LM211DR - 115ns Differential Comparator | Texas Instruments
MPN: LM211DR ✓ Hoạt độngLM211DR Tóm tắt
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.
Bộ thay thế dễ dàng lắp đặt cho LM211DR — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
LM211QDR
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
LM211DRE4
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
LM211DRG4
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
LM211DR2
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
LM311DR
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
LM211DR Tỷ lệ tối đa & tính chất điện
| 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 |
| Kiểu đầu ra | Open-collector / open-emitter |
| Logic Compatibility | DTL, MOS, RTL, and TTL |
| Input Configuration | Differential |
| Comparator Quantity | 1 comparator |
| Hộp | 8-pin SOIC |
| Kiểu lắp đặt | Surface mount |
| Output Drive Capability | Lamp or relay switching |
| Strobe Function | Differential comparator with strobe |
| Trạng thái RoHS | unknown |
Hướng dẫn cấu hình chân LM211DR 8-pin soic
Cấu hình chân cho LM211DR (8-pin soic gói). Thành phần số hiệu này có chân đầu vào, đầu ra và nguồn cung cấp. Tham khảo tài liệu thông số kỹ thuật của nhà sản xuất để biết cấu hình chân bù, bù trừ và chân kích hoạt. Hoàn hảo cho điều kiện tín hiệu và mạch khuếch đại.
Không có dữ liệu chân cụ thể sẵn có cho LM211DR.
Tham khảo: tài liệu kỹ thuật cho cấu hình chân đầy đủ.
Ứng dụng tiêu biểu
LM211DR phù hợp cho 6 Áp dụngs: 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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho LM211DR — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | 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 |
Bảo phân biệt quan trọng
- Faster threshold transition than the LM311DR (vsLM311DR)
- Wide supply operation for analog and logic rails (vsLM311DR)
- Automotive-oriented ordering option in the same family (vsLM211DR)
Ghi chú thiết kế
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.
Thông tin tuân thủ
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.