MIC2776N-YM5-TR Microprocessor Supervisory Circuit: Features and Application Design Guide
In the realm of electronic systems, ensuring a microprocessor operates reliably is paramount. The MIC2776N-YM5-TR is a sophisticated microprocessor supervisory circuit designed to monitor power supply voltages and provide critical control functions, thereby enhancing system integrity and preventing malfunctions. This highly integrated device from Microchip Technology serves as a guardian, offering a robust solution for a wide array of embedded applications.
Key Features of the MIC2776N-YM5-TR
The MIC2776N-YM5-TR stands out due to its combination of precision, flexibility, and compact packaging. Its most salient features include:
Precision Voltage Monitoring: At its core, the device features a high-accuracy voltage comparator that monitors the VDD supply. It asserts a reset signal whenever VDD drops below a fixed factory-set threshold (e.g., 2.93V, 3.08V, 4.38V, etc.), ensuring the microcontroller enters a known safe state during power-up, power-down, or brownout conditions.
Manual Reset Input: The inclusion of a manual reset input (MR) allows for a processor reset to be initiated by an external switch, a test button, or another logic circuit. This provides designers with added control for system debugging and user interaction.
Adjustable Reset Timeout Period: A key advantage is the adjustable reset pulse width. By connecting an external capacitor to the DELAY pin, engineers can tailor the duration of the asserted reset signal to meet the specific startup requirements of their chosen microprocessor.
Low Power Consumption: The device is engineered for very low supply current, typically drawing only microamps of current. This makes it exceptionally suitable for battery-powered and other power-sensitive portable applications.
Small Form Factor: Housed in a SOT-23-5 package, the MIC2776N-YM5-TR offers a full supervisory solution with a minimal PCB footprint, which is crucial for modern, space-constrained designs.
Application Design Guide
Integrating the MIC2776N-YM5-TR into a system is straightforward, but attention to detail ensures optimal performance.
1. Threshold Selection: First, select the appropriate variant of the IC with a reset threshold voltage (V_{RST}) that is slightly above the minimum operating voltage of your microprocessor. This ensures the MCU is held in reset before its power supply becomes unstable.
2. Basic Connection: The fundamental connection involves:
Connecting VDD to the monitored power rail.
Connecting GND to the system ground.
Connecting the RESET output directly to the reset pin of the microprocessor.
Leaving the MR pin unused can be simply pulled up to VDD with a resistor (e.g., 100kΩ).
3. Configuring the Reset Delay: The reset timeout period is set using a capacitor (C_{DELAY}) from the DELAY pin to ground. The relationship is typically linear; a larger capacitor value results in a longer reset pulse. Consult the datasheet for the exact formula to calculate the required capacitance for a desired delay (e.g., 100 ms, 1 sec).
4. Utilizing the Manual Reset: To implement a manual reset function, connect a momentary switch between the MR pin and ground. A pull-up resistor (e.g., 100kΩ) to VDD is required to keep the pin high when the switch is open. Pressing the switch pulls MR low, initiating a reset cycle.
5. PCB Layout Considerations: For maximum noise immunity, place the MIC2776N-YM5-TR as close as possible to the microprocessor's reset pin. Keep the traces short and route them away from noisy signals like clocks or switching power lines. Bypass the VDD pin with a 100nF ceramic capacitor placed near the IC.
ICGOODFIND: The MIC2776N-YM5-TR is an exceptional choice for designers seeking a highly reliable, compact, and feature-rich power management solution. Its precision monitoring, configurable reset pulse, and manual input capability make it a versatile guardian for microcontrollers in applications ranging from industrial controls and automotive systems to consumer electronics and IoT devices.
Keywords: Microprocessor Supervisor, Voltage Monitoring, Reset Circuit, Brownout Protection, SOT-23-5.
