LM2903MX - Dual Differential Comparator | Texas Instruments
料号： LM2903MX ✓ 量产中LM2903MX 概述
An analog comparator is an integrated circuit that evaluates two input voltages and changes its output state according to their relative polarity. Within the semiconductor hierarchy, a comparator belongs to the broader group of analog ICs and serves as an interface between sensors and digital logic. The LM2903MX is useful when a design needs to detect crossings, thresholds, overvoltage, undervoltage, or differences between two analog signals without converting them into a digital quantity.
The two channels operate independently, allowing one device to implement two unrelated threshold functions. Key features include comparison of input voltages near ground potential, a wide supply range, low current drain, and open-collector outputs that require an external pull-up resistor. Rail-to-rail input behavior is particularly valuable when the signal of interest lies close to either supply rail. The specified 1.3 us response time makes the comparators appropriate for power-line, protection, sensing, and general signal-conditioning circuits.
Typical uses include monitoring a divided battery voltage, detecting an over-temperature condition with a sensor, comparing an adjustable reference with an analog input, and translating a sensor threshold into a logic-level event. The open-collector topology also allows several comparator outputs to share a wired bus when each output has a suitable pull-up and the system design accounts for the resulting behavior.
PCB implementation should follow the manufacturer pin-description table and place input, output, and decoupling connections to minimize switching noise. Input traces should be kept short and away from high-current paths. Use a pull-up resistor sized for the target logic family, and verify its maximum current across all operating conditions. Do not substitute a push-pull output device without reviewing the full pinout and signal behavior.
This page compares the LM2903MX with documented same-footprint alternatives, summarizes verified electrical and package characteristics, and adds practical PCB, logic-interface, and replacement guidance for engineers evaluating this dual comparator.
直接替换替代料： LM2903MX ——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： LM2903MX （相同外形与封装尺寸） ——差异在于 Comparator Type, Operating Temperature Range, Package, Supply Current.
LM2903MX/NOPB
✅ 直接替换📋 参考替代料（不在目录中）
LM2903MX 最大额定值与电气特性
| Comparator Type | General Purpose |
| Number of Comparators | 2 |
| Supply Voltage Range, Single Supply | 2 V to 36 V |
| Supply Voltage Range, Dual Supply | 1 V to 18 V |
| Response Time | 1.3 us |
| 输出类型 | Open-Collector |
| Input Common-Mode Capability | Rail-to-Rail |
| Logic Compatibility | CMOS, MOS, TTL |
| Differential Input Voltage Range | ±38 V |
| 封装 | 8-SOIC, 0.154 in (3.90 mm) body width |
| 引脚数 | 8 pins |
| 工作温度范围 | -40 °C to +85 °C |
| Low Offset | 0.37 mV |
| Low Input Bias Current | 3.5 nA |
| 电源电流 | 200 uA per comparator |
| ESD Rating | 2 kV HBM |
LM2903MX 8-soic, 0.154 in (3.90 mm) body width 引脚配置指南
LM2903MX（8-soic, 0.154 in (3.90 mm) body width 封装）的引脚配置。 该模拟元件具有输入、输出和电源引脚。请参阅制造商数据手册以了解失调调零、补偿和使能引脚配置。适用于信号调理和放大器电路。
暂无详细引脚数据： LM2903MX.
请参阅 数据手册 以查看完整引脚配置。
典型应用
LM2903MX 适用于 6 应用s: Battery Voltage Monitoring, Over-Temperature Protection, Power-Supply Fault Detection, Sensor Threshold Conditioning, Zero-Crossing and Signal Detection, Motor and Solenoid Control Interface.
Battery Voltage Monitoring
The LM2903MX fits battery monitoring because each comparator can evaluate a divided pack voltage against an adjustable reference using the device's 2 V to 36 V single-supply range and rail-to-rail inputs. Connect one channel to a resistor-divider output and the other input to a precision reference, then use the 1.3 us response time to detect an undervoltage or overvoltage event. The open-collector output can pull up a logic interrupt, though the divider resistance, reference accuracy, and fault-current limits require separate validation.
推荐
Over-Temperature Protection
The LM2903MX can implement over-temperature protection by comparing a temperature-sensor signal with a threshold generated by a resistor network or reference. Its rail-to-rail input capability is useful when the sensor output approaches either supply rail, and the 1.3 us response time supports prompt shutdown signaling. Because the output is open-collector, a pull-up can drive a shutdown input or fault indicator. Component tolerances, sensor slope, hysteresis, and the propagation path should be evaluated together.
推荐
Power-Supply Fault Detection
The LM2903MX is appropriate for detecting an out-of-range power rail by comparing a scaled feedback voltage with a reference. Two independent channels can supervise positive and negative rails or implement upper and lower limits on one supply. The wide 2 V to 36 V operating range supports many industrial and automotive supply systems, while the open-collector output provides a flexible fault bus with an external pull-up. Designers should include input filtering, verify tolerance stack-up, and confirm that all inputs remain within rated conditions during faults.
推荐
Sensor Threshold Conditioning
The LM2903MX converts a sensor-derived analog threshold into a logic-compatible event by comparing the sensor output with a reference voltage. Rail-to-rail input behavior makes it useful for low-level current, voltage, and resistive sensing where the signal can lie close to ground. Its 1.3 us response time supports reasonably fast threshold recognition, and the open-collector output can be pulled up to the voltage used by CMOS, MOS, or TTL circuitry. Hysteresis may be added with positive feedback to prevent repeated switching near the threshold.
推荐
Zero-Crossing and Signal Detection
The LM2903MX can detect when an analog waveform crosses a reference by using one input for the signal and the other for the threshold. The rail-to-rail input range supports detection near the supply rails, and the specified 1.3 us response time provides a defined switching interval for control or measurement systems. Open-collector outputs can pull up a digital input without committing to a fixed push-pull logic voltage. Input-source impedance, noise, propagation delay, and input overvoltage should be checked for the selected waveform.
推荐
Motor and Solenoid Control Interface
The LM2903MX can supervise a motor current-sense or position signal before allowing a driver stage to operate. One channel may detect an upper current threshold while the other monitors a control or position condition, and the open-collector output can assert a shutdown input through an external pull-up. The 1.3 us response time helps identify threshold crossings, but actual protection latency also includes signal filtering and the downstream driver's response. Choose pull-up and driver interfaces that tolerate the application's voltage and fault conditions.
推荐
推荐产品汇总
工程参考数据： LM2903MX ——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 | LM2903MX/NOPB | LM2903MX | LM2903M |
|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | ROHM Semiconductor | onsemi |
| Package | 8-SOIC | 8-SOIC | 8-SOIC | 8-SOIC |
| Number of Pins | 8 pins | 8 pins | 8 pins | 8 pins |
关键差异点
- Two independent channels in one device （对比 LM2903MX/NOPB)
- Wide single-supply operating range （对比 LM2903MX)
- Rail-to-rail input comparison （对比 LM2903M)
- Defined response time （对比 LM2903M)
设计说明
Place the LM2903MX close to the signals being compared and keep input traces short. Reserve the exposed ground-lead connections according to the manufacturer layout guidance, connect the supply bypass capacitor at the device, and keep comparator traces away from switching nodes, motor phases, and high-current return paths. For high-impedance sensors, minimize leakage from board contamination and guard the input node when the layout permits.
Use an external pull-up resistor for each open-collector output and size it for the target CMOS, MOS, or TTL input. Verify both the pull-up high level and the maximum sink current at the lowest valid supply voltage. If multiple outputs share a wired node, confirm that only one output can actively pull the node low at a time and account for leakage from every connected device.
Do not treat the SOIC body width as proof of electrical compatibility. Compare pin functions, input common-mode limits, differential input rating, output sink current, response time, offset voltage, input bias current, operating temperature, and qualification before substituting a part. The LM2903MX supports a differential input voltage of up to ±38 V, but sustained operation near an absolute maximum rating should not be used as a normal operating condition.
A comparator can switch abruptly and create narrow current spikes even when its output changes infrequently. Keep the open-collector pull-up network close to the device or receiver, use a value that limits switching current without producing excessive rise time, and route the output away from sensitive analog inputs. Add hysteresis when noise near the threshold could cause repeated output transitions and associated EMI.
合规信息
The LM2903 product page and distributor records do not explicitly state the requested environmental or material-compliance classifications. Use the manufacturer product page and current declarations for the exact ordering code before making a compliance claim.
