C8051F124TB Silicon Laboratories Inc, C8051F124TB Datasheet - Page 115

• Manufacturer Part Number: C8051F124TB
• Description: MCU, MPU & DSP Development Tools With C8051F124 MCU
• Manufacturer: Silicon Laboratories Inc

Specifications of C8051F124TB

• Processor To Be Evaluated: C8051F12x and C8051F13x
• Interface Type: USB
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

9.2.
On the C8051F121/3/5/7 devices, the REF0CN register also allows selection of the voltage reference
source for ADC0 and ADC2, as shown in SFR Definition 9.2. Bits AD0VRS and AD2VRS in the REF0CN
register select the ADC0 and ADC2 voltage reference sources, respectively. The VREFA pin provides a
voltage reference input for ADC0 and ADC2, which can be connected to an external precision reference or
the internal voltage reference. ADC0 may also reference the DAC0 output internally, and ADC2 may refer-
ence the analog power supply voltage, via the VREF multiplexers shown in Figure 9.2.
Figure 9.2. Voltage Reference Functional Block Diagram (C8051F121/3/5/7)
Reference Configuration on the C8051F121/3/5/7
Reference
External
Voltage
Circuit
DGND
VDD
Recommended Bypass
4.7F
R1
Capacitors
+
0.1F
VREFA
VREF
Rev. 1.4
REF0CN
C8051F120/1/2/3/4/5/6/7
DAC0
DAC1
Ref
REFBE
x2
AV+
1
0
0
1
C8051F130/1/2/3
Band-Gap
BIASE
1.2V
EN
ADC2
ADC0
Ref
Ref
Bias to
ADCs,
DACs
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