C8051F353-GM Silicon Laboratories Inc, C8051F353-GM Datasheet - Page 133

• Manufacturer Part Number: C8051F353-GM
• Description: IC 8051 MCU 8K FLASH 28MLP
• Manufacturer: Silicon Laboratories Inc
• Series: C8051F35xr

Specifications of C8051F353-GM

• Program Memory Type: FLASH
• Program Memory Size: 8KB (8K x 8)
• Package / Case: 28-VQFN Exposed Pad, 28-HVQFN, 28-SQFN, 28-DHVQFN
• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 50MHz
• Connectivity: SMBus (2-Wire/I²C), SPI, UART/USART
• Peripherals: POR, PWM, Temp Sensor, WDT
• Number Of I /o: 17
• Ram Size: 768 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Data Converters: A/D 8x16b; D/A 2x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: C8051F3x
• Core: 8051
• Data Bus Width: 8 bit
• Data Ram Size: 768 B
• Interface Type: I2C/SMBus/SPI/UART
• Maximum Clock Frequency: 50 MHz
• Number Of Programmable I/os: 17
• Number Of Timers: 4
• Operating Supply Voltage: 2.7 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: KSK-SL-TOOLSTICK, PK51, CA51, A51, ULINK2
• Development Tools By Supplier: C8051F350DK
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 8-ch x 16-bit
• On-chip Dac: 2-ch x 8-bit
• No. Of I/o's: 17
• Ram Memory Size: 768Byte
• Cpu Speed: 50MHz
• No. Of Timers: 4
• Rohs Compliant: Yes
• Package: 28QFN
• Device Core: 8051
• Family Name: C8051F35x
• Maximum Speed: 50 MHz
• Data Rom Size: 128 B
• Height: 0.88 mm
• Length: 5 mm
• Supply Voltage (max): 3.6 V
• Supply Voltage (min): 2.7 V
• Width: 5 mm
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: 770-1006 - ISP 4PORT FOR SILABS C8051F MCU336-1083 - DEV KIT FOR F350/351/352/353
• Eeprom Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 336-1273

C8051F350/1/2/3
17.2.3. External RC Example
If an RC network is used as an external oscillator source for the MCU, the circuit should be configured as
shown in Figure 17.1, Option 2. The capacitor should be no greater than 100 pF; however for very small
capacitors, the total capacitance may be dominated by parasitic capacitance in the PCB layout. To deter-
mine the required External Oscillator Frequency Control value (XFCN) in the OSCXCN Register, first
select the RC network value to produce the desired frequency of oscillation. If the frequency desired is
100 kHz, let R = 246 kΩ and C = 50 pF:
3
3
f = 1.23( 10
) / RC = 1.23 ( 10
) / [ 246 * 50 ] = 0.1 MHz = 100 kHz
Referring to the table in SFR Definition 17.3, the required XFCN setting is 010b. Programming XFCN to a
higher setting in RC mode will improve frequency accuracy at an increased external oscillator supply cur-
rent.
17.2.4. External Capacitor Example
If a capacitor is used as an external oscillator for the MCU, the circuit should be configured as shown in
Figure 17.1, Option 3. The capacitor should be no greater than 100 pF; however for very small capacitors,
the total capacitance may be dominated by parasitic capacitance in the PCB layout. To determine the
required External Oscillator Frequency Control value (XFCN) in the OSCXCN Register, select the capaci-
tor to be used and find the frequency of oscillation from the equations below. Assume V
= 3.0 V and
DD
f = 150 kHz:
f = KF / (C x V
)
DD
0.150 MHz = KF / (C x 3.0)
Since the frequency of roughly 150 kHz is desired, select the K Factor from the table in SFR Definition 17.3
as KF = 22:
0.150 MHz = 22 / (C x 3.0)
C x 3.0 = 22 / 0.150 MHz
C = 146.6 / 3.0 pF = 48.8 pF
Therefore, the XFCN value to use in this example is 011b and C = 50 pF.
Rev. 1.1
133