attiny15l ATMEL Corporation, attiny15l Datasheet - Page 50

• Manufacturer Part Number: attiny15l
• Description: Attiny15l 8-bit Microcontroller With 1k Byte Flash
• Manufacturer: ATMEL Corporation

ADC Noise-canceling
Techniques
ADC Characteristics
50
Symbol
V
R
R
V
REF
REF
AIN
INT
ATtiny15L
Parameter
Resolution
Absolute Accuracy
Integral Non-linearity
Differential Non-linearity
Zero Error (Offset)
Conversion Time
Clock Frequency
Reference Voltage
Internal Voltage Reference
Reference Input Resistance
Analog Input Resistance
Digital circuitry inside and outside the ATtiny15L generates EMI, which might affect the
accuracy of analog measurements. If conversion accuracy is critical, the noise level can
be reduced by applying the following techniques:
1. The analog part of the ATtiny15L and all analog components in the application
2. Keep analog signal paths as short as possible. Make sure analog tracks run over
3. Use the ADC noise canceler function to reduce induced noise from the CPU.
4. If some Port B pins are used as digital outputs, it is essential that these do not
should have a separate analog ground plane on the PCB. This ground plane is
connected to the digital ground plane via a single point on the PCB.
the analog ground plane, and keep them well away from high-speed switching
digital tracks.
switch while a conversion is in progress.
Single-ended Conversion
Differential Conversion
Gain = 1x or 20x
Single-ended Conversion
V
ADC Clock = 200 kHz
Single-ended Conversion
V
ADC Clock = 1 MHz
Single-ended Conversion
V
ADC Clock = 2 MHz
V
V
V
Free Running Conversion
Single-ended Conversion
Differential Conversion
REF
REF
REF
REF
REF
REF
= 4V
= 4V
= 4V
> 2V
> 2V
> 2V
Condition
65.0
50.0
Min
2.0
2.0
2.4
6.0
100.0
10.0
16.0
2.56
10.0
Typ
8.0
1.0
4.0
0.5
0.5
1.0
V
CC
260.0
200.0
Max
13.0
V
2.0
2.7
CC
- 0.2
1187H–AVR–09/07
Units
LSB
LSB
LSB
LSB
LSB
LSB
Bits
Bits
kHz
MΩ
kΩ
µs
V
V
V