UCC39422PWTR

UCC39422PWTR Application Field and Working Principle

UCC39422PWTR is a single-channel step-down current-mode controller that belongs to the family of DC-DC switching controllers manufactured by Texas Instruments. It is used in applications such as car audio systems and LED drivers that require good transient response and high efficiency. The device is optimized for continuous inductor current limit. It features a wide input voltage operating range that can be adjusted from 4V up to 28V for applications requiring a high efficiency. It has a current limit accuracy of ±2.2% over load conditions from 0.05A to 5A. The device can support up to 16-times the output current along with a wide variety of protection features that provide system level design flexibility.

Features

• Wide 4V-28V operating range
• ±2.2% Current Limit Accuracy over load conditions from 0.05A to 5A
• 140mA peak gate drive capability
• High output accuracy over load, line, and temperature conditions
• Support up to 16-times the output current
• Integrated OVP, OCP, OLS, and Thermal Shutoff
• Internal VCC and Vref Regulators

Working Principle

UCC39422PWTR combines two unique digital architectures that provide precision current limit and pulse-width modulated (PWM) digital control with the features and flexibility needed for today’s applications. The PWM side of the device provides a flexible architecture capable of running with input voltages as low as 4V and is adjustable up to 28V. The current limit side of the device provides a ±2.2% accuracy over the load conditions, while allowing the user to select from a variety of protection features with the push of a button. Both architectures are incredibly power efficient and feature a low shutdown current of less than 20uA.

The current-limit control section consists of an integrated current limit circuit that, when enabled, continuously monitors the input current by comparator the difference between the current set and the current feedback signals. If the current limit circuit detects that the current limit has been exceeded, it will reduce the output voltage, protecting both the system and the controller from damage. The current limit can also be disabled; in this case, the output will be controlled by the pulse-width modulation (PWM) section.

The pulse-width modulation (PWM) section of the UCC39422PWTR is responsible for controlling the output voltage and frequency. It utilizes an on-board oscillator to generate a fixed frequency, adjustable frequency or a spread-spectrum signal to control the switching of the power MOSFETs. This ensures that the system can run efficiently while maintaining the desired voltage and frequency range. Additionally, the device has an adjustable shuttle voltage, which allows the output voltage to be set to the desired value.

The UCC39422PWTR device also offers a number of protection features including undervoltage lockout (UVLO), over-current protection (OCP), over-voltage protection (OVP), open-loop shutdown (OLS) and thermal shutoff (TSD). These features provide protection from unexpected system events and reduce system downtime.

Conclusion

The UCC39422PWTR is a single-channel step-down current-mode controller that combines two unique digital architectures to provide precision current limit and pulse-width modulated (PWM) digital control. It offers a wide input voltage operating range and adjustable output voltage shuttle. The device also provides protection features such as UVLO, OCP, OVP, OLS and TSD, which improve system performance and reliability. The UCC39422PWTR is ideal for applications requiring high efficiency and transient response.