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ADS5237

SBAS420A – AUGUST 2007 – REVISED OCTOBER 2007

Table 2. TERMINAL FUNCTIONS (continued)

NAME

PIN #

I/O

DESCRIPTION

D2_B

14

O

Data bit 8 (D2), channel B

D3_B

15

O

Data bit 7 (D3), channel B

D4_B

16

O

Data bit 6 (D4), channel B

D5_B

17

O

Data bit 5 (D5), channel B

D6_B

18

O

Data bit 4 (D6), channel B

D7_B

19

O

Data bit 3 (D7), channel B

D8_B

20

O

Data bit 2 (D8), channel B

D9_B (MSB)

21

O

Data bit 1 (D9), channel B

26

O

Data valid, channel A

22

O

Data valid, channel B

GND

4, 7, 23, 25, 44

Output buffer ground

50

I

Analog input, channel A

51

I

Complementary analog input, channel A

63

I

Analog input, channel B

62

I

Complementary analog input, channel B

INT/EXT

56

I

Reference select; 0 = External (default), 1 = Internal; force high to set for internal reference operation.

60

O

Bias current setting resistor of 56.2k

Ω to ground

When SEL = 0, MSBI (most significant bit Invert)

MSBI/SEN

41

I

1 = Binary two's complement, 0 = Straight offset binary (default)

When SEL = 1, SEN (serial write enable)

NC

10, 11, 27, 28

42

I

0 = Enabled (default), 1 = 3-state

When SEL = 1, SCLK (serial write clock)

6

I

Output enable, channel B (0 = Enabled [default], 1 = 3-state)

39

O

Over-range Indicator, channel A

9

O

Over-range Indicator, channel B

54

I/O

Bottom reference/bypass (2

Ω resistor in series with a 0.1μF capacitor to ground)

53

I/O

Top reference/bypass (2

Ω resistor in series with a 0.1μF capacitor to ground)

STPD, respectively. With SEL = 0, the serial interface is disabled. Setting SEL = 1 enables the serial

interface and configures pins 41, 42, and 45 as SEN, SCLK, and SDATA, respectively. Serial

SEL

1

I

registers can be programmed using these three signals. When used in this mode of operation, it is

essential to provide a low-going pulse on SEL in order to reset the serial interface registers as soon

as the device is powered up. SEL therefore also has the functionality of a RESET signal.

When SEL = 0, STPD (power-down)

STPD/SDATA

45

I

0 = Normal operation (default), 1 = Enabled

When SEL = 1, SDATA (serial write data)

VDRV

5, 8, 40, 43

Output buffer supply

Copyright © 2007, Texas Instruments Incorporated

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