LM2903QDG4 - Dual Differential Comparator, 36 V | Texas Instruments
MPN： LM2903QDG4 ✓ 啟用中LM2903QDG4 概覽
A differential comparator is an analog interface integrated circuit that compares two input voltages and changes its output state according to their relative polarity. The LM2903 belongs to the comparator hierarchy within analog and mixed-signal integrated circuits, where it bridges low-level sensor or signal voltages to a digital logic domain. Each half of the device can operate independently, allowing two comparisons in one package when the power supplies and input signals share a suitable common range.
The principal features are dual independent comparators, a wide 2 V to 36 V operating range, open-collector outputs, and logic compatibility with TTL, CMOS, and MOS devices. The open-collector architecture gives the output a defined pulled-up state when the output transistor is off and allows multiple open-collector outputs to share a wired bus when suitable, provided each output has its own pull-up path. The operating-temperature grade extends from -40 °C to 125 °C for industrial temperature conditions.
Each comparator uses a differential input stage and an open-collector output stage. A positive differential input produces the corresponding output state, while the magnitude and polarity of the differential input determine switching behavior. Because the outputs are open collector, external pull-up resistors are required for normal TTL or CMOS-compatible operation. The pull-up value controls rise time, power consumption, and susceptibility to bus capacitance, so it must be selected with the driven load and operating speed in mind.
Typical uses include monitoring a sensor threshold, detecting overvoltage or undervoltage conditions, comparing an analog measurement with a reference, and providing an open-collector signal to a microcontroller or logic gate. The wide supply range is useful for industrial control systems, automotive-adjacent sensing circuits, power-supply monitoring, and test equipment where input signals may exceed conventional low-voltage logic rails.
PCB layout should keep the exposed routes short and provide a stable ground reference close to the comparator. Place input and output components according to the manufacturer application guidance, and avoid routing high-current or switching-node copper directly beside the differential inputs. Pull-up resistors should connect to the intended logic supply rather than the comparator supply when separate output-interface voltage is required.
This page combines the manufacturer's device information, package details, operating limits, direct drop-in candidates, comparison parameters, and practical implementation guidance. It also identifies which electrical details require confirmation in the LM2903 family datasheet before production release.
直接替換替代品，適用於 LM2903QDG4 — 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： LM2903QDG4 （相同外形與佔位） — 差異在於 Package, Operating Temperature Range, Propagation Delay.
LM2903BIDR
✅ 直接替換聯絡詢價
查看資料表 →LM2903VQDRG4Q1
✅ 直接替換聯絡詢價
查看資料表 →LM2903D
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →LM2903DG
✅ 直接替換聯絡詢價
查看資料表 →LM2903VNG
✅ 直接替換📋 參考替代品（不在目錄中）
LM2903QDG4 最大額定值與電氣特性
| Comparator Type | Dual differential comparator |
| Number of Comparator Channels | 2 channels |
| Supply Voltage Range | 2 V to 36 V |
| Dual-Supply Total Voltage Range | 2 V to 36 V |
| 輸出類型 | Open-collector |
| Logic Compatibility | TTL, CMOS, and MOS compatible |
| Differential Input Type | Differential |
| 工作溫度範圍 | -40 °C to 125 °C |
| 封裝 | 8-pin SOIC, 3.90 mm width |
| 安裝類型 | Surface mount |
| Single-Supply Operation | Supported |
| Dual-Supply Operation | Supported |
| Independent Comparators | 2 independent channels |
| Differential Input Voltage Range | ±36 V |
| Output Pull-Up Requirement | External pull-up resistor required |
LM2903QDG4 腳位配置
| 腳位 1 | OUT 1 — Open-collector output of comparator channel 1 |
| 腳位 2 | IN 1- — Inverting input of comparator channel 1 |
| 腳位 3 | IN 1+ — Non-inverting input of comparator channel 1 |
| 腳位 4 | GND — Ground connection |
| 腳位 5 | IN 2+ — Non-inverting input of comparator channel 2 |
| 腳位 6 | IN 2- — Inverting input of comparator channel 2 |
| 腳位 7 | OUT 2 — Open-collector output of comparator channel 2 |
| 腳位 8 | VCC — Positive power supply |
典型應用
LM2903QDG4 適用於 6 應用s: Industrial Sensor Threshold Detection, Power-Supply Overvoltage Monitoring, Microcontroller Interface Conditioning, Battery Voltage Window Detection, Automotive Electrical Signal Conditioning, Test and Measurement Limit Detection.
Industrial Sensor Threshold Detection
The LM2903QDG4 is suitable for comparing a sensor signal with an adjustable reference when the circuit must operate from a 2 V to 36 V supply. One differential input receives the sensed voltage while the other receives the threshold, and the open-collector output changes state as their relationship crosses the comparison point. An external pull-up connects the output to the required logic rail. Its -40 °C to 125 °C grade supports industrial temperature conditions, but input common-mode limits and transient protection must be checked against the sensor output range.
推薦
Power-Supply Overvoltage Monitoring
The LM2903QDG4 can monitor a power rail by comparing a divided voltage against a reference and producing an open-collector fault indication. The wide 2 V to 36 V supply range permits use near industrial and distributed power systems, while the open-collector output can drive a wired-OR fault bus when each output has an appropriate pull-up. Because the comparison inputs can also see substantial differential voltage, use resistor dividers and clamping networks that keep both inputs within the manufacturer's absolute-maximum and common-mode limits.
推薦
Microcontroller Interface Conditioning
The LM2903QDG4 converts an analog threshold decision into a digital signal for a microcontroller input. Place the measured voltage and reference on the two inputs of one comparator, add the required open-collector pull-up to the microcontroller's logic supply, and route the result to a general-purpose input. TTL, CMOS, and MOS compatibility supports common logic families. The 8-pin SOIC package also provides two independent channels for redundant or dual-threshold decisions, while short PCB traces help preserve the accuracy of the common-mode input measurement.
推薦
Battery Voltage Window Detection
The LM2903QDG4 can implement upper and lower battery-voltage limits by using its two independent differential comparator channels. Each channel compares a resistor-divided battery voltage with a corresponding reference and provides an open-collector state for the charger, load switch, or monitoring controller. The device's broad single-supply range supports systems operating above low-voltage logic rails. Pull-up resistors should be referenced to the digital system supply, and the divider tolerances must be included in the overvoltage and undervoltage threshold calculations.
推薦
Automotive Electrical Signal Conditioning
The LM2903QDG4's wide supply range and -40 °C to 125 °C operating grade make its architecture relevant to automotive electrical monitoring, although the exact LM2903QDG4 qualification status must be confirmed for production automotive use. It can compare a conditioned vehicle signal with a reference and provide an open-collector output to another controller. The LM2903VQDRG4Q1 is the automotive-oriented comparison candidate when the required qualification is appropriate. Regardless of grade, protect inputs against automotive transients and route high-current paths away from the comparator.
推薦
Test and Measurement Limit Detection
The LM2903QDG4 can serve as a fast threshold element in bench instrumentation that converts an adjustable test point into a binary limit indication. Its two differential channels support over-limit and under-limit checks, while the open-collector output can drive a front-panel indicator or test-fixture input with an appropriate pull-up. Operation across a 2 V to 36 V supply range allows the comparator to be used near higher-voltage analog sections. For precision measurements, account for input offset, input bias current, and resistor tolerance rather than treating the switching point as ideal.
推薦
推薦產品摘要
工程參考資料，適用於 LM2903QDG4 — 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 | LM2903B | LM2903VQDRG4Q1 | LM2903DG | LM2903VNG |
|---|---|---|---|---|---|
| Package | 8-SOIC | 8-SOIC | 8-SOIC | 8-SOIC | 8-SOIC |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | onsemi | onsemi |
| Comparator Channels | 2 independent channels | 2 independent channels | 2 independent channels | 2 channels | 2 channels |
| Supply Voltage Range | 2 V to 36 V | 2 V to 36 V | 2 V to 36 V | 2 V to 36 V | 2 V to 36 V |
| Output Type | Open-collector | Open-collector | Open-collector | Open-collector | Open-collector |
主要差異化特點
- Broader differential-input range for the improved family version (對比LM2903B)
- Two independent channels in one compact package (對比LM2903DG)
- Automotive-oriented family alternative with comparable supply operation (對比LM2903VQDRG4Q1)
設計說明
Route the differential inputs as a compact, balanced pair over a continuous ground plane, and keep them away from switching nodes, inductors, and high-current return paths. Place the external pull-up resistor close to the open-collector output so its rise-time current has a short return path. The two comparator channels are independent, but sharing their supply and ground pins makes the ground reference particularly important: return current from one channel can otherwise disturb the threshold seen by the other channel.
In single-supply operation, connect VCC to the positive rail and GND to ground while respecting the 2 V to 36 V supply range. In dual-supply operation, the total voltage between the supplies must remain within 2 V to 36 V. Do not treat the supply-range limit as an input-range limit; independently verify each differential and common-mode input against the manufacturer absolute-maximum table, particularly when sensing industrial or automotive waveforms.
An open-collector output does not actively drive a valid high level, so every output must have an appropriate pull-up unless the output is intentionally used as a wired-OR node. Choose the pull-up supply to match the receiving logic family and select its resistance from the required rise time, capacitance, and power budget. Avoid using the comparator supply as the pull-up supply when the downstream logic uses a different voltage domain.
Do not substitute a comparator solely because it is also an 8-pin SOIC. Confirm the numbered pin functions, output polarity, input offset, common-mode range, propagation delay, supply restrictions, and temperature grade against the manufacturer datasheet. This is especially important when moving between Texas Instruments and onsemi LM2903 variants, because package identity alone does not guarantee identical threshold behavior or qualification.
合規資訊
The standard LM2903QDG4 is not established as an AEC-Q100-qualified device in the available manufacturer information. The related LM2903VQDRG4Q1 is identified as a Q1 automotive option. Other compliance fields require confirmation from the current manufacturer product documentation.