Evaluation Kit Adc Demo - Silicon Laboratories C8051F064-EK User Manual

C8051F064-EK

3. Evaluation Kit ADC Demo

The C8051F064 evaluation kit includes a demonstration of the noise performance of the 16-bit ADCs on the
C8051F064 device. A 1.25 V dc input signal is provided on the board as an input to the ADC input pins, AIN0 and
AIN1. The ADCs convert and store 32,768 samples (differential, 16-bit samples in 2s complement) in off-chip
SRAM. The PC application then downloads the data through the debug USB port. After processing these
conversions, the software generates a spectral plot (magnitude versus frequency) of the ADC input signal. The
spectral plot illustrates the C8051F064s noise floor for the given sample set. The minimum and maximum values
sampled, mean of values sampled, standard deviation, and dynamic range are displayed. To run the ADC Demo,
first configure the evaluation board and install the PC application.
3.1. ADC Demo Hardware Setup
Configure the evaluation board according to the instructions below. A diagram of the final configuration is shown in
Figure 2. Configuration shorting blocks may already be installed.
1. Place a shorting block on the J2 header connecting pin2 and pin3. This configures the evaluation board to
be powered from the DEBUG USB connector (J1).
2. Place a shorting block on the J4 header connecting pin2 and pin3. This configures the external voltage ref-
erence to be powered from the DEBUG USB connector (J1).
3. Place shorting blocks on the "V+" (J6) and "V–" (J8) headers.
4. Configure SRAM(U5): Place shorting blocks on J11 and on J14 connecting pin2 and pin3.
5. Connect one end of the provided USB cable to any available USB port on the PC.
6. Connect the other end of the USB cable into the USB connector on the board labeled "DEBUG" (J1). This
connection should power the board. Evaluation board power is indicated by the "PWR" LED (D4).
2
RESET P3.6
ADC1
C8051
J12
J16
ADC0
J5
J13
V+
Pin 1
J6
J8
V-
Figure 2. ADC Demo Hardware Setup
J11
SRAM
J14
F064
+3.3V
J2
Pin 1
5VDD
Pin 1
J4
J4
D3
D4
J3
P1.6 PWR STOP/RUN
Rev. 0.2
Pin 1
Pin 1
Pin 2
J15
USB Cable
DEBUG
J1
D2
DATA
D1
J7
To PC
USB Port