TPS78925DBVT

TPS78925DBVT is an adjustable voltage regulator belonging to the family of Linear Voltage Regulators of PMIC (Power Management Integrated Circuit). This device utilizes a revolutionary new architecture to provide a wide range of adjustable output supply from 1.5V to 5.5V.

Overview

The TPS78925DBVT is a high-efficiency DC-DC buck converter designed to provide a wide range of adjustable output voltage with high-accuracy and low output ripple. The device supports versatile current limit, over voltage and under voltage protection. It also supports programmable soft start and multiple frequency selection in order to decrease the number of external components. The TPS78925DBVT provides excellent transient performance with an adjustable output current up to 1A. Additionally, it provides a low quiescent current of only 2.3µA.

Features

• Adjustable Output Voltage Range: 1.5V to 5.5V.
• Switching Frequency: 400kHz to 2.2MHz.
• Power Efficiency: Up to 96%.
• Low Quiescent Current: 2.3µA.
• Current Limit Protection.
• Programmable Soft-Start.
• Reverse Voltage Protection.
• Under Voltage Lockout.

Applications

• Cellular Phones.
• Digital Cameras.
• Portable Media Players.
• MP3 Players.
• GPS Navigation Systems.
• Battery-Powered Systems.
• Automotive Applications.

Working Principle

The TPS78925DBVT is a non-synchronous buck converter based on two-level topology. The device consists of two main parts: the main power supply stage and the low-noise power supply rail. The main power supply stage is designed to handle the main load current while the low-noise power supply rail is designed to supply the low-noise analog blocks in the device. The main power supply stage consists of an internal P-channel MOSFET which is connected between the input voltage pin and the output voltage pin through a resistor and an inductor. The P-channel MOSFET is driven using a 4-level PWM technique in order to reduce the output voltage ripple. When the P-channel MOSFET is on, current flows through the inductor and the resistor, thus increasing the output voltage. When the P-channel MOSFET is off, current flows through the inductor in the opposite direction and the stored energy is released to the output voltage pin, thus decreasing the output voltage.

The low noise power supply rail consists of an internal N-channel MOSFET which is connected between the input voltage pin and the internal Vcc pin of the device. The N-channel MOSFET is driven using a 2-level PWM technique in order to reduce the output voltage ripple. When the N-channel MOSFET is on, current flows through the inductor and the resistor and the stored energy is released to the Vcc pin, thus increasing the Vcc voltage. When the N-channel MOSFET is off, current flows through the inductor in the opposite direction, thus decreasing the Vcc voltage.

The output voltage of the TPS78925DBVT is regulated using an internal voltage reference. The output voltage of the device is set via an external resistor divider from an input voltage range of 1.5V to 5.5V. The TPS78925DBVT also features an internal current limit protection and an internal over voltage protection. The device is available in a SOT-23 and WLCSP packages.