TPS62821DLCT Integrated Circuits (ICs)

TPS62821DLCT Application Field and Working Principle

The TPS62821DLCT is a 1-A Step-Down DC/DC converter with an adjustable output voltage range of 0.6 V to 3 V. This device is a member of Texas Instrument’s PowerStrip™ family and it was designed to deliver power directly from a single-cell Li-Ion Battery to various circuits and systems. Its output can be set to a voltage as low as 0.8 V, while its integrated low RDSON switches provide a typical efficiency of 96% at full-load. Its True Shutdown™ feature eliminates any internal power dissipations when the device is turned off.

The device offers accurate current-limit and overvoltage protection. The TPS62821DLCT can be used for applications such as point-of-load (POL) regulation, storage and computing, internet of things (IoT) devices, healthcare and wearable devices. It also provides accurate voltage regulation over a wide input voltage range from 2.3 V to 5.5 V and low quiescent current of 2.6 μA.

How it Works
The TPS62821DLCT operates in a fixed-frequency PWM buck mode, in which the switching frequency is determined by an internal oscillator. It utilizes an internal N-Channel MOSFET as its main switch. The switching of the internal MOSFET is controlled by the control block, which takes a reference voltage, typically generated by an external resistor divider, and compares this feedback voltage to an internal voltage reference.

When the feedback voltage is below the reference voltage, the error amplifier output is high, which turns on the internal MOSFET and allows power to flow from the input (BAT) to the output (Vout). The output voltage is regulated by controlling the on/off timing of the internal MOSFET. The MOSFET is switched on for a certain period of time and off for the rest of the cycle, resulting in a varying duty cycle. The output voltage is then regulated by changing the duty cycle.

The TPS62821DLCT also provides a Soft-Start feature that prevents output voltage overshoots and in-rush current problems by gradually increasing the output voltage. The Soft-Start feature gradually increases the output voltage from 0 V over a set amount of time. This feature can be enable/disable via the SS# pin.

Conclusion
The TPS62821DLCT is a 1-A DC/DC Step-Down converter that provides accurate voltage regulation over a wide input voltage range from 2.3 V to 5.5 V. It delivers power directly from a single-cell Li-Ion Battery and its integrated low RDSON switches provide a typical efficiency of 96% at full-load. It offers accurate current-limit and overvoltage protection, and its Soft-Start feature prevents output voltage overshoot and in-rush current problems. The device is suitable for applications such as POL regulation, storage and computing, IoT devices, healthcare, and wearable devices.