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ꢀ ꢉꢊꢋ ꢌ ꢁꢉ ꢍ ꢎꢏꢐ ꢀ ꢉꢑꢒꢓ ꢑꢓ ꢎꢔ ꢒꢓ ꢐꢐ ꢋꢒ
SLAS272F − JULY 2000 − REVISED JUNE 2004
electrical characteristics over recommended operating free-air temperature (unless otherwise
noted) (continued)
12-bit ADC, timing parameters
PARAMETER
TEST CONDITIONS
MIN
NOM
MAX
UNIT
For specified performance of ADC12
linearity parameters
2.2V/
3V
f
f
0.45
5
6.3
MHz
ADC12CLK
Internal ADC12
oscillator
ADC12DIV=0,
2.2 V/
3V
3.7
6.3
MHz
µs
ADC12OSC
f
=f
ADC12CLK ADC12OSC
C
≥ 5 µF, Internal oscillator,
2.2 V/
3 V
VREF+
2.06
3.51
f
= 3.7 MHz to 6.3 MHz
ADC12OSC
t
Conversion time
CONVERT
External f
ADC12SSEL ≠ 0
from ACLK, MCLK or SMCLK:
13×ADC12DIV×
ADC12CLK
µs
1/f
ADC12CLK
Turn on settling time of
the ADC
‡
t
t
(see Note 1)
100
ns
ADC12ON
R
= 400 Ω, R = 1000 Ω,
I
3 V
1220
1400
S
I
‡
Sampling time
ns
C = 30 pF
τ = [R + R ] x C (see Note 2)
I;
Sample
2.2 V
S
I
†
‡
Not production tested, limits characterized
Not production tested, limits verified by design
NOTES: 1. The condition is that the error in a conversion started after t
settled.
is less than 0.5 LSB. The reference and input signal are already
ADC12ON
2. Approximately ten Tau (τ) are needed to get an error of less than 0.5 LSB:
n+1
= ln(2
t
) x (R + R ) x C + 800 ns where n = ADC resolution = 12, R = external source resistance.
Sample
S
I
I
S
12-bit ADC, linearity parameters
PARAMETER
TEST CONDITIONS
/V ) min ≤ 1.6 V
MIN NOM MAX
UNIT
1.4 V ≤ (V
− V
− V
2
eREF+
REF− eREF−
/V
E
E
Integral linearity error
2.2 V/3 V
2.2 V/3 V
LSB
I
1.6 V < (V
) min ≤ [V
]
1.7
eREF+
REF− eREF−
(AVCC)
Differential linearity
error
(V
eREF+
VREF+
− V
/V
)
≤ (V
− V /V
),
REF− eREF− min
eREF+
= 10 µF (tantalum) and 100 nF (ceramic)
REF− eREF−
1
LSB
LSB
D
C
(V
− V
/V
)
≤ (V
eREF+
S
− V ),
/V
eREF+
Internal impedance of source R < 100 Ω,
REF− eREF− min
REF− eREF−
E
O
2.2 V/3 V
2
4
Offset error
Gain error
C
= 10 µF (tantalum) and 100 nF (ceramic)
VREF+
(V
− V
/V
)
≤ (V
eREF+
− V
/V
),
),
eREF+
REF− eREF− min
REF− eREF−
E
E
2.2 V/3 V
2.2 V/3 V
1.1
2
2
5
LSB
LSB
G
C
= 10 µF (tantalum) and 100 nF (ceramic)
VREF+
(V
− V
/V
)
≤ (V
eREF+
− V
/V
Total unadjusted
error
eREF+
REF− eREF− min
REF− eREF−
T
C
= 10 µF (tantalum) and 100 nF (ceramic)
VREF+
37
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