TPS54620RGYR

The TPS54620 is a fully featured 17V, 6A synchronous buck converter in a thermally enhanced 3.50mm×3.50mm QFN package, featuring high efficiency with integrated high-side and low-side MOSFETs, optimized for compact designs. Current mode control reduces component count, and selecting a higher switching frequency reduces inductor package size for further space savings. The output voltage startup ramp is controlled by the SS/TR pin, enabling independent power supply operation or operation in tracking mode. Additionally, proper configuration of the enable and open-drain power-good pins allows power sequencing. Cycle-by-cycle current limiting on the high-side FET protects the device under overload conditions, while low-side power current limiting prevents current runaway for enhanced functionality. A low-side sink current limit is also provided to disable the low-side MOSFET and prevent excessive reverse current. Thermal shutdown disables the device when the die temperature exceeds the thermal shutdown threshold. The device is a 17-V, 6-A, synchronous step-down (buck) converter with two integrated n-channel MOSFETs. To improve performance during line and load transients the device implements a constant frequency, peak current mode control which also simplifies external frequency compensation. The wide switching frequency of 200 kHz to 1600 kHz allows for efficiency and size optimization when selecting the output filter components. The switching frequency is adjusted using a resistor to ground on the RT/CLK pin. The device also has an internal phase lock loop (PLL) controlled by the RT/CLK pin that can be used to synchronize the switching cycle to the falling edge of an external system clock. The device has been designed for safe monotonic startup into pre-biased loads. The default start up is when VIN is typically 4.0V. The EN pin has an internal pull-up current source that can be used to adjust the input voltage under voltage lockout (UVLO) with two external resistors. In addition, the EN pin can be floating for the device to operate with the internal pull-up current. The total operating current for the device is approximately 600μA when not switching and under no load. When the device is disabled, the supply current is typically less than 2μA. The integrated MOSFETs allow for high efficiency power supply designs with continuous output currents up to 6 amperes. The MOSFETs have been sized to optimize efficiency for lower duty cycle applications.

Applications

• High-density distributed power systems
• High-performance point-of-load regulation
• Broadband, network interconnect, and fiber optic communication infrastructure

Key features

• Integrated 26mΩ/19mΩ MOSFETs
• Separate power rail: 1.6V to 17V on PVIN
• Switching frequency 200kHz to 1.6MHz
• Synchronization to external clock
• 0.8V ±1% voltage reference over temperature
• 2μA low quiescent current in shutdown
• Single start-up into pre-biased output
• Operating junction temperature range: -40°C to 150°C
• Adjustable soft-start/power sequencing
• Power good output monitoring for undervoltage and overvoltage
• Adjustable input undervoltage lockout
• Supported by SwitcherPro™ software tool