4

ADS820

®

PIN

DESIGNATOR

DESCRIPTION

1

GND

Ground

2

B1

Bit 1, Most Significant Bit

3

B2

Bit 2

4

B3

Bit 3

5

B4

Bit 4

6

B5

Bit 5

7

B6

Bit 6

8

B7

Bit 7

9

B8

Bit 8

10

B9

Bit 9

11

B10

Bit 10, Least Significant Bit

12

DNC

Do not connect.

13

DNC

Do not connect.

14

GND

Ground

15

+5V Power Supply

16

CLK

Convert Clock Input, 50% Duty Cycle

17

+5V Power Supply

18

OE

HI: High Impedance State. LO or Floating: Nor-

mal Operation. Internal pull-down resistor.

19

MSBI

Most Significant Bit Inversion, HI: MSB inverted

for complementary output. LO or Floating: Straight

output. Internal pull-down resistor.

20

+5V Power Supply

21

REFB

Bottom Reference Bypass. For external bypass-

ing of internal +1.25V reference.

22

CM

Common-Mode Voltage. It is derived by (REFT +

REFB)/2.

23

REFT

Top Reference Bypass. For external bypassing

of internal +3.25V reference.

24

+5V Power Supply

25

GND

Ground

26

IN

Input

27

IN

Complementary Input

28

GND

Ground

PIN DESCRIPTIONS

PIN CONFIGURATION

TOP VIEW

SOIC/SSOP

GND

Bit 1(MSB)

Bit 2

Bit 3

Bit 4

Bit 5

Bit 6

Bit 7

Bit 8

Bit 9

Bit 10 (LSB)

DNC

DNC

GND

GND

IN

IN

GND

+V

S

REFT

CM

REFB

+V

S

MSBI

OE

+V

S

CLK

+V

S

1

2

3

4

5

6

7

8

9

10

11

12

13

14

28

27

26

25

24

23

22

21

20

19

18

17

16

15

ADS820

DNC: Do Not Connect

TIMING DIAGRAM

SYMBOL

DESCRIPTION

MIN

TYP

MAX

UNITS

Convert Clock Period

50

100

µsns

Clock Pulse Low

24

25

ns

Clock Pulse High

24

25

ns

Aperture Delay

2

ns

3.9

ns

12.5

ns

Track

Hold

"N"

Hold

"N + 1"

Hold

"N + 2"

Hold

"N + 3"

Hold

"N + 4"

Hold

"N + 5"

Hold

"N + 6"

Track

Data Valid

N-7

Data Valid

N-6

INTERNAL

TRACK/HOLD

CONVERT

CLOCK

OUTPUT

DATA

t

D

t

2

t

1

DATA LATENCY

(6.5 Clock Cycles)

t

CONV

t

L

t

H

Track

Track

Track

Track

N-3

N-5

N-4

N-2

N-1

N

Track

Track

Data Valid

N-8

(1)

Data Invalid

NOTE: (1) “

” indicates the portion of the waveform that will stretch out at slower sample rates.