LM211P - High-Speed Voltage Comparator | Texas Instruments
MPN： LM211P ✓ 啟用中LM211P 概覽
A voltage comparator is an analog integrated circuit that compares two input voltages and changes its output state when one input crosses the other. The LM211P belongs to the comparator hierarchy within analog and mixed-signal semiconductors, where it bridges precision analog sensing and digital logic control. Its differential inputs support sensing of a sensor signal relative to a reference, while its open-collector output provides a flexible interface to pull-up-based digital systems.
The principal benefits are low input offset voltage, low input bias current, fast response, broad supply compatibility, and logic-level output compatibility. Its open-collector output can sink current from an external pull-up while remaining in an electrically inactive high-impedance state when turned off. This architecture is useful when the output must control a relay, lamp, indicator, or interface with a higher-voltage pull-up supply. The 8-PDIP through-hole package also simplifies prototyping, inspection, and repair in laboratory and industrial control systems.
The LM211, LM111, and LM311 form a related high-speed comparator family. The LM211P is suitable for dual-supply operation around ±15 V and single-supply operation beginning at 5 V. Its inputs can be isolated from system ground, while the output can be referenced through its pull-up arrangement to ground, VCC, or another suitable rail. This flexibility is important when the sensed signal and logic interface use different voltage domains.
Typical applications include overvoltage and undervoltage detection, sensor threshold conditioning, industrial control interfaces, relay activation, lamp indication, and conversion of analog events into logic-compatible signals. In such systems, the non-inverting input may receive a reference voltage and the inverting input may receive a feedback or sensor voltage, or the inputs may be reversed depending on the required switching polarity. The external pull-up resistor should be selected for the desired logic family and output current.
A key design consideration is the strobe and output arrangement. The strobe pins are used for gating or inhibit control, while the open-collector output requires an external pull-up. Designers should verify input common-mode limits, supply polarity, pull-up voltage, output sink current, and logic thresholds for the specific system rather than relying only on nominal logic compatibility.
This page consolidates verified manufacturer information, distributor pricing, pin-level guidance, application context, and strictly filtered drop-in alternatives. It distinguishes verified LM211 family options from mere functional equivalents and highlights the electrical checks required before replacing an original 8-pin comparator in an existing design.
直接替換替代品，適用於 LM211P — 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。
LM211PE4
✅ 直接替換📋 參考替代品（不在目錄中）
LM211PG4
✅ 直接替換📋 參考替代品（不在目錄中）
LM111P
✅ 直接替換📋 參考替代品（不在目錄中）
LM311P
✅ 直接替換📋 參考替代品（不在目錄中）
LM211P 最大額定值與電氣特性
| Comparator Type | Single differential voltage comparator |
| 封裝 | 8-PDIP |
| 安裝類型 | Through-hole |
| Supply Voltage, Single | 5 V minimum |
| Supply Voltage, Split | ±15 V |
| 輸出類型 | Open-collector |
| Logic Compatibility | TTL and MOS compatible |
| Response Time | 115 ns |
| Input Offset Voltage | 3 mV |
| Input Bias Current | 100 nA |
| Typical Input Current | 6 µA |
| Gain-Bandwidth Product | 106.02 dB |
| Output Current | 50 mA |
| Load Capability | Lamp and relay driving |
| Input Isolation | Inputs can be isolated from system ground |
LM211P 腳位配置
| 腳位 1 | STROBE — Comparator strobe input |
| 腳位 2 | IN- — Inverting input |
| 腳位 3 | IN+ — Non-inverting input |
| 腳位 4 | V- — Negative supply or ground connection |
| 腳位 5 | STROBE — Comparator strobe input |
| 腳位 6 | OUTPUT — Open-collector output |
| 腳位 7 | V+ — Positive supply connection |
| 腳位 8 | NC — Not connected |
典型應用
LM211P 適用於 6 應用s: Industrial Overvoltage Detection, Relay Threshold Control, Sensor Signal Conditioning, Lamp and Indicator Driving, Digital Logic Interface, Power Supply Sequence Monitoring.
Industrial Overvoltage Detection
The LM211P fits industrial overvoltage detection because its differential inputs can compare a scaled supply or signal against a reference, while its 115 ns reported response time limits detection delay. Its open-collector output can operate a relay, indicator, or digital fault input through an external pull-up. The circuit should include input attenuation, clamping, hysteresis for noise immunity, and protection from transients found on industrial power rails. Verify the comparator's exact input common-mode limits before choosing the divider values, and size the pull-up so the output remains compatible with the connected TTL or MOS input.
推薦
Relay Threshold Control
The LM211P is appropriate for relay threshold control because the Texas Instruments product page identifies relay driving as a supported application and the device provides an open-collector output. A pull-up establishes the inactive output voltage, and the comparator switches when the sensed input crosses the reference. A 115 ns reported response allows the comparator transition to be much faster than the mechanical relay, but flyback protection remains essential for the inductive coil. Use a suitable transistor or driver if relay current exceeds the verified 50 mA output-current listing.
推薦
Sensor Signal Conditioning
The LM211P can convert a slowly changing sensor voltage into a logic-compatible threshold event. Its 3 mV reported input offset and 100 nA reported input bias current are useful when the source impedance is sufficiently high, although application-specific error analysis remains necessary. The open-collector stage can be pulled up to the local logic voltage, while the comparator inputs may be biased above ground when suitable supply arrangements are used. Add positive feedback for hysteresis and verify input common-mode limits to prevent saturation near the rails.
推薦
Lamp and Indicator Driving
The LM211P can drive a lamp or indicator when its open-collector output sinks current from an appropriate pull-up supply. The verified LM211P listing reports a 50 mA output current, and the manufacturer description explicitly states that the comparator is capable of driving lamps. This arrangement can indicate an alarm, threshold crossing, or power state without requiring a logic-compatible push-pull output. Select the pull-up voltage and resistance to limit output current, and add protection if the lamp or wiring introduces inductive, capacitive, or transient effects.
推薦
Digital Logic Interface
The LM211P provides an economical bridge from an analog threshold to TTL- or MOS-compatible logic. Its open-collector output is not actively driven high, so an external pull-up resistor is required and determines both the high voltage and rising-edge speed. The verified 115 ns response time supports rapid event detection, although the complete transition interval must also account for the pull-up resistance and input capacitance. Maintain a clean ground reference and place the pull-up close to the receiving gate to reduce susceptibility to noise and slow edges.
推薦
Power Supply Sequence Monitoring
The LM211P can monitor a regulated rail by comparing a divided version of the supply against a reference and generating a discrete fault or power-good indication. The 115 ns reported response makes the comparator transition quick, but it does not remove the need for filtering when the monitored rail contains ripple or switching noise. Hysteresis helps prevent repeated output transitions near the threshold. The open-collector output can pull down a wired logic signal, while the pull-up rail establishes the asserted voltage. Confirm common-mode operation during startup and shutdown.
推薦
推薦產品摘要
工程參考資料，適用於 LM211P — 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 | LM211PE4 | LM211PG4 | LM111P | LM311P | LM211P |
|---|---|---|---|---|---|---|
| Package | 8-PDIP | 8-PDIP | 8-PDIP | 8-PDIP | 8-PDIP | 8-PDIP |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | onsemi |
| Comparator Type | Single differential voltage comparator | Single differential voltage comparator | Single differential voltage comparator | Single differential voltage comparator | Single differential voltage comparator | Single differential voltage comparator |
| Output Type | Open-collector | Open-collector | Open-collector | Open-collector | Open-collector | Open-collector |
主要差異化特點
- Broad supply compatibility in a through-hole comparator (對比onsemi LM211P)
- Fast reported switching response (對比LM111P)
- Documented sensor-friendly input figures (對比LM311P)
- Directly compatible with TTL and MOS logic interfaces (對比LM211PE4)
設計說明
The LM211P output is open-collector, so it does not actively drive a logic-high voltage. Place a suitable pull-up resistor between the output and the intended logic rail, and confirm that the pull-up voltage, resistor value, and load current remain within the comparator's limits. Avoid treating the output pin as a push-pull logic output or omitting the pull-up during breadboard testing.
Plan the supply rails for both single-supply and split-supply operation. The manufacturer identifies 5 V single supplies and ±15 V split supplies as supported arrangements, but the exact maximum ratings are not included in the supplied data. Confirm input common-mode range at startup, shutdown, and overvoltage conditions. If the comparator inputs are biased outside the ground-referenced range, connect V- appropriately and use suitable protection networks.
Use positive feedback to create hysteresis when noise or slow signal slopes could cause repeated output transitions near the threshold. Keep input traces short, maintain a low-impedance reference, and place the input-divider or sensor return close to the comparator ground reference. The reported 3 mV offset and 115 ns response describe device-level values; they do not remove the need for careful threshold and noise analysis.
When replacing an LM211P, verify pin 1 orientation and the complete 8-pin DIP footprint rather than relying on package appearance alone. LM111P and LM311P are related family devices, not unconditional equivalents. Check supply limits, differential-input polarity, common-mode range, strobe behavior, output-current capability, and pull-up requirements before substituting any listed alternative into production equipment.
合規資訊
The supplied verified manufacturer and distributor snippets do not state RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals status. AEC-Q100 is recorded as not applicable because the part is presented as a general-purpose comparator rather than an automotive-qualified device.
