Datasheet AD7890 (Analog Devices) - 6

AD7890 TIMING SPECIFICATIONS
VDD = 5 V ± 5%, AGND = DGND = 0 V, REF IN = 2.5 V, fCLK IN = 2.5 MHz external, MUX OUT connected to SHA IN.
Parameter1, 2 Limit at TMIN, TMAX (A, B, S Versions) Unit Conditions/Comments
f 3 CLKIN 100 kHz min Master Clock Frequency. For specified performance. 2.5 MHz max tCLKIN IN LO 0.3 × tCLK IN ns min Master Clock Input Low Time. tCLK IN HI 0 3 × tCLK IN ns min Master Clock Input High Time. tr4 25 ns max Digital Output Rise Time. Typically 10 ns. tf4 25 ns max Digital Output Fall Time. Typically 10 ns. tCONVERT 5.9 μs max Conversion Time. tCST 100 ns min CONVST Pulse Width. Self-Clocking Mode t1 tCLK IN HI + 50 ns max RFS Low to SCLK Falling Edge. t 5 2 25 ns max RFS Low to Data Valid Delay. t3 tCLK IN HI ns nom SCLK High Pulse Width. t4 tCLK IN LO ns nom SCLK Low Pulse Width. t 5 5 20 ns max SCLK Rising Edge to Data Valid Delay. t6 40 ns max SCLK Rising Edge to RFS Delay. t 6 7 50 ns max Bus Relinquish Time after Rising Edge of SCLK. t8 0 ns min TFS Low to SCLK Falling Edge. tCLK IN + 50 ns max t9 0 ns min Data Valid to TFS Falling Edge Setup Time (A2 Address Bit). t10 20 ns min Data Valid to SCLK Falling Edge Setup Time. t11 10 ns min Data Valid to SCLK Falling Edge Hold Time. t12 20 ns min TFS to SCLK Falling Edge Hold Time. External Clocking Mode t13 20 ns min RFS Low to SCLK Falling Edge Setup Time. t 5 14 40 ns max RFS Low to Data Valid Delay. t15 50 ns min SCLK High Pulse Width. t16 50 ns min SCLK Low Pulse Width. t 5 17 35 ns max SCLK Rising Edge to Data Valid Delay. t18 20 ns min RFS to SCLK Falling Edge Hold Time. t 6 19 50 ns max Bus Relinquish Time after Rising Edge of RFS. t 6 19A 90 ns max Bus Relinquish Time after Rising Edge of SCLK. t20 20 ns min TFS Low to SCLK Falling Edge Setup Time. t21 10 ns min Data Valid to SCLK Falling Edge Setup Time. t22 15 ns min Data Valid to SCLK Falling Edge Hold Time. t23 40 ns min TFS to SCLK Falling Edge Hold Time. 1 Sample tested at −25°C to ensure compliance. All input signals are specified with tr = tf = 5 ns (10% to 90% of 5 V) and timed from a voltage level of 1.6 V. 2 See Figure 10 to Figure 13. 3 The AD7890 is production tested with fCLK IN at 2.5 MHz. It is guaranteed by characterization to operate at 100 kHz. 4 Specified using 10% and 90% points on waveform of interest. 5 These numbers are measured with the load circuit of Figure 2 and defined as the time required for the output to cross 0.8 V or 2.4 V. 6 These numbers are derived from the measured time taken by the data output to change 0.5 V when loaded with the circuit of Figure 2. The measured number is then extrapolated back to remove effects of charging or discharging the 50 pF capacitor. This means that the times quoted in the timing characteristics are the true bus relinquish times of the part and as such are independent of external bus loading capacitances.
1.6mA TO OUTPUT 2.1V PIN 50pF
02 0
200µA
7- 35 01 Figure 2. Load Circuit for Access Time and Bus Relinquish Time Rev. C | Page 5 of 28 Document Outline FEATURES GENERAL DESCRIPTION FUNCTIONAL BLOCK DIAGRAM PRODUCT HIGHLIGHTS TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS TIMING SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TERMINOLOGY CONTROL REGISTER THEORY OF OPERATION CONVERTER DETAILS CIRCUIT DESCRIPTION AD7890-10 Analog Input AD7890-4 Analog Input AD7890-2 Analog Input TRACK/HOLD AMPLIFIER REFERENCE TIMING AND CONTROL CEXT FUNCTIONING SERIAL INTERFACE SELF-CLOCKING MODE Write Operation EXTERNAL CLOCKING MODE Read Operation Write Operation SIMPLIFYING THE INTERFACE MICROPROCESSOR/MICROCONTROLLER INTERFACE AD7890 TO 8051 INTERFACE AD7890 TO 68HC11 INTERFACE AD7890 TO ADSP-2101 INTERFACE AD7890 TO DSP56000 INTERFACE AD7890 TO TMS320C25/30 INTERFACE ANTIALIASING FILTER PERFORMANCE LINEARITY NOISE DYNAMIC PERFORMANCE EFFECTIVE NUMBER OF BITS OUTLINE DIMENSIONS ORDERING GUIDE