AD7709ABSOLUTE MAXIMUM RATINGS*PIN CONFIGURATION (TA = 25∞C, unless otherwise noted.) VDD to GND . –0.3 V to +7 V IOUT1124 XTAL1 PWRGND to AGND . –20 mV to +20 mV IOUT2223 XTAL2 Analog Input Voltage to GND . –0.3 V to VDD + 0.3 V REFIN1(+)322 VDD Reference Input Voltage to GND . –0.3 V to VDD + 0.3 V REFIN1(–)421 GND Total AIN/REFIN Current (Indefinite) . 30 mA AIN1520 DIN Digital Input Voltage to GND . –0.3 V to V AD7709 DD + 0.3 V AIN26TOP VIEW19 DOUT Digital Output Voltage to GND . –0.3 V to VDD + 0.3 V (Not to Scale)AIN3/P3718 RDY Operating Temperature Range . –40∞C to +85∞C AIN4/P4817 CS Storage Temperature Range . –65∞C to +150∞C AINCOM916 SCLK Junction Temperature . 150∞C REFIN2(+) 1015 RESET qJA Thermal Impedance . 97.9∞C/W REFIN2(–) 1114 P1/SW1 qJC Thermal Impedance . 14∞C/W P2/SW2 1213 PWRGND Lead Temperature, Soldering Vapor Phase (60 sec) . 215∞C Infrared (15 sec) . 220∞C *Stresses above those listed under Absolute Maximum Ratings may cause perma- nent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those listed in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ORDERING GUIDETemperaturePackagePackageModelRangeDescriptionOption AD7709ARU –40∞C to +85∞C TSSOP RU-24 AD7709BRU –40∞C to +85∞C TSSOP RU-24 EVAL-AD7709EB Evaluation Board CAUTION ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily WARNING! accumulate on the human body and test equipment and can discharge without detection. Although the AD7709 features proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended ESD SENSITIVE DEVICE to avoid performance degradation or loss of functionality. –8– REV. A Document Outline FEATURES INTERFACE POWER ON-CHIP FUNCTIONS APPLICATIONS GENERAL DESCRIPTION FUNCTIONAL BLOCK DIAGRAM TABLE OF CONTENTS SPECIFICATIONS TIMING CHARACTERISTICS ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION ORDERING GUIDE PIN FUNCTION DESCRIPTIONS Typical Performance Characteristics ADC CIRCUIT INFORMATION Overview Sigma-Delta ADC NOISE PERFORMANCE ON-CHIP REGISTERS Communications Register (A1, A0 = 0, 0) Status Register (A1, A0 = 0, 0; Power-On-Reset = 00H) Configuration Register (A1, A0 = 0, 1; Power-On-Reset = 000007H) Filter Register (A1, A0 = 1, 0; Power-On-Reset = 45h) ADC Data Result Register (A1, A0 = 1, 1; Power-On-Reset = 0000h CONFIGURING THE AD7709 DIGITAL INTERFACE MICROCOMPUTER/MICROPROCESSOR INTERFACING AD7709-to-68HC11 Interface AD7709-to-8051 Interface AD7709-to-ADSP-2103/ADSP-2105 Interface CIRCUIT DESCRIPTION Analog Input Channels Programmable Gain Amplifier Bipolar/Unipolar Configuration Data Output Coding Excitation Currents Crystal Oscillator Reference Input Reset Input Power-Down Mode Grounding and Layout APPLICATIONS Pressure Measurement Temperature Measurement 3-Wire RTD Configurations Smart Transmitters OUTLINE DIMENSIONS Revision History