Accuracy | 1% (A grade) | 2% (B grade) | 2% (C grade) | 1% (A grade) |
| Output Voltage Range | 2.495 V to 36 V | 2.495 V to 36 V | 2.495 V to 36 V | 2.495 V to 36 V |
| Cathode Current Range | 1 mA to 100 mA | 1 mA to 100 mA | 1 mA to 100 mA | 1 mA to 100 mA |
| Pinout Orientation | Reverse (K-A-Ref) | Reverse (K-A-Ref) - same | Reverse (K-A-Ref) - same | Forward (Ref-A-K) |
| Typical Output Impedance | 0.22 ohm | 0.22 ohm | 0.22 ohm | 0.22 ohm |
| Operating Temperature | -40 C to +125 C | -40 C to +125 C | -40 C to +125 C | -40 C to +125 C |
| Unit Price (qty 1000) | $0.18 | $0.14 | $0.12 | $0.18 |
주요 차별점
- Reverse pinout enables direct PCB mirroring of TL431 designs (vs TL431AIL3T)
- 1% initial accuracy with automotive temperature range in SOT-23-3 (vs TL432BIL3T)
- 100 mA cathode current in smallest industry-standard package (vs TL432AILP (TO-92))
설계 노트
Bias the TL432AIL3T cathode with a resistor Rbias = (VIN - VREF) / Ik. Choose Ik between 5 mA and 20 mA to optimize noise performance versus power dissipation. At Ik = 10 mA and VIN = 12 V, Rbias = (12 V - 2.495 V) / 10 mA = 950 ohm (use 1 kohm standard value). At Ik = 100 mA full load, dissipation in the TL432 reaches (VIN - VREF) x Ik = (36 V - 2.495 V) x 100 mA = 3.35 W - well above the SOT-23-3 package rating, so design for typical Ik = 10 mA to 30 mA.
Do not operate the TL432AIL3T below 1 mA cathode current - the reference will not regulate and may oscillate. Do not exceed 100 mA continuous cathode current or the SOT-23-3 package will overheat (estimated thermal resistance 250 C/W, junction rises 250 C at 1 W dissipation). Add a 0.1 uF to 10 uF bypass capacitor from Ref to Anode when used in switching supply feedback loops to prevent reference instability from injected switching noise.
Place the TL432AIL3T close to the optocoupler in isolated supply feedback layouts to minimize parasitic loop area. Keep high-current switching traces (primary-side MOSFET drain, secondary rectifier) away from the reference pin to avoid capacitive coupling of switching noise. Use a ground-plane pour under the device and connect the Anode pin directly to the ground plane with a short trace - any impedance in the Anode path appears as reference error.
규정 준수 정보
TL432AIL3T is specified for -40 C to +125 C automotive temperature range. For AEC-Q100 certified qualification, the Q1-suffix variant is required. RoHS and REACH compliant per STMicroelectronics product page.
