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Multirange inputs, serial 16-bit adcs, Figure 6. simplified analog input circuit, Figure 4. internal clock-mode conversion (mode 2) – Rainbow Electronics MAX1303 User Manual

Page 17: Figure 5. analog input current vs. input voltage

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Figure 6. Simplified Analog Input Circuit

MAX1302
MAX1303

R2

R1

V

SJ

*R

SOURCE

ANALOG
SIGNAL
SOURCE

R2

R1

V

SJ

*R

SOURCE

ANALOG
SIGNAL
SOURCE

IN_+

IN_+

*MINIMIZE R

SOURCE

TO AVOID GAIN ERROR AND DISTORTION.

MAX1302/MAX1303

8-/4-Channel, ±V

REF

Multirange Inputs,

Serial 16-Bit ADCs

______________________________________________________________________________________

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

0

0

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

HOLD

HIGH IMPEDANCE

t

ACQ

100ns to 400ns

f

INTCLK

≈ 4.5MHz

f

SAMPLE

≈ f

SCLK

/ 24 + f

INTCLK

/ 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