TSM1285 Demo Board
Page 2
TSM1285-EVB Rev. 1.0
Description
The TSM1285 demo board provides an easy-to-use
scheme for evaluating the TSM1285. The default
configuration of the demo board in conjunction with
the Nano River Technologies ViperBoard is for
operation at a supply voltage of V
DD
=+3.3V.
The TSM1285 demo board includes a
74ALVC164245 signal level translator in order to
translate signal levels from V
DD
of the TSM1285 to
+3.3V signal voltage levels necessary for the
ViperBoard. The TSM1285 and the ViperBoard are
connected via an on-board 34-pin ribbon socket (X1).
A separate power supply can be used to power the
TSM1285 from +2.7V to +3.6V. If evaluating the
TSM1285 demo board without the ViperBoard, a
single power supply is needed. A BNC connector is
available for the input of the TSM1285, AIN, and it is
recommended to use a low-noise signal generator in
order to acquire optimal SNR and THD results. Refer
to Table 1. Figure 6 shows the TSM1285 demo
board schematic, Figure 2 and Figure 3 show a
picture of the top and bottom of the TSM1285 demo
board, respectively. Figure 1 shows a picture of the
TSM1285 demo board with the ViperBoard
connected.
A USB cable is used to interface the ViperBoard to a
PC with Windows Vista 32-bit/Vista 64-bit/XP/7. For
the “Touchstone ADC Evaluation Platform GUI”
user’s manual and for the necessary driver and GUI
installer files needed to successfully evaluate the
TSM1285 with the ViperBoard, please refer to
www.silabs.com
.
Quick Start Procedure
Required Equipment
TSM1285
Demo
Board
Nano River Tech ViperBoard
USB
cable
Computer
with
Windows Vista 32-bit/64-bit/XP/7
ViperBoard driver and GUI software installed to
PC( refer to “Touchstone ADC Evaluation
Platform GUI” user’s manual)
Low-noise Signal Generator Stanford Research
Systems Model DS360 or better w/ BNC cable
In order to evaluate the TSM1285, jumper J2 is to be
set to position 1-2. The default configuration for J2 is
1-2. Refer to Figure 6 and Table 1. The default
configuration on the board is for V
DD
= +3.3V. The
following steps are to be performed:
1) Connect the TSM1285 demo board to the
ViperBoard via the 34-pin socket (X1).
2) Set the function generator frequency, amplitude,
and offset to 70kHz, 2.499V
PP
, and 1.25V,
respectively. Then, connect the BNC cable from
the signal generator to the BNC connector AIN on
the TSM1285 demo board. Set the output of the
signal generator to OFF.
3) To run the GUI, go to
Start > All Programs >
TouchStoneEvalBoard 2.2.10 > 01 Touchstone
Evaluation App
. The GUI should appear and on
the top right hand side, the status should be “PC
disconnected” and “No Type” for demo board
type. Both should be highlighted in red indicating
the ViperBoard and the TSM1285 demo board is
not connected.
4) Connect one side of the supplied USB cable to
the ViperBoard USB connector. Connect the
other side to a USB port on the PC. After
approximately three seconds, the status on the
GUI screen will switch to “PC Connected” and
“TSM1285” indicating the ViperBoard and the
TSM1285 demo board were recognized
successfully by the software. The green LED on
the TSM1285 demo board should be ON and the
green LED on the ViperBoard, D2, should be ON.
Use the default sampling rate of 300kSPS and an
FFT length of 8192.
5) Turn on the signal generator. On the GUI screen,
click on “continuous” in the sampling section, and
monitor the results on the screen. The top plot
shows a samples vs code plot and the bottom
plot is an FFT plot. The SNR and THD values
should be approximately 70dB and –80dB,
respectively. Please refer to Figure 4 for an
example of what the results should look like. In
this case, the SNR and THD values are 69dB and
-85dB, respectively.
Additional Functions
6) As shown in the TSM1285 ADC section, a
shutdown control function is available. If the
“shutdown” button is selected when sampling in
continuous mode, the TSM1285 will be in
shutdown mode and no additional conversions
