C8051F553-IM Silicon Laboratories Inc, C8051F553-IM Datasheet - Page 166

• Manufacturer Part Number: C8051F553-IM
• Description: IC 8051 MCU 32K FLASH 24-QFN
• Manufacturer: Silicon Laboratories Inc
• Series: C8051F55xr

Specifications of C8051F553-IM

• Program Memory Type: FLASH
• Program Memory Size: 32KB (32K x 8)
• Package / Case: 24-QFN
• 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: 18
• Ram Size: 2.25K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.25 V
• Data Converters: A/D 18x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Processor Series: C8051F5x
• Core: 8051
• Data Bus Width: 8 bit
• Data Ram Size: 2304 B
• Maximum Clock Frequency: 50 MHz
• Number Of Programmable I/os: 18
• Operating Supply Voltage: 1.8 V to 5.25 V
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: PK51, CA51, A51, ULINK2
• Development Tools By Supplier: C8051F540DK
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: 336-1691 - KIT DEVELOPMENT FOR C8051F560
• Eeprom Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 336-1686-5

C8051F55x/56x/57x






f
=
KF
R V
DD
Equation 18.2. C Mode Oscillator Frequency
For example: Assume V
= 2.1 V and f = 75 kHz:
DD
f = KF / (C x VDD) 
0.075 MHz = KF / (C x 2.1)
Since the frequency of roughly 75 kHz is desired, select the K Factor from the table in SFR Definition 18.6
(OSCXCN) as KF = 7.7:
0.075 MHz = 7.7 / (C x 2.1) 
C x 2.1 = 7.7 / 0.075 MHz 
C = 102.6 / 2.0 pF = 51.3 pF
Therefore, the XFCN value to use in this example is 010b.
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Rev. 1.1