Texas Instruments ADS8344NB, ADS8344 Datasheet

ADS8344

¤

ADS8344

16-Bit, 8-Channel Serial Output Sampling

ANALOG-TO-DIGITAL CONVERTER

FEATURES

● PIN FOR PIN WITH ADS7844

● SINGLE SUPPLY: 2.7V to 5V

● 8-CHANNEL SINGLE-ENDED OR

4-CHANNEL DIFFERENTIAL INPUT

● UP TO 100kHz CONVERSION RATE

● 84dB SINAD

● SERIAL INTERFACE

● QSOP-20 AND SSOP-20 PACKAGES

APPLICATIONS

● DATA ACQUISITION

● TEST AND MEASUREMENT EQUIPMENT

● INDUSTRIAL PROCESS CONTROL

● PERSONAL DIGITAL ASSISTANTS

● BATTERY-POWERED SYSTEMS

A

¤

D

S

8

3

4

SBAS139E – SEPTEMBER 2000 – REVISED SEPTEMBER 2006

DESCRIPTION

The ADS8344 is an 8-channel, 16-bit, sampling Analog-to-Digital (A/D) converter with a synchronous serial interface. Typical power dissipation is 10mW at a 100kHz throughput rate and a +5V supply. The reference voltage (V

) can be varied between 500mV and VCC, providing a

REF

corresponding input voltage range of 0V to V device includes a shutdown mode that reduces power dissipation to under 15µW. The ADS8344 is tested down to 2.7V operation.

Low power, high speed, and an on-board multiplexer make the ADS8344 ideal for battery-operated systems such as personal digital assistants, portable multi-channel data loggers, and measurement equipment. The serial interface also provides low-cost isolation for remote data acquisition. The ADS8344 is available in a QSOP-20 or SSOP-20 package and is ensured over the –40°C to +85°C temperature range.

REF

. The

CH0 CH1 CH2 CH3

COM

ADS8341 ADS8343

4-Channel Multiplexer

CH0 CH1 CH2 CH3 CH4 CH5 CH6 CH7

COM

V

REF

ADS8344 ADS8345

8-Channel Multiplexer

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

All trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters.

CDAC

www.ti.com

SAR

DCLK

Comparator

Serial

Interface

and

Control

CS SHDN D

IN

D

OUT

BUSY

ABSOLUTE MAXIMUM RATINGS

+V

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

CC

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

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.

(1)

+ 0.3V

CC

ELECTROSTATIC DISCHARGE SENSITIVITY

This integrated circuit can be damaged by ESD. Texas Instruments 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.

PACKAGE/ORDERING INFORMATION

MINIMUM

RELATIVE MAXIMUM SPECIFIED PACKAGE

PRODUCT (LSB) (%) RANGE DESIGNATOR PACKAGE-LEAD NUMBER NUMBER MEDIA, QUANTITY

ADS8344E 8 ±0.05 –40°C to +85°C DBQ QSOP-20 DBQ ADS8344E Rails, 56

ADS8344N " " " DB SSOP-20 DB ADS8344N Rails, 68

ADS8344EB 6 ±0.024 –40°C to +85°C DBQ QSOP-20 DBQ ADS8344EB Rails, 56

ADS8344NB " " " DB SSOP-20 DB ADS8344NB Rails, 68

NOTE: (1) For the most current package and ordering information, see the Package Option Addendum at the end of this data sheet, or see the TI web site at www.ti.com.

ACCURACY GAIN ERROR TEMPERATURE PACKAGE DRAWING ORDERING TRANSPORT

" " " " " " " ADS8344E/2K5 Tape and Reel, 2500

" " " " " " " ADS8344N/1K Tape and Reel, 1000

" " " " " " " ADS8344EB/2K5 Tape and Reel, 2500

" " " " " " " ADS8344NB/1K Tape and Reel, 1000

PIN CONFIGURATION

Top View SSOP

CH0

1

CH1

2

CH2

3

CH3

4 CH4 CH5 CH6 CH7

COM

SHDN

5

6

7

8

9

10

ADS8344

(1)

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

+V

20

CC

DCLK

19

CS

18

D

17

IN

16

BUSY

15

D

OUT

14

GND

13

GND

12

+V

CC

11

V

REF

7 CH6 Analog Input Channel 6 8 CH7 Analog Input Channel 7 9 COM

10 SHDN Shutdown. When LOW, the device enters a very

11 V

12 +V 13 GND Ground 14 GND Ground 15 D

16 BUSY Busy Output. Busy goes LOW when the D

17 D

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

19 DCLK External Clock Input. The clock speed determines the

20 +V

Ground reference for analog inputs. Sets zero code voltage in single–ended mode. Connect this pin to ground or ground reference point.

low-power shutdown mode. Voltage Reference Input. See Electrical Characteristics

REF

Table for ranges. Power Supply, 2.7V to 5V

CC

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

OUT

DCLK. This output is high impedance when CS is HIGH.

are being read and also when the device is converting. The Output is high impedance when CS is HIGH. Serial Data Input. If CS is LOW, data is latched on rising

IN

edge of D

into D high impedance.

conversion rate by the equation f Power Supply

CC

.

CLK

unless CS is LOW. When CS is HIGH, D

IN

DCLK

IN

= 24 • f

control bits

OUT

.

SAMPLE

is

2

ADS8344

SBAS139E

ELECTRICAL CHARACTERISTICS: +5V

At TA = –40°C to +85°C, +VCC = +5V, V

PARAMETER CONDITIONS MIN TYP MAX MIN TYP MAX UNITS RESOLUTION 16 ✻ BITS

ANALOG INPUT

Full-Scale Input Span Positive Input - Negative Input 0 V Absolute Input Range Positive Input –0.2

Capacitance 25 ✻ pF Leakage Current ±1 ✻ µA

SYSTEM PERFORMANCE

No Missing Codes 14 15 Bits Integral Linearity Error 86LSB Offset Error ±2 ±1mV Offset Error Match 1.2 4 ✻✻LSB Gain Error ±0.05 ±0.024 % Gain Error Match 1.0 4 ✻✻ LSB Noise 20 ✻ µVrms Power-Supply Rejection +4.75V < V

SAMPLING DYNAMICS

Conversion Time 16 ✻ CLK Cycles Acquisition Time 4.5 ✻ CLK Cycles Throughput Rate 100 ✻ kHz Multiplexer Settling Time 500 ✻ ns Aperture Delay 30 ✻ ns Aperture Jitter 100 ✻ ps Internal Clock Frequency SHDN = V External Clock Frequency 0.024 2.4 ✻✻MHz

DYNAMIC CHARACTERISTICS

Total Harmonic Distortion

(2)

Signal-to-(Noise + Distortion) V Spurious–Free Dynamic Range V Channel-to-Channel Isolation V

REFERENCE INPUT

Range 0.5 +V Resistance DCLK Static 5 ✻ GΩ Input Current 40 100 ✻✻ µA

DIGITAL INPUT/OUTPUT

Logic Family CMOS ✻ Logic Levels

V

IH

V

IL

V

OH

V

OL

Data Format Straight Binary ✻

POWER-SUPPLY REQUIREMENTS

+V

CC

Quiescent Current 1.5 2.0 ✻ mA

Power Dissipation 7.5 10 ✻ mW

TEMPERATURE RANGE

Specified Performance –40 +85 ✻✻°C

✻ Same specifications as ADS8344E, N.

NOTES: (1) LSB means Least Significant Bit. With V (PD1 = PD0 = 0) active or SHDN = GND.

REF

= +5V, f

= 100kHz, and f

SAMPLE

CLK

= 24 • f

= 2.4MHz, unless otherwise noted.

SAMPLE

ADS8344E, N ADS8344EB, NB

REF

+VCC + 0.2

✻✻V ✻✻V

Negative Input –0.2 +1.25 ✻✻V

< 5.25V 3 ✻ LSB

CC

DD

2.4 ✻ MHz

Data Transfer Only 0 2.4 ✻✻MHz

VIN = 5Vp-p at 10kHz –90 ✻ dB

= 5Vp-p at 10kHz 86 ✻ dB

IN

= 5Vp-p at 10kHz 92 ✻ dB

IN

= 5Vp-p at 10kHz 100 ✻ dB

IN

CC

f

= 12.5kHz 2.5 ✻ µA

SAMPLE

DCLK Static 0.001 3 ✻✻ µA

✻✻V

| IIH | ≤ +5µA 3.0 5.5 ✻✻V | IIL | ≤ +5µA –0.3 +0.8 ✻✻V

IOH = –250µA 3.5 ✻ V

IOL = 250µA 0.4 ✻ V

Specified Performance 4.75 5.25 ✻✻V

f

= 100kHz 300 ✻ µA

SAMPLE

Power-Down Mode

(3)

, CS = +V

equal to +5.0V, one LSB is 76µV. (2) First nine harmonics of the test frequency. (3) Auto power-down mode

REF

CC

3 ✻ µA

(1)

ADS8344

SBAS139E

3

ELECTRICAL CHARACTERISTICS: +2.7V

At TA = –40°C to +85°C, +VCC = +2.7V, V

PARAMETER CONDITIONS MIN TYP MAX MIN TYP MAX UNITS RESOLUTION 16 ✻ BITS

ANALOG INPUT

Full-Scale Input Span Positive Input - Negative Input 0 V Absolute Input Range Positive Input –0.2

Capacitance 25 ✻ pF Leakage Current ±1 ✻ µA

SYSTEM PERFORMANCE

No Missing Codes 14 15 Bits Integral Linearity Error 12 8 LSB Offset Error ±1 0.5 mV Offset Error Match 1.2 4 ✻✻ LSB Gain Error ±0.05 ±0.024 % of FSR Gain Error Match 14 ✻✻ LSB Noise 20 ✻ µVrms Power-Supply Rejection +2.7 < V

SAMPLING DYNAMICS

Conversion Time 16 ✻ CLK Cycles Acquisition Time 4.5 ✻ CLK Cycles Throughput Rate 100 ✻ kHz Multiplexer Settling Time 500 ✻ ns Aperture Delay 30 ✻ ns Aperture Jitter 100 ✻ ps Internal Clock Frequency SHDN = V External Clock Frequency 0.024 2.4 MHz

DYNAMIC CHARACTERISTICS

Total Harmonic Distortion

(2)

Signal-to-(Noise + Distortion) V Spurious-Free Dynamic Range V Channel-to-Channel Isolation V

REFERENCE INPUT

Range 0.5 +V Resistance DCLK Static 5 ✻ GΩ Input Current 13 40 ✻✻ µA

DIGITAL INPUT/OUTPUT

Logic Family CMOS ✻ Logic Levels

V

IH

V

IL

V

OH

V

OL

Data Format Straight Binary ✻

POWER-SUPPLY REQUIREMENTS

+V

CC

Quiescent Current 1.2 1.85 ✻✻ mA

Power Dissipation 3.2 5 ✻ mW

TEMPERATURE RANGE

Specified Performance –40 +85 ✻✻°C

✻ Same specifications as ADS8344E, N.

NOTES: (1) LSB means Least Significant Bit. With V (PD1 = PD0 = 0) active or SHDN = GND.

= +2.7V, f

REF

= 100kHz, and f

SAMPLE

CLK

= 24 • f

= 2.4MHz, unless otherwise noted.

SAMPLE

ADS8344E, N ADS8344EB, NB

REF

+VCC + 0.2

✻✻V ✻✻V

Negative Input –0.2 +0.2 ✻✻V

< +3.3V 3 ✻ LSB

CC

DD

2.4 ✻ MHz

When used with Internal Clock 0.024 2.0 ✻✻MHz

Data Transfer Only 0 2.4 ✻✻MHz

VIN = 2.5Vp-p at 1kHz –90 ✻ dB

= 2.5Vp-p at 1kHz 86 ✻ dB

IN

= 2.5Vp-p at 1kHz 92 ✻ dB

IN

= 2.5Vp-p at 10kHz 100 ✻ dB

IN

CC

f

= 12.5kHz 2.5 ✻ µA

SAMPLE

DCLK Static 0.001 3 ✻✻ µA

| I

| ≤ +5µA+V

IH

| I

| ≤ +5µA –0.3 +0.8 ✻✻V

IL

IOH = –250µA+V

IOL = 250µA 0.4 ✻ V

• 0.7 5.5 ✻✻V

CC

• 0.8 ✻ V

CC

✻✻V

Specified Performance 2.7 3.6 ✻✻V

f

= 100kHz 220 ✻ µA

SAMPLE

Power-Down Mode

(3)

, CS = +V

equal to +2.5V, one LSB is 38µV. (2) First nine harmonics of the test frequency. (3) Auto power-down mode

REF

CC

3 ✻ µA

(1)

4

ADS8344

SBAS139E

TYPICAL CHARACTERISTICS: +5V

CHANGE IN SIGNAL-TO-(NOISE+DISTORTION)

vs TEMPERATURE

–40 –25 0 20 50 75 100

Temperature (°C)

Delta from +25°C (dB)

0.2

0.0

–0.2

–0.4

–0.6

–0.8

0.4 fIN = 9.985kHz, –0.2dB

At TA = +25°C, +VCC = +5V, V

= +5V, f

REF

= 100kHz, and f

SAMPLE

DCLK

= 24 • f

SAMPLE

= 2.4MHz, unless otherwise noted.

FREQUENCY SPECTRUM

(4096 Point FFT; f

0

–20 –40 –60 –80

–100

Amplitude (dB)

–120 –140 –160

0 1020304050

SIGNAL-TO-NOISE RATIO AND SIGNAL-TO-

100

90

(NOISE+DISTORTION) vs INPUT FREQUENCY

= 1.001kHz, –0.2dB)

IN

Frequency (kHz)

SNR

FREQUENCY SPECTRUM

(4096 Point FFT; f

0

–20 –40 –60 –80

–100

Amplitude (dB)

–120 –140 –160

0 1020304050

SPURIOUS-FREE DYNAMIC RANGE AND TOTAL

100

HARMONIC DISTORTION vs INPUT FREQUENCY

90

= 9.985kHz, –0.2dB)

IN

Frequency (kHz)

SFDR

–100

–90

80

70

SNR and SINAD (dB)

60

15.0

14.5

14.0

13.5

13.0

12.5

12.0

Effective Number of Bits

11.5

11.0

SINAD

101 100

Frequency (kHz)

EFFECTIVE NUMBER OF BITS

vs INPUT FREQUENCY

101 100

Frequency (kHz)

80

SFDR (dB)

70

NOTE: (1) First Nine Harmonics of the Input Frequency

60

(1)

THD

101 100

Frequency (kHz)

–80

THD (dB)

–70

–60

ADS8344

SBAS139E

5

TYPICAL CHARACTERISTICS: +5V (Cont.)

At TA = +25°C, +VCC = +5V, V

= +5V, f

REF

= 100kHz, and f

SAMPLE

DCLK

= 24 • f

= 2.4MHz, unless otherwise noted.

SAMPLE

2

1

0

–1

ILE (LSB)

–2

–3

–4

0000

3.0

2.5

2.0

INTEGRAL LINEARITY ERROR vs CODE

H

4000

8000

H

Output Code

WORST CASE CHANNEL-TO-CHANNEL

OFFSET MATCH vs TEMPERATURE

C000

DIFFERENTIAL LINEARITY ERROR vs CODE

3

2

1

0

DLE (LSB)

–1

–2

–3

FFFF

H

0000

H

4000

H

8000

H

C000

FFFF

H

Output Code

WORST CASE CHANNEL-TO-CHANNEL

2.0

GAIN MATCH vs TEMPERATURE

1.5

1.0

Offset Match (LSB)

1.5

1.0 –50 –25 0 25 50 75 100

Temperature (°C)

3

CHANGE IN OFFSET vs TEMPERATURE

2

1

0

–1

Delta from 25°C (LSB)

–2

–3

–50 –25 0 25 50 75 100

Temperature (°C)

Gain Match (LSB)

0.5

0.0 –50 –25 0 25 50 75 100

Temperature (°C)

1.0

CHANGE IN GAIN vs TEMPERATURE

0.5

0.0

Delta from 25°C (LSB)

–0.5

–50 –25 0 25 50 75 100

Temperature (°C)

6

ADS8344

SBAS139E

TYPICAL CHARACTERISTICS: +5V (Cont.)

At TA = +25°C, +VCC = +5V, V

= +5V, f

REF

= 100kHz, and f

SAMPLE

DCLK

= 24 • f

= 2.4MHz, unless otherwise noted.

SAMPLE

1.8

1.7

1.6

1.5

Supply Current (mA)

1.4

1.3 –50 –25 0 25 50 75 100

SUPPLY CURRENT vs TEMPERATURE

Temperature (°C)

POWER DOWN SUPPLY CURRENT

3.0

2.5

2.0

Supply Current (µA)

1.5

1.0 –50 –25 0 25 50 75 100

vs TEMPERATURE

Temperature (°C)

ADS8344

SBAS139E

7