Texas Instruments LM211DR Overview
The Texas Instruments LM211DR is a high-performance voltage comparator designed for applications requiring fast response, low input offset voltage, and wide operating voltage range. It is a precision device capable of operating with both single and dual power supplies, widely used in analog circuits for threshold detection, zero crossing detectors, pulse generation, and other switching applications.
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Key Features
* Wide power supply voltage range: from ±5 V up to ±15 V or 3 V to 32 V single supply
* Low input offset voltage and input bias current
* High-speed response with typical propagation delay of 300 ns
* Open-collector output stage for wired-AND capability and easy level shifting
* TTL compatible output for easy interface with digital logic
* Differential input voltage range equal to the supply voltage
* High gain and wide input common-mode voltage range
* Low input bias current (typically 25 nA)
* Available in 8-pin Dual In-line Package (DIP) and Small Outline Integrated Circuit (SOIC) packages
* Designed for a variety of analog and digital interface circuits
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Detailed Specifications
* Input Offset Voltage: Typically 2 mV, max 7 mV
* Input Bias Current: Typically 25 nA at 25°C
* Input Offset Current: Typically 5 nA
* Input Voltage Range: ±15 V or 3 V to 32 V (single supply)
* Supply Current: Typically 1.5 mA per comparator
* Propagation Delay: 300 ns typical at 5 V overdrive
* Output Stage: Open-collector transistor capable of sinking up to 30 mA
* Output Voltage Low (VOL): Typically 0.1 V at 4 mA output current
* Common-Mode Input Voltage Range: Extends to within 2 V of the supply rails
* Differential Input Voltage: Can withstand input voltages beyond supply rails
* Power Dissipation: Typically 700 mW depending on package and thermal conditions
* Operating Temperature Range: 0°C to 70°C (commercial) or -40°C to 85°C (industrial versions available)
* Package: 8-pin PDIP (LM211DR) and SOIC versions
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Functional Description
The LM211DR is a voltage comparator that compares the voltages applied to its two input terminals and outputs a digital signal indicating which input is higher. The device features an open-collector output transistor, enabling multiple outputs to be wired together in a wired-AND configuration, which is useful for certain logic applications.
Its input stage supports common-mode voltages equal to the supply voltage, making it versatile for various applications. The device’s high gain and low offset voltage ensure accurate switching thresholds.
The LM211DR's relatively fast propagation delay and low supply current make it well-suited for timing and pulse applications, as well as general-purpose voltage comparison tasks.
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Typical Applications
* Zero crossing detectors
* Voltage level detectors and window comparators
* Oscillator and pulse generator circuits
* Overvoltage and undervoltage detection
* Analog-to-digital interface circuits
* Digital logic level conversion and interfacing
* Battery voltage monitoring and control
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Electrical Characteristics (Typical Values)
* Input Offset Voltage: 2 mV typical, ensuring precise threshold detection
* Input Bias Current: 25 nA, allowing operation with high impedance sensors
* Propagation Delay: 300 ns typical at 5 V overdrive, supporting moderate-speed switching
* Output Sink Current: Up to 30 mA, capable of driving LEDs or digital inputs directly
* Supply Current: 1.5 mA, suitable for low-power applications
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Thermal and Mechanical Information
* The 8-pin PDIP package provides standard mounting and thermal dissipation with a thermal resistance of approximately 100 °C/W junction-to-ambient without additional heat sinking
* The device is also available in SOIC packages offering a smaller footprint for compact PCB designs
* Proper PCB layout and thermal considerations are recommended for applications involving higher power dissipation
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Summary
The Texas Instruments LM211DR is a versatile and reliable voltage comparator featuring wide supply voltage range, low offset, and fast response time. Its open-collector output allows flexible interfacing with digital logic and multiple devices. Suitable for various analog signal detection and digital interfacing applications, the LM211DR offers a balanced combination of performance, power consumption, and package options for industrial and commercial use.
