Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsData collecting ICsData acquisition IC - AD converter (ADC) External PDIP 8

ADS1286

DESCRIPTION

The ADS1286 is a 12-bit, 20kHz analog-to-digital

converter with a differential input and sample and hold

amplifier and consumes only 250µA of supply cur-

rent. The ADS1286 offers an SPI and SSI compatible

serial interface for communications over a two or three

wire interface. The combination of a serial two wire

interface and micropower consumption makes the

ADS1286 ideal for remote applications and for those

requiring isolation.

The ADS1286 is available in a 8-pin plastic mini DIP

and a 8-lead SOIC.

12-Bit Micro Power Sampling

ANALOG-TO-DIGITAL CONVERTER

FEATURES

● SERIAL INTERFACE

● GUARANTEED NO MISSING CODES

● 20kHz SAMPLING RATE

● LOW SUPPLY CURRENT: 250µA

SAR

Control

Serial

Interface

OUT

Comparator

S/H Amp

CS/SHDN

DCLOCK

+In

REF

–In

CDAC

ADS1286

APPLICATIONS

● REMOTE DATA ACQUISITION

● ISOLATED DATA ACQUISITION

● TRANSDUCER INTERFACE

● BATTERY OPERATED SYSTEMS

1996 Burr-Brown Corporation PDS-1335B Printed in U.S.A. October, 1998

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/ • Cable: BBRCORP • Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132

SBAS053

Summary of content (17 pages)

PAGE 1
® ADS ADS1286 128 ADS 6 128 6 12-Bit Micro Power Sampling ANALOG-TO-DIGITAL CONVERTER FEATURES DESCRIPTION ● ● ● ● The ADS1286 is a 12-bit, 20kHz analog-to-digital converter with a differential input and sample and hold amplifier and consumes only 250µA of supply current. The ADS1286 offers an SPI and SSI compatible serial interface for communications over a two or three wire interface.
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SPECIFICATIONS At TA = TMIN to TMAX, +VCC = +5V, VREF = +5V, fSAMPLE = 12.5kHz, , fCLK = 16 • fSAMPLE, unless otherwise specified. ADS1286, ADS1286A PARAMETER CONDITIONS MIN +In – (–In) +In –In 0 –0.2 –0.2 ANALOG INPUT Full-Scale Input Range Absolute Input Voltage ADS1286K, ADS1286B ADS1286C, ADS1286L MAX MIN MAX MIN VREF VCC +0.2 +0.
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ABSOLUTE MAXIMUM RATINGS(1) ELECTROSTATIC DISCHARGE SENSITIVITY +VCC ..................................................................................................... +6V Analog Input ....................................................... –0.3V to (+VCC + 300mV) Logic Input ......................................................... –0.3V to (+VCC + 300mV) Case Temperature ......................................................................... +100°C Junction Temperature .............................
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TYPICAL PERFORMANCE CURVES At TA = +25, VCC = +5V, VREF = +5V, fSAMPLE = 12.5kHz, fCLK = 16 • fSAMPLE, unless otherwise specified. REFERENCE CURRENT vs SAMPLE RATE REFERENCE CURRENT vs TEMPERATURE 4.0 3.5 2.0 Reference Current (µA) Reference Current (µA) 2.5 1.5 1.0 0.5 3.0 2.5 2.0 1.5 1.0 0 0 2 4 6 8 10 12 –55 –40 –25 Sample Rate (kHz) 0 25 70 85 Temperature (°C) CHANGE IN OFFSET vs TEMPERATURE CHANGE IN OFFSET vs REFERENCE VOLTAGE 0.6 5 0.
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TYPICAL PERFORMANCE CURVES (CONT) At TA = +25, VCC = +5V, VREF = +5V, fSAMPLE = 12.5kHz, fCLK = 16 • fSAMPLE, unless otherwise specified. EFFECTIVE NUMBER OF BITS vs REFERENCE VOLTAGE DIFFERENTIAL LINEARITY ERROR vs CODE 3.0 Differential Linearity Error (LSB) 11.75 11.5 11.25 11 10.75 10.5 10.25 2.0 1.0 0 –1.0 –2.0 –3.0 10 0.
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TYPICAL PERFORMANCE CURVES (CONT) At TA = +25, VCC = +5V, VREF = +5V, fSAMPLE = 12.5kHz, fCLK = 16 • fSAMPLE, unless otherwise specified. 4096 POINT FFT PEAK-TO-PEAK NOISE vs REFERENCE VOLTAGE 10 0 Peak-to-Peak Noise (LSB) 9 Magnitude (dB) –25 –50 –75 –100 8 7 6 5 4 3 2 1 –125 0 0 2 4 0.1 6 1 Reference Voltage (V) Frequency (kHz) POWER SUPPLY REJECTION vs RIPPLE FREQUENCY 10 CHANGE GAIN vs TEMPERATURE 0 0.15 VRIPPLE = 20mV –20 0.
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TYPICAL PERFORMANCE CURVES (CONT) At TA = +25, VCC = +5V, VREF = +5V, fSAMPLE = 12.5kHz, fCLK = 16 • fSAMPLE, unless otherwise specified. DIGITAL INPUT LINE THRESHOLD vs SUPPLY VOLTAGE INTEGRAL LINEARITY ERROR vs CODE Digital Input Threshold Voltage (V) 3 2.0 1.0 0 –1.0 –2.0 –3.0 2.5 2 1.5 1 0.5 0 0 2048 Code 4095 3 3.25 3.5 3.75 4 4.25 4.5 4.75 5 5.25 5.5 Supply Voltage (V) INPUT LEAKAGE CURRENT vs TEMPERATURE 10 Leakage Current (nA) Integral Linearity Error (LSB) 3.0 1 0.1 0.
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TIMING DIAGRAMS AND TEST CIRCUITS 1.
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tCYC CS/SHDN POWER DOWN tSUCS DCLOCK tCSD DOUT HI-Z NULL BIT B11 B10 B9 (MSB) tSMPL NULL BIT HI-Z B8 B7 B6 B5 B4 B3 B2 B1 B0(1) tCONV B11 B10 B9 B8 tDATA Note: (1) After completing the data transfer, if further clocks are applied with CS LOW, the ADC will output LSB-First data then followed with zeroes indefinitely.
PAGE 10
REDUCED REFERENCE OPERATION MINIMIZING POWER DISSIPATION In systems that have significant time between conversions, the lowest power drain will occur with the minimum CS LOW time. Bringing CS LOW, transferring data as quickly as possible, and then bringing it back HIGH will result in the lowest current drain. This minimizes the amount of time the device draws power. After a conversion the A/D automatically shuts down even if CS is held LOW.
PAGE 11
+5V +5V +5V R8 46kΩ D1 R1 150kΩ TC1 R9 1kΩ OPA237 C2 0.1µF R3 500kΩ R2 59kΩ 0.4V R7 10Ω R6 1MΩ C1 10µF VREF MUX 0.2V ADS1286 DOUT A0 CS/SHDN A1 Thermocouple TC3 R4 1kΩ C4 10µF ISO Thermal Block R10 1kΩ DCLOCK C3 0.1µF TC2 0.3V U2 U1 R5 500Ω U3 C5 0.1µF R11 1kΩ 0.1V R12 1kΩ µP 3-Wire Interface U4 FIGURE 5. Thermocouple Application Using a MUX to Scale the Input Range of the ADS1286. +VCC REF200 (100µA) 0.
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PACKAGE OPTION ADDENDUM www.ti.
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PACKAGE OPTION ADDENDUM www.ti.
PAGE 14
PACKAGE OPTION ADDENDUM www.ti.com 24-Jul-2013 LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device.
PAGE 15
PACKAGE MATERIALS INFORMATION www.ti.com 14-Jul-2012 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant ADS1286U/2K5 SOIC D 8 2500 330.0 12.4 6.4 5.2 2.1 8.0 12.0 Q1 ADS1286UA/2K5 SOIC D 8 2500 330.0 12.4 6.4 5.2 2.1 8.0 12.0 Q1 ADS1286UL/2K5 SOIC D 8 2500 330.0 12.4 6.4 5.2 2.1 8.0 12.
PAGE 16
PACKAGE MATERIALS INFORMATION www.ti.com 14-Jul-2012 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) ADS1286U/2K5 SOIC D 8 2500 367.0 367.0 35.0 ADS1286UA/2K5 SOIC D 8 2500 367.0 367.0 35.0 ADS1286UL/2K5 SOIC D 8 2500 367.0 367.0 35.
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IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, enhancements, improvements and other changes to its semiconductor products and services per JESD46, latest issue, and to discontinue any product or service per JESD48, latest issue. Buyers should obtain the latest relevant information before placing orders and should verify that such information is current and complete.