Microchip MCP6241UT-E/OT Operational Amplifier: Key Features and Application Circuits
The Microchip MCP6241UT-E/OT is a single-channel, general-purpose operational amplifier (op-amp) that stands out for its exceptional combination of low power consumption and rail-to-rail input and output operation. Housed in a compact SOT-23-5 package, this op-amp is an ideal choice for space-constrained, battery-powered, and portable applications where efficiency and performance are critical.
Key Features
The defining characteristics of the MCP6241UT-E/OT make it a versatile component for modern electronic design:
Low Power Consumption: This device features an ultra-low quiescent current of typically 50 µA, making it perfect for battery-operated devices that require long operational life.
Rail-to-Rail Input/Output (RRIO): The input common-mode voltage range extends beyond both supply rails, and the output voltage swing reaches close to the supply rails. This maximizes the dynamic range in low-voltage applications, which is crucial when operating from a single supply as low as 1.8V to 5.5V.
Low Offset Voltage: With a typical input offset voltage of 500 µV, the amplifier provides good DC accuracy for precision applications such as sensor interfacing and signal conditioning.
Gain Bandwidth Product: The 50 kHz gain bandwidth product is well-suited for a wide range of low-frequency analog signal processing tasks, including audio filtering and transducer amplification.
Small Package (SOT-23-5): The tiny form factor is essential for modern portable and miniaturized electronics, allowing for high-density PCB layouts.
Application Circuits
The MCP6241UT-E/OT can be configured in numerous standard op-amp circuits. Here are two common practical applications:
1. Photodiode Transimpedance Amplifier (TIA)
A fundamental circuit for converting the small current from a photodiode into a measurable voltage is the TIA. The MCP6241 is exceptionally well-suited for this in portable spectrometers, light meters, or smoke detectors due to its low input bias current and rail-to-rail output.
Circuit Operation: The photodiode is connected between the op-amp's inverting input and ground. A feedback resistor (R_F) is connected from the output back to the inverting input. The non-inverting input is biased to a reference voltage, often ground (0V) for single-supply operation. The output voltage (V_OUT) is calculated as V_OUT = I_PD × R_F, where I_PD is the photodiode current. The low power consumption ensures minimal drain on the battery.
2. Active Low-Pass Filter (1st Order)
Filtering out high-frequency noise from a signal is a common requirement. A simple first-order active low-pass filter can be built using the MCP6241.
Circuit Operation: This configuration uses the op-amp in a non-inverting amplifier topology. A resistor (R1) and capacitor (C1) are placed in series between the inverting input and ground to form the RC network that sets the filter's cut-off frequency (f_c = 1 / (2π × R1 × C1)). The rail-to-rail input/output capability allows the filtered signal to utilize the full supply voltage range, preserving signal integrity. This circuit is ideal for anti-aliasing or signal smoothing in data acquisition systems powered by a single Li-ion cell.
The Microchip MCP6241UT-E/OT is a highly efficient and compact operational amplifier that delivers essential performance for low-voltage, power-sensitive designs. Its rail-to-rail operation and minuscule power draw make it a superior choice for amplifying and conditioning signals from sensors and transducers in the Internet of Things (IoT), medical devices, and handheld instrumentation. Its robustness and versatility in fundamental circuits ensure reliable performance across a wide array of applications.
Keywords:
Operational Amplifier, Low Power, Rail-to-Rail, SOT-23-5, Photodiode Amplifier
