Figure 6. Simplified Analog Input Circuit
MAX1302
R2
R1
VSJ
*RSOURCE
ANALOG
SIGNAL
SOURCE
R2
R1
VSJ
*RSOURCE
ANALOG
SIGNAL
SOURCE
IN_+
*MINIMIZE RSOURCE TO AVOID GAIN ERROR AND DISTORTION.
MAX1302
8-Channel, ±VREF Multirange Inputs,
Serial 16-Bit ADC
______________________________________________________________________________________
17
CS
SCLK
1
2
3
4
5
6
7
8
17
18
19
20
21
22
23
24
DIN
S
C2
C1
C0
0
ANALOG INPUT
TRACK AND HOLD*
TRACK
DOUT
B15
B14
B13
B12
B11
B10
B9
B8
B7
B6
B5
B4
B3
B2
B1
B0
BYTE 1
BYTE 2
BYTE 3
SSTRB
INTCLK**
1
2
3
25
26
27
28
9
10
11
12
13
14
15
16
10
11
12
13
14
HOLD
HIGH IMPEDANCE
tACQ
100ns to 400ns
fINTCLK
≈ 4.5MHz
fSAMPLE
≈ fSCLK / 24 + fINTCLK / 28
*TRACK AND HOLD TIMING IS CONTROLLED BY INTCLK, AND IS NOT ACCESSIBLE TO THE USER.
**INTCLK IS AN INTERNAL SIGNAL AND IS NOT ACCESSIBLE TO THE USER.
SAMPLING INSTANT
Figure 4. Internal Clock-Mode Conversion (Mode 2)
-1.5
-0.5
-1.0
0.5
0
1.0
1.5
ANALOG INPUT VOLTAGE (V)
ANALOG
INPUT
CURRENT
(mA)
-6
-2
0
-4
2
4
6
Figure 5. Analog Input Current vs. Input Voltage