4.9 ADC Electrical Specifications

Table 4-12. ADC AC Electrical Specifications
AC Characteristics			Standard Operating Conditions: V_DD = 1.9V to 3.6V (unless otherwise stated) Operating Temperature: -40°C ≤ T_A ≤ +85°C for Industrial Temp
Param. No.	Symbol	Characteristics	Min.	Typ.	Max.	Units	Conditions
Device Supply
ADC_1	VDD_A	ADC module supply	VDD_A_(min)	—	VDD_A_(max)	V	—
Reference Inputs
ADC_2	V_REF⁽⁴⁾	Absolute reference voltage (V_REFH-V_REFL) ⁽⁴⁾	GND-0.3	—	VDD_A+0.3	V	—
ADC_3	V_REF	Reference voltage high (external reference buffers)	GND+1.8	—	VDD_A	V	—
ADC_4	V_REFL	Reference voltage low (external reference buffers)	GND	—	VDD_A-1.8	V	—
ADC_4a	R_REF	Suggested V_REF impedance	—	—	25	Ω	Resistance from source to the V_REFP/V_REFM input, including RSource, PCB trace, pads and on-chip routing
ADC_4b	V_CM	Analog input Common mode voltage	GND + V_REF/2	—	VDD_A - V_REF/2	V	—
ADC_4c	V_DIFF	Differential analog input voltage (seldiff = 1)	2*(V_REFH - V_REFL)			V	—
ADC_4d	VSING	Single-ended analog input voltage (seldiff = 0)	V_REFL	—	V_REFH	—	—
ADC_4e	RIN_INT	ADC internal resistance	—	—	200	Ω	Internal sampling switch resistance
ADC_4f	RIN_SYS	External input resistance to meet the maximum speed	—	—	125	Ω	Resistance from VINP/VINM to signal source. Include RSource + RPad + RPCB + Rroute
ADC_4g	RSRC	Maximum source impedance to meet 2 MSPS at 12-bit	—	—	500	Ω	—
ADC_4g	RSRC	Maximum source impedance to meet 1 MSPS at 12-bit	—	—	1400	Ω	—
Analog Input Range
ADC_7	A_FS	Full-scale analog input signal range (Single-ended)	GND	—	V_REF	V	V_REF = VDD_A_(max)
ADC_11	T_SETTLING	ADC stabilization time	—	10	—	µs	—

Table 4-13. ADC Single-Ended Mode AC Electrical Specifications
AC Characteristics			Standard Operating Conditions: V_DD = 1.9V to 3.6V (unless otherwise stated) Operating Temperature: -40°C ≤ T_A ≤ +85°C for Industrial Temp
Param. No.	Symbol	Characteristics	Min.	Typical	Max.	Units	Conditions
Single-Ended Mode ADC Accuracy
SADC_11	Res	Resolution	6	—	12	bits	Selectable 8-, 10-, 12-bit resolution ranges
SADC_13	EN0B⁽³⁾	Effective number of bits	6.3	—	—	bits	2 Msps, Internal V_REF, VDD_A = V_DDIO = 3.3V
SADC_19	INL⁽³⁾	Integral non linearity	-13.737	—	2.869	LSb	2 Msps, Internal V_REF, VDD_A = V_DDIO = 3.3V
SADC_25	DNL⁽³⁾	Differential non linearity	-1.628	—	1.736	LSb	2 Msps, Internal V_REF, VDD_A = V_DDIO = 3.3V
SADC_31	GERR⁽³⁾	Gain error	-8.198	—	-4.697	LSb	2 Msps, Internal V_REF, VDD_A = V_DDIO = 3.3V
SADC_37	E0FF⁽³⁾	Offset error	4.905	—	25.094	LSb	2 Msps, Internal V_REF, VDD_A = V_DDIO = 3.3V
Single-Ended Mode ADC Dynamic Performance
SADC_49	SINAD^(1,2,3)	Signal to noise and distortion	39.728	—	—	dB	V_REF = VDD_A = V_DDIO = 3.3V at 12-bit resolution, max sampling rate^(1,2)
SADC_51	SNR^(1,2,3)	Signal to noise ratio	39.747	—	—
SADC_53	SFDR^(1,2,3)	Spurious free dynamic range	61.32	—	—
SADC_55	THD^(1,2,3)	Total harmonic distortion	—	—	-59.346
Note: Characterized with an analog input sine wave = (FTP(max)/100). Example: FTP(max) = 1 Msps/100 = 10 kHz sine wave. Sine wave peak amplitude = 96% ADC_ Full Scale amplitude input with 12-bit resolution. Spec values collected under the following additional conditions: At least (3) SERCOM, (2) TCC and (2) TC peripheral clocks active but the same peripherals disabled, not running. At least (6) I/O pins toggling simultaneously at > 6 MHz, not adjacent to analog input pin; (3) with external 2 ma pull-up loads & (3) with external 2 ma pull-down loads on the side of the package shared by V_DDANA. 12-bit resolution mode. ADC functional device operation with either internal or external V_REF < 2.4V is functional but not characterized. ADC will function but with degraded accuracy of approximately ~((0.06 * 2n)/V_REF) LSBs over full scale range, where n=#bits. ADC accuracy is limited by internal VREF accuracy + drift, MCU generated noise plus user's application noise/accuracy on V_DDANA, GNDANA. Value taken over 7 harmonics.

Table 4-14. ADC Conversion AC Electrical Requirements
AC Characteristics			Standard Operating Conditions: V_DD = 1.9V to 3.6V (unless otherwise stated) Operating Temperature: -40°C ≤ T_A ≤ +85°C for Industrial Temp
Param. No.	Symbol	Characteristics	Min.	Typ.	Max.	Units	Conditions
ADC_ Clock Requirements
ADC_57	TAD	ADC clock period	—	20.8	—	ns	V_REF = VDD_A = 3.3V
ADC Single-Ended Throughput Rates
ADC_59	FTPR (Single-ended mode)	Throughput rate⁽⁴⁾ (Single-ended)	0.01	—	2	Msps	12-bit resolution, DIV_SHR = 2
Note: ADC_ Sample time = ((SAMPCTRL.SAMPLEN + 1) * TAD) and SAMPCTRL.OFFCOMP = `0`. ADC_ HDW forces sample time to 4TAD when SAMPCTRL.OFFCOMP = `1`; user SAMPCTRL.SAMPLEN is ignored. ADC Throughput Rate FTP = ((1/((TSAMP + TCNV) TAD))/(# of user active analog inputs in use on specific target ADC module)). Note: Specification values assume only one AINx channel in use. SAMPCTRL.R2R = `1`. (Must be set to ‘`1`’ in ADC differential mode).

Table 4-15. ADC Sample AC Electrical Requirements
AC Characteristics			Standard Operating Conditions: V_DD = 1.9V to 3.6V (unless otherwise stated) Operating Temperature: -40°C ≤ T_A ≤ +85°C for Industrial Temp
Param. No.	Symbol	Characteristics	Min.	Typ.	Max.	Units	Conditions
ADC_63	TSAMP	ADC sample time ^(1,2,3,5)	1^(1,5)	—	—	TAD	12-bit TAD(min), Ext Analog Input Rsource ≤ 147Ω
							10-bit TAD(min), Ext Analog Input Rsource ≤ 504Ω
							8-bit TAD(min), Ext Analog Input Rsource ≤ 1,000Ω
			2^(1,5)	—	—		12-bit TAD(min), Ext Analog Input Rsource ≤ 2,272Ω
							10-bit TAD(min), Ext Analog Input Rsource ≤ 3,008Ω
							8-bit TAD(min), Ext Analog Input Rsource ≤ 4,000Ω
			3^(1,5)	—	—		12-bit TAD(min), Ext Analog Input Rsource ≤ 4,416Ω
							10-bit TAD(min), Ext Analog Input Rsource ≤ 5,504Ω
							8-bit TAD(min), Ext Analog Input Rsource ≤ 6,976Ω
			4^(1,2,5)	—	—		12-bit TAD(min), Ext Analog Input Rsource ≤ 6,560Ω
							10-bit TAD(min), Ext Analog Input Rsource ≤ 8,000Ω
							8-bit TAD(min), Ext Analog Input Rsource ≤ 9,984Ω
			5^(1,5)	—	—		12-bit TAD(min), Ext Analog Input Rsource ≤ 8,704 Ω
							10-bit TAD(min), Ext Analog Input Rsource ≤ 10,496Ω
							8-bit TAD(min), Ext Analog Input Rsource ≤ 12,992Ω
			6^(1,5,6)	—	—		12-bit TAD(min), Ext Analog Input Rsource ≤ 10,880Ω
							10-bit TAD(min), Ext Analog Input Rsource ≤ 12,992Ω
							8-bit TAD(min), Ext Analog Input Rsource ≤ 16,000Ω
			—	—	—	ns	With DAC as input
			—	—	—	ns	With temperature sensor as input
ADC_65	TCNV	Conversion time ⁽³⁾ (Single-Ended mode)	12			TAD	12-bit resolution
			11				10-bit resolution
			9				8-bit resolution
Note: When SAMPCTRL.OFFCOMP = `0`: TSAMP = (((RSAMPLE + RSOURCE) * CSAMPLE * (#Bits Resolution + 2) * ln(2))/TAD)+1 rounded down to nearest whole integer User SAMPCTRL.SAMPLEN = (TSAMP – 1) When SAMPCTRL.OFFCOMP = `1`: TSAMP = 4 (Forced by HDW) User SAMPCTRL.SAMPLEN = (n/a, Ignored by HDW) ADC Throughput Rate FTP = ((1/((TSAMP + TCNV) * TAD))/(# of user active analog inputs in use on specific target ADC module)). Note: Specification values assume only one AINx channel in use. SAMPCTRL.R2R = `1`. (Must be set to ‘`1`’ in ADC differential mode). TSAMP ≥ (INT[((RSAMPLE + RSOURCE) * CSAMPLE * (#Bits Resolution+2) * ln(2))/TAD]+1). For RSOURCE values exceeding TSAMP = 6 sample time condition, use the formula in Note 5 to calculate.