Introduction (Board Overview)
2
SLVUB61 – July 2017
Copyright © 2017, Texas Instruments Incorporated
TPS65291 EVM User's Guide
Trademarks
MSP430 is a trademark of Texas Instruments.
All other trademarks are the property of their respective owners.
1
Introduction (Board Overview)
The TPS65291EVM allows designers to evaluate the operation and performance of the TPS65291 PMU.
The TPS65291EVM is simple to test, requiring only a single power supply at the input, a USB cable
connected to a computer running the GUI, and a load at the output to measure performance. With no load
or a light load on the EVM, only the USB cable is required to power the TPS65291 device from the 5 V
provided by the VBUS wire of USB. The computer and GUI is used to communicate to the TPS65291
device through the SPI protocol.
The 50-mA BUCK2 output of the TPS65291 device is always-on, meaning it is enabled when an
adequately high voltage of at least 3.0 V is applied to the B2_VIN pin by a power supply. The performance
of BUCK2 can be measured without additional connections.
The 1-A BUCK1 output and the LDO_SW (configurable LDO or switch) output of the TPS65291 device
must be enabled by communicating to the TPS65291 device through SPI from a host controller. On the
EVM, an MSP430™ MCU is programmed as a USB2ANY device, and the SPI signals (CLK, MOSI, MISO,
and CS) are hard-wired to the TPS65291 device so that only a USB cable must be plugged into the EVM
to enable BUCK1 and LDO_SW. The B1_VIN pin can be shorted to the B2_VIN pin to provide power to
both DC-DC bucks.
The TPS65291EVM is
perforated
such that the printed circuit board (PCB) is split into two distinct
sections. The upper section, shown in
, contains the TPS65291 device, required passive
components, test points, and banana jacks for applying input power and loads. The lower section of the
PCB contains components not relevant to the evaluation of the TPS65291 device. Instead, the MSP430
MCU and other simple circuitry on this section of the PCB are used for communicating to the TPS65291
device through SPI and controlling the device from a computer with a USB cable.
If the two sections of the PCB are split apart, they can be connected by using a standard keyed 10-pin
ribbon cable with 2 rows by 5 pins and 100-mil pitch. The lower half is now a standard USB2ANY device
with SPI, I
2
C, 2 GPIOs, and a controllable 3.3-V output rail provided by a 150-mA LDO.
