1 Background

The Texas Instruments TPS54120 EVM (PWR103) helps design engineers evaluate the operation and performance of the TPS54120 (Switcher + LDO) for possible use in their own circuit application. This particular EVM configuration contains all of the external components required for a low-noise 1-A solution with internal thermal and current limit shutdowns, and enable circuitry in a 3.5-mm × 5.5-mm, QFN, thermally enhanced PowerPad? package.

The power input of the IC (PVIN) is rated for 1.6 V to 17 V while the control input (VIN) is rated for 4.5 V to 17 V. The TPS54120 provides both inputs, but this EVM is designed and tested using the PVIN connected to VIN with a minimum input voltage of 7 V. Rated input voltage and output current range for the evaluation module are given in Table 1-1. This evaluation module is designed to demonstrate the small printed-circuit-board areas that can be achieved when designing with the TPS54120 device. The switching frequency is externally set at a nominal 480 KHz.

The integrated switcher (SW) and LDO are optimized to allow the TPS54120 to achieve high efficiencies and a low output noise. The compensation components are external to the integrated circuit (IC), and an external divider allows for an adjustable LDO output voltage from 0.8 V to 6 V. Additionally, the TPS54120 provides adjustable slow start, tracking, and enable inputs. The TPS54120, including other external components that is capable of delivering up to 1-A low noise supply to the load.