link to page 5 link to page 5 link to page 6 link to page 8 link to page 8 link to page 5 link to page 5 link to page 5 link to page 6 link to page 6 link to page 6 link to page 6 link to page 12 AD6644DIGITAL SPECIFICATIONS AVCC = 5 V, DVCC = 3.3 V; TMIN = −25°C, TMAX = +85°C, unless otherwise noted. Table 2.AD6644AST-40 AD6644AST-65ParameterTempTest Level1MinTypMaxMinTypMaxUnit ENCODE INPUTS (ENCODE, ENCODE) Differential Input Voltage2 Full IV 0.4 0.4 V p-p Differential Input Resistance 25°C V 10 10 kΩ Differential Input Capacitance 25°C V 2.5 2.5 pF LOGIC OUTPUTS (D13 to D0, DRY, OVR) Logic Compatibility CMOS CMOS Logic 1 Voltage3 Full V 2.5 2.5 V Logic 0 Voltage3 Full V 0.4 0.4 V Output Coding Twos complement Twos complement DMID Full V DVCC/2 DVCC/2 V 1 See the Explanation of Test Levels section. 2 All ac specifications tested by driving ENCODE and ENCODE differentially. Reference Figure 18 for performance vs. encode power. 3 Digital output logic levels: DVCC = 3.3 V, CLOAD = 10 pF. Capacitive loads >10 pF degrade performance. SWITCHING SPECIFICATIONS AVCC = 5 V, DVCC = 3.3 V; ENCODE and ENCODE = maximum conversion rate MSPS; TMIN = –25°C, TMAX = +85°C, unless otherwise noted. Table 3.AD6644AST-40 AD6644AST-65ParameterTempTest Level1MinTypMaxMinTypMaxUnit Maximum Conversion Rate Full II 40 65 MSPS Minimum Conversion Rate Full IV 15 15 MSPS ENCODE Pulse Width High Full IV 10 6.5 ns ENCODE Pulse Width Low Full IV 10 6.5 ns 1 See the Explanation of Test Levels section. AVCC = 5 V, DVCC = 3.3 V; ENCODE and ENCODE = maximum conversion rate MSPS; TMIN = −25°C, TMAX = +85°C, CLOAD = 10 Pf, unless otherwise noted. Table 4.AD6644AST-40/65ParameterNameTempTest Level1Min TypMaxUnit ENCODE INPUT PARAMETERS2 Encode Period @ 65 MSPS tENC Full V 15.4 ns Encode Period @ 40 MSPS tENC Full V 25 ns Encode Pulse Width High3 @ 65 MSPS tENCH Full IV 6.2 7.7 9.2 ns Encode Pulse Width Low @ 65 MSPS tENCL Full IV 6.2 7.7 9.2 ns ENCODE/DATA READY Encode Rising to Data Ready Falling tDR Full IV 2.6 3.4 4.6 ns Encode Rising to Data Ready Rising tE_DR tENCH + tDR @ 65 MSPS (50% Duty Cycle) Full IV 10.3 11.1 12.3 ns @ 40 MSPS (50% Duty Cycle) Full IV 15.1 15.9 17.1 ns ENCODE/DATA (D13:0), OVR ENCODE to DATA Falling Low tE_FL Full IV 3.8 5.5 9.2 ns ENCODE to DATA Rising Low tE_RL Full IV 3.0 4.3 6.4 ns ENCODE to DATA Delay (Hold Time)4 tH_E Full IV 3.0 4.3 6.4 ns ENCODE to DATA Delay (Setup Time)5 tS_E tENC − tE_FL Encode = 65 MSPS (50% Duty Cycle) Full IV 6.2 9.8 11.6 ns Encode = 40 MSPS (50% Duty Cycle) Full IV 15.9 19.4 21.2 ns Rev. D | Page 4 of 24 Document Outline FEATURES APPLICATIONS GENERAL DESCRIPTION PRODUCT HIGHLIGHTS FUNCTIONAL BLOCK DIAGRAM TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS DC SPECIFICATIONS DIGITAL SPECIFICATIONS SWITCHING SPECIFICATIONS AC SPECIFICATIONS TIMING DIAGRAM ABSOLUTE MAXIMUM RATINGS EXPLANATION OF TEST LEVELS Test Level THERMAL RESISTANCE ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS EQUIVALENT CIRCUITS TERMINOLOGY THEORY OF OPERATION APPLYING THE AD6644 Encoding the AD6644 Analog Input Power Supplies Digital Outputs Layout Information Jitter Considerations EVALUATION BOARD OUTLINE DIMENSIONS ORDERING GUIDE