LM2903Q2T - Dual Low-Power Voltage Comparator | STMicroelectronics
部品番号: LM2903Q2T ✓ 生産中LM2903Q2T 概要
A voltage comparator is an analog mixed-signal IC that compares an input voltage with a reference voltage and changes its output state when the relationship between those voltages changes. The LM2903 belongs to the comparator hierarchy, which sits between general-purpose analog signal conditioning and system-level protection or control. Its open-collector outputs can be pulled up to a suitable supply rail, allowing interface compatibility with TTL, CMOS, MOS, and other digital logic when the output circuit is designed correctly.
The LM2903Q2T is specifically suited to low-power applications because the manufacturer identifies it as a low-power dual comparator. Its two independent channels provide flexibility in battery-operated equipment, industrial sensing, automotive electronics, consumer products, and embedded control systems. The 2 x 2 mm DFN package also supports compact layouts where board area is limited, although its exposed thermal pad and fine-pitch assembly requirements require careful PCB design.
The comparator output architecture is open collector, so an external pull-up resistor is generally required to establish a high output level. The output transistor can sink current when the comparator condition is met, while the pull-up network determines the high-state voltage and rise time. This configuration is useful for wired-AND signal aggregation, but it also means that the output voltage, transition timing, and allowable sink current depend on the external resistor and load.
The LM2903 family is designed for operation from a single supply or split supplies, making it appropriate for systems that require comparison of signals referenced to ground or signals that exceed ground when both positive and negative rails are available. Because the exact electrical limits, common-mode range, output timing, and automotive qualification details are not shown in the retrieved product summaries, final circuit design should use the manufacturer datasheet and its recommended operating conditions.
A compact application should include local input filtering when sensor leads are long or noisy, a defined output pull-up, and adequate copper around the exposed pad when both channels operate continuously. The small DFN package can reduce board space, but its compact size does not eliminate thermal or assembly constraints. Use the manufacturer pin configuration and land pattern when assigning inputs, outputs, supply pins, and the exposed pad.
This page combines the LM2903Q2T product identity, verified manufacturer and distributor references, application guidance, package considerations, and design notes. It also explains why open-collector operation, power-supply topology, output pull-up design, and thermal layout determine whether the comparator works reliably in a real system.
ドロップイン代替品: LM2903Q2T — 同一パッケージでピン互換。PCBの作り直しが必要な異なるパッケージの部品は除外されています。
LM2903YDT
✅ ドロップイン📋 参考代替品（カタログ未掲載）
LM2903Q2T 最大定格＆電気的特性
| Comparator Type | Dual, independent voltage comparator |
| Product Description | Low-power dual voltage comparator |
| Number of Channels | 2 |
| Supply Configuration | Single supply or split supply |
| 出力タイプ | Open-collector |
| Output Characteristic | Rail-to-rail |
| Application Classification | Standard general-purpose comparator |
| パッケージ | 8-DFN, 2 x 2 mm |
| 実装タイプ | Surface mount |
LM2903Q2T ピン構成
| ピン 1 | OUT1 — Comparator 1 open-collector output |
| ピン 2 | IN1- — Comparator 1 inverting input |
| ピン 3 | IN1+ — Comparator 1 non-inverting input |
| ピン 4 | V- — Negative supply connection |
| ピン 5 | IN2+ — Comparator 2 non-inverting input |
| ピン 6 | IN2- — Comparator 2 inverting input |
| ピン 7 | OUT2 — Comparator 2 open-collector output |
| ピン 8 | V+ — Positive supply connection |
主な用途
LM2903Q2T の用途: 6 件s: Battery-Powered Threshold Detection, Automotive Sensor Interface, Industrial Overvoltage Monitoring, Sensor Signal Conditioning, Consumer Equipment Window Comparator, Portable Instrumentation.
Battery-Powered Threshold Detection
The LM2903Q2T is suitable for detecting when a battery-derived voltage crosses a decision threshold because it combines two independent low-power comparator channels with a compact 8-DFN 2 x 2 mm footprint. One channel can compare a divided battery voltage with a reference, while the other can monitor a second condition or provide a complementary result. Single-supply operation simplifies portable systems that do not require negative rails. Place the input divider close to the comparator when possible, add filtering for noisy sources, and use a pull-up resistor appropriate to the downstream logic. The main design checks are the common-mode range, supply limits, output timing, and quiescent current from the manufacturer datasheet.
おすすめ
Automotive Sensor Interface
The dual architecture of the LM2903Q2T allows two vehicle sensor signals to be evaluated independently, making it a natural candidate for automotive monitoring functions such as sensor-limit detection or signal conditioning. The Q2 family designation points toward automotive use, although the exact AEC-Q100 grade and temperature limits should be confirmed for the ordering code. An open-collector output allows the comparator to interface with a pull-up rail and other wired logic systems. Automotive PCB design must account for transient exposure, ground offset, connector noise, and thermal conditions around the compact DFN package. Use the manufacturer qualification information and application guidance before releasing the design for production.
おすすめ
Industrial Overvoltage Monitoring
The LM2903Q2T can monitor divided versions of two industrial supply rails and provide open-collector fault indications when either voltage exceeds a set threshold. The device's wide supply positioning and dual independent channels are useful when one controller must supervise multiple power domains. Reference and feedback traces should be kept away from switching nodes and motor wiring, while input RC networks can suppress repeated threshold crossings caused by conducted or radiated noise. The output pull-up should use the system logic rail, and its sink capability must be checked against the fault-indicator load. Confirm operating limits and transient immunity against the specific industrial environment.
おすすめ
Sensor Signal Conditioning
The LM2903Q2T converts a low-level analog sensor condition into a digital decision for a controller, which is useful in resistive, capacitive, and current-sense monitoring circuits. Its two channels permit independent threshold detection without duplicating the comparator package. Small input offsets or noise near the threshold can cause chatter, so the design should include hysteresis, filtering, and a deliberate reference arrangement. The open-collector output can pull up to a logic rail, allowing direct connection to suitable digital inputs while keeping the analog and digital grounds arranged to minimize injected current. Use the exact input-offset, common-mode, and response-time limits when sizing resistor networks and capacitors.
おすすめ
Consumer Equipment Window Comparator
Two LM2903Q2T channels can form a window-comparison arrangement in consumer equipment, where one channel detects an upper limit and the other detects a lower limit. This supports functions such as supply-range checks, battery-charge status indication, or input-signal qualification. The compact DFN package helps reduce board area in space-constrained products, while open-collector outputs can feed a pulled-up status line or combine with other fault signals. Hysteresis is especially important when the monitored quantity has slow noise or temperature drift near a threshold. Validate the resistor divider, reference stability, output rise time, and exposed-pad thermal performance across the intended product environment.
おすすめ
Portable Instrumentation
The LM2903Q2T supports threshold and limit functions in portable test equipment where low power and compact area are important. Two channels can evaluate an upper and lower bound, indicate signal presence, or supervise a divided rail. The open-collector output works well with a pull-up to the instrument's logic supply, and the low-power dual-channel configuration can reduce component count compared with two separate comparator packages. For accurate measurements, keep the reference network away from display and switching circuitry, establish filtering based on measured noise, and use hysteresis to prevent display or relay chatter. Confirm supply-current and temperature behavior against the instrument's operating environment.
おすすめ
おすすめ製品の概要
エンジニアリング参考データ: LM2903Q2T — 比較、設計ガイダンス、コンプライアンス情報。
選定ガイド
代替品との比較
| パラメータ | この製品 | LM2903YDT |
|---|---|---|
| Package | 8-DFN, 2 x 2 mm | 8-DFN, 2 x 2 mm |
| Brand | STMicroelectronics | STMicroelectronics |
| Comparator Type | Dual low-power voltage comparator | Dual low-power voltage comparator |
| Number of Channels | 2 | 2 |
| Output Type | Open collector | Open collector |
| Supply Configuration | Single supply or split supply | Single supply or split supply |
| Mounting Type | Surface mount | Surface mount |
主な差別化要因
- Compact dual-channel implementation （vs LM2903YDT)
- Open-collector interface flexibility （vs LM2903YDT)
- Single- and split-supply operation （vs LM2903YDT)
設計ノート
Place input and supply decoupling components close to the LM2903Q2T pins, and route the exposed pad according to the manufacturer land pattern. The 2 x 2 mm DFN package has limited thermal-copper area, so uninterrupted ground-plane connection and nearby vias can improve heat spreading. Keep comparator input traces away from switching nodes, relay coils, high-current return paths, and inductor edges to reduce false threshold transitions.
Do not treat an open-collector output as a push-pull logic output. Install a pull-up resistor to a compatible positive supply, check the comparator's maximum sink current, and account for output capacitance when estimating the rising edge. If the output drives a long trace or slow load, use a lower pull-up value within the sink-current limit; if noise is the concern, balance pull-up strength against transition speed.
Add hysteresis to prevent output chatter when the compared signal approaches the reference slowly or contains noise. A positive-feedback resistor from the output to the appropriate input can create a controlled threshold gap, but its value must be checked against the open-collector output state. For long sensor connections, use filtering close to the comparator and keep the reference network on a quiet analog area of the board.
Estimated: confirm that both comparator channels can operate within the package and board temperature limits at the intended supply voltage. Actual dissipation depends on the input common-mode voltage, output duty cycle, pull-up current, and ambient temperature. Because the exact electrical limits and thermal resistance are not stated in the retrieved summaries, calculate worst-case conditions and use the manufacturer datasheet before selecting copper area or additional cooling.
コンプライアンス情報
The retrieved product summaries identify the Q2 family and automotive comparator context, but they do not explicitly state the compliance status or exact qualification grade for LM2903Q2T. Confirm these attributes in the manufacturer datasheet and product documentation.
