55.21 ADC Electrical Specifications

Table 55-25. ADC Electrical Specifications
AC CHARACTERISTICS Standard Operating Conditions: VDD = AVDD = 1.71V to 3.63V (unless otherwise stated)

Operating temperature:

-40°C ≤ TA ≤ +85°C for Industrial Temperature
Param. No. Symbol Characteristics Min. Typ. Max. Units Conditions
Device Supply
ADC_1 AVDD ADC Module Supply AVDD(min) — AVDD(max) V —
Reference Inputs
ADC_3 VREF(1) ADC Reference Voltage The greater of AVDD(min) or 2.4V — AVDD-0.4 V External Reference

VREF ≤ AVDD -0.4V
AVDD V Internal Reference

VREF ≤ AVDD
Analog Input Range
ADC_7 AFS Full-Scale Analog Input Signal Range AVSS — VREF V Single-Ended
ADC_9 -VREF — +VREF V Differential
ADC10 VCMIN Input common mode voltage AVSS VREF/2 AVDD — CTRLA.R2R =1
Note (2) VREF/2 Note (2) — CTRLA.R2R =0
ADC_11 TSETTLING ADC Stabilization Time — 10 — µs CTRLA.ENABLE=1 or

CTRLA.ONDEMAND=1
Note:
  1. ADC functional device operation with external VREF<2.4V is functional, but not characterized. ADC will function, but with degraded accuracy of approximately ~((0.06 * 2n) / VREF) LSB’s over full scale range, where "n"= # bits. ADC accuracy is limited by internal VREF accuracy + drift, MCU generated noise plus users application noise/accuracy on AVDD, AVSS.
  2. Limit the input common mode voltage using the following equations (where, VCMIN is the input channel common mode voltage):

    When CTRLA.R2R = 0:

    • VCMIN < 0.75*VREF
    • VCMIN > Maximum of (0, VREF-AVDD-0.7, 1.25*VREF-AVDD)

    These values are based on simulation. They are not covered by production test limits or characterization.
Table 55-26. ADC Single Ended Mode Electrical Specifications
AC CHARACTERISTICS Standard Operating Conditions: VDD = AVDD = 1.71V to 3.63V (unless otherwise stated)

Operating temperature:

-40°C ≤ TA ≤ +85°C for Industrial Temperature
Param. No. Symbol Characteristics Min. Typ. Max. Units Conditions
SINGLE ENDED MODE ADC Accuracy (4)
SADC_11 Res Resolution 8 — 12 bits Selectable 8, 10, 12 bit Resolution Ranges
SADC_13 ENOB (1,2) Effective Number of bits 8.9 — — bits 1Msps, Internal VREF=

AVDD=VDD=3.3V
SADC_15 8.9 — — bits 1Msps, External VREF=2.4V,

AVDD=VDD=3.3V
SADC_19 INL Integral Nonlinearity -3.2 — 3.2 LSB 1Msps, Internal VREF=AVDD=VDD=3.3V
SADC_21 -3.5 — 3.5 LSB 1Msps, External VREF=2.4V,

AVDD=VDD=3.3V
SADC_25 DNL Differential Nonlinearity -1 — 1 LSB 1Msps, Internal VREF=AVDD=VDD=3.3V
SADC_27 -1 — 1.1 LSB 1Msps, External VREF=2.4V,

AVDD=VDD=3.3V
SADC_31 GERR Gain Error -12.3 — 12.3 LSB 1Msps, Internal VREF=AVDD=VDD=3.3V,

REFCTRL.REFCOMP=1
-8.2 — 12.3 LSB 1Msps, External VREF=2.4V,

AVDD=VDD=3.3V,

REFCTRL.REFCOMP=1
SADC_37 EOFF Offset Error -22.4 — 8.7 LSB 1Msps, Internal VREF=AVDD=VDD=3.3V,

SAMPCTRL.OFFCOMP=1
-31.8 — 22.2 LSB 1Msps, External VREF=2.4V,

AVDD=VDD=3.3V,

SAMPCTRL.OFFCOMP=1
SADC_43 TUE Total Unadjusted Error -18.3 — 18.3 LSB 1Msps, Internal VREF=AVDD=VDD=3.3v,

REFCTRL.REFCOMP=1,

SAMPCTRL.OFFCOMP=1
SADC_47 -19.1 — 19.1 LSB 1Msps, External VREF=2.4V,

AVDD=VDD=3.3V,

REFCTRL.REFCOMP=1,

SAMPCTRL.OFFCOMP=1
SINGLE ENDED MODE ADC Dynamic Performance (4)
SADC_49 SINAD (1,2) Signal to Noise and Distortion 55.7 — — dB VREF=AVDD=VDD=3.3V at 12bit max sampling rate
SADC_51 SNR (1,2) Signal to Noise ratio 54.7 — —
SADC_53 SFDR (1,2) Spurious Free Dynamic Range 67.9 — —
SADC_55 THD (1,2,3) Total Harmonic Distortion — — -65.8
SADC_57 Nrms Noise RMS — — 2.2 LSB VREF = AVDD = VDD = 3.3V,

Constant Input Voltage
— — 3.6 LSB External VREF = 2.4V, AVDD = VDD = 3.3V,

Constant Input Voltage
Note:
  1. Characterized with an analog input sine wave = (FTP(max) / 100). Example: FTP(max)=1Msps/100 = 10kHz sine wave.
  2. Sinewave peak amplitude = 96% ADC_ Full Scale amplitude input with 12bit resolution.
  3. Value taken over 7 harmonics.
  4. ADC is configured in 12bits mode, All registers are at the reset default value unless otherwise stated.
Table 55-27. ADC Differential Mode Electrical Specifications
AC CHARACTERISTICS Standard Operating Conditions: VDD = AVDD = 1.71V to 3.63V (unless otherwise stated)

Operating temperature :

-40°C ≤ TA ≤ +85°C for Industrial Temperature
Param. No. Symbol Characteristics Min. Typ. Max. Units Conditions
DIFFERENTIAL MODE ADC Accuracy (4)
DADC_11 Res Resolution 8 — 12 bits Selectable 8, 10, 12 bit Resolution Ranges
DADC_13 ENOB (1,2) Effective Number of bits 10.5 — — bits 1Msps, Internal

VREF=AVDD=VDD=3.3V
DADC_15 10.5 — — bits 1Msps, External VREF=2.4V,

AVDD=VDD=3.3V
DADC_19 INL Integral Nonlinearity -1.5 — 1.5 LSB 1Msps, Internal

VREF=AVDD=VDD=3.3V
DADC_21 -1.5 — 1.5 LSB 1Msps, External VREF=2.4V,

AVDD=VDD=3.3V
DADC_25 DNL Differential Nonlinearity -1 — 1 LSB 1Msps, Internal

VREF=AVDD=VDD=3.3V
DADC_27 -1 — 1 LSB 1Msps, External VREF=2.4V,

AVDD=VDD=3.3V
DADC_31 GERR Gain Error -7.4 — 6.6 LSB 1Msps, Internal

VREF=AVDD=VDD=3.3V,

REFCTRL.REFCOMP=1
-3.7 — 7.4 LSB 1Msps, External VREF=2.4V,

AVDD=VDD=3.3V,

REFCTRL.REFCOMP=1
-8.2 — 6.6 LSB 1Msps, Internal

VREF=AVDD=VDD=3.3V,

REFCTRL.REFCOMP=0
-30.4 — 27.1 LSB 1Msps, External VREF=2.4V,

AVDD=VDD=3.3V,

REFCTRL.REFCOMP=0
DADC_37 EOFF Offset Error -3.6 — 3.0 LSB 1Msps, Internal

VREF=AVDD=VDD=3.3V,

SAMPCTRL.OFFCOMP=1
-4.5 — 3.6 LSB 1Msps, External VREF=2.4V,

AVDD=VDD=3.3V,

SAMPCTRL.OFFCOMP=1
-11.8 — 12.3 LSB 1Msps, Internal

VREF=AVDD=VDD=3.3V,

SAMPCTRL.OFFCOMP=0
-16.9 — 16.8 LSB 1Msps, External VREF=2.4V,

AVDD=VDD=3.3V,

SAMPCTRL.OFFCOMP=0
DADC_43 TUE Total Unadjusted Error -5.2 — 5.2 LSB 1Msps, Internal

VREF=AVDD=VDD=3.3V,

REFCTRL.REFCOMP=1,

SAMPCTRL.OFFCOMP=1
DADC_45 -5.6 — 5.6 LSB 1Msps, External VREF=2.4V,

AVDD=VDD=3.3V,

REFCTRL.REFCOMP=1,

SAMPCTRL.OFFCOMP=1
DIFFERENTIAL MODE ADC Dynamic Performance (4)
DADC_49 SINAD (1,2) Signal to Noise and Distortion 65.3 — — dB VREF=AVDD=VDD=3.3V

at 12bit max sampling rate
DADC_51 SNR (1,2) Signal to Noise ratio 64.7 — —
DADC_53 SFDR (1,2) Spurious Free Dynamic Range 76.6 — —
DADC_55 THD (1,2,3) Total Harmonic Distortion — — -78.6
DADC_57 Nrms Noise RMS — — 3.1 LSB VREF = AVDD = VDD = 3.3V,

Constant Input Voltage
— — 4.1 LSB External VREF = 2.4V,

AVDD = VDD = 3.3V,

Constant Input Voltage
Note:
  1. Characterized with an analog input sine wave = (FTP(max) / 100). Example: FTP(max)=1Msps/100 = 10kHz sine wave.
  2. Sinewave peak amplitude = 96% ADC_ Full Scale amplitude input with 12bit resolution.
  3. Value taken over 7 harmonics.
  4. ADC is configured in 12bits mode, All registers are at the reset default value unless otherwise stated.
Table 55-28. ADC Conversion Electrical Requirements (2)
AC CHARACTERISTICS Standard Operating Conditions: VDD = AVDD = 1.71V to 3.63V (unless otherwise stated)

Operating temperature:

-40°C ≤ TA ≤ +85°C for Industrial Temperature
Param. No. Symbol Characteristics Min. Typ. Max. Units Conditions
ADC_ Clock Requirements
ADC_57 TAD ADC Clock Period 62.5 — 6250 ns —
ADC_58 fGCLK_ADCx ADCx Module GCLK max input freq — — FCLK_51 MHz FCLK_51: Refer to Maximum Clock Frequencies Electrical Specifications
ADC Single-Ended Throughput Rates
ADC_59 FTPR (1) (Single-Ended Mode) Throughput Rate

(Single-Ended)

 12.31 — 1231 ksps 12-bit resolution,

Rsource ≤ 147 Ω,

SAMPCTRL.OFFCOMP=0,

SAMPCTRL.SAMPLEN=0
13.33 — 1333 10-bit resolution,

Rsource ≤ 504 Ω,

SAMPCTRL.OFFCOMP=0,

SAMPCTRL.SAMPLEN=0
16 — 1600 8-bit resolution,

Rsource ≤ 1,000 Ω,

SAMPCTRL.OFFCOMP=0,

SAMPCTRL.SAMPLEN=0
10 — 1000 ksps 12-bit resolution,

Rsource ≤ 6,560 Ω

SAMPCTRL.OFFCOMP=1,

SAMPCTRL.SAMPLEN=n/a
10.67 — 1067 10-bit resolution,

Rsource ≤ 8,000 Ω

SAMPCTRL.OFFCOMP=1,

SAMPCTRL.SAMPLEN=n/a
12.31 — 1231 8-bit resolution,

Rsource ≤ 9,984 Ω

SAMPCTRL.OFFCOMP=1,

SAMPCTRL.SAMPLEN=n/a
ADC Differential Mode Throughput Rates
ADC_61 FTPR (1)

(Differential Mode)

 Throughput Rate

(Differential Mode)

 12.31 — 1231 ksps 12-bit resolution,

Rsource ≤ 147 Ω,

SAMPCTRL.OFFCOMP=0,

SAMPCTRL.SAMPLEN=0
14.55 — 1455 10-bit resolution,

Rsource ≤ 504 Ω,

SAMPCTRL.OFFCOMP=0,

SAMPCTRL.SAMPLEN=0
17.78 — 1778 8-bit resolution,

Rsource ≤ 1,000 Ω,

SAMPCTRL.OFFCOMP=0,

SAMPCTRL.SAMPLEN=0

10 — 1000 ksps 12-bit resolution,

Rsource ≤ 6,560 Ω

SAMPCTRL.OFFCOMP=1,

SAMPCTRL.SAMPLEN=n/a
11.43 — 1143 10-bit resolution,

Rsource ≤ 8,000 Ω

SAMPCTRL.OFFCOMP=1,

SAMPCTRL.SAMPLEN=n/a
13.33 — 1333 8-bit resolution,

Rsource ≤ 9,984 Ω

SAMPCTRL.OFFCOMP=1,

SAMPCTRL.SAMPLEN=n/a
Note:
  1. 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.
  2. These values are based on simulation, and not covered by production test limits or characterization.
Table 55-29. ADC Sample Electrical Requirements (3)
AC CHARACTERISTICS Standard Operating Conditions: VDD = AVDD = 1.71V to 3.63V (unless otherwise stated)

Operating temperature:

-40°C ≤ TA ≤ +85°C for Industrial Temperature
Param. No. Symbol Characteristics Min. Typ. Max. Units Conditions
ADC_63 TSAMP ADC Sample Time (1,2,4) 1 — — TAD 12 bit TAD(min),

Ext Analog Input Rsource ≤ 147 Ω
10 bit TAD(min),

Ext Analog Input Rsource ≤ 504 Ω
8 bit TAD(min),

Ext Analog Input Rsource ≤ 1,000 Ω
2 — — 12 bit TAD(min),

Ext Analog Input Rsource ≤ 2,272 Ω
10 bit TAD(min),

Ext Analog Input Rsource ≤ 3,008 Ω
8 bit TAD(min),

Ext Analog Input Rsource ≤ 4,000 Ω
3 — — 12 bit TAD(min),

Ext Analog Input Rsource ≤ 4,416 Ω
10 bit TAD(min),

Ext Analog Input Rsource ≤ 5,504 Ω
8 bit TAD(min),

Ext Analog Input Rsource ≤ 6,976 Ω
4 — — 12 bit TAD(min),

Ext Analog Input Rsource ≤ 6,560 Ω
10 bit TAD(min),

Ext Analog Input Rsource ≤ 8,000 Ω
8 bit TAD(min),

Ext Analog Input Rsource ≤ 9,984 Ω
5 — — 12 bit TAD(min),

Ext Analog Input Rsource ≤ 8,704 Ω
10 bit TAD(min),

Ext Analog Input Rsource ≤ 10,496 Ω
8 bit TAD(min),

Ext Analog Input Rsource ≤ 12,992 Ω
6 — — 12 bit TAD(min),

Ext Analog Input Rsource ≤ 10,880 Ω
10 bit TAD(min),

Ext Analog Input Rsource ≤ 12,992 Ω
8 bit TAD(min),

Ext Analog Input Rsource ≤ 16,000 Ω
DAC_15, DAC_17 — — ns With DAC as input

DAC_15, DAC_17: Refer to

DAC Module Electrical Specifications

ADC_65 TCNV Conversion Time (Single-Ended Mode) 12 TAD 12-bit resolution
11 10-bit resolution
9 8-bit resolution
ADC_67 Conversion Time (Differential Mode) 12 TAD 12-bit resolution
10 10-bit resolution
8 8-bit resolution
ADC_69 CSAMPLE ADC Internal Sample Cap — — 3 pF —
ADC_71 RSAMPLE ADC Internal impedance — — 2000 Ω —
Note:
  1. 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)
  2. When SAMPCTRL.OFFCOMP=1:
    • TSAMP = 4 (Forced by HDW)
    • User SAMPCTRL.SAMPLEN = (n/a, Ignored by HDW)
  3. These values are based on simulation and are not covered by production test limits or characterization.
  4. TSAMP ≥ (INT[((RSAMPLE + RSOURCE) * CSAMPLE * (#Bits Resolution+2) * ln(2)) / TAD]+1).