TLV431AE5TA - 1.24V Adj Shunt Reference ±1% | Diodes Inc
MPN: TLV431AE5TA ✓ Hoạt độngTLV431AE5TA Tóm tắt
A shunt voltage reference is a three-terminal non-isolated regulator that maintains a fixed voltage between its reference and anode pins whenever the cathode-to-anode voltage exceeds the programmed output. It belongs to the broader family of voltage references (sub-category of power management ICs), which also includes series references, buried-zener references, and bandgap references. TLV-style parts sit at the low-voltage end, optimized for rails common in battery-powered and 3.3 V/5 V logic systems where classic 2.5 V/5 V TL431 references have insufficient headroom. The TLV431 is the lower-VREF counterpart to the TL431, sharing the same basic two-resistor feedback topology.
Key features include ±1% voltage tolerance at 25°C, ±2.0% accuracy over the entire industrial temperature range to 85°C, low cathode saturation voltage for efficient low-dropout operation, and low dynamic impedance. The TLV431A series is offered in several accuracy grades (A/B), while the TLV431E5 suffix in this part indicates the SC-74A / SOT-753 tape-and-reel packaging variant.
Architecturally the device uses a bandgap-style cell plus a feedback amplifier that compares the divided output against the internal 1.24 V reference, then modulates cathode current to hold the programmed node stable. Because it is a shunt part, the user must provide a series resistor from the supply, and the cathode current must remain above the regulator's minimum operating point across all load conditions.
Typical applications include secondary-side regulation in isolated switch-mode power supplies (as the error-amplifier reference), adjustable precision clamp circuits, low-voltage adjustable zener replacements, and portable/battery-powered equipment rails. It is also commonly used as a comparator with reference in battery chargers and monitors.
When designing, always size the series resistor so the cathode current stays above the minimum regulation point (typically ~80 µA for TLV431) but below the 15 mA absolute maximum; use 1% divider resistors to preserve VOUT accuracy, and bypass noisy nodes with a small capacitor if oscillation is observed.
This page synthesizes distributor pricing, drop-in alternates, and practical design notes not found in the manufacturer datasheet alone.
Bộ thay thế dễ dàng lắp đặt cho TLV431AE5TA — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
Các biến thể trong loạt này
Các mẫu cùng loạt có thể lắp đặt dễ dàng tương thích với TLV431AE5TA (cùng hình factor và footprint) — khác nhau ở Package, Reference Type.
TLV431AILT
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
TLV431AINT
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
TLV431AINX
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
TL431ACDBVR
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
TL432BSA-7
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →TLV431AE5TA Tỷ lệ tối đa & tính chất điện
| Reference Type | Shunt, Adjustable |
| Output Voltage (Nominal) | 1.24 V |
| Khoảng điện áp đầu ra | 1.24 V to 18 V (programmable) |
| Initial Accuracy (TLV431A) | ±1% at 25°C |
| Accuracy Over Temperature | ±2.0% to 85°C industrial range |
| Maximum Cathode Voltage (VKA max) | 18 V |
| Maximum Cathode Current (IKA) | 15 mA (Diodes datasheet; up to 20 mA on Zetex datasheet) |
| Khoảng nhiệt độ hoạt động | -40°C to +85°C (industrial) |
| Hộp | SOT-25 (SC-74A, SOT-753) |
| Kiểu lắp đặt | Surface Mount |
| Số lượng chân | 5 |
| Trạng thái RoHS | Compliant |
| Lead-Free / Halogen-Free | Lead-free (per Diodes product page) |
| Datasheet Pages | 16 (Zetex / Diodes Inc. datasheet) |
Cấu hình chân TLV431AE5TA
| Chân 1 | REF — Reference input (connects to resistor divider) |
| Chân 2 | A — Anode (ground reference) |
| Chân 3 | NC — Not connected (per datasheet) |
| Chân 4 | K — Cathode (VKA, regulated output / clamp) |
| Chân 5 | A — Anode (ground reference, tied to pin 2) |
Ứng dụng tiêu biểu
TLV431AE5TA phù hợp cho 6 Áp dụngs: Secondary-Side SMPS Regulation, Portable / Battery-Powered Equipment, Adjustable Precision Zener Replacement, Comparator-With-Reference in Battery Chargers, Low-Voltage Reference for ADC/DAC Front Ends, Industrial Control Loop Setpoint.
Secondary-Side SMPS Regulation
The TLV431AE5TA's 1.24 V reference and 18 V maximum cathode voltage make it ideal for secondary-side regulation in isolated switch-mode power supplies (SMPS). Used as an error-amplifier reference in the optocoupler feedback path, it compares the divided output against VREF and drives the TL431-style feedback loop. With ±1% initial accuracy and ±2% industrial temperature drift, it supports 5 V/12 V rails typical of AC-DC adapters and DC-DC bricks.
Được đề xuất
Portable / Battery-Powered Equipment
The 1.24 V nominal reference of the TLV431AE5TA is well below the voltage of a single Li-ion cell (3.0-4.2 V), enabling sub-2.5 V rails from a single-cell battery. Used as a programmable low-voltage reference in portable medical, IoT sensor nodes, and wearable devices, it draws negligible cathode current at light loads. Its small SOT-25 footprint (2.9 mm x 1.6 mm) is suited for compact handheld enclosures where board area is constrained.
Được đề xuất
Adjustable Precision Zener Replacement
The TLV431AE5TA replaces legacy 1N47xx-series zener diodes in voltage-clamp and precision-shunt applications. Zeners drift considerably with current and temperature, while the TLV431AE5TA delivers a flat voltage-vs-current characteristic with ±1% initial accuracy. Used as a programmable sub-18 V clamp on RS-485 transceivers and op-amp supply pins, it provides quieter, more stable protection than a raw zener.
Được đề xuất
Comparator-With-Reference in Battery Chargers
In single- and multi-cell Li-ion charger circuits, the TLV431AE5TA acts as a low-cost precision comparator-with-reference, sensing battery voltage through a divider and driving a charge-enable transistor. With its 1.24 V reference point, designers can set any cell-voltage threshold from 3.0 V to 4.2 V by resistor selection. Its 15 mA cathode sink drives discrete MOSFET gates or BJT bases directly without an additional buffer stage.
Được đề xuất
Low-Voltage Reference for ADC/DAC Front Ends
Precision ADCs and DACs often require a sub-2.5 V reference that cannot be supplied by a TL431 (VREF 2.495 V). The TLV431AE5TA, programmed to 1.25 V or 2.048 V by two external resistors, supplies a quiet ratiometric reference for 16-bit SAR ADCs and audio DACs operating from 3.3 V rails. Its low dynamic impedance holds the reference stable during ADC conversion bursts.
Được đề xuất
Industrial Control Loop Setpoint
In 24 V industrial PLCs and process-control loops, the TLV431AE5TA supplies an adjustable precision reference for analog setpoint potentiometers, setpoint calibrators, and 4-20 mA loop excitation. Its 18 V max cathode voltage covers the 15 V regulated rail common in industrial sensors, while the 1.24 V baseline allows sub-5 V analog setpoints without resorting to a separate low-voltage reference.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho TLV431AE5TA — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | TLV431AILT | TLV431AINT | TLV431AINX | TL431ACDBVR | TL432BSA-7 |
|---|---|---|---|---|---|---|
| Brand | Diodes Incorporated | Diodes Incorporated | Diodes Incorporated | Diodes Incorporated | Texas Instruments | Diodes Incorporated |
| Package | SOT-25 (SC-74A, SOT-753) - 5 pins | SOT-25 - same | SOT-25 - same | SOT-25 - same | SOT-23-5 - 5-pin SMD (footprint-compatible) | SOT-23-5 - 5-pin SMD (footprint-compatible) |
| Reference Voltage (VREF) | 1.24 V | 1.24 V | 1.24 V | 1.24 V | 2.495 V (rescale divider) | 1.24 V (typical TL432) |
| Initial Accuracy | ±1% (TLV431A grade) | ±1% (TLV431A grade) | ±1% (TLV431A grade) | ±1% (TLV431A grade) | ±1% (TL431A grade) | ±1% (TL432B grade) |
| Max Cathode Voltage (VKA) | 18 V | 18 V | 18 V | 18 V | 36 V | 18 V |
| Max Cathode Current | 15 mA | 15 mA | 15 mA | 15 mA | 100 mA | 100 mA |
| Operating Temperature | -40°C to +85°C (industrial) | -40°C to +85°C | -40°C to +85°C | -40°C to +85°C | -40°C to +125°C (automotive Q1) | -40°C to +125°C |
| Unit Price (qty 1, USD) | $0.45 | ~$0.45 (same die, packaging variant) | ~$0.45 (same die, packaging variant) | ~$0.45 (same die, packaging variant) | ~$0.18 (cross-brand reference) | ~$0.20 (same-brand TL432) |
Bảo phân biệt quan trọng
- Five-pin SOT-25 with explicit REF pin simplifies PCB layout (vsTL431ACDBVR)
- 1.24 V VREF enables sub-2.5 V precision rails (vsTL431ACDBVR)
- Diodes-sourced, broad secondary-market availability (vsTLV431AILT)
Ghi chú thiết kế
Estimated: when designing with the TLV431AE5TA, the most common pitfall is letting the cathode current drop below the minimum regulation point (~80 µA for TLV431) at light load, which causes output voltage droop and oscillation. Size the series resistor RS so IKA(min) = (VIN - VOUT)/RS > 80 µA under maximum VOUT and minimum load, AND IKA(max) = (VIN - VOUT)/RS < 15 mA under minimum VOUT and full load. Always include a small (100 nF to 1 µF) capacitor on the cathode if the load is dynamic or the source is inductive.
Keep the TLV431AE5TA divider-resistor loop tight and short. Use 1% tolerance resistors for R1/R2 to preserve the ±1% reference accuracy. Place the TLV431AE5TA close to the load it regulates; long traces add inductance that can couple noise into the reference node. Use a ground plane under the device to keep thermal resistance low (SOT-25 has limited power dissipation - typically 250 mW at 25°C derating).
The TLV431AE5TA SOT-25 package has a typical power dissipation of 250 mW at 25°C, derated linearly to zero at +150°C. The dominant thermal source is the cathode current times VKA. Estimated: at VKA = 5 V and IKA = 10 mA, Pdiss = 50 mW; at VKA = 15 V and IKA = 15 mA, Pdiss = 225 mW - approaching the 250 mW limit. For continuous operation above 5 mA at high VKA, ensure adequate copper pour or use a larger DPAK reference part.
Thông tin tuân thủ
RoHS compliant and lead-free per Diodes Incorporated product page. Halogen-free status not explicitly stated in the verified web data; consult the latest manufacturer datasheet revision. Not AEC-Q100 qualified - the TLV431 series is industrial-grade, not automotive-grade. Conflict-mineral compliance per Diodes Incorporated corporate policy.
