link to page 23 link to page 12 link to page 4 link to page 4 link to page 4 link to page 4 link to page 23 AD7908/AD7918/AD7928Data SheetParameterB Version1UnitTest Conditions/Comments LOGIC OUTPUTS Output High Voltage, VOH VDRIVE − 0.2 V min ISOURCE = 200 μA, AVDD = 2.7 V to 5.25 V Output Low Voltage, VOL 0.4 V max ISINK = 200 μA Floating-State Leakage Current ±1 μA max Floating-State Output Capacitance3 10 pF max Output Coding Straight (natural) binary Coding bit set to 1 Twos complement Coding bit set to 0 CONVERSION RATE Conversion Time 800 ns max 16 SCLK cycles with SCLK at 20 MHz Track-and-Hold Acquisition Time 300 ns max Sine wave input 300 ns max Full-scale step input Throughput Rate 1 MSPS max See Serial Interface section POWER REQUIREMENTS AVDD 2.7/5.25 V min/max VDRIVE 2.7/5.25 V min/max I 4 DD Digital inputs = 0 V or VDRIVE Normal Mode (Static) 600 μA typ AVDD = 2.7 V to 5.25 V, SCLK On or Off Normal Mode (Operational) 2.7 mA max AVDD = 4.75 V to 5.25 V, fSCLK = 20 MHz 2 mA max AVDD = 2.7 V to 3.6 V, fSCLK = 20 MHz Using Auto Shutdown Mode 960 μA typ fSAMPLE = 250 kSPS 0.5 μA max (Static) Full Shutdown Mode 0.5 μA max SCLK on or off (20 nA typ) Power Dissipation4 Normal Mode (Operational) 13.5 mW max AVDD = 5 V, fSCLK = 20 MHz 6 mW max AVDD = 3 V, fSCLK = 20 MHz Auto Shutdown Mode (Static) 2.5 μW max AVDD = 5 V 1.5 μW max AVDD = 3 V Full Shutdown Mode 2.5 μW max AVDD = 5 V 1.5 μW max AVDD = 3 V 1 Temperature ranges as follows: B version: −40°C to +85°C. 2 See Terminology section. 3 Sample tested @ 25°C to ensure compliance. 4 See Power vs. Throughput Rate section. Rev. E | Page 4 of 28 Document Outline Features General Description Functional Block Diagram Product Highlights Revision History Specifications AD7908 Specifications AD7918 Specifications AD7928 Specifications Timing Specifications Absolute Maximum Ratings ESD Caution Pin Configuration and Function Descriptions Terminology Typical Performance Characteristics Performance Curves Control Register Sequencer Operation SHADOW Register Circuit Information Converter Operation Analog Input ADC Transfer Function Handling Bipolar Input Signals Typical Connection Diagram Analog Input Selection Digital Inputs VDRIVE Reference Modes of Operation Normal Mode (PM1 = PM0 = 1) Full Shutdown Mode (PM1 = 1, PM0 = 0) Auto Shutdown Mode (PM1 = 0, PM0 = 1) Powering Up the AD7908/AD7918/AD7928 Power vs. Throughput Rate Serial Interface Microprocessor Interfacing AD7908/AD7918/AD7928 to TMS320C541 AD7908/AD7918/AD7928 to ADSP-21xx AD7908/AD7918/AD7928 to DSP563xx Application Hints Grounding and Layout Evaluating the AD7908/AD7918/AD7928 Performance Outline Dimensions Ordering Guide Automotive Products