C8051F061-GQR Silicon Laboratories Inc, C8051F061-GQR Datasheet - Page 56

• Manufacturer Part Number: C8051F061-GQR
• Description: IC 8051 MCU 64K FLASH 64TQFP
• Manufacturer: Silicon Laboratories Inc
• Series: C8051F06xr

Specifications of C8051F061-GQR

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 25MHz
• Connectivity: CAN, SMBus (2-Wire/I²C), SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, Temp Sensor, WDT
• Number Of I /o: 24
• Program Memory Size: 64KB (64K x 8)
• Program Memory Type: FLASH
• Ram Size: 4.25K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Data Converters: A/D 2x16b, 8x10b; D/A 2x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-TQFP, 64-VQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

C8051F060/1/2/3/4/5/6/7
5.3.3. Settling Time Requirements
The ADC requires a minimum tracking time before an accurate conversion can be performed. This tracking
time is determined by the ADC input resistance, the ADC sampling capacitance, any external source resis-
tance, and the accuracy required for the conversion. Figure 5.5 shows the equivalent ADC input circuits for
both Differential and Single-ended modes. Notice that the equivalent time constant for both input circuits is
the same. The required settling time for a given settling accuracy (SA) may be approximated by
Equation 5.1. An absolute minimum tracking time of 280 ns is required prior to the start of a conversion.
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 (16).
56
TOTAL
AIN0
AIN1
is the sum of the ADC input resistance and any external source resistance.
RC
Differential Mode
Input
= R
AIN
R
R
* C
AIN
AIN
SAMPLE
= 30
= 30
Figure 5.5. ADC0 and ADC1 Equivalent Input Circuits
Equation 5.1. ADC0 Settling Time Requirements


t
C
C
SAMPLE
SAMPLE
=
ln
= 80pF
= 80pF


------ -
SA
2
n


Rev. 1.2

R
TOTAL
AIN0
AIN1
C
or
SAMPLE
Single-Ended Mode
RC
Input
= R
AIN
R
* C
AIN
SAMPLE
= 30

C
SAMPLE
= 80pF