LM211QD - 115ns Differential Comparator | Texas Instruments
N.º da peça: LM211QD ✓ AtivoLM211QD Visão geral
A differential comparator is an analog integrated circuit that compares two input voltages and changes its output state when the differential input crosses a threshold. The LM211 belongs to the broader comparator hierarchy within analog and interface ICs, where it bridges the voltage-domain gap between analog sensors or signal chains and digital control logic. Its single-channel architecture provides a clear threshold decision while its wide supply range supports both 5 V logic and dual ±15 V analog systems.
Key specifications include a maximum response time of 115 ns, maximum input bias current of 300 nA, and maximum input offset current of 70 nA. The device supports operation across -40°C to +125°C, making it suitable for industrial temperature ranges. Its open-collector and open-emitter output architecture supports wired logic and allows pull-up or pull-down networks to establish the desired output level.
The LM211 architecture includes differential inputs and strobe control for coordinating comparator decisions in larger systems. The open-collector output can sink logic-level current, while the open-emitter structure provides complementary open-ended drive. Because open outputs do not establish a passive high level by themselves, external pull-up resistors are normally required when interfacing the collector output to TTL or MOS logic.
Typical applications include pulse-width and timing circuits, zero-cross detection, sensor thresholding, overvoltage and undervoltage indication, industrial control interfaces, and relay or lamp activation. Its 115 ns response time supports decisions where propagation delay matters, while the 3.5 V to 30 V supply range permits use in both low-voltage logic systems and higher-voltage analog equipment.
When designing a circuit around the LM211QD, begin with the output pull-up network and confirm that its resistor value satisfies the required sink current, rise time, and power dissipation. Keep comparator inputs away from switching nodes and high-current return paths, and use the strobe pin only according to the manufacturer timing and logic guidance.
This page combines the LM211QD specifications, pin-compatible replacement information, application guidance, and selection criteria to support faster design decisions than a basic distributor listing. Use the Request a Quote form on this page for current commercial availability, price, and lead-time requirements.
Alternativas drop-in para LM211QD — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
LM211QDG4
✅ Drop-In ⚠️ Especificações não verificadas📋 Alternativa de referência (fora do catálogo)
LM211DR
✅ Drop-In ⚠️ Especificações não verificadasConsulte o preço
Ver ficha técnica →LM211MDREP
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
LM211QDRQ1
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
LM211D
✅ Drop-InConsulte o preço
Ver ficha técnica →LM211QD Classificações máximas e características elétricas
| Comparator Type | Single differential comparator with strobe |
| Response Time | 115 ns |
| Supply Voltage Range | 3.5 V to 30 V |
| Number of Channels | 1 channel |
| Tipo de saída | Open-collector and open-emitter |
| Maximum Input Bias Current | 300 nA |
| Maximum Input Offset Current | 70 nA |
| Strobe Function | Yes |
| TTL Output Compatibility | Compatible |
| MOS Logic Compatibility | Compatible |
| Supported Dual Supply | ±15 V |
| Supported Logic Supply | 5 V |
| Faixa de temperatura de operação | -40°C to +125°C |
| Encapsulamento | 8-pin SOIC (D) |
| Contagem de pinos | 8 pins |
| Tipo de montagem | Surface mount |
| Output Load Capability | Lamp and relay driving |
Guia de Configuração de Pinos do LM211QD 8-pin soic (d)
Configuração de pinos para LM211QD (pacote 8-pin soic (d)). Este componente analógico possui pinos de entrada, saída e alimentação. Consulte o datasheet do fabricante para configurações de offset null, compensação e pino de enable. Ideal para circuitos de condicionamento de sinal e amplificadores.
Nenhum dado detalhado de pinagem disponível para LM211QD.
Consulte a ficha técnica para a configuração completa dos pinos.
Aplicações típicas
LM211QD é adequado para 6 aplicaçãos: Pulse and Timing Control, Industrial Sensor Thresholding, Overvoltage and Undervoltage Detection, Zero-Cross and Level Detection, Lamp and Relay Interface, TTL and MOS Logic Interfacing.
Pulse and Timing Control
The LM211QD is appropriate for pulse-width, edge, and timing circuits because its 115 ns response time provides a defined propagation interval for threshold transitions. It can compare a rapidly changing signal against a reference and then drive a TTL or MOS input through the open-collector output. Designers should include an appropriate pull-up resistor and account for the resistor-capacitor output rise time in addition to the specified 115 ns response time.
Recomendado
Industrial Sensor Thresholding
The LM211QD can convert a sensor or analog measurement into a digital decision for industrial control equipment. Its differential inputs, 300 nA maximum input bias current, and 70 nA maximum input offset current help limit errors in high-impedance sensing arrangements, while the -40°C to +125°C range supports demanding ambient conditions. The open-collector output should use a pull-up network matched to the required logic family and system noise margin.
Recomendado
Overvoltage and Undervoltage Detection
The LM211QD is well suited to power-supply monitoring because it can operate from 3.5 V to 30 V and switch a logic indication when a monitored voltage crosses a reference threshold. The 115 ns response permits rapid fault signaling, and the open-emitter output offers additional open-ended drive flexibility. A production design should account for input common-mode limits, output pull-up components, and fault-state behavior documented in the manufacturer datasheet.
Recomendado
Zero-Cross and Level Detection
The LM211QD can detect a signal crossing a reference level in zero-cross, window, or level-detection circuits. Its 115 ns response time is useful when the system must react quickly to a transition, and its differential input arrangement allows the threshold to be referenced to a local return rather than an arbitrary system ground. Protective series resistance and careful routing are important when the monitored waveform contains fast edges or high common-mode excursions.
Recomendado
Lamp and Relay Interface
The LM211QD can control lamps and relays by combining its comparator decision with an appropriate transistor or driver stage. The comparator provides the low-current threshold decision, while the external driver handles the load current and voltage isolation. Its open-collector output requires a pull-up arrangement, and the selected switching device must be checked for coil transients, saturation voltage, and current limits. The 3.5 V to 30 V supply range supports varied control platforms.
Recomendado
TTL and MOS Logic Interfacing
The LM211QD is intended for interfacing analog decisions with TTL and MOS logic systems. Its open-collector output can sink current for a low state, while an external pull-up resistor establishes the high state, and the open-emitter output adds a complementary open-ended output structure. Designers should select the pull-up value from the required rise time, sink-current capability, power consumption, and noise-immunity requirements rather than choosing it solely from the supply voltage.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para LM211QD — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | LM211QDG4 | LM211DR | LM211MDREP | LM211QDRQ1 | LM211D |
|---|---|---|---|---|---|---|
| Package | 8-pin SOIC (D) | 8-pin SOIC (D) | 8-pin SOIC (D) | 8-pin SOIC (D) | 8-pin SOIC (D) | 8-pin SOIC (D) |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | National Semiconductor Corporation |
| Function | Single differential comparator with strobe | LM211-family differential comparator | LM211-family differential comparator | Differential comparator with strobes | LM211-family differential comparator | Compatible differential comparator |
| Response Time | 115 ns | 115 ns | 115 ns | 115 ns | 115 ns | 115 ns |
Principais diferenciais
- Fast single-comparator response (vs LM211D)
- Wide single-supply operating range (vs LM211MDREP)
- Dual open-ended output structures (vs LM211QDRQ1)
Notas de projeto
Treat the open-collector output as requiring an external pull-up resistor. Without one, the output cannot establish a valid high state on its own. Select the resistor using the required rise time, input capacitance, pull-up current, and available sink current rather than applying a universal value. Also confirm that the open-emitter output is connected to a compatible pull-down or driver arrangement before powering the circuit.
Route the differential input traces as a compact pair and keep them away from switching-node copper, relay coils, and high-current return paths. Place the input-network components close to the comparator pins to minimize parasitic pickup. When the input source is high impedance, provide a defined bias path within the device's input-current and common-mode limits, and use a ground reference that remains stable during output transitions.
The 115 ns response time does not by itself determine the usable bandwidth of the complete interface. The open-collector rise time depends on the pull-up resistance and total node capacitance, so calculate that time separately for the intended logic load. For high fan-out or long interconnects, use a lower pull-up resistance within the sink-current limit or add a suitable buffer to preserve edge quality and maintain noise margin.
Informações de conformidade
The LM211QD is not identified as an AEC-Q100-qualified automotive part in the manufacturer product documentation. RoHS, REACH, lead-free, halogen-free, and conflict-minerals status require confirmation from the applicable manufacturer compliance documentation.
