LM4040B25FTA - 2.5V 0.2% Shunt Voltage Reference | Diodes Inc
料号： LM4040B25FTA ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $0.48 | $0.48 |
| 10 | $0.42 | $4.20 |
| 100 | $0.35 | $35.00 |
| 500 | $0.28 | $140.00 |
| 1,000 | $0.22 | $220.00 |
| 3,000 | $0.17 | $510.00 |
LM4040B25FTA 概述
A shunt voltage reference is a two-terminal device that regulates voltage by steering excess current to ground, similar to a Zener diode but with much tighter initial accuracy, lower dynamic impedance, and a lower temperature coefficient. Shunt references belong to the broader voltage-reference category, sitting in the signal-chain hierarchy as the precision calibration source for ADCs, DACs, regulators, and instrumentation. They are typically biased by the load current itself or by a separate resistor from a higher supply rail, and they draw whatever current is necessary to hold VOUT constant.
Key features include 4 mV typical cathode voltage tolerance, 1 mA test current for specification, very low dynamic impedance across the operating current range, and excellent long-term stability. The part is offered in industry-standard SOT-23-3 packaging with pinout that is compatible with TI LM4040 and TI LM4040-N families, simplifying second-source design. The Diodes Incorporated version is described by the manufacturer as a pin-for-pin compatible alternative to the TI LM4040 voltage reference.
The internal bandgap reference cell and trimmed thin-film resistors deliver precision performance in a wide variety of operating conditions. The architecture is a low-noise bandgap with curvature correction and dynamic-element matching, which yields the low 20 ppm/°C drift and tight initial accuracy. This translates to reliable ADC measurement accuracy over temperature and simplifies the analog front-end calibration in instrumentation, where heavy switch-mode supply noise can degrade accuracy.
Typical applications include ADC and DAC reference inputs, portable battery-powered equipment, notebook computers, cell phones, solar-powered systems, precision regulators, and automotive powertrain and chassis electronics where AEC-Q100 variants are required. The wide 60 µA to 15 mA cathode current range makes the LM4000B25FTA particularly well-suited for both low-power battery monitors and higher-current industrial loops.
When designing with this part, choose the bias resistor so that the cathode current stays between 60 µA and 15 mA across all load and temperature conditions. The device is stable with any capacitor on the cathode, including 0 µF (no bypass), so PCB designers do not need to add a minimum ESR capacitor as a voltage reference, simplifying the BOM. For best noise performance, place the device close to the load and use a low-impedance ground return.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found on the manufacturer datasheet.
直接替换替代料： LM4040B25FTA ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： LM4040B25FTA （相同外形与封装尺寸） ——差异在于 Output Voltage, Package, Dynamic Impedance, Operating Temperature Range, Temperature Coefficient.
快速对比工具——选择替代料号进行并排对比：
LM4040B25FTA
✅ 直接替换✓ 有现货
$0.17 / 个
查看数据手册 →LM4040C25FTA
✅ 直接替换📋 参考替代料（不在目录中）
LM4040A25FTA
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
LM4040D25FTA
✅ 直接替换 ⚠️ 规格未核验✓ 有现货
$0.16 / 个
查看数据手册 →LM4040BIM3-2.5/NOPB
✅ 直接替换📋 参考替代料（不在目录中）
LM4040AIM3-2.5/NOPB
✅ 直接替换✓ 有现货
$0.48 / 个
查看数据手册 →LM4040CIM3-2.5/NOPB
✅ 直接替换📋 参考替代料（不在目录中）
LM4040B25FTA 最大额定值与电气特性
| Reference Type | Shunt Voltage Reference |
| 输出电压 | 2.5 V |
| Initial Accuracy (B Grade) | ±0.2 % |
| Temperature Coefficient (max) | 100 ppm/°C |
| Temperature Coefficient (typ) | 20 ppm/°C |
| Cathode Current Range | 60 µA to 15 mA |
| Cathode Voltage Tolerance | ±4 mV (typ) |
| Dynamic Impedance | < 1 Ω (over operating current) |
| Operating Temperature (Ambient) | -40 °C to +85 °C |
| Junction Temperature Range | -40 °C to +125 °C |
| 封装 | SOT-23-3 |
| 安装类型 | Surface Mount |
| 输出配置 | Fixed |
| 引脚数 | 3 |
| RoHS 状态 | Compliant |
| Capacitive Load Stability | Stable with all capacitive loads (no minimum ESR required) |
LM4040B25FTA 引脚配置
| 引脚 1 | K (Cathode) — Reference output / positive terminal |
| 引脚 2 | A (Anode) — Ground / negative terminal |
| 引脚 3 | NC — Not connected (per datasheet) |
典型应用
LM4040B25FTA 适用于 6 应用s: ADC and DAC Reference Voltage, Portable Battery-Powered Equipment, Notebook Computer and Cell Phone Power Rails, Solar-Powered Systems, Precision Regulators and Calibration Circuits, Automotive Powertrain and Chassis Electronics.
ADC and DAC Reference Voltage
The LM4040B25FTA's 2.5 V ±0.2% initial accuracy and 20 ppm/°C typical temperature coefficient make it an ideal reference for 16-bit and lower-precision ADCs and DACs that operate from a 3.3 V or 5 V analog rail. It provides a low-impedance, low-noise reference that minimizes ADC gain error and INL/DNL drift over temperature. Placed close to the converter's REF input with a bias resistor from the analog supply, it holds the full-scale calibration within the converter's specified accuracy budget without requiring a precision op-amp buffer in most cases.
推荐
Portable Battery-Powered Equipment
The wide 60 µA to 15 mA cathode current range enables the LM4040B25FTA to operate directly from a single Li-ion or two AA cells with a single bias resistor. At low Iq it draws minimal current, extending battery life, and at higher load it can source up to 15 mA for sensor excitation or measurement circuits. The SOT-23-3 footprint occupies only a few square millimeters, making it ideal for wearables, handheld instruments, and IoT sensor nodes where PCB area and battery life are primary constraints.
推荐
Notebook Computer and Cell Phone Power Rails
The LM4040B25FTA's small SOT-23-3 footprint and minimal external component count (one bias resistor, no bypass capacitor required) make it well-suited for compact consumer electronics such as notebook computers, smartphones, and tablets. It can serve as the precision reference for battery gas-gauge ICs, display bias generators, or audio codec reference rails. Its 20 ppm/°C drift supports stable operation across the device's full thermal range without recalibration.
推荐
Solar-Powered Systems
In solar battery chargers and photovoltaic monitors, the LM4040B25FTA provides a stable 2.5 V reference for open-circuit voltage measurement, current-sense amplifier threshold, and MPPT comparator circuits. The 60 µA minimum cathode current allows operation at very low solar panel output during dim-light conditions, while the 15 mA upper limit supports daytime peak load. The wide operating temperature range handles outdoor thermal cycling from sub-zero to high-summer temperatures.
推荐
Precision Regulators and Calibration Circuits
The 2.5 V ±0.2% accuracy of the LM4040B25FTA supports use as the reference for precision LDO post-regulators, programmable voltage references, and calibration sources. It can be combined with an op-amp to generate higher or lower fixed voltages (e.g., 5.0 V or 1.25 V) with the same 20 ppm/°C stability, enabling traceable calibration standards. The low dynamic impedance keeps the output stable across load variations, simplifying the regulator compensation design.
推荐
Automotive Powertrain and Chassis Electronics
While the standard LM4040B25FTA is suitable for non-safety automotive applications, the LM4040Q AEC-Q100-qualified variant from Diodes Incorporated is recommended for powertrain and chassis applications where automotive grade screening is required. The 2.5 V reference can power sensor excitation, throttle position sensing, brake pressure transducers, and other analog signal-conditioning circuits in ECU modules. Operating reliably from -40 °C to 85 °C ambient (and up to 125 °C junction), it handles underhood thermal stress.
推荐
推荐产品汇总
工程参考数据： LM4040B25FTA ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | LM4040C25FTA | LM4040BIM3-2.5/NOPB | LM4040AIM3-2.5/NOPB | LM4040CIM3-2.5/NOPB |
|---|---|---|---|---|---|
| Brand | Diodes Incorporated | Diodes Incorporated | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | SOT-23-3 | SOT-23-3 | SOT-23-3 | SOT-23-3 | SOT-23-3 |
| Output Voltage | 2.5 V | 2.5 V | 2.5 V | 2.5 V | 2.5 V |
| Initial Accuracy | ±0.2 % (B grade) | ±0.5 % (C grade) | ±0.2 % (B grade) | ±0.1 % (A grade) | ±0.5 % (C grade) |
| Temperature Coefficient (max) | 100 ppm/°C | 100 ppm/°C | 100 ppm/°C | 100 ppm/°C | 100 ppm/°C |
| Capacitive Load Stability | Stable (any cap, no minimum ESR) | Stable (any cap, no minimum ESR) | Stable (any cap, no minimum ESR) | Stable (any cap, no minimum ESR) | Stable (any cap, no minimum ESR) |
| Automotive Grade (AEC-Q100) | No (Q variant available separately) | No (Q variant available separately) | Available in Q version | Available in Q version | Available in Q version |
| Pin-to-pin Replacement of Target | — | Yes, same package and pinout | Yes, manufacturer-confirmed pin-for-pin compatible | Yes, same SOT-23-3 pinout | Yes, same SOT-23-3 pinout |
关键差异点
- Pin-for-pin compatible with TI LM4040 （对比 TI LM4040BIM3-2.5/NOPB)
- Tightest B-grade initial accuracy in same family （对比 LM4040C25FTA)
- Upgrade path to A-grade via same footprint （对比 LM4040AIM3-2.5/NOPB)
设计说明
Choose the bias resistor so that the cathode current stays between 60 µA and 15 mA across all load and temperature conditions. Estimated: for Vsupply=5 V, Vref=2.5 V, max load=1 mA, R_bias = (5-2.5) V / (60 µA + 1 mA) ≈ 2.4 kΩ. Verify with bench measurement at min/max temperature, since the LM4040 has low dynamic impedance across the operating range.
The LM4040B20FTA is stable with any capacitive load including 0 µF, so no bypass capacitor is required. However, if the trace length to the load (e.g., ADC REF input) exceeds several centimeters, add a 100 nF ceramic capacitor as close to the load as possible to filter high-frequency noise. Place the device near the load to minimize IR drop and noise pickup.
Do not confuse the SOT-23-3 pinout with the TO-92 (through-hole) variant; the SOT-23-3 has pin 1 = Cathode, pin 2 = Anode, pin 3 = NC, whereas the TO-92 may have a different pin order. Also, the standard MTP I2C variant is not AEC-Q100 qualified; for automotive applications, order the MTP Q suffix variant from Diodes Incorporated or use the TI LM3104-N AEC-Q100 part.
合规信息
RoHS compliant per Diodes Incorporated product page. Standard LM4040B25FTA is not AEC-Q100 qualified; choose LM4040Q variant from Diodes Incorporated for automotive grade screening.
