EVM Assembly and Configuration
3
EVM Assembly and Configuration
3.1
Configure the Isolated Communications Interface
3.1.1
5V vs 3.3V Selection
In the ISO-COMMS section of the PCB, there are two jumpers. JP5 selects 5V or 3.3V I/O operation
across the isolation boundary. The Aardvark adapter supplied with the EVM uses 3.3V logic, but is 5V
tolerant. JP5 should be configured for 3.3V operation with the supplied Aardvark interface adapter,
although either position will work correctly. For connection to a user supplied microcontroller, select the
appropriate voltage.
3.1.2
Use USB Power from Aardvark
JP1 selects power from the USB connection through the Aardvark when installed in the
“
USB
”
position.
3.2
Configure the EVM board
3.2.1
Use with Cells
Remove jumpers JP1-18 (18) located near the black battery connectors P1-P3 to reduce the current draw
of the board. It is OK to leave the jumpers in place; they connect a 1K precision resistor between each
adjacent pair of cell inputs and are supplied to use the EVM with power supplies in place of cells (see the
Use with ~12-26VDC Power Supply
).
Connect cells to the supplied mating connectors with screw terminals BEFORE plugging the connector
into the EVM at P1, the large black connector on the left edge of the board. The most negative cell
connects to the most bottom of the black connector (P1).
The bottom-most pin of the battery connector is the most negative connection to the board from the
battery stack. This is the negative end of cell 1. The next pin up the connector is the positive end of cell 1
(and the negative end of cell 2). The connections proceed in this fashion up the connector to pin 7, which
is the most positive voltage from the battery stack connected to each IC. Pin 7 of P1 (P1.7) is connected
to P2.1 on the board. The same is true of P2.7 and P3.1. P3.7 is connected to the top of the PCB (most
positive voltage), while P1.1 is connected to the bottom of the PCB (most negative voltage).
The battery connections should be made secure, a loose connection may result in device destruction.
Ideally, the cells are connected to one another by secure means such as welding, and only tap points are
brought over to the EVM from each cell-to-cell interconnection.
Although the device is immune to the effects of a random connection sequence, the ideal connection
sequence is from pin P1.1 to pin 3.7 in order.
TI recommends that users unfamiliar with the EVM and/or li-ion cells begin by using power supplies as
outlined in the next section.
2
bq76PL536 EVM Quick Start Guide
SLUU437B
–
October 2010
–
Revised May 2011
Copyright
©
2010
–
2011, Texas Instruments Incorporated
