ADS1225IRGVTG4

AD ¨ S1 22 5 AD S1 ADS1225 ADS1226 ¨ 22 6 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 FEATURES DESCRIPTION 1 • • • • • 2 • • • • • • • • • 100SPS Data Rate (High-Speed Mode) Single-Cycle Settling Easy Conversion Control with START Pin Automatic Shutdown Low Noise: 4µVRMS Noise (High-Resolution Mode) Input Multiplexer with Two Differential Channels (ADS1226) Voltage Reference Supports Ratiometric Measurements Self-Calibrating Simple Read-Only 2-Wire Serial Interface Internal High-Impedance Input Buffer Internal Temperature Sensor Internal Oscillator Low-Power: 1mW While Operating, < 1µA During Shutdown Analog and Digital Supplies: 2.7V to 5.5V APPLICATIONS • • • Hand-Held Instrumentation Portable Medical Equipment Industrial Process Control The ADS1225 and ADS1226 are 24-bit delta-sigma analog-to-digital (A/D) converters. They offer excellent performance, ease-of-use, and low power in a small 4mm × 4mm QFN package and are well-suited for demanding high-resolution measurements, especially in portable and other space-saving and power-constrained applications. The ADS1225 and ADS1226 convert on command using a dedicated START pin. Simply pulse this pin to initiate a conversion. Data is read in a single cycle for retrieval over a 2-wire serial interface that easily connects to popular microcontrollers like the MSP430. After the conversion completes, the ADS1225 and ADS1226 automatically shuts down all circuitry. Internal features include a two-channel multiplexer (ADS1226), selectable input buffer, temperature sensor, and oscillator. The full-scale range is defined by the external voltage reference with support provided for up to a 5V differential input signal. Two operating modes allow for speed (100SPS data rate, 15µVRMS noise) or resolution (4µVRMS noise, 16SPS data rate). The ADS1225/6 supports 2.7 to 5.5V analog and digital supplies. Power consumption is 1mW while converting with 3V supplies. The ADS1225 and ADS1226 are fully specified over an extended industrial temperature range of –40°C to +105°C. TEMPEN AVDD VREFP VREFN DVDD START AINP1 AINN1 MUX Buffer AINP2 DS ADC Serial Interface SCLK DRDY/DOUT AINN2 Oscillator MUX BUFEN MODE GND ADS1226 Only 1 2 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 the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright © 2006–2009, Texas Instruments Incorporated 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. 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. ORDERING INFORMATION For the most current package and ordering information, see the Package Option Addendum located at the end of this data sheet or see the TI web site at www.ti.com. ABSOLUTE MAXIMUM RATINGS (1) Over operating free-air temperature range, unless otherwise noted. ADS1225, ADS1226 UNIT –0.3 to +6 V AVDD to GND DVDD to GND –0.3 to +6 V 100, momentary mA 10, continuous mA Analog input voltage to GND –0.3 to AVDD +0.3 V Digital input voltage to GND –0.3 to AVDD +0.3 V +150 °C Operating temperature range –55 to +125 °C Storage temperature range –50 to +150 °C Input current Maximum junction temperature (1) 2 Stresses above these ratings may cause permanent damage. Exposure to absolute maximum conditions for extended periods may degrade device reliability. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those specified is not implied. Submit Documentation Feedback Copyright © 2006–2009, Texas Instruments Incorporated Product Folder Link(s): ADS1225 ADS1226 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. ADS1225, ADS1226 PARAMETER TEST CONDITIONS MIN TYP MAX UNIT Analog Input Full-scale input voltage Absolute input voltage Differential input impedance Common-mode input impedance AINP – AINN ±VREF V Buffer off; AINP, AINN with respect to GND GND – 0.1 AVDD + 0.1 Buffer on; AINP, AINN with respect to GND GND + 0.05 AVDD – 1.5 V V Buffer off 2 MΩ Buffer on 1 GΩ Buffer off 4 MΩ System Performance Resolution Data rate Integral nonlinearity (INL) 24 Bits High-Speed mode 75 100 125 SPS (1) High-Resolution mode 12 16 22 SPS (1) % of FSR (2) 0.0005 0.0020 Offset error End-point fit 60 200 Offset error drift 0.3 Gain error 0.004 Gain error drift 0.025 % 0.3 ppm/°C 95 dB dB Common-mode rejection At dc Analog power-supply rejection At dc, ± 10% Δ in AVDD 95 Digital power-supply rejection At dc, DVDD = 2.7V to 5.5V 80 dB High-Speed mode 1.5 ppm of FSR, rms High-Resolution mode 0.4 ppm of FSR, rms TA = +25°C 106 mV 360 µV/°C Noise 85 µV µV/°C Temperature Sensor Temperature sensor voltage Temperature sensor coefficient Voltage Reference Input Reference input voltage 0.5 AVDD V Negative reference input VREF = VREFP – VREFN GND – 0.1 VREFP – 0.5 V Positive reference input VREFN + 0.5 AVDD + 0.1 Voltage reference impedance (1) (2) 1.5 V MΩ SPS = samples per second. FSR = full-scale range = 2 × VREF. Copyright © 2006–2009, Texas Instruments Incorporated Product Folder Link(s): ADS1225 ADS1226 Submit Documentation Feedback 3 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 + 0.1 V VIL GND – 0.1 0.2 DVDD V VOH IOH = 1mA VOL IOL = 1mA 0.8 DVDD V Input leakage 0.2 DVDD V ±10 µA V Power Supply AVDD 2.7 5.5 DVDD 2.7 5.5 AVDD current DVDD current Total power dissipation V Shutdown