K20P81M100SF2_1109 Datasheet, PDF (48/75 Pages) Freescale Semiconductor, Inc – K20 Sub-Family Data Sheet

Peripheral operating requirements and behaviors
Table 30. 16-bit ADC with PGA characteristics (continued)
Symbol
SNR
Description
Signal-to-noise
ratio
Conditions
• Gain=1
• Gain=64
Min.
Typ.¹
Max.
Unit
80
90
—
dB
52
66
—
dB
THD
Total harmonic
distortion
• Gain=1
• Gain=64
85
100
—
dB
49
95
—
dB
SFDR
Spurious free
dynamic range
• Gain=1
• Gain=64
85
105
—
dB
53
88
—
dB
ENOB
Effective number
of bits
• Gain=1, Average=4
• Gain=64, Average=4
11.6
13.4
—
bits
7.2
9.6
—
bits
• Gain=1, Average=32
12.8
14.5
—
bits
• Gain=2, Average=32
11.0
14.3
—
bits
• Gain=4, Average=32
7.9
13.8
—
bits
• Gain=8, Average=32
7.3
13.1
—
bits
• Gain=16, Average=32
6.8
12.5
—
bits
• Gain=32, Average=32
6.8
11.5
—
bits
• Gain=64, Average=32
7.5
10.6
—
bits
Notes
16-bit
differential
mode,
Average=32
16-bit
differential
mode,
Average=32,
f_in=100Hz
16-bit
differential
mode,
Average=32,
f_in=100Hz
16-bit
differential
mode,f_in=100H
z
SINAD
Signal-to-noise
plus distortion
ratio
See ENOB
6.02 × ENOB + 1.76
dB
1. Typical values assume V_DDA =3.0V, Temp=25°C, f_ADCK=6MHz unless otherwise stated.
2. This current is a PGA module adder, in addition to and ADC conversion currents.
3. Between IN+ and IN-. The PGA draws a DC current from the input terminals. The magnitude of the DC current is a strong
function of input common mode voltage (V_CM) and the PGA gain.
4. _{Gain = 2}^PGAG
5. After changing the PGA gain setting, a minimum of 2 ADC+PGA conversions should be ignored.
6. Limit the input signal swing so that the PGA does not saturate during operation. Input signal swing is dependent on the
PGA reference voltage and gain setting.
6.6.2 CMP and 6-bit DAC electrical specifications
Table 31. Comparator and 6-bit DAC electrical specifications
Symbol Description
Min.
Typ.
Max.
Unit
V_DD
Supply voltage
1.71
—
3.6
V
I_DDHS Supply current, High-speed mode (EN=1, PMODE=1)
—
—
200
μA
Table continues on the next page...
K20 Sub-Family Data Sheet Data Sheet, Rev. 6, 9/2011.
48
Freescale Semiconductor, Inc.