Datasheet AD7938, AD7939 (Analog Devices) - 8

AD7938/AD7939 Data Sheet ABSOLUTE MAXIMUM RATINGS
TA = 25°C, unless otherwise noted. Stresses at or above those listed under Absolute Maximum Ratings may cause permanent damage to the product. This is a
Table 5.
stress rating only; functional operation of the product at these
Parameter Rating
or any other conditions above those indicated in the operational VDD to AGND/DGND −0.3 V to +7 V section of this specification is not implied. Operation beyond VDRIVE to AGND/DGND −0.3 V to VDD + 0.3 V the maximum operating conditions for extended periods may Analog Input Voltage to AGND −0.3 V to VDD + 0.3 V affect product reliability. Digital Input Voltage to DGND −0.3 V to +7 V VDRIVE to VDD −0.3 V to VDD + 0.3 V Digital Output Voltage to DGND −0.3 V to VDRIVE + 0.3 V
ESD CAUTION
VREFIN to AGND −0.3 V to VDD + 0.3 V AGND to DGND −0.3 V to +0.3 V Input Current to Any Pin ±10 mA Except Supplies1 Operating Temperature Range Commercial (B Version) −40°C to +85°C Storage Temperature Range −65°C to +150°C Junction Temperature 150°C θJA Thermal Impedance 108.2°C/W (LFCSP) 121°C/W (TQFP) θJC Thermal Impedance 32.71°C/W (LFCSP) 45°C/W (TQFP) Lead Temperature, Soldering Reflow Temperature (10 sec to 30 sec) 255°C ESD 1.5 kV 1 Transient currents of up to 100 mA do not cause SCR latch-up. Rev. D | Page 8 of 36 Document Outline FEATURES GENERAL DESCRIPTION PRODUCT HIGHLIGHTS REVISION HISTORY SPECIFICATIONS AD7938 SPECIFICATIONS AD7939 SPECIFICATIONS TIMING SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS TERMINOLOGY ON-CHIP REGISTERS CONTROL REGISTER SEQUENCER OPERATION Writing to the Control Register to Program the Sequencer SHADOW REGISTER CIRCUIT INFORMATION CONVERTER OPERATION ADC TRANSFER FUNCTION TYPICAL CONNECTION DIAGRAM ANALOG INPUT STRUCTURE ANALOG INPUTS Single-Ended Mode Differential Mode Driving Differential Inputs Using an Op Amp Pair Pseudo Differential Mode ANALOG INPUT SELECTION Traditional Multichannel Operation (SEQ = SHDW = 0) Using the Sequencer: Programmable Sequence (SEQ = 0, SHDW = 1) Consecutive Sequence (SEQ = 1, SHDW = 1) REFERENCE Digital Inputs VDRIVE Input PARALLEL INTERFACE Reading Data from the AD7938/AD7939 Writing Data to the AD7938/AD7939 POWER MODES OF OPERATION Normal Mode (PM1 = PM0 = 0) Autoshutdown (PM1 = 0; PM0 = 1) Autostandby (PM1 = 1; PM0 = 0) Full Shutdown Mode (PM1 =1; PM0 = 1) POWER vs. THROUGHPUT RATE MICROPROCESSOR INTERFACING AD7938/AD7939 to ADSP-21xx Interface AD7938/AD7939 to ADSP-21065L Interface AD7938/AD7939 to TMS32020, TMS320C25, and TMS320C5x Interface AD7938/AD7939 to 80C186 Interface APPLICATION HINTS GROUNDING AND LAYOUT PCB DESIGN GUIDELINES FOR CHIP SCALE PACKAGE EVALUATING AD7938/AD7939 PERFORMANCE OUTLINE DIMENSIONS ORDERING GUIDE