C8051F120-GQR Silicon Laboratories Inc, C8051F120-GQR Datasheet - Page 59

• Manufacturer Part Number: C8051F120-GQR
• Description: IC 8051 MCU FLASH 128K 100TQFP
• Manufacturer: Silicon Laboratories Inc
• Series: C8051F12xr

Specifications of C8051F120-GQR

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 100MHz
• Connectivity: EBI/EMI, SMBus (2-Wire/I²C), SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, Temp Sensor, WDT
• Number Of I /o: 64
• Program Memory Size: 128KB (128K x 8)
• Program Memory Type: FLASH
• Ram Size: 8.25K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 V
• Data Converters: A/D 8x8b, 8x12b; D/A 2x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 100-TQFP, 100-VQFP
• Processor Series: C8051F1x
• Core: 8051
• Data Bus Width: 8 bit
• Data Ram Size: 8.25 KB
• Interface Type: I2C, SMBus, SPI, UART
• Maximum Clock Frequency: 100 MHz
• Number Of Programmable I/os: 64
• Number Of Timers: 5
• Operating Supply Voltage: 2.7 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: PK51, CA51, A51, ULINK2
• Development Tools By Supplier: C8051F120DK
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 12 bit, 8 Channel
• On-chip Dac: 12 bit, 2 Channel
• For Use With: 336-1285 - KIT DEV EMBEDDED MODEM336-1284 - KIT DEV EMBEDDED ETHERNET336-1224 - DEVKIT-F120/21/22/23/24/25/26/27
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

5.2.3. Settling Time Requirements
A minimum tracking time is required before an accurate conversion can be performed. This tracking time is
determined by the ADC0 MUX resistance, the ADC0 sampling capacitance, any external source resis-
tance, and the accuracy required for the conversion. Figure 5.4 shows the equivalent ADC0 input circuits
for both Differential and Single-ended modes. Notice that the equivalent time constant for both input cir-
cuits is the same. The required settling time for a given settling accuracy ( SA ) may be approximated by
Equation 5.1. When measuring the Temperature Sensor output, R
minimum settling time of 1.5 µs is required after any MUX or PGA selection. Note that in low-power track-
ing mode, three SAR clocks are used for tracking at the start of every conversion. For most applications,
these three SAR clocks will meet the tracking requirements.
Where:
SA is the settling accuracy, given as a fraction of an LSB (for example, 0.25 to settle within 1/4 LSB)
t is the required settling time in seconds
R
n is the ADC resolution in bits (12).
TOTAL
AIN0.x
AIN0.y
is the sum of the ADC0 MUX resistance and any external source resistance.
RC
Differential Mode
MUX Select
MUX Select
Input
= R
MUX
R
R
* C
Equation 5.1. ADC0 Settling Time Requirements
MUX
MUX
SAMPLE
= 5k
= 5k
Figure 5.4. ADC0 Equivalent Input Circuits
t
C
C
SAMPLE
SAMPLE
=
ln
= 10pF
= 10pF


------ -
SA
2
n



Rev. 1.4
R
TOTAL
C8051F120/1/2/3/4/5/6/7
C
AIN0.x
SAMPLE
Single-Ended Mode
TOTAL
RC
MUX Select
Input
C8051F130/1/2/3
= R
reduces to R
MUX
R
* C
MUX
SAMPLE
= 5k
MUX
C
. An absolute
SAMPLE
= 10pF
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