C8051F961-A-GM Silicon Labs, C8051F961-A-GM Datasheet - Page 100

• Manufacturer Part Number: C8051F961-A-GM
• Description: 8-bit Microcontrollers - MCU 128KB, DC-DC, LCD AES, QFN40
• Manufacturer: Silicon Labs

Specifications of C8051F961-A-GM

• Rohs: yes
• Core: 8051
• Processor Series: C8051
• Data Bus Width: 8 bit
• Maximum Clock Frequency: 25 MHz
• Program Memory Size: 128 KB
• Data Ram Size: 8448 B
• On-chip Adc: Yes
• Operating Supply Voltage: 2.5 V to 3.3 V
• Operating Temperature Range: - 40 C to + 85 C
• Package / Case: QFN-40
• Mounting Style: SMD/SMT
• Number Of Programmable I/os: 34
• Number Of Timers: 4

C8051F96x
5.9. Voltage and Ground Reference Options
The voltage reference MUX is configurable to use an externally connected voltage reference, the internal
voltage reference, or one of two power supply voltages (see Figure 5.10). The ground reference MUX
allows the ground reference for ADC0 to be selected between the ground pin (GND) or a port pin dedi-
cated to analog ground (P0.1/AGND).
The voltage and ground reference options are configured using the REF0CN SFR described on SFR
Definition 5.15. REF0CN: Voltage Reference Control. Electrical specifications are can be found in the
Electrical Specifications Chapter.
Important Note About the V
inputs. When using an external voltage reference or the internal precision reference, P0.0/VREF should be
configured as an analog input and skipped by the Digital Crossbar. When using AGND as the ground refer-
ence to ADC0, P0.1/AGND should be configured as an analog input and skipped by the Digital Crossbar.
Refer to Section “27. Port Input/Output” on page 351 for complete Port I/O configuration details. The exter-
nal reference voltage must be within the range 0  V
at the same dc voltage potential as GND.
100
4.7 F
B yp ass C apa citors
R eco m m en ded
G N D
V D D
+
R 1
R e ference
E xternal
V olta ge
C ircuit
0 .1 F
Figure 5.10. Voltage Reference Functional Block Diagram
P 0 .1/A G N D
P 0.0/V R E F
V B A T
REF
G N D
and AGND Inputs: Port pins are used as the external V
Rev. 0.5
R e gu late d D ig ital S up ply
H igh S p ee d R e ference
REF
R E F 0C N
Intern al 1.65V
Intern al 1 .8V
 VDD and the external ground reference must be
E N
Te m p S enso r
R E FG N D
0 0
0 1
1 0
1 1
0
1
REF
and AGND
(to A D C )
(to A D C )
V R E F
G rou nd
A D C
In put
M u x