Microchip MCP6232T-E/MS Dual Op-Amp: Features and Application Circuits
The MCP6232T-E/MS from Microchip Technology is a dual operational amplifier that combines low power consumption with rail-to-rail input and output operation, making it an excellent choice for a wide range of portable and battery-powered applications. Housed in a space-saving 8-pin MSOP package, this op-amp is designed for systems where board space and power efficiency are critical.
A key feature of the MCP6232 is its ultra-low quiescent current, typically drawing only 20 µA per amplifier. This minimal power requirement significantly extends battery life in portable devices. Despite its low power consumption, it offers a gain bandwidth product of 20 kHz, which is suitable for many signal conditioning and sensor interface applications, particularly with low-frequency signals. Its rail-to-rail input and output capability allows the signals to swing close to both power supply rails, maximizing the dynamic range in low-voltage single-supply systems (operating from 1.8V to 5.5V). This is essential for modern microcontroller-based systems where 3.3V or 5V single supplies are common.
Application Circuits
1. Photodiode Transimpedance Amplifier (TIA):
A common use for a precision, low-power op-amp like the MCP6232 is in converting the small current from a photodiode into a measurable voltage. The photodiode is connected between the inverting input and ground. A feedback resistor (RF) is placed between the output and the inverting input, setting the gain (Vout = -Ipd × RF). The rail-to-rail output ensures the maximum possible output swing for a given supply voltage, improving the signal-to-noise ratio.
2. Active Low-Pass Filter:
The MCP6232 is well-suited for implementing active filters in signal conditioning paths. A simple 2-pole Sallen-Key low-pass filter configuration can be built using one amplifier of the dual package, two resistors, and two capacitors. This circuit attenuates high-frequency noise while passing lower-frequency signals from sensors like thermistors or potentiometers. Its low power consumption prevents the filter from becoming a significant drain on the battery.
3. Voltage Follower/Buffer:
Due to its high input impedance and low output impedance, the MCP6232 is ideal as a unity-gain buffer. This circuit is used to isolate a high-impedance signal source (e.g., a sensor) from a low-impedance load, preventing the load from affecting the accuracy of the sensed signal. The rail-to-rail operation ensures the buffered signal is a faithful reproduction of the input, even near the power supply limits.
4. Window Comparator:
Utilizing both amplifiers in the dual package, a window comparator circuit can be constructed to determine whether a sensor's output voltage lies within a specific predefined range. The outputs of the two op-amps, configured as comparators, can be wired to logic gates or a microcontroller to trigger an alert if the voltage falls outside the "window."
ICGOODFIND: The Microchip MCP6232T-E/MS stands out as a highly efficient and versatile dual op-amp, perfectly balancing ultra-low power consumption with rail-to-rail performance. Its suitability for space-constrained, battery-operated designs makes it a superior choice for sensor interfacing, signal conditioning, and active filtering in portable consumer electronics, medical devices, and industrial sensor modules.
Keywords: Low Power Consumption, Rail-to-Rail I/O, Photodiode Amplifier, Active Filter, Battery-Powered Applications
