Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsData collecting ICsData acquisition IC - AD converter (ADC) External VQFN 16

ADS1225

ADS1226

FEATURES DESCRIPTION

APPLICATIONS

MUX

SerialInterface

ADC

VREFP VREFN

Buffer

AVDD DVDD

GNDMUX

ADS1226Only

AINP1

AINN1

AINP2

AINN2

DRDY/DOUT

SCLK

TEMPEN

START

Oscillator

MODE

BUFEN

ADS1225

ADS1226

www.ti.com

....................................................................................................................................................... SBAS346C – MAY 2006 – REVISED JANUARY 2009

24-Bit Analog-to-Digital Converter

with One- and Two-Channel Differential Inputs and Internal Oscillator

• 100SPS Data Rate (High-Speed Mode)

The ADS1225 and ADS1226 are 24-bit delta-sigma

analog-to-digital (A/D) converters. They offer

• Single-Cycle Settling

excellent performance, ease-of-use, and low power in

• Easy Conversion Control with START Pin

a small 4mm × 4mm QFN package and are

• Automatic Shutdown

well-suited for demanding high-resolution

• Low Noise: 4 µ V

RMS

Noise (High-Resolution measurements, especially in portable and other

space-saving and power-constrained applications.

Mode)

• Input Multiplexer with Two Differential

The ADS1225 and ADS1226 convert on command

Channels (ADS1226)

using a dedicated START pin. Simply pulse this pin to

initiate a conversion. Data is read in a single cycle for

• Voltage Reference Supports Ratiometric

retrieval over a 2-wire serial interface that easily

Measurements

connects to popular microcontrollers like the

• Self-Calibrating

MSP430. After the conversion completes, the

• Simple Read-Only 2-Wire Serial Interface

ADS1225 and ADS1226 automatically shuts down all

circuitry.

• Internal High-Impedance Input Buffer

Internal features include a two-channel multiplexer

• Internal Temperature Sensor

(ADS1226), selectable input buffer, temperature

• Internal Oscillator

sensor, and oscillator. The full-scale range is defined

• Low-Power: 1mW While Operating, < 1 µ A

by the external voltage reference with support

During Shutdown

provided for up to a 5V differential input signal. Two

operating modes allow for speed (100SPS data rate,

• Analog and Digital Supplies: 2.7V to 5.5V

15 µ V

RMS

noise) or resolution (4 µ V

RMS

noise, 16SPS

data rate).

• Hand-Held Instrumentation

The ADS1225/6 supports 2.7 to 5.5V analog and

digital supplies. Power consumption is 1mW while

• Portable Medical Equipment

converting with 3V supplies. The ADS1225 and

• Industrial Process Control

ADS1226 are fully specified over an extended

industrial temperature range of – 40 ° C to +105 ° C.

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.

2 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 the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.

Summary of content (29 pages)

PAGE 1
AD ¨ S1 22 5 AD S1 ADS1225 ADS1226 ¨ 22 6 www.ti.com .......................................................................................................................................................
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ADS1225 ADS1226 SBAS346C – MAY 2006 – REVISED JANUARY 2009 ....................................................................................................................................................... www.ti.com 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.
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ADS1225 ADS1226 www.ti.com ....................................................................................................................................................... SBAS346C – MAY 2006 – REVISED JANUARY 2009 ELECTRICAL CHARACTERISTICS All specifications at TA = –40°C to +105°C, AVDD = +5V, DVDD = +3V, and VREF = +5V, unless otherwise noted.
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ADS1225 ADS1226 SBAS346C – MAY 2006 – REVISED JANUARY 2009 ....................................................................................................................................................... www.ti.com ELECTRICAL CHARACTERISTICS (continued) All specifications at TA = –40°C to +105°C, AVDD = +5V, DVDD = +3V, and VREF = +5V, unless otherwise noted. ADS1225, ADS1226 PARAMETER TEST CONDITIONS MIN TYP MAX UNIT Digital Input/Output Logic levels VIH 0.8 DVDD DVDD + 0.
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ADS1225 ADS1226 www.ti.com ....................................................................................................................................................... SBAS346C – MAY 2006 – REVISED JANUARY 2009 PIN CONFIGURATION START 1 SCLK 2 DVDD AVDD VREFP VREFN 16 15 14 13 RGV PACKAGE QFN-16, 4.0mm × 4.0mm (TOP VIEW) 12 GND 11 AINN1 AINP1 ADS1225 7 8 NC 9 MODE 4 6 BUFEN TEMPEN 10 5 3 GND DRDY/DOUT NC PIN DESCRIPTIONS—ADS1225 TERMINAL NAME NO.
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ADS1225 ADS1226 SBAS346C – MAY 2006 – REVISED JANUARY 2009 ....................................................................................................................................................... www.ti.com START 1 SCLK 2 DVDD AVDD VREFP VREFN 16 15 14 13 RGV PACKAGE QFN-16, 4.0mm × 4.0mm (TOP VIEW) 12 GND 11 AINN1 ADS1226 8 AINN2 AINP2 9 7 4 MODE BUFEN 6 AINP1 TEMPEN 10 5 3 MUX DRDY/DOUT PIN DESCRIPTIONS—ADS1226 TERMINAL NAME NO.
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ADS1225 ADS1226 www.ti.com ....................................................................................................................................................... SBAS346C – MAY 2006 – REVISED JANUARY 2009 TYPICAL CHARACTERISTICS At TA = +25°C, AVDD = +5V, DVDD = +3V, and VREF = +5V, unless otherwise noted.
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ADS1225 ADS1226 SBAS346C – MAY 2006 – REVISED JANUARY 2009 ....................................................................................................................................................... www.ti.com TYPICAL CHARACTERISTICS (continued) At TA = +25°C, AVDD = +5V, DVDD = +3V, and VREF = +5V, unless otherwise noted.
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ADS1225 ADS1226 www.ti.com ....................................................................................................................................................... SBAS346C – MAY 2006 – REVISED JANUARY 2009 TYPICAL CHARACTERISTICS (continued) At TA = +25°C, AVDD = +5V, DVDD = +3V, and VREF = +5V, unless otherwise noted. NOISE vs INPUT VOLTAGE NOISE vs INPUT VOLTAGE 0.9 0.7 High-Resolution Mode Buffer Off 0.6 0.7 Noise (ppm of FSR, rms) Noise (ppm of FSR, rms) 0.8 0.6 0.5 0.4 0.3 0.
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ADS1225 ADS1226 SBAS346C – MAY 2006 – REVISED JANUARY 2009 ....................................................................................................................................................... www.ti.com OVERVIEW ANALOG INPUTS (AINx+, AINx–) The ADS1225 and ADS1226 are 24-bit delta-sigma A/D converters. Figure 19 shows a conceptual diagram of the device. The ADS1225 has a single channel, while the ADS1226 allows for one of two input channels to be selected through a multiplexer.
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ADS1225 ADS1226 www.ti.com ....................................................................................................................................................... SBAS346C – MAY 2006 – REVISED JANUARY 2009 Analog Input Measurement Without the Input Buffer With the buffer disabled by setting the BUFEN pin low, the ADS1225 and ADS1226 measure the input signal using internal capacitors that are continuously charged and discharged.
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ADS1225 ADS1226 SBAS346C – MAY 2006 – REVISED JANUARY 2009 ....................................................................................................................................................... www.ti.com TEMPERATURE SENSOR Internal diodes provide temperature-sensing capability.
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ADS1225 ADS1226 www.ti.com ....................................................................................................................................................... SBAS346C – MAY 2006 – REVISED JANUARY 2009 INTERNAL OSCILLATOR MODE The ADS1225 and ADS1226 have an internal oscillator and run without an external crystal or oscillator. The ADS1225 and ADS1226 have two modes of operation, allowing for High-Speed or High-Resolution.
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ADS1225 ADS1226 SBAS346C – MAY 2006 – REVISED JANUARY 2009 ....................................................................................................................................................... www.ti.com Table 4. Ideal Output Code vs Input Signal The ADS1225 and ADS1226 can be configured to continuously convert by holding the START pin high as shown in Figure 27. With START held high, a new conversion starts immediately after the previous conversion completes.
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ADS1225 ADS1226 www.ti.com ....................................................................................................................................................... SBAS346C – MAY 2006 – REVISED JANUARY 2009 DATA RETRIEVAL Avoid data retrieval during the update period. DRDY/DOUT remain at the state of the last bit shifted out until it is taken high (see t6), indicating that new data is being updated.
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ADS1225 ADS1226 SBAS346C – MAY 2006 – REVISED JANUARY 2009 ....................................................................................................................................................... www.ti.com SELF-CALIBRATION When the calibration is complete, DRDY/DOUT goes low, indicating that new data is ready.
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ADS1225 ADS1226 www.ti.com ....................................................................................................................................................... SBAS346C – MAY 2006 – REVISED JANUARY 2009 APPLICATION INFORMATION EXPOSED THERMAL PAD ADS1226 GND pin and bypass capacitors directly to it. Avoid ringing on the digital inputs. Small resistors (≈100Ω) in series with the digital pins can help by controlling the trace impedance. Place these resistors at the source end.
PAGE 18
ADS1225 ADS1226 SBAS346C – MAY 2006 – REVISED JANUARY 2009 ....................................................................................................................................................... www.ti.com SMALL INPUT SIGNALS measurement of approximately 1V while keeping the noise contribution of the OPA2333 low. The noise is low enough compared to full-scale to create a several-thousand count weigh scale, even in High-Speed mode.
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ADS1225 ADS1226 www.ti.com ....................................................................................................................................................... SBAS346C – MAY 2006 – REVISED JANUARY 2009 LARGE INPUT SIGNALS Many industrial applications require measurement of signals that go beyond 5V. The ADS1225 can be used to measure large input signals with the help of an INA159. The precision, level translation differential amplifier converts a ±10V input to a 5V input scale.
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ADS1225 ADS1226 SBAS346C – MAY 2006 – REVISED JANUARY 2009 ....................................................................................................................................................... www.ti.
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ADS1225 ADS1226 www.ti.com ....................................................................................................................................................... SBAS346C – MAY 2006 – REVISED JANUARY 2009 Revision History Changes from Revision B (August 2007) to Revision C ................................................................................................
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PACKAGE OPTION ADDENDUM www.ti.
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PACKAGE OPTION ADDENDUM www.ti.com 11-Apr-2013 (4) Multiple Top-Side Markings will be inside parentheses. Only one Top-Side Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation of the previous line and the two combined represent the entire Top-Side Marking for that device. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided.
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PACKAGE MATERIALS INFORMATION www.ti.com 14-Jul-2012 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing ADS1225IRGVR VQFN RGV 16 SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant 2500 330.0 12.4 4.25 4.25 1.15 8.0 12.0 Q2 ADS1225IRGVT VQFN RGV 16 250 180.0 12.4 4.25 4.25 1.15 8.0 12.0 Q2 ADS1226IRGVR VQFN RGV 16 2500 330.0 12.4 4.25 4.25 1.15 8.0 12.
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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) ADS1225IRGVR VQFN RGV 16 2500 367.0 367.0 35.0 ADS1225IRGVT VQFN RGV 16 250 210.0 185.0 35.0 ADS1226IRGVR VQFN RGV 16 2500 367.0 367.0 35.0 ADS1226IRGVT VQFN RGV 16 250 210.0 185.0 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.