LM2903MX - Dual Differential Comparator | Texas Instruments
MPN： LM2903MX ✓ 啟用中LM2903MX 概覽
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.
直接替換替代品，適用於 LM2903MX — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： LM2903MX （相同外形與佔位） — 差異在於 Comparator Type, Operating Temperature Range, Package, Supply Current.
LM2903MX/NOPB
✅ 直接替換📋 參考替代品（不在目錄中）
LM2903MX 最大額定值與電氣特性
| 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 |
| 輸出類型 | Open-Collector |
| Input Common-Mode Capability | Rail-to-Rail |
| Logic Compatibility | CMOS, MOS, TTL |
| Differential Input Voltage Range | ±38 V |
| 封裝 | 8-SOIC, 0.154 in (3.90 mm) body width |
| 腳位數 | 8 pins |
| 工作溫度範圍 | -40 °C to +85 °C |
| Low Offset | 0.37 mV |
| Low Input Bias Current | 3.5 nA |
| 供應電流 | 200 uA per comparator |
| ESD Rating | 2 kV HBM |
LM2903MX 8-soic, 0.154 in (3.90 mm) body width 腳位配置指南
LM2903MX（8-soic, 0.154 in (3.90 mm) body width 封裝）的腳位配置。 此類比元件具有輸入、輸出與電源腳位。偏移歸零、補償與致能腳位配置請參閱製造商資料表。適用於訊號調理與放大器電路。
無詳細腳位定義資料： LM2903MX.
請參閱 資料表 以查看完整腳位配置。
典型應用
LM2903MX 適用於 6 應用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.
推薦
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.
推薦
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.
推薦
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.
推薦
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.
推薦
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.
推薦
推薦產品摘要
工程參考資料，適用於 LM2903MX — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | 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 |
主要差異化特點
- Two independent channels in one device (對比LM2903MX/NOPB)
- Wide single-supply operating range (對比LM2903MX)
- Rail-to-rail input comparison (對比LM2903M)
- Defined response time (對比LM2903M)
設計說明
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.
合規資訊
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.
