TPS611781RNWR

TPS611781RNWR Application Field and Working Principle

The TPS611781RNWR is a high-efficiency monolithic synchronous buck regulator IC. It belongs to the family of DC-DC switching regulators and belongs to the PMIC - voltage regulators category. This device is designed to provide high-efficiency and low-noise power supply for a wide range of applications. It offers adjustable output current and voltage, over-current protection and over-temperature protection.

Key Specifications

• Input Voltage Range: 2.5V to 6V
• Output Voltage Range: 0.8V to 5.5V
• Continuous Output Current: Maximum 2A
• Switching Frequency: 300 kHz to 1.2 MHz
• External Synchronization Possible
• Onboard PFET switch
• 60mV Reference Voltage
• Constant Frequency Current-Mode Control

Applications

• USB PD System: USB Type-C Charger
• Mobile Devices: Tablet, Smartphone and Wearable
• Industrial: Equipment, Automation System and Battery Backup Power

Working Principle

The TPS611781RNWR is a synchronous step-down DC/DC switching regulator. It is used to maintain the desired output voltage and current to the load while regulating the input voltage level. The device operates at a switching frequency of 300 kHz to 1.2 MHz, which can be externally synchronized by the user. The device is powered by 2.5V up to 6.5V input voltage and the output voltage range is 0.8V up to 5.5V. The device offers over-current protection, over-temperature protection and a current-mode constant frequency as default.

The switching regulator works on the principle of utilizing a power switch to rapidly convert AC input energy from the source into output energy with the desired characteristics. The power switching occurs at a much higher frequency than can be realized with a linear voltage regulator, and therefore allows for high-efficiency operation. The output voltage is regulated by pulse-width modulation (PWM) control.

The internal FET switch is actuated in synchronization with an internal oscillator. The output voltage is set by an external resistor, Rfeedback. The output voltage of the device is monitored continually and the duty-cycle and frequency of the oscillator is adjusted accordingly. When the output voltage drops below the setting point, the duty-cycle is increased and the output voltage is restored to the desired value. Phase-shift control is used to ensure stability of the output voltage and reduce output noise. If the output voltage exceeds the set point, the duty cycle is decreased accordingly.

The TPS611781RNWR also features an advanced current-mode control with a fixed frequency, constant off-time DESAT protection, and Over Temperature Protection (OTP). The extra feedback pin provides current limiting protection, which supports large load step response times and reduces the possibility of overshoot and ringing. This makes the TPS611781RNWR an ideal switched power supply for a variety of applications, such as USB Type-C charger and other mobile devices.