C8051F35x-DK
8
Rev. 0.3
6.6. Analog I/O (J6)
Many of the C8051F350 target device’s port pins are connected to the J6 terminal block. Connections for VDDA,
AGND, ADC external voltage refences, IDAC outputs and ADC inputs are available. Refer to Table 4 for the J6 ter-
minal block connections.
6.7. IDAC Connectors (J7, J11)
The C8051F350 target board also features two Current-to-Voltage 1 K
Ω
load resistors that may be connected to
the 10-bit current-mode Digital-to-Analog Converters (IDACs) on port pins P1.6 and P1.7. Install a shorting block
on J7 to connect the IDAC0/P1.6 pin of the target device to a load resistor. Install a second shorting block on J11 to
connect the IDAC1/P1.7 pin of the target device to a load resistor. The IDAC signals are then routed to the J1 and
J6 connectors.
6.8. USB Debug Adapter Target Board Power Connector (J8)
The USB Debug Adapter includes a connection to provide power to the target board. This connection is routed
from J4[10] to J8[1]. Place a shorting block at header J8[2-3] to power the board directly from an ac/dc power
adapter. Place a shorting block at header J8[1-2] to power the board from the USB Debug Adapter. Please note
that the second option is not supported with either the EC1 or EC2 Serial Adapters.
6.9. Thermistor Connector Block (J12)
A thermistor circuit is included on the board which allows for a ratiometric measurement of the included thermistor.
To use the circuit, remove the shorting blocks on the IDAC headers (J7, J11) and the External Voltage Reference
headers (J13, J14). Next, connect all of the signals on the thermistor connector block (J12). Software on the chip
can be written to use IDAC0 as a reference current source for the circuit. The current creates a voltage across R27
which is used as an external Voltage Reference input, while the voltage across the thermistor (R26) can be mea-
sured by connecting AIN0.0 to the AIN+ ADC input, and AIN0.1 to the AIN- ADC input.
6.10. External Voltage Reference (J13, J14)
A precision 2.5V voltage reference source is also included on the C8051F350 target board. To use this circuit as a
reference source for the ADC, place shorting block on headers J13 and J14. Note that software on the device
should be configured to use an external reference when using this configuration. When using the internal (on-chip)
reference source, headers J13 and J14 should be left open.
Table 4. J6 Terminal Block Pin Descriptions
Pin #
Description
Pin #
Description
1
IDAC0
8
AIN3
2
IDAC1
9
AIN4
3
VREF+
10
AIN5
4
VREF–
11
AIN6
5
AIN0
12
AIN7
6
AIN1
13
AGND
7
AIN2
14
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