UC2845AD Integrated Circuits (ICs)

Due to market price fluctuations, if you need to purchase or consult the price. You can contact us or emial to us:   sales@allicdata.com

UC2845AD Application Field and Working Principle

UC2845AD is a DC DC switching controller belonging to the Passive and Discrete Semiconductor category of power management integrated circuits (PMICs) and specifically located within the Voltage Regulators area of PMICs.

This controller is employed in a wide range of applications such as DC-DC converters, portable adapters, battery chargers, LED drivers and telecom rectifiers.

Operating Principle

The UC2845AD provides a precision regulated output by continuously sensing the output voltage and providing a pulse-width-modulated (PWM) signal to the associated driver stage. The frequency of the signal is determined by the external resistor-capacitor network and stays constant at light or no load.

The UC2845AD can also work with a synchronous rectification scheme that provides improved efficiency as compared to a diode rectification scheme. This can be done by connecting the “Comp” pin to an external gate driver in order to control a power MOSFET. Please note that in this mode the output voltage accuracy is reduced.

Features

The UC2845AD offers a range of features that make this switching controller appropriate for many applications. These features include:

• Wide input Voltage range of 7V to 40V
• Programmable oscillator frequency range of 40kHz to 1MHz
• Precision 2.5V reference
• External programmable soft-start
• Fault detection and latching
• Output current sensing
• Inherent sync-rectification control

Pins

The UC2845AD features 16 pins; eight control pins, one voltage sensing pin and five power supply pins. The control pins consists of an input pin for controlling the output voltage and two other functions, two mode pins for setting up the controller, a power-good indicator pin, two pins for controlling the current limit, two pins for programming the oscillator frequency and a clock synchronization pin.

The voltage sensing pin is used to detect the output voltage of the switching regulator. The power supply pins consist of two supply pins for the logic part of the controller and three supply pins for the gate drivers.

Protection

The UC2845AD has several built-in protection mechanisms. These include over-current protection, under-voltage lockout, thermal shutdown and short circuit protection. There is also a power-good indicator that signals whether the output voltage is within the allowable range.

The UC2845AD also has a fault-latching system that latches the protection state if the fault persists. This is reset with a logic low on reset pin.

Conclusion

The UC2845AD is a versatile switching controller suitable for a wide range of applications. It has many features and protection mechanisms that make it an ideal choice for designers. With an input voltage range of 7V to 40V and precision 2.5V reference, the UC2845AD provides an efficient and stable output voltage.

The specific data is subject to PDF, and the above content is for reference