2 Description

The TPS542A52EVM-059 is set up to allow the user to easily measure the performance of the TPS542A52 buck converter under a wide range of input voltages and load currents. The EVM features two fully independent circuits.

The first circuit that will be discussed is the lower half, or bottom circuit, of the EVM as described in Section 3, and is denoted by U1. This circuit maximizes efficiency and performance of the TPS542A52 in applications that are less constrained by layout area. The second circuit that will be discussed is the upper half, or top circuit, of the EVM as described in Section 4, and is denoted by U1_2. This circuit highlights the small layout area (17 mm × 14 mm) that is required by the TPS542A52 converter and all external components while still delivering high performance and efficiency for space-critical applications.

The TPS542A52 features fixed-frequency voltage-mode control with user-configurable internal compensation, switching frequency, current limit, and soft-start timing. It also features selectable pulse-frequency modulation (PFM) for high light-load efficiency. These features are configured using external resistors. Optionally, a SYNC pin for PWM control can be synchronized to an external clock for low system noise.

Other features include an enable pin, adjustable undervoltage lockout (UVLO), an open-drain power good indicator, and a typical shutdown quiescent current draw of 12 μA.

The output voltage is programmable from 0.5 V to 5.5 V, and is set with a resistive divider between SREF and AGND, with the mid-point of the divider being tapped from the VSET pin.

The low R_DS(on) switching MOSFETs allow for high efficiency while maintaining low junction temperatures at high levels of output current. The TPS542A52 is capable of delivering 15 A of current to a load with no air flow at ambient temperatures up to 95°C, and up to 14 A with no external air flow at ambient temperatures of 105°C.

The extended operating junction temperature of -40°C to +150°C makes the TPS542A52 an excellent choice for applications with rigorous thermal requirements. Examples of these applications can be seen in Section 2.1.

The rated input voltage, output voltage, and output current of both circuits featured in the TPS542A52EVM-059 are shown in Table 2-1. The nominal input voltage of the EVM is 12 V, and the default output voltage is 1 V.