32.8 ADC Characteristics

Table 32-10. ADC Characteristics, Single Ended Channel
Symbol	Parameter	Condition	Min.	Typ	Max	Units
	Resolution		-	10	-	Bits
TUE	Absolute accuracy (Including INL, DNL, quantization error, gain and offset error)	V_REF = 4V, V_CC = 5V,  CLK_ADC = 250kHz	-	3.5	7	LSB
		V_REF = 4V, V_CC = 5V, CLK_ADC = 1MHz	-	4	10	LSB
		V_REF = 4V, V_CC = 5V,  CLK_ADC = 250kHz Noise Reduction Mode	-	3	7	LSB
		V_REF = 5V, V_CC = 4V,  CLK_ADC = 1MHz  Noise Reduction Mode	-	3.5	10	LSB
INL	Integral Non-Linearity	V_REF = 4V, V_CC = 5V,  CLK_ADC = 250kHz	-	0.6	3	LSB
DNL	Differential Non-Linearity	V_REF = 4V, V_CC = 5V,  CLK_ADC = 250kHz	-	0.3	1	LSB
	Gain Error	V_REF = 4V, V_CC = 5V,  CLK_ADC = 250kHz	-7	3.5	7	LSB
	Offset Error	V_REF = 4V, V_CC = 5V,  CLK_ADC = 250kHz	-5	-2.5	-0	LSB
	Conversion Time	Free Running Conversion	13	-	260	μs
	Clock Frequency		50	-	1000	kHz
AV_CC⁽¹⁾	Analog Supply Voltage		V_CC - 0.3	-	V_CC + 0.3	V
V_REF	Reference Voltage		1.0	-	AV_CC	V
V_IN	Input Voltage		GND	-	V_REF	V
	Input Bandwidth		-	38.5	-	kHz
V_INT	Internal Voltage Reference 1.1V		1.0	1.1	1.2	V
V_INT	Internal Voltage Reference 2.56V	V_DD > 3V	2.3	2.56	2.8	V
R_REF	Reference Input Resistance		-	32	-	kΩ
R_AIN	Analog Input Resistance		-	100	-	MΩ

Note:

AV_CCabsolute min./max: 1.8V/5.5V

Table 32-11. ADC Characteristics, Differential Channels
Symbol	Parameter	Condition	Min	Typ	Max	Units
	Resolution	Gain = 1×	-	10	-	Bits
		Gain = 10×	-	10	-
		Gain = 200×	-	10	-
TUE	Absolute Accuracy (Including INL, DNL Quantization Error and Offset Error)	Gain = 1×, V_CC = 5V, V_REF = 4V, CLK_ADC = 250 kHz	0	12	20	LSB
		Gain = 10×, V_CC = 5 V, V_REF = 4V, CLK_ADC = 250 kHz	-10	14	30
		Gain = 200×, V_CC = 5V, V_REF = 4V, CLK_ADC = 250 kHz	-10	10	30
INL	Integral Non-linearity ⁽¹⁾	Gain = 1×, V_CC = 5V, V_REF = 4V, CLK_ADC = 250 kHz	-	1	3.5	LSB
		Gain = 10×, V_CC = 5V, V_REF = 4V, CLK_ADC = 250 kHz	-	1	3.5
		Gain = 200×, V_CC = 5V, V_REF = 4V, CLK_ADC = 250 kHz	-	2	4
DNL	Differential Non-linearity⁽¹⁾	Gain = 1×, V_CC = 5V, V_REF = 4V, CLK_ADC = 250 kHz	-	0.5	2	LSB
		Gain = 10×, V_CC = 5V, V_REF = 4V, CLK_ADC = 250 kHz	-	0.75	2.5
		Gain = 200×, V_CC = 5V, V_REF = 4V, CLK_ADC = 250 kHz	-	0.75	2.5
	Gain Error	Gain = 1×, V_CC = 5V, VREF = 4V, CLK_ADC = 250 kHz	-20	10	40	LSB
		Gain = 10×, VCC = 5V, VREF = 4V, CLK_ADC = 250 kHz	-20	10	40
		Gain = 200×, V_CC = 5V, V_REF = 4V, CLK_ADC = 250 kHz	-20	2	20
	Midcode Offset	Gain = 1×, V_CC = 5V, V_REF = 4V, CLK_ADC = 250 kHz	-10	-3.5	10	LSB
		Gain = 10×, V_CC = 5V, V_REF = 4V, CLK_ADC = 250 kHz	-15	-3.5	15
		Gain = 200×, V_CC = 5V, V_REF = 4V, CLK_ADC = 250 kHz	-20	3	20
	Conversion Time		52	-	260	μs
	Clock Frequency		50	-	250	kHz
AVCC	Analog Supply Voltage		V_CC - 0.3	-	V_CC + 0.3	V
V_REF	Reference Voltage⁽²⁾		2.0	-	AV_CC - 0.5
V_DIFF	Input Differential Voltage		0	-	V_REF/Gain
	ADC Conversion Output		-511	-	511	LSB
	Input Bandwidth		-	-	9.6	kHz
V_INT	Internal Voltage Reference 1.1V		1.0	1.1	1.2	V
V_INT	Internal Voltage Reference 2.56V	V_DD>3.3V (rational: V_INT(max)+0.5V)	2.3	2.56	2.8	V
R_REF	Reference Input Resistance		-	32	-	kΩ

Note:

INL and DNL are calculated based on 90% of FSR (Full Scale Range).
It is not recommended to use an external AREF higher than (Vdd-1V) in differential mode, as this will affect ADC accuracy.

ATmega324PB

32.8 ADC Characteristics