Broadcom
ACPL-C740-EvalKit-UG100
9
ACPL-C740 Evaluation Kit Board
User Guide
Isolated Sigma-Delta Modulator
PCB Modifications
1. Vdd1 is supplied from the 5V/5V isolated DC-DC converter using the push-pull transformer method. Vdd1 can also be
supplied externally. To do that, ensure that R1 is disconnected.
2. The ACPL-C740 Vdd2 is supplied from the 3.3V regulator. To check the performance or troubleshoot the ACPL-C740
component only at Vdd2 = 5V, short Pin 1 and Pin2 of the J5 connector on the C740-SDM-EVBDv2 board. The Vdd2 is
then supplied directly from the USB power, 5VCC.
Note that R18 must be removed on the FPGA-EVBD board.
3. Green LED1–4 signals the detection of ACPL-C740. To modify the FPGA, use these LED indicators for other functions.
4. The H1 and H2 connector pins are physically connected to the FPGA. To modify the FPGA, use these connector pins
for input (I/P) or input/output (I/O).
Troubleshooting
If the green DONE LED does not come on after switching on SW1, reset the FPGA by pressing SW2 once. If the problem
arises, perform a full board reset by pressing SW3 once.
Each evaluation board is functionally checked and tested. before being sent to the customer. If a problem continues to arise,
consult a Broadcom Application Engineer. If need be, Broadcom will send a new board.
Appendix
Figure 6: PCB Description
ACPL-C740
Isolated Sigma-
Delta Modulator
pSemi PE22100
transformer driver
Shunt
Resistor
Mounting
SW1 board turn
on switch
Xilinx Spartan
XC3S250E
FPGA
SW2 reset
FPGA to
default setting
USB
Connector
Interface
SW3 board
power on
sequence reset
Xilinx JTAG
Interface
ACPL-C40 Low
Voltage Side
Connections
I/P pins
physically
connected to
FPGA
I/O pins
physically
connected to
FPGA
LED “5VIN”
indicates
presence of USB
connection
USB UART /
FIFO IC
EEPROM to
store USB
chipset
settings
Nonvolatile flash
memory to store
FPGA bitfile
LED “DONE”
indicates power
on sequence
complete
LED “HB”
application
software is
running
LED “UPLOAD”
indicates FPGA
bitfile is being
uploaded
Undefined LED
2,3,4 Indicators
LED1-4 indicates
that FPGA detects
ACPL-C740
C740-SDM-Evbdv2
FPGA-Evbd
Wurth 750313638
transformer coil
Ablic S-1200B50
5V-5V voltage
regulator
Isolated DC -DC Converter
