LM211DR - 115ns Differential Comparator | Texas Instruments
料号： LM211DR ✓ 量产中LM211DR 概述
A voltage comparator is an analog signal-processing IC that compares two input voltages and changes its output state when the difference crosses a defined threshold. In the electronic-component hierarchy, an LM211 comparator belongs to the comparator category, then to analog interface ICs, and ultimately to integrated circuits. It provides a decision function between sensors, transducers, dividers, and digital control logic without converting the compared quantity into a coded data stream.
The LM211 family operates from wide supply ranges, including positive 5 V logic systems and positive or negative 15 V analog supplies. Its high-speed response supports decisions that must occur quickly, while the open-collector output can interface with TTL and MOS circuits and drive loads such as lamps or relays. These characteristics make it useful when a logic system needs a fast threshold event rather than a continuous analog voltage.
The differential input arrangement permits comparison of two changing voltages rather than one signal against ground alone. Input offset and common-mode limits remain important when selecting the input operating region, and the supply voltage must remain within the stated 3.5 V to 30 V range. Because the output stage is open-collector or open-emitter, an external pull-up resistor is generally required to establish a valid high output level in a wired logic interface.
Typical LM211DR applications include sensor threshold detection, pulse-width and timing comparisons, industrial control interfaces, lamp or relay drive with suitable interface circuitry, and general-purpose logic conditioning. The 115 ns response time is especially useful where the comparator serves as a fast boundary detector between an analog node and a digital control system.
In a practical circuit, place the comparator close to the signals being compared, route high-impedance input nodes carefully, and provide stable bypassing for the supply pins. Add the pull-up component required by the open-collector output stage and verify that relay, lamp, or other inductive loads are isolated or protected from transients.
This product page combines manufacturer application guidance, package and timing details, orderable alternatives, and implementation-focused design notes. It also organizes the LM211DR for engineers who need to understand its logic compatibility, supply requirements, replacement choices, and PCB-level constraints before beginning a board design.
直接替换替代料： LM211DR ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
LM211QDR
✅ 直接替换📋 参考替代料（不在目录中）
LM211DRE4
✅ 直接替换📋 参考替代料（不在目录中）
LM211DRG4
✅ 直接替换📋 参考替代料（不在目录中）
LM211DR2
✅ 直接替换📋 参考替代料（不在目录中）
LM311DR
✅ 直接替换📋 参考替代料（不在目录中）
LM211DR 最大额定值与电气特性
| Comparator Type | Single high-speed differential comparator |
| Response Time | 115 ns |
| Supply Voltage Range | 3.5 V to 30 V |
| Positive Logic Supply Example | 5 V |
| Dual-Supply Example | ±15 V |
| 输出类型 | Open-collector / open-emitter |
| Logic Compatibility | DTL, MOS, RTL, and TTL |
| Input Configuration | Differential |
| Comparator Quantity | 1 comparator |
| 封装 | 8-pin SOIC |
| 安装类型 | Surface mount |
| Output Drive Capability | Lamp or relay switching |
| Strobe Function | Differential comparator with strobe |
| RoHS 状态 | unknown |
LM211DR 8-pin soic 引脚配置指南
LM211DR（8-pin soic 封装）的引脚配置。 该模拟元件具有输入、输出和电源引脚。请参阅制造商数据手册以了解失调调零、补偿和使能引脚配置。适用于信号调理和放大器电路。
暂无详细引脚数据： LM211DR.
请参阅 数据手册 以查看完整引脚配置。
典型应用
LM211DR 适用于 6 应用s: Industrial Sensor Threshold Detection, Pulse-Width and Timing Monitoring, Relay and Lamp Drive Interface, TTL and MOS Logic Conditioning, Portable Equipment Battery Monitoring, Test and Measurement Limit Detection.
Industrial Sensor Threshold Detection
The LM211DR fits industrial sensor interfaces that require a fast decision when a measured voltage crosses a programmed limit. Its 115 ns response time allows the comparator to detect a threshold crossing with little added delay, while the differential inputs can compare a sensor-derived voltage against a reference. The 3.5 V to 30 V supply range supports both low-voltage logic and higher-voltage analog control systems. The open-collector output can feed a controller input through a suitable pull-up resistor, although galvanic isolation, filtering, and surge protection may be required for long sensor wiring.
推荐
Pulse-Width and Timing Monitoring
The LM211DR is suitable for pulse-width, delay, and event-timing circuits because its 115 ns response time preserves short timing intervals better than a slower general-purpose comparator. A reference voltage can be applied to one differential input while a ramp, discharge waveform, or rectified pulse drives the other. The resulting open-collector transition can mark the timing event for a timer or logic gate. Designers should include hysteresis where noise near the threshold could cause repeated transitions, and should account for the pull-up resistor's RC delay when interpreting sub-microsecond events.
推荐
Relay and Lamp Drive Interface
The LM211DR can serve as the decision stage in lamp, relay, or other discrete-load interface circuits. According to the Texas Instruments product page, the comparator is capable of driving lamps or relays, while its output levels are compatible with common TTL and MOS circuits. The designer must choose the appropriate pull-up and drive transistor or other interface stage, add flyback protection for inductive loads, and keep switching transients away from the differential inputs. A 115 ns decision interval is useful when rapid threshold transitions are more important than a modulated analog output level.
推荐
TTL and MOS Logic Conditioning
The LM211DR works well as a boundary between an analog voltage node and digital logic because its output levels are compatible with most TTL and MOS circuits. A 5 V supply arrangement is explicitly supported by the LM211 family, while the 3.5 V to 30 V operating range allows integration into systems with different rail requirements. Add an external pull-up resistor to convert the open-collector or open-emitter output into a valid high state. Check the receiving logic family's input thresholds and the permissible output-current limits before finalizing the interface.
推荐
Portable Equipment Battery Monitoring
The LM211DR can monitor a divided battery or power-rail voltage and signal a digital controller when a threshold is crossed. Its 115 ns response time produces a quick fault or warning event, and the 3.5 V minimum supply supports low-voltage systems. The comparator's wide 3.5 V to 30 V operating range also permits operation from a protected higher-voltage rail. In portable equipment, low quiescent demand, input bias effects, and the comparator's input common-mode limits must be reviewed carefully; an open-collector output also allows the system to use a low-pull-up voltage if appropriate.
推荐
Test and Measurement Limit Detection
The LM211DR is appropriate for instrument and test-fixture circuits that must identify when a measured voltage exceeds a programmed limit. Its differential input arrangement supports comparison against a precision reference, and the 115 ns response time helps minimize timing uncertainty at the decision point. The open-collector output can trigger a counter, capture system, alarm input, or relay through appropriate interfacing. For accurate measurements, keep the reference and signal paths short, bypass the supply pins locally, and use controlled grounding to avoid offset or switching noise from producing false threshold events.
推荐
推荐产品汇总
工程参考数据： LM211DR ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | LM211QDR | LM211DRE4 | LM211DRG4 | LM211DR2 | LM311DR |
|---|---|---|---|---|---|---|
| Package | 8-pin SOIC | 8-pin SOIC | 8-pin SOIC | 8-pin SOIC | 8-pin SOIC | 8-pin SOIC |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Comparator Type | Single high-speed differential comparator | Single high-speed differential comparator | Single high-speed differential comparator | Single high-speed differential comparator | Single high-speed differential comparator | Single voltage comparator |
| Response Time | 115 ns | 115 ns | 115 ns | 115 ns | 115 ns | 200 ns |
| Supply Voltage Range | 3.5 V to 30 V | 3.5 V to 30 V | 3.5 V to 30 V | 3.5 V to 30 V | 3.5 V to 30 V | 3.5 V to 30 V |
| Output Type | Open-collector / open-emitter | Open-collector / open-emitter | Open-collector / open-emitter | Open-collector / open-emitter | Open-collector / open-emitter | Open-collector |
| Logic Compatibility | DTL, MOS, RTL, and TTL | DTL, MOS, RTL, and TTL | DTL, MOS, RTL, and TTL | DTL, MOS, RTL, and TTL | DTL, MOS, RTL, and TTL | DTL, MOS, RTL, and TTL |
关键差异点
- Faster threshold transition than the LM311DR （对比 LM311DR)
- Wide supply operation for analog and logic rails （对比 LM311DR)
- Automotive-oriented ordering option in the same family （对比 LM211DR)
设计说明
The open-collector output does not actively drive a high level, so an external pull-up resistor is required. Calculate the resistor from the receiver's input-current requirement, the pull-up supply voltage, and the comparator's permissible output sink current. Place the resistor near the receiving logic input so that trace capacitance does not create excessive RC delay at the 115 ns decision speed.
Keep the differential input traces short, route them away from relay-coil and switching-supply nodes, and minimize parasitic capacitance between the input and output nodes. Grounding errors and supply transients can move the apparent threshold. Use a quiet reference source for the second input and provide local supply bypassing; the manufacturer datasheet should be used for the exact input common-mode, offset, and bypass recommendations.
The 3.5 V to 30 V supply range permits multiple rail choices, but the selected voltage must support the input signals, output pull-up, and connected logic. Check the output-sink-current limit at the chosen temperature and ensure the pull-up source does not exceed the output-stage rating. A 5 V arrangement suits many TTL systems, while ±15 V can be useful when both positive and negative analog signals participate in the comparison.
If the comparator controls a relay or lamp, treat the load as an EMI source. Add the appropriate flyback diode or snubber across an inductive load, maintain separation between the switching path and the comparator inputs, and connect the input-referenced return directly to the quiet analog ground. These measures prevent the load transient from creating a false output transition or shifting the comparison threshold.
合规信息
No definitive RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals statement was identified for the exact LM211DR ordering code. The LM211QDR is identified as an automotive-qualified ordering option, but its exact qualification documentation should be checked during component approval.