Datasheet

Test Setup and Results

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1.3.5 Input Voltage Rails

The EVM is designed to accommodate different input voltage levels for the power stage and control logic.

During normal operation, the PVIN and VIN inputs are connected using a jumper across JP1. The single

input voltage is supplied at J1. If desired, these two input voltage rails may be separated by removing the

jumper across JP1. Two input voltages must then be provided at both J1 and J2.

2 Test Setup and Results

This section describes how to properly connect, set up, and use the TPS54821EVM-049 evaluation

module. The section also includes test results typical for the evaluation module and covers efficiency,

output voltage regulation, load transients, loop response, output ripple, input ripple, and start-up.

2.1 Input/Output Connections

The TPS54821EVM-049 is provided with input/output connectors and test points as shown in Table 4. A

power supply capable of supplying 4 A must be connected to J1 through a pair of 20 AWG wires. The

jumper across JP1 must be in place. See Section 1.3.5 for split-input voltage rail operation. The load must

be connected to J4 through a pair of 20 AWG wires. The maximum load current capability must be 8 A.

Wire lengths must be minimized to reduce losses in the wires. Test-point TP1 provides a place to monitor

the V

input voltages with TP2 providing a convenient ground reference. TP9 is used to monitor the output

voltage with TP10 as the ground reference.

Table 4. EVM Connectors and Test Points

Reference Designator Function

J1 PVIN input voltage connector. (See Table 1 for V

range.)

J2 VIN input voltage connector. Not normally used.

J3 2-pin header for tracking voltage input and ground

J4 V

OUT

, 3.3 V at 8 A maximum

J5 2-pin header for tracking output and ground

JP1 PVIN to VIN jumper. Normally closed to tie VIN to PVIN for common rail voltage operation.

JP2 2-pin header for enable. Connect EN to ground to disable, open to enable.

TP1 PVIN test point at PVIN connector

TP2 GND test point at PVIN connector

TP3 VIN test point at VIN connector

TP4 GND test point at VIN connector

TP5 Test point provided to connect external voltage source for PWRGD pullup.

TP6 PWRGD test point

TP7 PH test point

TP8 Test point between voltage divider network and output. Used for loop response measurements.

TP9 Output voltage test point at VOUT connector

TP10 GND test point at VOUT connector

TPS54821EVM-049, 8-A, SWIFT™ Regulator— Evaluation Module SLVU479–October 2011

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