MAX1238EEE Maxim Integrated Products, MAX1238EEE Datasheet - Page 9

• 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

Figure 2. MAX1238/MAX1239 Simplified Functional Diagram
Figure 3. Load Circuit
The MAX1236–MAX1239 analog-to-digital converters
(ADCs) use successive-approximation conversion tech-
niques and fully differential input track/hold (T/H) cir-
cuitry to capture and convert an analog signal to a
serial 12-bit digital output. The MAX1236/MAX1237 are
4-channel ADCs, and the MAX1238/MAX1239 are 12-
channel ADCs. These devices feature a high-speed, 2-
wire serial interface supporting data rates up to 1.7MHz.
SDA
2.7V to 3.6V and 4.5V to 5.5V, Low-Power,
4-/12-Channel, 2-Wire Serial, 12-Bit ADCs
_______________________________________________________________________________________
AIN11/REF
Detailed Description
AIN10
GND
AIN0
AIN1
AIN2
AIN3
AIN4
AIN5
AIN6
AIN7
AIN8
AIN9
SDA
SCL
V
V
DD
DD
I
I
OL
OH
400pF
CONFIGURATION REGISTER
ANALOG
INPUT
V
MUX
INPUT SHIFT REGISTER
OUT
SETUP REGISTER
REF
4.096V (MAX1238)
2.048V (MAX1239)
T/H
REFERENCE
12-BIT
ADC
CONTROL
LOGIC
Figure 2 shows the simplified internal structure for the
MAX1238/MAX1239.
The MAX1236–MAX1239 operates from a single supply
and consumes 670µA (typ) at sampling rates up to
94.4ksps. The MAX1237/MAX1239 feature a 2.048V
internal reference and the MAX1236/MAX1238 feature
a 4.096V internal reference. All devices can be config-
ured for use with an external reference from 1V to V
The MAX1236–MAX1239 analog-input architecture con-
tains an analog-input multiplexer (mux), a fully differen-
tial track-and-hold (T/H) capacitor, T/H switches, a
comparator, and a fully differential switched capacitive
digital-to-analog converter (DAC) (Figure 4).
In single-ended mode, the analog input multiplexer con-
nects C
CS[3:0] (see the Configuration/Setup Bytes (Write Cycle)
section) and GND (Table 3). In differential mode, the
analog-input multiplexer connects C
analog inputs selected by CS[3:0] (Table 4).
During the acquisition interval, the T/H switches are in
the track position and C
T/H
OSCILLATOR
MAX1238
MAX1239
INTERNAL
OUTPUT SHIFT
between the analog input selected by
REGISTER
AND RAM
Analog Input and Track/Hold
T/H
charges to the analog input
T/H
Power Supply
to the “+” and “-”
DD
.
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