ADS1232 ADS1234 SBAS350 – JUNE 2005 Ultra Low-Noise, 24-Bit Analog-to-Digital Converter • • • • • • • • • • • • DESCRIPTION Up to 23.5 Effective Bits RMS Noise: – 17nV at 10Hz – 44nV at 80Hz On-Board Low Noise Gain-Amp 19.2-Bit Noise-Free Resolution at Gain = 64 Simultaneous 50Hz and 60Hz Rejection: – Internal Clock: 110 dB – External Clock: 130 dB ±1% Low-Drift On-Board Oscillator Selectable Gains of 1, 2, 64, and 128 Selectable 10/80SPS Conversion Rates 2-Channel Differential Input with Built-In Temp sensor (ADS1232) 4-Channel Differential Input (ADS1234) External Reference up to AVDD Simple Serial Digital Interface Supply Range: 2.7V to 5.3V –40°C to +105°C Temperature Range The ADS1232 and ADS1234 are precision analog-to-digital (A/D) converters featuring true 23.5 effective-bit performance and exceptional ease of use. Selectable gains of 1, 2, 64, or 128 allow full-scale differential input ranges of ±2.5V to ±19.5mV with a +5V reference. While the ADS1232 offers a two-channel differential input and a built-in temperature sensor, the ADS1234 features a four-channel differential input multiplexer. A very low-noise Gain-Amp features low differential input current to minimize errors when using high-impedance transducers. An on-board oscillator is provided for excellent 50Hz and 60Hz rejection without an external clock source. The devices also feature a low current driver to accommodate an external crystal; they also accept external clock sources for all applications. All of the features of the ADS1232/ADS1234 are hard-wire selected, without software programming. Data is accessed over a simple serial interface compatible with popular microcontrollers such as the MSP430. The ADS1232 is available in the 24-pin TSSOP package, and the ADS1234 is available in the 28-pin TSSOP. APPLICATIONS • • • • Weigh Scales Strain Gauges Bridge Sensors Industrial Process Control CAP AVDD REFP REFN DVDD GAIN [1:0] AINP1 AINN1 AINP2 AINN2 AINP3 AINN3 A = 1, 2, 64, 128 Input Mux PDWN DRDY/DOUT ∆Σ ADC PGA AINP4 AINN4 SCLK Internal Oscillator SPEED External Oscillator A1/TEMP(1) A0 AGND CAP XTAL1/CLKIN XTAL2 DGND ADS1234 Only NOTE: (1) A1 for ADS1234, TEMP for ADS1232. 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. PRODUCT PREVIEW information concerns products in the formative or design phase of development. Characteristic data and other specifications are design goals. Texas Instruments reserves the right to change or discontinue these products without notice. Copyright © 2005, Texas Instruments Incorporated PRODUCT PREVIEW FEATURES • • ADS1232 ADS1234 www.ti.com SBAS350 – JUNE 2005 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 (1) PRODUCT PACKAGE-LEAD PACKAGE DESIGNATOR SPECIFIED TEMPERATURE RANGE PACKAGE MARKING ADS1232 TSSOP-24 PW –40°C to 105°C ADS1232 ADS1234 TSSOP-28 PW –40°C to 105°C ADS1234 (1) ORDERING NUMBER TRANSPORT MEDIA, QUANTITY ADS1232IPWT Tape and Reel, 250 ADS1232IPWR Tape and Reel, 2500 ADS1234IPWT Tape and Reel, 250 ADS1234IPWR Tape and Reel, 2500 For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI website at www.ti.com. PRODUCT PREVIEW ABSOLUTE MAXIMUM RATINGS over operating free-air temperature range (unless otherwise noted) (1) ADS1232, ADS1234 UNIT AVDD to AGND –0.3 to +6 V DVDD to DGND –0.3 to +6 V AGND to DGND –0.3 to +0.3 V Input Current 100, Momentary mA Input Current 10, Continuous mA Analog Input Voltage to AGND –0.3 to AVDD + 0.3 V Digital Input Voltage to DGND –0.3 to DVDD + 0.3 V Maximum Junction Temperature +150 °C Operating Temperature Range –40 to +105 °C Storage Temperature Range –60 to +150 °C +300 °C Lead Temperature (soldering, 10s) (1) 2 Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. ADS1232 ADS1234 www.ti.com SBAS350 – JUNE 2005 ELECTRICAL CHARACTERISTICS: VREF = +5V All specifications TA = –40°C to +105°C, AVDD = DVDD = VREFP = +5V, VREFN = AGND, Internal Oscillator, SPEED = Low, Gain = 64 (unless otherwise specified). ADS1232, ADS1234 PARAMETER CONDITIONS MIN TYP MAX UNIT Analog Inputs Full-Scale Input Voltage (AINP - AINN) Common-mode Input Range ±0.5VREF/Gain AINxP or AINxN with respect to GND, Gain = 1 Gain = 64, 128 Differential Input Current AGND – 0.1 AVDD + 0.1 (0.5)AVDD – 1 Gain = 1, 2 Gain = 64, 128 V (0.5)AVDD + 1 V V 500 nA 50 nA System Performance Conversion Rate Digital Filter Settling Time Integral Non-Linearity (INL) Input Offset Error (2) Input Offset Error Drift Gain Error (3) Gain Error Drift Normal-mode Rejection (4) Common-mode Rejection No missing codes 24 TBD 80 TBD SPS Internal Oscillator, SPEED = Low TBD 10 TBD SPS External Oscillator, SPEED = High fCLK / 61440 External Oscillator, SPEED = Low fCLK / 491520 Full Settling SPS SPS 4 Conversions Differential input, End point fit Gain = 1, 2 ±0.0002 ±0.0015 Differential input, End point fit Gain = 64, 128 ±0.0010 TBD % of FSR % of FSR (1) ±0.2 TBD ppm of FS Gain = 64 ±2 TBD ppm of FS Gain = 1 1 Gain = 1 Gain = 64 µV/°C 15 nV/°C Gain = 1 0.001 TBD Gain = 64 0.001 TBD Gain = 1 % % 0.5 ppm/°C ±4 ppm/°C Internal oscillator, 50Hz and 60Hz 100 110 dB External oscillator, 50Hz and 60Hz, ±1Hz 120 130 dB at DC, Gain = 1, ∆VDD = 1V TBD 100 dB at DC, Gain = 64, ∆VDD = 0.1V TBD 75 dB at DC, Gain = 1, ∆VDD = 1V TBD 100 dB at DC, Gain = 64, ∆VDD = 0.1V TBD 85 dB Gain = 64 Input-Referred Noise Power-Supply Rejection Bits Internal Oscillator, SPEED = High PRODUCT PREVIEW Resolution See Noise Performance Tables Voltage Reference Input Voltage Reference Input (VREF) VREF = VREFP - VREFN 1 AVDD AVDD + 0.1V V Negative Reference Input (VREFN) AGND – 0.1 VREFP – 1.0 V Positive Reference Input (VREFP) VREFN + 1.0 AVDD + 0.1 V Voltage Reference Input Current (1) (2) (3) (4) 50 nA FSR = full scale range = VREF/Gain Offset calibration can minimize these errors to the level of noise at any temperature. Gain errors are calibrated at the factory (AVDD = +5V, all gains, TA = +25°C). Specification is assured by the combination of design and final production test. 3 ADS1232 ADS1234 www.ti.com SBAS350 – JUNE 2005 ELECTRICAL CHARACTERISTICS: VREF = +5V (continued) All specifications TA = –40°C to +105°C, AVDD = DVDD = VREFP = +5V, VREFN = AGND, Internal Oscillator, SPEED = Low, Gain = 64 (unless otherwise specified). ADS1232, ADS1234 PARAMETER CONDITIONS MIN TYP MAX UNIT Digital Logic Levels VIH 0.6 DVDD DVDD + 0.1 V VIL DGND 0.3 DVDD V VOH IOH = 1mA VOL IOL = 1mA Input Leakage DVDD – 0.4 V 0.2 DVDD V ±10 µA 5.3 V 600 TBD µA 1500 TBD µA 700 TBD µA 1600 TBD µA Standby mode 0.1 TBD µA Power-down 0.1 TBD µA Normal mode, DVDD = 3V, Gain = 1, 2 90 TBD µA Normal mode, DVDD = 3V, Gain = 64, 128 90 TBD µA Normal mode, DVDD = 5V, Gain = 1, 2 110 TBD µA Normal mode, DVDD = 5V, Gain = 64, 128 110 TBD µA Standby mode, SCLK = High 50 TBD µA Power-down 0.1 TBD µA Normal mode, AVDD = DVDD = 3V, Gain = 1, 2 2.1 TBD mW Normal mode, AVDD = DVDD = 5V, Gain = 1, 2 4 TBD mW Normal mode, AVDD = DVDD = 3V, Gain = 64, 128 4.8 TBD mW Normal mode, AVDD = DVDD = 5V, Gain = 64, 128 8.6 TBD mW Standby TBD TBD mW Power-down TBD TBD mW 0 < VIN < DVDD Power Supply Power Supply Voltage (AVDD, DVDD) 2.7 Normal mode, AVDD = 3V, Gain = 1, 2 Normal mode, AVDD = 3V, Gain = 64, 128 PRODUCT PREVIEW Analog Supply Current Digital Supply Current Power Dissipation, Total 4 Normal mode, AVDD = 5V, Gain = 1, 2 Normal mode, AVDD = 5V, Gain = 64, 128 ADS1232 ADS1234 www.ti.com SBAS350 – JUNE 2005 DEVICE INFORMATION DVDD 1 28 DRDY/DOUT DGND 2 27 SCLK XTAL1/CLKIN 3 26 PDWN DVDD 1 24 DRDY/DOUT DGND 2 23 SCLK XTAL1/CLKIN 3 22 PDWN XTAL2 4 25 SPEED XTAL2 4 21 SPEED DGND 5 24 GAIN1 DGND 5 20 GAIN1 DGND 6 23 GAIN0 DGND 6 19 GAIN0 A1 7 22 AVDD ADS1234 TEMP 7 18 AVDD A0 8 21 AGND A0 8 17 AGND CAP 9 20 REFP CAP 9 16 REFP CAP 10 19 REFN CAP 10 15 REFN AINP1 11 18 AINP2 AINP1 11 14 AINP2 AINN1 12 17 AINN2 AINN1 12 13 AINN2 AINP3 13 16 AINP4 AINN3 14 15 AINN4 PRODUCT PREVIEW ADS1232 5 ADS1232 ADS1234 www.ti.com SBAS350 – JUNE 2005 DEVICE INFORMATION (continued) PIN DESCRIPTIONS TERMINAL NAME ADS1232 ADS1234 ANALOG/DIGITAL INPUT/OUTPUT DVDD 1 1 Digital Digital Power Supply: 2.7V to 5.3V DGND 2 2 Digital Digital Ground XTAL1/ CLKIN 3 3 Digital/Digital Input XTAL2 4 4 Digital External Clock Output pin. See text for more details. DGND 5 5 Digital Digital Ground DGND 6 6 Digital Digital Ground TEMP 7 – Digital Input Onboard Temperature Diode Enable Input pin A1 – 7 Digital Input Input Mux Select Input pin (MSB) A0 8 8 Digital Input Input Mux Select Input pin (LSB): PRODUCT PREVIEW CAP 9 9 CAP 10 AINP1 11 AINN1 DESCRIPTION External Clock Input: Typically 4.9152MHz. Ties low to activate Internal Oscillator. Can also use external Crystal Oscillator across XTAL1/CLKIN and XTAL2 pins. See text for more details. A1 A0 Channel 0 0 AIN1 0 1 AIN2 1 0 AIN3 1 1 AIN4 Analog Gain Amp Bypass Capacitor Connection 10 Analog Gain Amp Bypass Capacitor Connection 11 Digital Input Positive Analog Input Channel 1 12 12 Digital Input Negative Analog Input Channel 1 AINP3 – 13 Digital Input Positive Analog Input Channel 3 AINN3 – 14 Digital Input Negative Analog Input Channel 3 AINN4 – 15 Digital Input Negative Analog Input Channel 4 AINP4 – 16 Digital Input Positive Analog Input Channel 4 AINN2 13 17 Digital Input Negative Analog Input Channel 2 AINP2 14 18 Digital Input Positive Analog Input Channel 2 REFN 15 19 Digital Input Negative Reference Input pin REFP 16 20 Digital Input Positive Reference Input pin AGND 17 21 Analog Analog Ground AVDD 18 22 Analog Analog Power Supply, 2.7V to 5.3V GAIN0 19 23 Digital Input Gain Select Input pin (LSB) GAIN1 20 24 Digital Input Gain Select Input pin (MSB): SPEED 21 25 Digital Input GAIN1 GAIN0 PGA 0 0 1 0 1 2 1 0 64 1 1 128 Output Data Rate Select Input pin: SPEED DATA RATE 0 10Hz 1 80Hz PDWN 22 26 Digital Input Power Down Input pin: Holding this pin low powers down the entire converter and resets the A/D converter. SCLK 23 27 Digital Input Serial Clock Input pin: Clock out data on the rising edge. Used to initiate Offset Calibration and Sleep modes. See text for more details. DRDY/ DOUT 24 28 Digital Input Dual-Purpose Output: Data Ready: Indicates valid data by going low. Data Output: Outputs data, MSB first, on the first rising edge of SCLK. 6 ADS1232 ADS1234 www.ti.com SBAS350 – JUNE 2005 NOISE PERFORMANCE The ADS1232/1234 offer outstanding noise performance that can be optimized for a givven full-scale range using the on-chip programmable gain amplifier, Table 1, Table 2, Table 3, and Table 4 summarize the typical noise performance with inputs shorted externally for different gains, data rates and voltage reference values. The RMS and Peak-to-Peak noise are referred to the input. The Effective Number of Bits (ENOB) is defined as: • ENOB = ln (FSR/RMS noise)/ln(2) The Noise Free Bits are defined as: • Noise-Free Bits = ln (FSR/Peak-to-Peak Noise)/ln(2) Where FSR (Full-Scale Range) = VREF/Gain GAIN RMS NOISE PEAK-TO-PEAK NOISE ENOB (rms) NOISE-FREE BITS 1 420nV 1.79µV 23.5 21.4 2 270nV 900nV 23.1 21.4 64 19nV 125nV 22.0 19.2 128 17nV 110nV 21.1 18.4 PRODUCT PREVIEW Table 1. AVDD = 5V, VREF = 5V, Data Rate = 10SPS Table 2. AVDD = 5V, VREF = 5V, Data Rate = 80SPS GAIN RMS NOISE PEAK-TO-PEAK NOISE ENOB (rms) NOISE-FREE BITS 1 1.36µV 8.3µV 21.8 19.2 18.8 2 850nV 5.5µV 21.5 64 48nV 307nV 20.6 18 128 44nV 247nV 19.7 17.2 Table 3. AVDD = 3V, VREF = 3V, Data Rate = 10SPS GAIN RMS NOISE PEAK-TO-PEAK NOISE ENOB (rms) 1 450nV 2.8µV 22.6 NOISE-FREE BITS 20 2 325nV 1.8µV 22.1 19.7 64 20nV 130nV 21.2 18.5 128 18nV 115nV 20.3 17.6 Table 4. AVDD = 3V, VREF = 3V, Data Rate = 80SPS GAIN RMS NOISE PEAK-TO-PEAK NOISE ENOB (rms) NOISE-FREE BITS 1 2.2µV 12µV 20.4 17.9 2 1.2µV 6.8µV 20.2 17.8 64 54nV 340nV 19.7 17.1 128 48nV 254nV 18.9 16.5 7 PACKAGE OPTION ADDENDUM www.ti.com 29-Jun-2005 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Drawing Pins Package Eco Plan (2) Qty Lead/Ball Finish MSL Peak Temp (3) ADS1232IPW PREVIEW TSSOP PW 24 60 TBD Call TI Call TI ADS1232IPWR PREVIEW TSSOP PW 24 2000 TBD Call TI Call TI ADS1234IPW PREVIEW TSSOP PW 28 50 TBD Call TI Call TI ADS1234IPWR PREVIEW TSSOP PW 28 2000 TBD Call TI Call TI (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. 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. (2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS) or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. TBD: The Pb-Free/Green conversion plan has not been defined. Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes. Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material) (3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release. In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis. Addendum-Page 1 MECHANICAL DATA MTSS001C – JANUARY 1995 – REVISED FEBRUARY 1999 PW (R-PDSO-G**) PLASTIC SMALL-OUTLINE PACKAGE 14 PINS SHOWN 0,30 0,19 0,65 14 0,10 M 8 0,15 NOM 4,50 4,30 6,60 6,20 Gage Plane 0,25 1 7 0°– 8° A 0,75 0,50 Seating Plane 0,15 0,05 1,20 MAX PINS ** 0,10 8 14 16 20 24 28 A MAX 3,10 5,10 5,10 6,60 7,90 9,80 A MIN 2,90 4,90 4,90 6,40 7,70 9,60 DIM 4040064/F 01/97 NOTES: A. B. C. D. All linear dimensions are in millimeters. This drawing is subject to change without notice. Body dimensions do not include mold flash or protrusion not to exceed 0,15. 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