LM2903DG4 - Dual Open-Collector Comparator | Texas Instruments
MPN： LM2903DG4 ✓ 啟用中LM2903DG4 概覽
A comparator is an analog integrated circuit that evaluates two input voltages and produces a digital logic state indicating which input is higher. The LM2903 is a dual differential comparator, placing two independent comparator channels in one package. Within the broader semiconductor hierarchy, it is a comparator, analog IC, and interface/amplifier-class signal-conditioning component used to translate small analog voltage relationships into logic-compatible decisions.
Each LM2903 channel supports operation from a single supply or from dual supplies. The open-collector outputs can sink output current while presenting a high-impedance state when the output is inactive. According to the Texas Instruments LM2903 product information, the outputs are compatible with TTL, MOS, and CMOS logic. This makes the device useful when an external pull-up resistor is required to establish the inactive output voltage.
The two channels are electrically independent, allowing one comparator to monitor a control threshold while the other handles a second signal, alarm, or protection event. Common-mode input voltage range includes ground, and the differential input rating equals the maximum-rated supply voltage. These characteristics support sensing arrangements in which signals may approach the lower supply rail, subject to the limits stated in the manufacturer datasheet.
Typical applications include overvoltage and undervoltage detection, industrial sensor interfaces, battery monitoring, window or threshold detection, relay-control logic, and general-purpose signal conditioning. The wide supply range also makes the device useful in 5 V, 12 V, and 24 V industrial systems when the relevant operating limits are observed.
Designers should account for open-collector pull-up requirements, input common-mode limits, output sink-current capability, and unused-channel handling. A pull-up resistor must be selected to establish a valid logic-high voltage without exceeding the device's output-current limits. Input filtering may also be required when noisy signals could cause repeated transitions near the comparison threshold.
This page combines manufacturer identification, package details, cross-reference information, and engineering guidance for threshold detection and open-collector interface design. It also highlights the operating conditions that should be checked before using a substitute or family variant on an existing board.
直接替換替代品，適用於 LM2903DG4 — 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： LM2903DG4 （相同外形與佔位） — 差異在於 Package, Output Type.
LM2903DG
✅ 直接替換聯絡詢價
查看資料表 →LM2903DRG4
✅ 直接替換聯絡詢價
查看資料表 →LM2903DR
✅ 直接替換聯絡詢價
查看資料表 →LM2903DRG3
✅ 直接替換聯絡詢價
查看資料表 →LM2903BDR
✅ 直接替換📋 參考替代品（不在目錄中）
LM2903DG4 最大額定值與電氣特性
| Comparator Type | Dual differential comparator |
| Number of Channels | 2 channels |
| Supply Configuration | Single or dual supply |
| Maximum-Rated Supply Voltage | 32 V |
| Tested Differential Input Voltage | 30 V |
| Supply-Current Drain | 0.4 mA typical per comparator |
| 輸出類型 | Open-collector |
| Output Compatibility | TTL, MOS, and CMOS compatible |
| Common-Mode Input Range | Includes ground |
| 封裝 | 8-pin SOIC, 0.154 inch (3.90 mm) width |
| 安裝類型 | Surface mount |
LM2903DG4 8-pin soic, 0.154 inch (3.90 mm) width 腳位配置指南
LM2903DG4（8-pin soic, 0.154 inch (3.90 mm) 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： LM2903DG4.
請參閱 資料表 以查看完整腳位配置。
典型應用
LM2903DG4 適用於 6 應用s: Industrial Overvoltage and Undervoltage Detection, Battery Voltage Monitoring, Sensor Signal Conditioning, Power-Supply Sequencing and Fault Logic, Relay and Discrete Logic Interfacing, Automotive and 24 V Control-System Interfaces.
Industrial Overvoltage and Undervoltage Detection
The LM2903DG4 fits dual-rail supervision because it contains two independent differential comparator channels in one 8-pin SOIC package. One channel can compare a monitored supply with an upper threshold and the other can detect a lower threshold, reducing component count in 12 V or 24 V control systems. Its 32 V maximum-rated supply voltage supports wider operating rails than many low-voltage comparators. The open-collector outputs can directly pull down a supervisor or alert line when an external pull-up establishes the inactive state. Designers must ensure the monitored voltage stays within the applicable common-mode range and that fault conditions cannot exceed the absolute-maximum limits.
推薦
Battery Voltage Monitoring
The LM2903DG4 can monitor a battery pack with two differential channels, using one comparison for a high-charge limit and the other for a low-discharge limit. Its 0.4 mA typical supply-current drain per comparator helps limit the burden on a low-power battery system, while the 32 V maximum-rated supply provides margin for monitored automotive or industrial battery rails. The open-collector outputs are suitable for driving a pulled-up warning or disconnect signal. Because battery nodes can exhibit transients and large transients during load changes, engineers should add filtering and verify both the common-mode input range and differential input rating before connecting them directly.
推薦
Sensor Signal Conditioning
The LM2903DG4 converts a differential sensor signal into a logic decision, making it appropriate for threshold switches, level detectors, and window comparators. Two independent channels allow complementary conditions to be evaluated without sharing internal circuitry. Its differential input capability is useful when the monitored quantity is represented across two nodes rather than relative to ground, while the common-mode range including ground simplifies low-side sensing. The open-collector output can trigger a pulled-up digital input, relay-control circuit, or status LED driver. For noisy sensor nodes, add an input filter with a time constant that prevents repeated output toggling while preserving the required response time.
推薦
Power-Supply Sequencing and Fault Logic
The LM2903DG4 can evaluate two supply rails and generate open-drain fault indications for a power-supply controller. Each independent channel compares a feedback or divided rail voltage with a reference, while the open-collector outputs allow wired fault signals to be combined using pull-up resistors. The low 0.4 mA typical drain per comparator reduces the load imposed on monitored rails. A robust implementation should include hysteresis or input filtering to avoid chatter near the switching threshold, and it must account for the time required for the open-collector node to rise after release. Those timing details depend on the pull-up resistance and total bus capacitance.
推薦
Relay and Discrete Logic Interfacing
The LM2903DG4 is suitable for controlling a relay driver or digital input from an analog threshold because its open-collector output can sink current from a pulled-up control node. This configuration is common in industrial controls where a transistor or relay coil driver should not be connected directly to the comparator. The output interface can also pull down a TTL, MOS, or CMOS input according to the Texas Instruments compatibility statement. Designers should calculate the pull-up current at the selected logic voltage and confirm that the relay-driver transistor has adequate base or gate drive. Flyback protection remains necessary for inductive loads and should be placed according to the relay-driver topology.
推薦
Automotive and 24 V Control-System Interfaces
The LM2903DG4 can support 24 V control-system monitoring when the signal and supply conditions remain inside the datasheet limits. Its 32 V maximum-rated supply and tested 30 V differential input capability provide useful headroom for industrial environments where short transients can occur. The dual-channel arrangement permits two independent threshold checks, while the open-collector output supports pulled-up fault signaling. In an automotive design, qualification status and transient immunity must be checked for the exact ordering code rather than inferred from the family name. Input protection, grounding, and connector filtering are particularly important when long wiring runs couple external noise into the comparison nodes.
推薦
推薦產品摘要
工程參考資料，適用於 LM2903DG4 — 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 | LM2903DG | LM2903DRG4 | LM2903DR | LM2903DRG3 | LM2903BDR |
|---|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 8-SOIC | 8-SOIC - same package | 8-SOIC - same package | 8-SOIC - same package | 8-SOIC - same package | 8-SOIC - same package |
| Comparator Type | Dual differential comparator | Dual differential comparator | Dual differential comparator | Dual differential comparator | Dual differential comparator | Dual differential comparator |
| Number of Channels | 2 channels | 2 channels | 2 channels | 2 channels | 2 channels | 2 channels |
| Output Type | Open-collector | Open-collector | Open-collector | Open-collector | Open-collector | Open-collector |
| Logic Compatibility | TTL, MOS, and CMOS compatible | TTL, MOS, and CMOS compatible | TTL, MOS, and CMOS compatible | TTL, MOS, and CMOS compatible | TTL, MOS, and CMOS compatible | TTL, MOS, and CMOS compatible |
| Supply Configuration | Single or dual supply | Single or dual supply | Single or dual supply | Single or dual supply | Single or dual supply | Single or dual supply |
主要差異化特點
- Two independent channels in one SOIC package (對比LM2904P3)
- Open-collector interface with explicit logic-family compatibility (對比TLV2402ID)
- Wide supply range for industrial threshold detection (對比MCP6043-E/P)
設計說明
Do not connect a logic-high supply directly to an open-collector output. Use a pull-up resistor between the output node and the intended logic-high rail, then verify that the pull-up current at the low output state remains within the LM2903DG4 sink-current limit. The output must also be allowed to rise only to a voltage permitted by the connected logic device. A lower pull-up resistance improves rising-edge speed but increases current and power when the output is low.
Inputs crossing the comparison threshold can produce repeated output transitions when noise is present. Add hysteresis with positive feedback or filter the signal with an RC network, then calculate the added delay using the resistance and capacitance. Keep the filtering close to the comparator pins to reduce pickup from nearby switching nodes, and confirm that the filter does not create excessive response latency in safety- or timing-critical loops.
Place the open-collector pull-up resistor close to the LM2903DG4 output and the receiving logic input to minimize the trace area that can act as an antenna. Route comparator input traces away from power-switching nodes and relay-coil wiring. Use a continuous ground plane, provide a nearby supply bypass capacitor as recommended by the manufacturer application guidance, and maintain clearance between exposed nets and board edges where high voltage transients are possible.
The 0.4 mA typical drain per comparator applies to the comparator supply current and excludes current drawn through an external pull-up resistor. Estimated total supply demand with two channels is 0.8 mA typical before output and logic loads are included. Use this estimate for battery-budget calculations, but verify the operating-current limits and test conditions in the Texas Instruments datasheet for the selected grade and temperature range.
合規資訊
The LM2903DG4 is identified as a general-purpose dual differential comparator. No specific RoHS, REACH, lead-free, halogen-free, or conflict-minerals statement was identified for the exact ordering code.
