LM2903D - Dual Open-Collector Comparator | Texas Instruments
MPN: LM2903D ✓ সক্রিয়LM2903D সারাংশ
An analog comparator is an integrated circuit that compares two input voltages and produces a logic-level output indicating which input is higher. The LM2903D belongs to the comparator hierarchy within analog and mixed-signal semiconductors, providing a simple alternative to an operational amplifier configured as a comparator. Its two channels operate independently, allowing one package to implement two threshold decisions or to control complementary functions in a single circuit.
The open-collector outputs are a defining electrical feature. Each output transistor can pull its output low, but it cannot actively drive the output high, so an external pull-up resistor is required. Multiple open-collector outputs can share one pull-up to create a wired-AND arrangement. This architecture also provides a useful form of output isolation while remaining compatible with standard 5 V and 3.3 V digital logic levels when the pull-up rail is selected appropriately.
The 2 V to 36 V supply capability allows operation from low-voltage analog systems through conventional industrial control rails. Its 300 ns response time supports applications where decisions must be made faster than typical slow comparators but where nanosecond-level precision is unnecessary. The operating temperature range covers industrial environments, although production designs should still verify temperature-dependent input offset, output-current, and propagation-delay behavior using the selected manufacturer's complete datasheet.
Typical uses include industrial sensor conditioning, battery monitoring, overvoltage detection, window or level comparators, relay and solenoid interfaces, and digital control systems that require open-collector outputs. The SOIC-8 package is also appropriate for through-hole-style PCB assembly and manual rework, although SOIC-8 is larger than modern comparator packages such as SOT-23 and MSOP-8 variants.
When designing with the LM2903D, always place the input and pull-up networks close to their associated pins, and account for input common-mode limits at the selected supply voltage. A pull-up resistor is not optional because the open-collector output cannot source current. Reviewing the voltage drop across the pull-up and the output transistor's current rating is essential when several outputs share the same node.
This page consolidates verified distributor listings, manufacturer references, pin-compatible alternatives, package details, and practical circuit guidance. It also distinguishes directly interchangeable devices from higher-speed or higher-precision alternatives whose electrical behavior may require different design assumptions.
এর জন্য ড্রপ-ইন বিকল্প LM2903D — একই package, pin-to-pin compatible। ভিন্ন package-এর যেসব পার্টে PCB rework প্রয়োজন সেগুলো বাদ দেওয়া হয়েছে।
এই সিরিজের ভ্যারিয়েন্ট
একই সিরিজের মডেল যেগুলো drop-in compatible LM2903D (একই form factor এবং footprint) — পার্থক্য রয়েছে Package, Output Type, Number of Channels, Operating Temperature Range, Response Time.
LM393D
✅ ড্রপ-ইনমূল্যের জন্য যোগাযোগ করুন
ডেটাশিট দেখুন →LM2903D
✅ ড্রপ-ইনমূল্যের জন্য যোগাযোগ করুন
ডেটাশিট দেখুন →LM2903D
✅ ড্রপ-ইনমূল্যের জন্য যোগাযোগ করুন
ডেটাশিট দেখুন →TS393IDT
✅ ড্রপ-ইন📋 রেফারেন্স বিকল্প (ক্যাটালগে নেই)
MC33902D
✅ ড্রপ-ইন📋 রেফারেন্স বিকল্প (ক্যাটালগে নেই)
LM2903D সর্বোচ্চ রেটিং ও বৈদ্যুতিক বৈশিষ্ট্য
| Comparator Type | Dual differential comparator |
| Number of Channels | 2 channels |
| Supply Voltage Range | 2 V to 36 V |
| আউটপুট টাইপ | Open-collector |
| Response Time | 300 ns |
| প্যাকেজ | 8-pin SOIC |
| মাউন্টিং টাইপ | Surface mount |
| অপারেটিং তাপমাত্রার পরিসর | -40 °C to +125 °C |
| Supply Configuration | Single supply or split supply |
| Channel Independence | Two independent comparator channels |
| Output Logic Style | Open-collector, pull-up resistor required |
| Propagation Delay | 300 ns response time |
LM2903D পিন কনফিগারেশন
| পিন 1 | OUT1 — Comparator channel 1 open-collector output |
| পিন 2 | IN1- — Comparator channel 1 inverting input |
| পিন 3 | IN1+ — Comparator channel 1 non-inverting input |
| পিন 4 | GND — Ground connection |
| পিন 5 | IN2+ — Comparator channel 2 non-inverting input |
| পিন 6 | IN2- — Comparator channel 2 inverting input |
| পিন 7 | OUT2 — Comparator channel 2 open-collector output |
| পিন 8 | VCC — Positive supply connection |
সাধারণ ব্যবহার
LM2903D এর জন্য উপযুক্ত 6 অ্যাপ্লিকেশনs: Industrial Sensor Threshold Detection, Battery Voltage Monitoring, Overvoltage and Undervoltage Protection, Relay and Solenoid Interfacing, Open-Collector Wired-AND Logic, Temperature and Level Monitoring.
Industrial Sensor Threshold Detection
The LM2903D fits industrial sensor conditioning because its two independent channels can each compare a conditioned sensor signal against a reference, with a 2 V to 36 V supply range covering common control rails and a 300 ns response time suitable for relatively slow threshold decisions. Place one input on the sensor signal and the other on a precision reference or resistor-divider node. Each open-collector output can drive a digital input or an alert signal, but an external pull-up resistor is required because the output only sinks current. The tradeoff is that open-collector rise time depends on the pull-up resistance and any attached input capacitance, so choose the resistor value to balance noise immunity against response speed.
সুপারিশকৃত
Battery Voltage Monitoring
The LM2903D is appropriate for battery-monitoring circuits because it operates from 2 V to 36 V and provides two independent threshold comparisons in one package. One channel can compare a divided pack voltage with a reference, while the other monitors a cell or charger status signal. The 300 ns response time is more than adequate for slow battery events and avoids introducing unnecessary switching activity into low-energy systems. Because accuracy is usually limited by the reference divider, comparator offset, and input bias effects rather than response speed, use matched resistors and a stable reference. An open-collector output with a pull-up can feed a microcontroller input, though a low-leakage pull-up may be needed on long battery-connected nodes.
সুপারিশকৃত
Overvoltage and Undervoltage Protection
The LM2903D can implement window-style protection by assigning its two channels to upper and lower voltage thresholds. Its 2 V to 36 V supply capability suits many 5 V, 12 V, and 24 V industrial systems, while the 300 ns response time provides prompt comparator decisions without requiring a high-speed part. The open-collector outputs can be wired together to create a single fault indication when both protection conditions are active. This arrangement requires one shared pull-up resistor and careful review of the output sink-current rating when both channels assert simultaneously. The design remains dependent on the selected manufacturer's input common-mode range, particularly near the minimum operating supply, and that value must be confirmed from the complete datasheet.
সুপারিশকৃত
Relay and Solenoid Interfacing
The LM2903D is well suited to relay and solenoid interfaces because its open-collector outputs isolate the comparator from the driven load and allow a relay coil or driver stage to be referenced separately. The output can pull a logic-gated driver input low, while the pull-up establishes the high state and limits current during switching. A 300 ns response time is more than sufficient for supervisory rather than high-speed switching functions. When driving an inductive load, place the flyback diode directly across the coil or driver output and keep it close to the load connection. Confirm the open-collector sink-current rating and thermal behavior at the maximum coil voltage, especially when both channels can conduct simultaneously.
সুপারিশকৃত
Open-Collector Wired-AND Logic
The LM2903D can implement wired-AND logic because multiple open-collector outputs may share a common pull-up resistor. This is useful when several independent fault conditions must produce one active-low system indication. The shared node remains high unless any comparator sinks it, allowing the logic function to be built without additional gate packages. The 300 ns response time is adequate for supervisory fault aggregation, although the actual node transition speed also depends on total bus capacitance and the pull-up value. Keep the shared trace short, account for leakage from every connected output, and verify that simultaneous assertions do not exceed the individual output transistor's sink-current capability.
সুপারিশকৃত
Temperature and Level Monitoring
The LM2903D supports dual-channel temperature or level monitoring by comparing two conditioned analog signals against independent references. For temperature sensing, one channel can monitor a thermistor divider and the other can provide an upper-limit alarm; for liquid-level systems, separate probes can drive the two inputs. Its 2 V to 36 V operating range covers common industrial supplies, and the 300 ns response time is more than sufficient for slow thermal and tank-level changes. Open-collector outputs simplify interfacing to alarm inputs, although the pull-up voltage should match the receiving logic. Sensor resistance tolerance, input offset, humidity effects, and probe leakage will normally dominate measurement accuracy more than comparator speed.
সুপারিশকৃত
সুপারিশকৃত পণ্যের সারসংক্ষেপ
এর জন্য ইঞ্জিনিয়ারিং রেফারেন্স ডেটা LM2903D — তুলনা, ডিজাইন গাইডেন্স এবং কমপ্লায়েন্স তথ্য।
নির্বাচন গাইড
বিকল্পের সাথে তুলনা
| পারামিটার | এই পণ্য | LM393D | LM2903D | LM2903D | TS393IDT | MC33902D |
|---|---|---|---|---|---|---|
| Package | 8-pin SOIC | 8-pin SOIC | 8-pin SOIC | 8-pin SOIC | 8-pin SOIC | 8-pin SOIC |
| Brand | Texas Instruments | Texas Instruments | STMicroelectronics | onsemi | STMicroelectronics | onsemi |
| Comparator Configuration | Dual differential comparator | Dual differential comparator | Dual differential comparator | Dual differential comparator | Dual differential comparator | Dual differential comparator |
| Output Type | Open-collector | Open-collector | Open-collector | Open-collector | Open-collector | Open-collector |
| Channel Independence | Two independent channels | Two independent channels | Two independent channels | Two independent channels | Two independent channels | Two independent channels |
| Number of Pins | 8 pins | 8 pins | 8 pins | 8 pins | 8 pins | 8 pins |
| Wired-AND Output Support | Yes, with external pull-up | Yes, with external pull-up | Yes, with external pull-up | Yes, with external pull-up | Yes, with external pull-up | Yes, with external pull-up |
মূল পার্থক্যসমূহ
- Single package provides two independent threshold-comparison channels (বনামLM393D)
- Wide 2 V to 36 V supply operation (বনামTS393IDT)
- Open-collector outputs support wired-AND fault aggregation (বনামMC33902D)
- 300 ns response time balances speed and general-purpose control (বনামLM2903D)
ডিজাইন নোট
Do not treat the open-collector output as a push-pull logic output. Every output node requires an external pull-up resistor, and the resistor must connect to a supply that keeps the high level within the receiving device's input limits. If several outputs share a node, calculate the worst-case sink current when all channels assert simultaneously and verify it against the selected manufacturer's output-current limit.
Check the complete input common-mode range at the actual supply voltage before finalizing a design. The verified snippets establish a 2 V to 36 V supply capability but do not provide the full common-mode limits. In low-voltage systems, a signal that exceeds the allowed input range can disturb the internal bias nodes even though the supply itself is within specification. Confirm offset, input bias current, and output-current data from the selected manufacturer's current datasheet.
Keep the input traces short and connect the bypass capacitor between VCC and GND close to the device. Place each pull-up resistor near its associated output or near the shared wired-AND receiver to minimize parasitic capacitance and noise pickup. In analog sensing circuits, route the two comparator inputs away from relay-coil and switching-node traces, and use a ground reference that remains stable beneath the comparator pins.
The observed output rise time is set by the pull-up resistance and total node capacitance rather than only by the comparator's internal response time. A smaller pull-up produces a faster edge but increases current and susceptibility to transient noise; a larger pull-up reduces power while slowing the transition. Validate the resulting edge rate with the longest PCB trace and the actual input-device capacitance instead of relying only on the 300 ns response-time figure.
কমপ্লায়েন্স তথ্য
The supplied web data contains ordering, package, basic electrical, and distributor information but no explicit RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals declarations. These fields therefore remain unknown rather than being inferred.