MCP6291-E/P - 10MHz RAIL-to-Rail Op Amp | Microchip
MPN: MCP6291-E/P ✓ ActiveMCP6291-E/P Overview
An operational amplifier is a voltage-gain component used to amplify small signals, buffer high-impedance sources, compare voltages, and implement feedback-control loops. Within the broader semiconductor hierarchy, the MCP6291-E/P belongs to the amplifier IC class, where its combination of low power consumption, wide bandwidth, and rail-to-rail behavior supports portable instrumentation, sensor interfaces, and low-voltage signal-processing systems.
Principal operating features include 2.4 V to 5.5 V single-supply operation, 10 MHz typical gain-bandwidth product, 65-degree phase margin, 7 V/us slew rate, and 85 dB typical common-mode rejection. Rail-to-rail inputs allow signals to approach the supply limits, while rail-to-rail outputs improve dynamic range in low-voltage systems where the output must swing close to the available supply rails.
The low-power architecture is significant because it limits the supply demand of continuously operating analog stages. The 1 mA typical quiescent current is particularly useful in battery-powered equipment, while the 10 MHz bandwidth provides useful closed-loop performance for moderate-frequency signals. The 7 V/us slew rate helps preserve large-signal response when the amplifier drives higher capacitance or operates at higher frequencies.
Typical applications include portable sensor conditioning, low-voltage audio and communication interfaces, current-to-voltage conversion, active filtering, buffer stages, and precision threshold detection. The device is also suitable for laboratory and test equipment operating from a 5 V rail where a conventional through-hole package simplifies prototyping, inspection, and manual assembly.
When using the MCP6291-E/P, account for output-current capability, capacitive-load stability, input common-mode range, and the noise gain selected by the feedback network. Decoupling capacitors should be placed close to the supply pins, and unused inputs must be tied to a defined common-mode potential rather than left floating.
This product page combines the manufacturer specifications with application-oriented engineering guidance, package and pin information, design notes, and a strict assessment of drop-in replacement options. The analysis distinguishes genuine pin-compatible substitutions from package-only equivalents so engineers can make PCB-level decisions without relying on incomplete cross-reference listings.
Drop-in alternatives for MCP6291-E/P — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
No drop-in alternatives available for this product.
Request AlternativesMCP6291-E/P Maximum Ratings & Electrical Characteristics
| Amplifier Type | Single general-purpose operational amplifier |
| Number of Amplifier Circuits | 1 circuit |
| Gain-Bandwidth Product | 10 MHz typical |
| Phase Margin | 65 degrees |
| Slew Rate | 7 V/us |
| Minimum Supply Voltage | 2.4 V |
| Maximum Supply Voltage | 5.5 V |
| Quiescent Current | 1.0 mA typical |
| Common-Mode Rejection Ratio | 85 dB typical |
| Input Bias Current | 0.0050 uA typical |
| Input Common-Mode Range | Rail-to-rail input |
| Output Swing | Rail-to-rail output |
| Operating Temperature Range | -40 C to +125 C |
| Package | 8-pin PDIP |
| Pin Count | 8 pins |
| Mounting Type | Through-hole |
| Noise Density | 8.7 nV/sqrt(Hz) at 10 kHz |
MCP6291-E/P Pin Configuration
| Pin 1 | NC — Not connected |
| Pin 2 | IN- — Inverting input |
| Pin 3 | IN+ — Non-inverting input |
| Pin 4 | V- — Negative supply |
| Pin 5 | NC — Not connected |
| Pin 6 | OUT — Output |
| Pin 7 | V+ — Positive supply |
| Pin 8 | NC — Not connected |
Typical Applications
MCP6291-E/P is suitable for 6 applications: Portable Sensor Signal Conditioning, Battery-Powered Analog Monitoring, Low-Voltage Active Filtering, Communications Interface Buffering, Precision Threshold Detection, Laboratory and Test Equipment.
Portable Sensor Signal Conditioning
The MCP6291-E/P suits low-voltage sensor front ends that need amplification close to 3.3 V or 5 V. Its 1.0 mA typical quiescent current limits continuous supply demand, while rail-to-rail input operation allows sensor signals to approach either supply rail. The 10 MHz gain-bandwidth product provides more closed-loop bandwidth than a basic micropower amplifier, supporting common instrumentation blocks such as strain-gauge bridges, temperature sensors, and low-level analog sensors. Place the amplifier close to the sensor and ground plane, keep input traces short, and select resistor values that control the noise gain while maintaining stable operation.
Battery-Powered Analog Monitoring
The MCP6291-E/P is useful in battery-powered monitoring systems where every milliamp of supply current affects operating time. Its 1.0 mA typical quiescent current is modest for an amplifier providing 10 MHz typical gain-bandwidth product and 7 V/us slew rate. Rail-to-rail inputs and outputs can improve signal utilization in compact 2.4 V to 5.5 V designs. The amplifier can buffer sensor outputs, amplify comparator-style signals, or form the active stage of a low-frequency filter. Confirm that the battery voltage remains inside the operating range and evaluate shutdown architecture at the system level if standby consumption dominates the design.
Low-Voltage Active Filtering
The MCP6291-E/P can implement active low-pass, high-pass, or band-pass stages in 3.3 V and 5 V instrumentation. Its 10 MHz gain-bandwidth product and 65-degree phase margin provide useful closed-loop performance above the frequency range of many micropower op amps. Rail-to-rail output operation helps preserve signal amplitude when filter stages operate near the supply rails. Select resistor and capacitor values around the desired cutoff frequency, verify noise gain at every stage, and check capacitive loading. Stable filter design also requires attention to parasitic capacitance, grounding, and the amplifier's response at the highest intended signal frequency.
Communications Interface Buffering
The MCP6291-E/P can serve as a general-purpose buffer or gain stage in low-speed and moderate-frequency communications equipment. Its 7 V/us slew rate and 10 MHz typical gain-bandwidth product support signals beyond very-low-frequency sensor interfaces, while the 2.4 V to 5.5 V supply range accommodates compact transceivers and digital subsystems powered at 3.3 V or 5 V. Rail-to-rail inputs and outputs are valuable when logic-level signals occupy much of the available voltage range. Keep sensitive high-speed routing separate from the amplifier output, use a low-impedance reference for driven inputs, and confirm the communication interface's bandwidth and capacitive-load requirements.
Precision Threshold Detection
The MCP6291-E/P can compare a sensor voltage with a reference in a threshold-detection or alarm circuit. Rail-to-rail input operation increases the usable input range in low-voltage systems, and the 85 dB typical common-mode rejection ratio helps reject common-mode disturbances when both comparison signals share a similar midpoint. The 1.0 mA typical quiescent current supports continuous monitoring, while the 10 MHz bandwidth provides ample response for many control signals. For accurate thresholds, use a stable reference, account for input offset voltage, avoid placing the amplifier directly beside high-current switching paths, and use hysteresis when noise near the decision point could cause repeated transitions.
Laboratory and Test Equipment
The 8-pin PDIP package makes the MCP6291-E/P convenient for laboratory prototypes, educational instruments, and service equipment assembled on perforated boards or through-hole sockets. Its 10 MHz typical gain-bandwidth product, 7 V/us slew rate, and single-supply operation from 2.4 V to 5.5 V provide a versatile amplifier stage for buffer, gain, and active-filter experiments. Through-hole construction also simplifies inspection and individual replacement. Designers should still observe the same high-frequency layout practices used for surface-mount parts, including short feedback paths, a low-impedance ground reference, and short supply-bypass connections.
Engineering reference data for MCP6291-E/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product |
|---|---|
| Package | 8-pin PDIP |
| Brand | Microchip Technology |
| Amplifier Count | 1 circuit |
| Supply Voltage Range | 2.4 V to 5.5 V |
| Gain-Bandwidth Product | 10 MHz typical |
| Slew Rate | 7 V/us |
| Quiescent Current | 1.0 mA typical |
| Common-Mode Rejection Ratio | 85 dB typical |
| Input and Output Swing | Rail-to-rail input and output |
| Operating Temperature | -40 C to +125 C |
Design Notes
Place the supply-bypass capacitor immediately adjacent to pins 7 and 4, with a short, low-impedance connection to the ground plane. Keep the inverting-input feedback trace short and isolate it from high-current switching paths. Because an operational amplifier can amplify small signals, ground-reference offsets and long input routes can become significant even when the 10 MHz gain-bandwidth product appears ample for the intended signal.
Do not treat MCP6291-E/SN or MCP6291T-E/SN as direct replacements for MCP6291-E/P. The former uses an 8-pin SOIC package and the latter uses SOT-23, while the target uses an 8-pin PDIP footprint. Although their amplifier functions are closely related, substituting either part requires a land-pattern and assembly change. Verify the exact pin arrangement and electrical limits before revising a PCB.
Check the closed-loop gain, output-swing limits, and capacitive load before using the amplifier as a high-speed logic buffer. The 10 MHz typical gain-bandwidth product and 7 V/us slew rate are useful performance figures, but stable operation still depends on noise gain and the feedback network. Keep the loop compact, use a stable feedback topology, and avoid long cable or high-capacitance loads without an appropriate isolation resistor.
The 1.0 mA typical quiescent current is a major advantage for portable designs, but total supply demand also includes output current and load-dependent losses. Calculate the average and peak current from the operating mode, not from the quiescent value alone. Confirm that the selected 2.4 V to 5.5 V source remains valid throughout battery discharge, startup, and temperature variation.
Compliance Information
No specific RoHS, REACH, lead-free, halogen-free, or conflict-minerals declaration was identified for this ordering code. AEC-Q100 qualification is not applicable to this general-purpose operational amplifier.