SmartFusion DC and Switching Characteristics
2-80 Revision 10
Analog-to-Digital Converter (ADC)
Unless otherwise noted, ADC direct input performance is specified at 25°C with nominal power supply
voltages, with the output measured using the external voltage reference with the internal ADC in 12-bit
mode and 500 KHz sampling frequency, after trimming and digital compensation.
Table 2-95 • ADC Specifications
Specification Test Conditions Min. Typ. Max. Units
Input voltage range (for driving ADC
over its full range)
2.56 V
Gain error ±0.4 ±0.7 %
–40ºC to +100ºC ±0.4 ±0.7 %
Input referred offset voltage ±1 ±2 mV
–40ºC to +100ºC ±1 ±2
Integral non-linearity (INL) RMS deviation from BFSL
12-bit mode 1.71 LSB
10-bit mode 0.60 1.00 LSB
8-bit mode 0.2 0.33 LSB
Differential non-linearity (DNL) 12-bit mode 2.4 LSB
10-bit mode 0.80 0.94 LSB
8-bit mode 0.2 0.23 LSB
Signal to noise ratio 62 64 dB
Effective number of bits (ENOB)
EQ 10
–1 dBFS input
12-bit mode 10 KHz 9.9 10 Bits
12-bit mode 100 KHz 9.9 10 Bits
10-bit mode 10 KHz 9.5 9.6 Bits
10-bit mode 100 KHz 9.5 9.6 Bits
8-bit mode 10 KHz 7.8 7.9 Bits
8-bit mode 100 KHz 7.8 7.9 Bits
Full power bandwidth At –3 dB; –1 dBFS input 300 KHz
Analog settling time To 0.1% of final value (with 1 Kohm source
impedance and with ADC load)
2µs
Input capacitance Switched capacitance (ADC sample
capacitor)
12 15 pF
Cs: Static capacitance (Figure 2-44 on page 2-81)
CM[n] input 5 7 pF
TM[n] input 5 7 pF
ADC[n] input 5 7 pF
Input resistance Rin: Series resistance (Figure 2-44)2K
Rsh: Shunt resistance, exclusive of
switched capacitance effects (Figure 2-44)
10 M
Note: All 3.3 V supplies are tied together and varied from 3.0 V to 3.6 V. 1.5 V supplies are held constant.
ENOB
SINAD 1.76 dB–
6.02 dB/bit
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