C8051F040-TB Silicon Laboratories Inc, C8051F040-TB Datasheet - Page 70

• Manufacturer Part Number: C8051F040-TB
• Description: BOARD PROTOTYPING W/C8051F040
• Manufacturer: Silicon Laboratories Inc
• Type: MCUr

Specifications of C8051F040-TB

• Contents: Board
• Processor To Be Evaluated: C8051F04x
• Interface Type: USB
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: C8051F040
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

C8051F040/1/2/3/4/5/6/7
6.1.1. Analog Input Configuration
The analog multiplexer routes signals from external analog input pins, Port 3 I/O pins (programmed to be
analog inputs), a High Voltage Difference Amplifier, and an on-chip temperature sensor as shown in
Figure 6.2.
Analog signals may be input from four external analog input pins (AIN0.0 through AIN0.3) as differential or
single-ended measurements. Additionally, Port 3 I/O Port Pins may be configured to input analog signals.
Port 3 pins configured as analog inputs are selected using the Port Pin Selection register (AMX0PRT). Any
number of Port 3 pins may be selected simultaneously as inputs to the AMUX. Even numbered Port 3 pins
and odd numbered Port 3 pins are routed to separate AMUX inputs. (Note: Even port pins and odd port
pins that are simultaneously selected will be shorted together as “wired-OR”.) In this way, differential mea-
surements may be made when using the Port 3 pins (voltage difference between selected even and odd
Port 3 pins) as shown in Figure 6.2.
The High-Voltage Difference Amplifier (HVDA) will accept analog input signals and reject up to 60 volts
common-mode for differential measurement of up to the reference voltage to the ADC (0 to VREF volts).
The output of the HVDA can be selected as an input to the ADC using the AMUX as any other channel is
selected for measurement.
70
PAIN0EN
PAIN2EN
PAIN4EN
PAIN6EN
PAIN1EN
PAIN3EN
PAIN5EN
PAIN7EN
HVAIN +
HVAIN -
HVCAP
HVREF
AIN0.0
AIN0.1
AIN0.2
AIN0.3
P3.6
P3.4
P3.2
P3.0
P3.7
P3.5
P3.3
P3.1
Figure 6.2. Analog Input Diagram
AGND
TEMP SENSOR
P3EVEN
(WIRED-OR)
(WIRED-OR)
P3ODD
AMP
HV
Rev. 1.5
+
+
+
+
-
-
-
-
0
1
2
3
4
5
6
7
8
AMUX
(SE or
9-to-1
DIFF)
X
AMX0CF
AMX0SL
ADC
10-Bit
SAR