MAX1238EEE Maxim Integrated Products, MAX1238EEE Datasheet - Page 20

• Manufacturer Part Number: MAX1238EEE
• Description: ADC (A/D Converters)
• Manufacturer: Maxim Integrated Products

Specifications of MAX1238EEE

• Number Of Adc Inputs: 12
• Architecture: SAR
• Conversion Rate: 94.4 KSPs
• Resolution: 12 bit
• Interface Type: I2C
• Voltage Reference: Internal 4.096 V
• Supply Voltage (max): 5 V
• Mounting Style: SMD/SMT
• Package / Case: QSOP-16
• Lead Free Status / Rohs Status: No

Effective number of bits (ENOB) indicates the global
accuracy of an ADC at a specific input frequency and
sampling rate. An ideal ADC’s error consists of quanti-
zation noise only. With an input range equal to the
ADC’s full-scale range, calculate the ENOB as follows:
Total harmonic distortion (THD) is the ratio of the RMS
sum of the input signal’s first five harmonics to the fun-
damental itself. This is expressed as:
where V
V
harmonics.
Spurious-free dynamic range (SFDR) is the ratio of the
RMS amplitude of the fundamental (maximum signal
component) to the RMS value of the next largest distor-
tion component.
2.7V to 3.6V and 4.5V to 5.5V, Low-Power,
4-/12-Channel, 2-Wire Serial, 12-Bit ADCs
20
5
THD
are the amplitudes of the 2nd- through 5th-order
______________________________________________________________________________________
SINAD dB
1
=
is the fundamental amplitude, and V
20
(
ENOB = (SINAD - 1.76)/6.02
×
)
Spurious-Free Dynamic Range
=
log
20
⎛
⎜
⎜
⎝
Total Harmonic Distortion
×
⎛
⎜
⎝
Effective Number of Bits
log
V
2
2
⎡
⎢
⎣
NoiseRMS THDRMS
+
V
3
SignalRMS
2
V
+
1
+
V
4
2
+
2
V
5
through
2
⎤
⎥
⎦
⎞
⎟
⎠
⎞
⎟
⎟
⎠
TOP VIEW
RC NETWORK*
C
REF
**AIN11/REF (MAX1238/MAX1239)
*RC NETWORK IS OPTIONAL
ANALOG
INPUTS
0.1μF
AIN3/REF
2kΩ
AIN0
AIN1
AIN0
AIN1
AIN2
AIN3
AIN4
AIN5
AIN6
AIN7
AIN2
0.1μF
Typical Operating Circuit
1
2
3
4
5
6
7
8
1
2
4
3
AIN0
AIN1
AIN3**/REF
MAX1238
MAX1239
MAX1236
MAX1237
QSOP
MAX
Pin Configurations
MAX1236
MAX1237
MAX1238
MAX1239
3.3V or 5V
GND
V
5V
μC
DD
SDA
SCL
16
15
14
13
12
11
10
6
8
7
5
9
5V
V
GND
SDA
SCL
AIN8
AIN9
AIN10
AIN11/REF
V
GND
SDA
SCL
SDA
SCL
DD
DD
R
R
*R
*R
P
P
S
S