MCP6541RT-E/OT Microchip Comparator: Datasheet, Application Circuit, and Pinout Guide
The MCP6541RT-E/OT from Microchip Technology is a single-channel, push-pull output comparator renowned for its ultra-low power consumption and wide operating voltage range. Housed in a space-saving SOT-23-5 package, this component is a cornerstone for portable, battery-powered, and general-purpose analog circuit design. This guide delves into its key specifications, a fundamental application circuit, and a detailed pinout description.
Datasheet Overview and Key Specifications
The MCP6541 family is designed to operate from a single supply voltage as low as 1.6V and up to 5.5V, making it compatible with both single-cell Li-Ion and two-cell alkaline battery systems. Its most striking feature is its exceptionally low quiescent current, typically just 600 nA (0.6 µA). This minimal power draw is crucial for applications where extending battery life is paramount.
Other critical specifications from the datasheet include:
Input Common-Mode Voltage Range: Extends from VSS - 0.3V to VDD + 0.3V, allowing the device to handle signals beyond the supply rails, which simplifies circuit design.
Low Input Bias Current: Typically 1 pA, minimizing the impact on high-impedance signal sources.
Propagation Delay: Although not designed for high-speed applications (typ. 4.5 µs at 5V), it is sufficient for many monitoring and control tasks like level detection.
Rail-to-Rail Input and Output: Ensures the maximum dynamic range is available for both sensing and driving subsequent logic stages.
A Fundamental Application Circuit: Battery Voltage Monitor
A common use for the MCP6541RT-E/OT is as a low-battery warning indicator. The circuit configuration is a simple non-inverting comparator.
Components Required:
MCP6541RT-E/OT Comparator
Two resistors (R1, R2) to form a voltage divider
A reference voltage source (e.g., a Zener diode or the supply itself)
An output indicator (LED with a current-limiting resistor or a logic input to an MCU)
Circuit Operation:
1. Reference Voltage (VREF): A voltage divider from the supply (VDD) is created using R1 and R2. This sets a fixed reference voltage at the inverting input (-IN). For example, to trigger at 3.0V in a 5V system, R1 and R2 would be chosen to provide a 3.0V reference.
2. Battery Voltage (VBAT): The monitored battery voltage is fed directly into the non-inverting input (+IN).
3. Comparison: As long as VBAT is above VREF, the output drives high (to VDD), keeping an LED off (or sending a 'high' signal to an MCU). When the battery voltage drops below VREF, the output switches to a low state (VSS), turning on the LED to provide a visual low-battery warning.
This circuit exemplifies the MCP6541RT-E/OT's strength: providing a clear digital signal from an analog input with negligible power drain on the battery it is monitoring.
Pinout Guide (SOT-23-5 Package)
Understanding the pin configuration is essential for correct PCB layout:
Pin 1 (VOUT): Push-Pull Output. This pin drives high or low based on the comparison result.
Pin 2 (VSS): Ground Connection. This is the negative supply pin.
Pin 3 (IN+): Non-Inverting Input. The input for the signal to be compared.
Pin 4 (IN-): Inverting Input. The input for the reference voltage.
Pin 5 (VDD): Positive Supply Voltage. Connects to the positive power supply (1.6V to 5.5V).
The MCP6541RT-E/OT stands out as an exceptional choice for ultra-low-power analog comparison tasks. Its ability to operate down to 1.6V and draw mere nanoamps of current makes it a premier solution for extending battery life in portable and remote devices. The combination of rail-to-rail input, a tiny form factor, and robust performance solidifies its role as a fundamental component in power-sensitive design.
Keywords:
1. Ultra-Low Power
2. Comparator
3. Rail-to-Rail
4. Battery Monitoring
5. SOT-23-5
