Texas Instruments ADS7816 Datasheet

ADS7816

DESCRIPTION

The ADS7816 is a 12-bit, 200kHz sampling analogto-digital converter. It features low power operation with automatic power down, a synchronous serial interface, and a differential input. The reference voltage can be varied from 100mV to 5V, with a corresponding resolution from 24µV to 1.22mV.

Low power, automatic power down, and small size make the ADS7816 ideal for battery operated systems or for systems where a large number of signals must be acquired simultaneously. It is also ideal for remote and/or isolated data acquisition. The ADS7816 is available in an 8-pin plastic mini-DIP, an 8-lead SOIC, or an 8-lead MSOP package.

12-Bit High Speed Micro Power Sampling

ANALOG-TO-DIGITAL CONVERTER

1996 Burr-Brown Corporation PDS-1355B Printed in U.S.A., March, 1997

International Airport Industrial Park • Mailing Address: PO Box 11400, Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706 • Tel: (520) 746-1111 • Twx: 910-952-1111

Internet: http://www.burr-brown.com/ • FAXLine: (800) 548-6133 (US/Canada Only) • Cable: BBRCORP • Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132

FEATURES

● 200kHz SAMPLING RATE

● MICRO POWER:

1.9mW at 200kHz 150

µW at 12.5kHz

● POWER DOWN: 3

µA Max

● 8-PIN MINI-DIP, SOIC, AND MSOP

● DIFFERENTIAL INPUT

● SERIAL INTERFACE

APPLICATIONS

● BATTERY OPERATED SYSTEMS

● REMOTE DATA ACQUISITION

● ISOLATED DATA ACQUISITION

SAR

Control

Serial

Interface

OUT

Comparator

S/H Amp

CS/SHDN

DCLOCK

+In

REF

–In

CDAC



OPA658

ADS7816

SBAS061

ADS7816

SPECIFICATIONS

At –40°C to +85°C, +VCC = +5V, V

REF

= +5V, f

SAMPLE

= 200kHz, f

CLK

= 16 • f

SAMPLE

, unless otherwise specified.

ADS7816 ADS7816B ADS7816C

PARAMETER CONDITIONS MIN TYP MAX MIN TYP MAX MIN TYP MAX UNITS ANALOG INPUT

Full-Scale Input Span +In – (–In) 0

REF

✻✻✻✻V

Absolute Input Voltage +In –0.2

+0.2

✻✻✻✻V

–In –0.2 +0.2 ✻✻✻✻V Capacitance 25 ✻✻pF Leakage Current ±1 ✻✻µA

SYSTEM PERFORMANCE

Resolution 12 ✻✻Bits No Missing Codes 11 12 ✻ Bits Integral Linearity Error ±0.5 ±2 ±0.5 ±2 ±0.5 ±1 LSB

(1)

Differential Linearity Error ±0.5 ±2 ±0.5 ±1 ±0.25 ±0.75 LSB Offset Error ±4 ✻✻LSB Gain Error ±4 ✻✻LSB Noise 33 ✻✻µVrms Power Supply Rejection 82 ✻✻dB

SAMPLING DYNAMICS

Conversion Time 12 ✻✻

Clk Cycles

Acquisition Time 1.5 ✻✻

Clk Cycles

Throughput Rate 200 ✻✻kHz

DYNAMIC CHARACTERISTICS

Total Harmonic Distortion V

= 5.0Vp-p at 1kHz –84 ✻✻dB

= 5.0Vp-p at 5kHz –82 ✻✻dB

SINAD V

= 5.0Vp-p at 1kHz 72 ✻✻dB

Spurious Free Dynamic Range V

= 5.0Vp-p at 1kHz 86 ✻✻dB

REFERENCE INPUT

Voltage Range 0.1 5 ✻✻✻✻V Resistance

CS = GND, f

SAMPLE

= 0Hz

5 ✻✻GΩ

CS = V

5 ✻✻GΩ

Current Drain At Code 710h 38 100 ✻✻ ✻✻µA

SAMPLE

= 12.5kHz

2.4 20 ✻✻ ✻✻µA

CS = V

0.001 3 ✻✻ ✻✻µA

DIGITAL INPUT/OUTPUT

Logic Family CMOS ✻✻ Logic Levels:

IIH = +5µA3

+0.

3 ✻✻✻✻V

IIL = +5µA –0.3 0.8 ✻✻✻✻V

IOH = –250µA 3.5 ✻✻V

IOL = 250µA 0.4 ✻✻V

Data Format Straight Binary ✻✻

POWER SUPPLY REQUIREMENTS

Specified Performance 4.50 5.25 ✻✻✻✻V

Quiescent Current 380 700 ✻✻ ✻✻µA

SAMPLE

= 12.5kHz

(2, 3)

30 ✻✻µA

SAMPLE

= 12.5kHz

(3)

280 400 ✻✻µA

Power Down

CS =

VCC, f

SAMPLE

= 0Hz

3 ✻✻µA

TEMPERATURE RANGE

Specified Performance –40 +85 ✻✻✻✻°C

✻ Specifications same as grade to the left.

NOTE: (1) LSB means Least Significant Bit, with V

REF

equal to +5V, one LSB is 1.22mV. (2) f

CLK

= 3.2MHz, CS = VCC for 251 clock cycles out of every 256. (3) See

the Power Dissipation section for more information regarding lower sample rates.

ADS7816

The information provided herein is believed to be reliable; however, BURR-BROWN assumes no responsibility for inaccuracies or omissions. BURR-BROWN assumes no responsibility for the use of this information, and all use of such information shall be entirely at the user’s own risk. Prices and specifications are subject to change without notice. No patent rights or licenses to any of the circuits described herein are implied or granted to any third party. BURR-BROWN does not authorize or warrant any BURR-BROWN product for use in life support devices and/or systems.

ELECTROSTATIC DISCHARGE SENSITIVITY

Electrostatic discharge can cause damage ranging from performance degradation to complete device failure. BurrBrown Corporation 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

(1)

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

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

+ 0.3V)

Logic Input ............................................................. –0.3V to (+V

+ 0.3V)

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.

PIN CONFIGURATION

PIN ASSIGNMENTS

PIN NAME DESCRIPTION

REF

Reference Input. 2 +In Non Inverting Input. 3 –In Inverting Input. Connect to ground or to remote ground sense point. 4 GND Ground. 5 CS/SHDN Chip Select when LOW, Shutdown Mode when HIGH. 6D

OUT

The serial output data word is comprised of 12 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 12 edges. 7 DCLOCK Data Clock synchronizes the serial data transfer and determines conversion speed.

8+V

Power Supply.

PACKAGE/ORDERING INFORMATION

MAXIMUM MAXIMUM

INTEGRAL DIFFERENTIAL PACKAGE

LINEARITY ERROR LINEARITY ERROR TEMPERATURE DRAWING

PRODUCT (LSB) (LSB) RANGE PACKAGE NUMBER

(1)

ADS7816P ±2 ±2 –40°C to +85°C Plastic DIP 006 ADS7816U ±2 ±2 –40°C to +85°C SOIC 182 ADS7816E ±2 ±2 –40°C to +85°C MSOP 337 ADS7816PB ±2 ±1 –40°C to +85°C Plastic DIP 006 ADS7816UB ±2 ±1 –40°C to +85°C SOIC 182 ADS7816EB ±2 ±1 –40°C to +85°C MSOP 337 ADS7816PC ±1 ±0.75 –40°C to +85°C Plastic DIP 006 ADS7816UC ±1 ±0.75 –40°C to +85°C SOIC 182 ADS7816EC ±1 ±0.75 –40°C to +85°C MSOP 337

NOTE: (1) For detailed drawing and dimension table, please see end of data sheet, or Appendix C of Burr-Brown IC Data Book.

1 2 3 4

8 7 6 5

+VCC DCLOCK D

OUT



CS/SHDN

REF

 +In –In

GND

ADS7816



8-Pin PDIP,

8-Lead SOIC,

8-Lead MSOP

ADS7816

TYPICAL PERFORMANCE CURVES

At TA = +25°C, VCC = +5V, V

REF

= +5V, f

SAMPLE

= 200kHz, and f

CLK

= 16 • f

SAMPLE

, unless otherwise specified.

CHANGE IN OFFSET vs REFERENCE VOLTAGE

5

4.5 4

3.5 3

2.5 2

1.5 1

0.5 0

Change in Offset (LSB)

12345

Reference Voltage (V)



CHANGE IN OFFSET vs TEMPERATURE

0.6

0.4

0.2

0

–0.2

–0.4

–0.6

Delta from 25°C (LSB)

–55 –40 –25 0 25 70 85

Temperature (°C)

CHANGE IN GAIN vs REFERENCE VOLTAGE

4

3.5 3

2.5 2

1.5 1

0.5 0

Change in Gain (LSB)

12345

Reference Voltage (V)

CHANGE IN GAIN vs TEMPERATURE

0.15

0.1

0.05

0

–0.05

–0.1

–0.15

Delta from 25°C (LSB)

–55 –40 –25 0 25 70 85

Temperature (°C)

EFFECTIVE NUMBER OF BITS 

vs REFERENCE VOLTAGE

12

11.75

11.5

11.25 11

10.75

10.5

10.25 10

Effective Number of Bits (rms)

0.1 1 10 Reference Voltage (V)

PEAK-TO-PEAK NOISE vs REFERENCE VOLTAGE

10

9 8 7 6 5 4 3 2 1 0

Peak-to-Peak Noise (LSB)

0.1 1 10 Reference Voltage (V)

ADS7816

SIGNAL-TO-(NOISE + DISTORTION) vs INPUT LEVEL

80 70 60 50 40 30 20 10

Signal-to-(Noise Ratio Plus Distortion) (dB)

–40 –35 –30 –25 –20 –15 –10 –5 0

Input Level (dB)

SIGNAL-TO-(NOISE + DISTORTION) vs FREQUENCY

100

90 80 70 60 50 40 30 20 10

Signal-to-(Noise + Distortion) (dB)

1 10 100

Frequency (kHz)

TYPICAL PERFORMANCE CURVES (CONT)

At TA = +25°C, VCC = +5V, V

REF

= +5V, f

SAMPLE

= 200kHz, and f

CLK

= 16 • f

SAMPLE

, unless otherwise specified.

POWER SUPPLY REJECTION vs RIPPLE FREQUENCY

0 –10 –20 –30 –40 –50 –60 –70 –80 –90

Power Supply Rejection (dB)

1 10 100 1000 10000

Ripple Frequency (kHz)

TOTAL HARMONIC DISTORTION vs FREQUENCY

0 –10 –20 –30 –40 –50 –60 –70 –80 –90

–100

Total Harmonic Distortion (dB)

1 10 100

Frequency (kHz)

FREQUENCY SPECTRUM

(2048 Point FFT; f

= 9.9kHz, –0.5dB)

0 –10 –20 –30 –40 –50 –60 –70 –80 –90

–100 –110 –120

Amplitude (dB)

0 255075100

Frequency (kHz)

SPURIOUS FREE DYNAMIC RANGE and

SIGNAL-TO-NOISE RATIO vs FREQUENCY

100

90 80 70 60 50 40 30 20 10

Spurious Free Dynamic Range

and Signal-to-Noise Ratio (dB)

1 10 100

Frequency (kHz)

Spurious Free Dynamic Range

Signal-to-Noise Ratio

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