BURR-BROWN ADS8320 User Manual

ADS8320

SBAS108B – MAY 2000 – REVISED DECEMBER 2005

16-Bit, High-Speed, 2.7V to 5V

ANALOG-TO-DIGITAL CONVERTER

FEATURES

● 100kHz SAMPLING RATE

● MICRO POWER:

1.8mW at 100kHz and 2.7V

0.3mW at 10kHz and 2.7V

● POWER DOWN: 3µA max

● MSOP-8 PACKAGE

● PIN-COMPATIBLE TO ADS7816 AND ADS7822

● SERIAL (SPI™/SSI) INTERFACE

APPLICATIONS

● BATTERY-OPERATED SYSTEMS

● REMOTE DATA ACQUISITION

● ISOLATED DATA ACQUISITION

● SIMULTANEOUS SAMPLING,

MULTICHANNEL SYSTEMS

● INDUSTRIAL CONTROLS

● ROBOTICS

● VIBRATION ANALYSIS

DESCRIPTION

The ADS8320 is a 16-bit sampling analog-to-digital (A/D)
converter with ensured specifications over a 2.7V to 5.25V
supply range. It requires very little power even when oper­ating at the full 100kHz data rate. At lower data rates, the
high speed of the device enables it to spend most of its time
in the power-down mode—the average power dissipation is
less than 100µW at 10kHz data rate.

The ADS8320 also features operation from 2.0V to 5.25V,
a synchronous serial (SPI/SSI compatible) interface, and a
differential input. The reference voltage can be set to any
level within the range of 500mV to VCC.

Ultra-low power and small size make the ADS8320 ideal
for portable and battery-operated systems. It is also a
perfect fit for remote data acquisition modules, simulta­neous multi-channel systems, and isolated data acquisi­tion. The ADS8320 is available in an MSOP-8 package.

micro

Power Sampling

SAR

V

REF

+In

–In

S/H Amp

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.

SPI is a trademark of Motorola, Inc. All other 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

Comparator

Copyright © 2000-2005, Texas Instruments Incorporated

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Control

Serial

Interface

D

OUT

DCLOCK

CS/SHDN

SPECIFICATIONS: +VCC = +5V

At –40°C to +85°C, V

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

ANALOG INPUT

Full-Scale Input Span +In – (–In) 0 V
Absolute Input Range +In –0.1

Capacitance 45 ✻ pF
Leakage Current 1 ✻ nA

SYSTEM PERFORMANCE

No Missing Codes 14 15 Bits
Integral Linearity Error ±0.008 ±0.018 ±0.006 ±0.012
Offset Error ±1 ±2 ±0.5 ±1mV
Offset Temperature Drift ±3 ✻ µV/°C
Gain Error ±0.05 ±0.024 %
Gain Temperature Drift ±0.3 ✻ ppm/°C
Noise 20 ✻ µVrms
Power Supply Rejection Ratio +4.7V < V

SAMPLING DYNAMICS

Conversion Time 16 ✻
Acquisition Time 4.5 ✻
Throughput Rate 100 ✻ kHz
Clock Frequency Range 0.024 2.4 ✻✻MHz

DYNAMIC CHARACTERISTICS

Total Harmonic Distortion V
SINAD V
Spurious Free Dynamic Range V
SNR 90 92 dB

REFERENCE INPUT

Voltage Range 0.5 V
Resistance

Current Drain 40 80 ✻✻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

V

CC

Range

(2)

Quiescent Current 900 1700 ✻✻µA

Power Dissipation 4.5 8.5 ✻✻mW
Power Down CS = V

TEMPERATURE RANGE

Specified Performance –40 +85 ✻✻°C

✻ Specifications same as ADS8320E.

NOTES: (1) LSB means Least Significant Bit. With V
(3) f

= 2.4MHz, CS = VCC for 216 clock cycles out of every 240. (4) See the Power Dissipation section for more information regarding lower sample rates.

CLK

= +5V,–IN = GND, f

REF

= 100kHz, and f

SAMPLE

= 24 • f

CLK

, unless otherwise specified.

SAMPLE

ADS8320E ADS8320EB

REF

V

CC

✻✻V

+ 0.1

✻✻V

–In –0.1 +1.0 ✻✻V

< 5.25V 3 ✻ LSB

CC

= 5Vp-p at 10kHz –84 –86 dB

IN

= 5Vp-p at 10kHz 82 84 dB

IN

= 5Vp-p at 10kHz 84 86 dB

IN

✻✻V

CS = GND, f

CS = V

f

SAMPLE

CS = V

= 0Hz

SAMPLE

CC

= 10kHz 0.8 ✻ µA

CC

IIH = +5µA 3.0

5 ✻ GΩ
5 ✻ GΩ

0.1

CC

3

VCC + 0.3

✻ µA

✻✻V

IIL = +5µA –0.3 0.8 ✻✻V

IOH = –250µA 4.0 ✻ V

IOL = 250µA 0.4 ✻ V

Specified Performance 4.75 5.25 ✻✻V

2.0 5.25 ✻✻V

(3, 4)

= 10kHz

f

SAMPLE

CC

equal to +5.0V, one LSB is 0.076mV. (2) See Typical Performance Curves for more information.

REF

200 ✻ µA

0.3 3 ✻✻µA

% of FSR

(1)

Clk Cycles
Clk Cycles

2

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ADS8320

SBAS108B

SPECIFICATIONS: +VCC = +2.7V

At –40°C to +85°C, V

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

ANALOG INPUT

Full-Scale Input Span +In – (–In) 0 V
Absolute Input Range +In –0.1

Capacitance 45 ✻ pF
Leakage Current 1 ✻ nA

SYSTEM PERFORMANCE

No Missing Codes 14 15 Bits
Integral Linearity Error ±0.008 ±0.018 ±0.006 ±0.012
Offset Error ±1 ±2 ±0.5 ±1mV
Offset Temperature Drift ±3 ✻ µV/°C
Gain Error ±0.05 ±0.024 % of FSR
Gain Temperature Drift ±0.3 ✻ ppm/°C
Noise 20 ✻ µVrms
Power Supply Rejection Ratio +2.7V < V

SAMPLING DYNAMICS

Conversion Time 16 ✻
Acquisition Time 4.5 ✻
Throughput Rate 100 ✻ kHz
Clock Frequency Range 0.024 2.4 ✻✻MHz

DYNAMIC CHARACTERISTICS

Total Harmonic Distortion V
SINAD V
Spurious Free Dynamic Range V
SNR 88 90 dB

REFERENCE INPUT

Voltage Range 0.5 V
Resistance

Current Drain 20 50 ✻✻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

VCC Range

(3)

Quiescent Current 650 1300 ✻✻µA

Power Dissipation 1.8 3.8 ✻✻mW
Power Down CS = V

TEMPERATURE RANGE

Specified Performance –40 +85 ✻✻°C

✻ Specifications same as ADS8320E.

Notes: (1) LSB means Least Significant Bit. With V
in this power supply range. (3) See the Typical Performance Curves for more information. (4) f
(5) See the Power Dissipation section for more information regarding lower sample rates.

= 2.5V, –IN = GND, f

REF

= 100kHz, and f

SAMPLE

= 24 • f

CLK

, unless otherwise specified.

SAMPLE

ADS8320E ADS8320EB

REF

V

CC

✻✻V

+ 0.1

✻✻V

–In –0.1 +0.5 ✻✻V

< +3.3V 3 ✻ LSB

CC

= 2.7Vp-p at 1kHz –86 –88 dB

IN

= 2.7Vp-p at 1kHz 84 86 dB

IN

= 2.7Vp-p at 1kHz 86 88 dB

IN

✻✻V

CS = GND, f

CS = V

CS = V

SAMPLE

CC

CC

= 0Hz

IIH = +5µA 2.0

5 ✻ GΩ
5 ✻ GΩ

0.1

CC

3

VCC + 0.3

✻✻µA

✻✻V

IIL = +5µA –0.3 0.8 ✻✻V

IOH = –250µA 2.1 ✻ V

IOL = 250µA 0.4 ✻ V

Specified Performance 2.7 3.3 ✻✻V

2.0 5.25 ✻✻V

See Note 2 2.0 2.7 ✻✻V

(4,5)

= 10kHz

f

SAMPLE

CC

equal to +2.5V, one LSB is 0.038mV. (2) The maximum clock rate of the ADS8320 is less than 2.4MHz

REF

100 ✻ µA

0.3 3 ✻✻µA

= 2.4MHz, CS = VCC for 216 clock cycles out of every 240.

CLK

% of FSR

(1)

Clk Cycles
Clk Cycles

ADS8320

SBAS108B

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3

PIN CONFIGURATION

Top View MSOP

ELECTROSTATIC
DISCHARGE SENSITIVITY

V

REF

+In
–In

GND

1
2

ADS8320

3
4

8
7
6
5

+V

CC

DCLOCK
D

OUT

CS/SHDN

PIN ASSIGNMENTS

PIN NAME DESCRIPTION

1V
2 +In Non Inverting Input.
3 –In Inverting Input. Connect to ground or to remote

4 GND Ground.
5 CS/SHDN Chip Select when LOW, Shutdown Mode when

6D

7 DCLOCK Data Clock synchronizes the serial data transfer

8+V

REF

OUT

CC

Reference Input.

ground sense point.

HIGH.
The serial output data word is comprised of 16

bits of data. In operation the data is valid on the
falling edge of DCLOCK. The
second clock pulse after the falling edge of CS
enables the serial output. After one null bit the
data is valid for the next 16 edges.

and determines conversion speed.
Power Supply.

Electrostatic discharge can cause damage ranging from
performance degradation to complete device failure. Texas
Instruments recommends that all integrated circuits be handled
and stored using appropriate ESD protection methods.

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
published specifications.

ABSOLUTE MAXIMUM RATINGS

VCC....................................................................................................... +6V

Analog Input..............................................................–0.3V to (V

Logic Input ...............................................................................–0.3V to 6V

Case Temperature ......................................................................... +100°C

Junction Temperature .................................................................... +150°C

Storage Temperature..................................................................... +125°C

External Reference Voltage .............................................................. +5.5V

NOTE: (1) Stresses above these ratings may permanently damage the device.

(1)

+ 0.3V)

CC

PACKAGE/ORDERING INFORMATION

MAXIMUM NO
INTEGRAL MISSING

LINEARITY CODE SPECIFICATION

PRODUCT (%) (LSB) PACKAGE DESIGNATOR RANGE MARKING

ADS8320E 0.018 14 MSOP-8 DGK –40°C to +85 °C A20 ADS8320E/250 Tape and Reel
ADS8320E
ADS8320EB 0.012 15 MSOP-8 DGK –40°C to +85°C A20 ADS8320EB/250 Tape and Reel
ADS8320EB

NOTE: (1) For the most current product and ordering information, see the Package Option Addendum at the end of this data sheet, or see the TI website at
www.ti.com. (2) Performance Grade information is marked on the reel. (3) Models with a slash(/) are available only in Tape and reel in quantities indicated (for
example, /250 indicates 250 units per reel, /2K5 indicates 2500 devices per reel). Ordering 2500 pieces of ”ADS8320E/2K5“ will get a single 2500-piece Tape and
Reel.

ERROR ERROR PACKAGE TEMPERATURE PACKAGE ORDERING TRANSPORT

"" " " " "ADS8320E/2K5 Tape and Reel
"" " " " "ADS8320EB/2K5 Tape and Reel

(1)

(2)

NUMBER

(3)

MEDIA

4

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ADS8320

SBAS108B

TYPICAL PERFORMANCE CURVES

POWER DOWN SUPPLY CURRENT

vs TEMPERATURE

600

500

400

300

200

100

0

Supply Current (nA)

–50 –25 0 25 50 75 100

Temperature (°C)

5V

At TA = +25°C, VCC = +5V, V

REF

= +5V, f

SAMPLE

= 100kHz, f

CLK

= 24 • f

, unless otherwise specified.

SAMPLE

INTEGRAL LINEARITY ERROR vs CODE (+25°C)

2 0

1.0

0.0

–1.0
–2.0
–3.0
–4.0

Integral Linearity Error (LSB)

–5.0
–6.0

1200

0000

H

4000

SUPPLY CURRENT vs TEMPERATURE

1000

800

600

DIFFERENTIAL LINEARITY ERROR vs CODE (+25°C)

3.0

2.0

1.0

0.0

–1.0

–2.0

Differential Linearity Error (LSB)

–3.0

H

8000

C000

H

FFFF

H

H

0000

4000

H

H

Hex Code

8000

H

Hex Code

C000

FFFF

H

H

5V

2.7V

400

Supply Current (µA)

200

0

–50 –25 0 25 50 75 100

Temperature (°C)

QUIESCENT CURRENT vs V

1200

1000

800

600

Quiescent Current (µA)

400

200

12345

V

(V)

CC

CC

MAXIMUM SAMPLE RATE vs V

CC

1000

100

10

Sample Rate (kHz)

1

12345

V

(V)

CC

ADS8320

SBAS108B

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5