LM1851M

Product Overview

Category: Integrated Circuit (IC)

Use: Voltage Comparator

Characteristics: - High-speed voltage comparator - Low input offset voltage - Wide supply voltage range - Rail-to-rail output swing - Low quiescent current - Small package size

Package: SOP-8 (Small Outline Package)

Essence: The LM1851M is a high-performance voltage comparator IC used in various electronic circuits. It compares two input voltages and provides a digital output based on the comparison result.

Packaging/Quantity: The LM1851M is typically sold in reels containing 2500 units.

Specifications

• Supply Voltage Range: 2V to 36V
• Input Offset Voltage: 1mV (maximum)
• Input Bias Current: 25nA (maximum)
• Response Time: 5ns (typical)
• Output Current: 20mA (maximum)
• Operating Temperature Range: -40°C to +85°C

Pin Configuration

The LM1851M has 8 pins arranged as follows:

```

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| | --| IN(-) 1|-- VCC --| IN(+) 2|-- OUT --| GND 3|-- NC --| NC 4|-- NC --| NC 5|-- NC --| NC 6|-- NC --| NC 7|-- NC --| NC 8|-- NC |___________| ```

Functional Features

1. High-Speed Operation: The LM1851M offers fast response time, making it suitable for applications requiring quick voltage comparisons.

2. Low Input Offset Voltage: With a maximum offset voltage of 1mV, the LM1851M ensures accurate and precise voltage comparisons.

3. Wide Supply Voltage Range: The IC can operate within a wide range of supply voltages, from 2V to 36V, providing flexibility in various circuit designs.

4. Rail-to-Rail Output Swing: The output of the LM1851M can swing close to both the positive and negative supply rails, maximizing the dynamic range of the comparator.

5. Low Quiescent Current: The IC consumes low quiescent current, minimizing power consumption and extending battery life in portable applications.

6. Small Package Size: The SOP-8 package offers compact dimensions, enabling space-efficient PCB layouts.

Advantages

• High-speed operation allows for quick voltage comparisons.
• Accurate and precise voltage comparisons due to low input offset voltage.
• Wide supply voltage range provides flexibility in circuit design.
• Rail-to-rail output swing maximizes dynamic range.
• Low quiescent current minimizes power consumption.
• Small package size enables space-efficient PCB layouts.

Disadvantages

• Limited number of pins may restrict the complexity of circuit designs.
• Not suitable for applications requiring high output current.

Working Principles

The LM1851M compares the voltages applied to its IN(+) and IN(-) inputs. If the voltage at IN(+) is higher than that at IN(-), the output (OUT) goes high. Conversely, if the voltage at IN(-) is higher, the output goes low. This behavior makes the LM1851M ideal for various voltage monitoring and control applications.

Detailed Application Field Plans

The LM1851M finds application in the following fields:

1. Battery Management Systems: Voltage monitoring and protection circuits in battery management systems benefit from the LM1851M's accurate voltage comparisons and low power consumption.

2. Industrial Automation: The IC is used in industrial automation systems for tasks such as level detection, motor control, and fault detection.

3. Audio Equipment: The LM1851M can be employed in audio equipment for volume control, audio level detection, and signal processing.

4. Power Supplies: Voltage monitoring and regulation circuits in power supplies utilize the LM1851M to ensure stable and reliable operation.

Detailed and Complete Alternative Models

1. LM339: A quad voltage comparator with similar characteristics and pin configuration.
2. LM311: A high-speed voltage comparator with differential inputs and adjustable hysteresis.
3. LM393: A dual voltage comparator with low power consumption and wide supply voltage range.

These alternative models offer different features and specifications, allowing designers to choose the most suitable option for their specific application requirements.

In conclusion, the LM1851M is a high-performance voltage comparator IC that offers fast operation, accurate voltage comparisons, and low power consumption. Its small package size and wide supply voltage range make it versatile for various electronic circuit designs. With its rail-to-rail output swing, the LM1851M ensures maximum dynamic range. While it has limitations in terms of pin count and output current, it finds applications in battery management systems