ADS7844

4

SBAS100A

www.ti.com

PIN CONFIGURATION

Top View

PIN DESCRIPTIONS

PIN

NAME

DESCRIPTION

1

CH0

Analog Input Channel 0.

2

CH1

Analog Input Channel 1.

3

CH2

Analog Input Channel 2.

4

CH3

Analog Input Channel 3.

5

CH4

Analog Input Channel 4.

6

CH5

Analog Input Channel 5.

7

CH6

Analog Input Channel 6.

8

CH7

Analog Input Channel 7.

9

COM

Ground reference for analog inputs. Sets zero code

voltage in single ended mode. Connect this pin to ground

or ground reference point.

10

SHDN

Shutdown. When LOW, the device enters a very low

power shutdown mode.

11

VREF

Voltage Reference Input. See Specification Table for

ranges.

12

+VCC

Power Supply, 2.7V to 5V.

13

GND

Ground

14

GND

Ground

15

DOUT

Serial Data Output. Data is shifted on the falling edge of

DCLK. This output is high impedance when

CS is high.

16

BUSY

Busy Output. Busy goes low when the DIN control bits

are being read and also when the device is converting.

The Output is high impedance when CS is High.

17

DIN

Serial Data Input. If CS is LOW, data is latched on rising

edge of DCLK.

18

CS

Chip Select Input. Active LOW. Data will not be clocked

into DIN unless CS is low. When CS is high DOUT is high

impedance.

19

CLK

External Clock Input. The clock speed determines the

conversion rate by the equation fCLK = 16 • fSAMPLE.

20

+VCC

Power Supply

1

2

3

4

5

6

7

8

9

10

CH0

CH1

CH2

CH3

CH4

CH5

CH6

CH7

COM

SHDN

+V

CC

D

CLK

CS

D

IN

BUSY

D

OUT

GND

GND

+V

CC

V

REF

20

19

18

17

16

15

14

13

12

11

ADS7844

MINIMUM

RELATIVE

MAXIMUM

SPECIFIED

ACCURACY

GAIN ERROR

TEMPERATURE

PACKAGE

ORDERING

TRANSPORT

PRODUCT

(LSB)

(LSB)

RANGE

PACKAGE-LEAD

DESIGNATOR

NUMBER

MEDIA, QUANTITY

ADS7844E

±2

±4

–40

°C to +85°C

QSOP-20

DBQ

ADS7844E

Rails, 56

"

"

"

"

"

"

ADS7844E/2K5

Tape and Reel, 2500

ADS7844N

"

"

"

SSOP-20

DB

ADS7844N

Rails, 68

"

"

"

"

"

"

ADS7844N/1K

Tape and Reel,1000

ADS7844EB

±1

±3

–40

°C to +85°C

QSOP-20

DBQ

ADS7844EB

Rails, 56

"

"

"

"

"

"

ADS7844EB/2K5

Tape and Reel, 2500

ADS7844NB

"

"

"

SSOP-20

DB

ADS7844NB

Rails, 68

"

"

"

"

"

"

ADS7844NB/1K

Tape and Reel, 1000

NOTES: (1) For the most current package and ordering information, see the Package Option Addendum at the end of this data sheet.

PACKAGE/ORDERING INFORMATION(1)

ABSOLUTE MAXIMUM RATINGS(1)

+VCC to GND ........................................................................ –0.3V to +6V

Analog Inputs to GND ............................................ –0.3V to +VCC + 0.3V

Digital Inputs to GND ........................................................... –0.3V to +6V

Power Dissipation .......................................................................... 250mW

Maximum Junction Temperature ................................................... +150

°C

Operating Temperature Range ........................................ –40

°C to +85°C

Storage Temperature Range ......................................... –65

°C to +150°C

Lead Temperature (soldering, 10s) ............................................... +300

°C

NOTE: (1) Stresses above those listed under “Absolute Maximum Ratings”

may cause permanent damage to the device. Exposure to absolute maximum

conditions for extended periods may affect device reliability.

ELECTROSTATIC

DISCHARGE SENSITIVITY

This integrated circuit can be damaged by ESD. Texas Instru-

ments recommends that all integrated circuits be handled with

appropriate precautions. Failure to observe proper handling and

installation procedures can cause damage.

ESD damage can range from subtle performance degradation to

complete device failure. Precision integrated circuits may be more

susceptible to damage because very small parametric changes

could cause the device not to meet its published specifications.