MAX1338 Datasheet, PDF (19/24 Pages) Maxim Integrated Products – 14-Bit, 4-Channel, Software-Programmable, Multiranging, Simultaneous-Sampling ADC

14-Bit, 4-Channel, Software-Programmable,
Multiranging, Simultaneous-Sampling ADC
Table 4. Code Table with V_REF = 2.500V
INPUT VOLTAGE (V)
±10V INPUT
RANGE
SELECTED
±5V INPUT
RANGE
SELECTED
±2.5V INPUT
RANGE
SELECTED
±1.25V INPUT
RANGE
SELECTED
9.9988
9.9976
0.0012
0
-0.0012
-9.9988
-10.0000
4.9994
4.9988
0.0006
0
-0.0006
-4.9994
-5.0000
2.4998
2.4997
0.0002
0
-0.0002
-2.4998
-2.5000
1.2499
1.2498
0.0001
0
-0.0001
-1.2499
-1.2500
DECIMAL
EQUIVALENT
OUTPUT
(CODE₁₀)
8191
8190
1
0
-1
-8191
-8192
TWO’S COMPLEMENT
BINARY OUTPUT CODE
01 1111 1111 1111 → 0x1FFF
01 1111 1111 1110 → 0x1FFE
00 0000 0000 0001 → 0x0001
00 0000 0000 0000 → 0x0000
11 1111 1111 1111 → 0x3FFF
10 0000 0000 0001 → 0x2001
10 0000 0000 0000 → 0x2000
Definitions
Integral Nonlinearity (INL)
Integral nonlinearity is the deviation of the values on an
actual transfer function from a straight line. For these
devices, this straight line is a line drawn between the
endpoints of the transfer function, once offset and gain
errors have been nulled.
Differential Nonlinearity (DNL)
Differential nonlinearity is the difference between an
actual step width and the ideal value of 1 LSB. For
these devices, the DNL of each digital output code is
measured and the worst-case value is reported in the
Electrical Characteristics table. A DNL error specifica-
tion of less than ±1 LSB guarantees no missing codes
and a monotonic transfer function.
Offset Error
Offset error indicates how well the actual transfer func-
tion matches the ideal transfer function at a single point.
Typically, the point at which the offset error is specified
is at or near the zero scale of the transfer function or at
or near the midscale of the transfer function.
For the MAX1338, the ideal zero-scale digital output
transition from 0x3FFF to 0x0000 occurs with an analog
input voltage of zero. Offset error is the amount of ana-
log input-voltage deviation between the measured input
voltage and the calculated input voltage at the zero-
scale transition.
Table 5. Input Ranges
SELECTED
FULL-SCALE ALLOWABLE
INPUT
RANGE (V)
V_REFADC
(V)
INPUT RANGE
(V)
COMMON-MODE
RANGE (V)
2.0
±10
2.5
3.0
2.0
±5
2.5
3.0
2.0
±2.5
2.5
3.0
2.0
±1.25
2.5
3.0
±8
±10
±12
±4
±5
±6
±2
±2.5
±3
±1
±1.25
±1.5
±5
±5
±5
±2.5
±2.5
±2.5
±1.25
±1.25
±1.25
±0.625
±0.625
±0.625
Table 6. LSB Size with V_REF = 2.500V
SELECTED
INPUT RANGE
(V)
±10
±5
±2.5
±1.25
GAIN MULTIPLIER
(A)
8
4
2
1
LSB SIZE (mV)
1.2207
0.6104
0.1526
0.0736
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