MIC28511-2YFL-TR

The MIC28511-2YFL-TR is a DC-DC switching voltage regulator used in various applications. It is a dual output voltage regulator with an input voltage range of 2.5V to 5.5V. The device is well-suited for portable electronic products, including smart phones, tablets, and other digital devices. It is designed to provide the high efficiency and low quiescent current required for today’s power-constrained products.

The MIC28511-2YFL-TR can accommodate two output voltage (Vout1 and Vout2) configurations. Vout1 ranges from 0.8V to 2.3V, and Vout2 ranges from 1.2V to 3.6V. It has a switching frequency of 500kHz, allowing for fast transient response and excellent thermal performance. The maximum output current ratings are 0.5A (for Vout1) and 1.2A (for Vout2).The device also has a Power Good output pin that can be used to signal the system when the output is above or below a specified threshold. The device operates with a power dissipation of 2.5W (Vin=5V and both outputs loaded) and is specified over an operating temperature range of -40°C to +85°C.

Working Principle

The MIC28511-2YFL-TR employs a buck-boost switching regulator topology to provide regulation of both under voltage problems (low output voltage) as well as over voltage issues (high output voltage). This regulator topology is well suited for applications where the battery voltage can vary. The device is available in a PFM (Pulse Frequency Modulation) and a PWM (Pulse Width Modulation) mode, allowing it to be used in a wide variety of low power applications such as those found in portable devices.

In PFM Mode

In pulse frequency modulation (PFM) mode, the device is operated in an automatic light-load or very fast transient mode. In this mode, the device operates with very low power consumption as the switching frequency is reduced when the load current decreases from its nominal value. This mode of operation is well-suited for portable electronic devices since it further reduces power consumption by regulating the output voltage with a minimum number of switching cycles.

In PWM Mode

In pulse width modulation (PWM) mode, the device is operated in a constant on/off switching mode, providing very fast and accurate voltage regulation. This mode is typically used in applications where rapid response to load transient is required, such as while charging a battery.

Output Voltage Regulation

The MIC28511-2YFL-TR uses current mode control to regulate the output voltage. The output voltage is adjusted by controlling the amount of current flowing through a sense resistor, which is connected in series with the output. The controller continuously monitors the output voltage and adjusts the amount of current flowing through the sense resistor to maintain the output voltage within the specified tolerance. The device also uses the power-good pin to indicate if the output voltage is within the specified limits.

Protection Features

The MIC28511-2YFL-TR is designed to protect against current, over-temperature and short circuit events. The device contains an over-current protection (OCP), a thermal protection (TP), and an output short circuit protection (SCP). OCP is an internal current-sense design which monitors the output current and shuts down the device when the output current exceeds a preset limit. The TP is an on-chip thermal sensor which shuts down the device when the die temperature reaches a preset limit. The SCP will detect an output short circuit and automatically shut down the device until the fault condition is removed.

Conclusion

The MIC28511-2YFL-TR is a dual output switching regulator with an input voltage range of 2.5V to 5.5V and two output voltages. It has a switching frequency of 500kHz and is available in both PFM and PWM modes to ensure maximum efficiency in various portable electronic devices. It also has features such as over-current, over-temperature, and output short circuit protection to ensure reliable operation. The device is an ideal choice for applications where low power consumption and high efficiency are important.