link to page 7 link to page 7 link to page 7 link to page 7 link to page 7 AD9271DIGITAL SPECIFICATIONS AVDD = 1.8 V, DRVDD = 1.8 V, CWVDD = 3.3 V, 400 mV p-p differential input, 1.0 V internal ADC reference, AIN = −0.5 dBFS, unless otherwise noted. Table 2. Parameter 1 Temperature MinTypMaxUnit CLOCK INPUTS (CLK+, CLK−) Logic Compliance CMOS/LVDS/LVPECL Differential Input Voltage2 Full 250 mV p-p Input Common-Mode Voltage Full 1.2 V Input Resistance (Differential) 25°C 20 kΩ Input Capacitance 25°C 1.5 pF LOGIC INPUTS (PDWN, STBY, SCLK) Logic 1 Voltage Full 1.2 3.6 V Logic 0 Voltage Full 0.3 V Input Resistance 25°C 30 kΩ Input Capacitance 25°C 0.5 pF LOGIC INPUT (CSB) Logic 1 Voltage Full 1.2 3.6 V Logic 0 Voltage Full 0.3 V Input Resistance 25°C 70 kΩ Input Capacitance 25°C 0.5 pF LOGIC INPUT (SDIO) Logic 1 Voltage Full 1.2 DRVDD + 0.3 V Logic 0 Voltage Full 0 0.3 V Input Resistance 25°C 30 kΩ Input Capacitance 25°C 2 pF LOGIC OUTPUT (SDIO)3 Logic 1 Voltage (IOH = 800 μA) Full 1.79 V Logic 0 Voltage (IOL = 50 μA) Full 0.05 V DIGITAL OUTPUTS (D+, D−), (ANSI-644)1 Logic Compliance LVDS Differential Output Voltage (VOD) Full 247 454 mV Output Offset Voltage (VOS) Full 1.125 1.375 V Output Coding (Default) Offset binary DIGITAL OUTPUTS (D+, D−), (LOW POWER, REDUCED SIGNAL OPTION)1 Logic Compliance LVDS Differential Output Voltage (VOD) Full 150 250 mV Output Offset Voltage (VOS) Full 1.10 1.30 V Output Coding (Default) Offset binary 1 See the AN-835 Application Note, Understanding High Speed ADC Testing and Evaluation, for a complete set of definitions and how these tests were completed. 2 Specified for LVDS and LVPECL only. 3 Specified for 13 SDIO pins sharing the same connection. Rev. B | Page 7 of 60 Document Outline FEATURES APPLICATIONS GENERAL DESCRIPTION FUNCTIONAL BLOCK DIAGRAM TABLE OF CONTENTS REVISION HISTORY PRODUCT HIGHLIGHTS SPECIFICATIONS AC SPECIFICATIONS DIGITAL SPECIFICATIONS SWITCHING SPECIFICATIONS ADC TIMING DIAGRAMS ABSOLUTE MAXIMUM RATINGS THERMAL IMPEDANCE ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS EQUIVALENT CIRCUITS TYPICAL PERFORMANCE CHARACTERISTICS THEORY OF OPERATION ULTRASOUND CHANNEL OVERVIEW Low Noise Amplifier (LNA) Active Impedance Matching LNA Noise INPUT OVERDRIVE Input Overload Protection CW DOPPLER OPERATION Crosspoint Switch TGC OPERATION Variable Gain Amplifier Gain Control VGA Noise Antialiasing Filter ADC CLOCK INPUT CONSIDERATIONS Clock Duty Cycle Considerations Clock Jitter Considerations Power Dissipation and Power-Down Mode Digital Outputs and Timing SDIO Pin SCLK Pin CSB Pin RBIAS Pin Voltage Reference Internal Reference Operation External Reference Operation SERIAL PORT INTERFACE (SPI) HARDWARE INTERFACE MEMORY MAP READING THE MEMORY MAP TABLE RESERVED LOCATIONS DEFAULT VALUES LOGIC LEVELS APPLICATIONS INFORMATION DESIGN GUIDELINES Power and Ground Recommendations Exposed Paddle Thermal Heat Slug Recommendations EVALUATION BOARD POWER SUPPLIES INPUT SIGNALS OUTPUT SIGNALS DEFAULT OPERATION AND JUMPER SELECTION SETTINGS QUICK START PROCEDURE SCHEMATICS AND ARTWORK OUTLINE DIMENSIONS ORDERING GUIDE