Datasheet AD7923 (Analog Devices) - 6

link to page 6 link to page 6 link to page 6 link to page 6 link to page 6 link to page 6 link to page 6
Data Sheet AD7923 TIMING SPECIFICATIONS
AVDD = 2.7 V to 5.25 V, VDRIVE ≤ AVDD, REFIN = 2.5 V, TA = TMIN to TMAX, unless otherwise noted.1
Table 2. Limit at TMIN, TMAX Parameter AVDD = 3 V AVDD = 5 V Unit Description
f 2 SCLK 10 10 kHz min 20 20 MHz max tCONVERT 16 × tSCLK 16 × tSCLK tQUIET 50 50 ns min Minimum quiet time required between CS rising edge and start of next conversion t2 10 10 ns min CS to SCLK set-up time t 3 3 35 30 ns max Delay from CS until DOUT three-state disabled t 3 4 40 40 ns max Data access time after SCLK falling edge t5 0.4 × tSCLK 0.4 × tSCLK ns min SCLK low pulse width t6 0.4 × tSCLK 0.4 × tSCLK ns min SCLK high pulse width t7 10 10 ns min SCLK to DOUT valid hold time t 4 8 15/45 15/35 ns min/max SCLK falling edge to DOUT high impedance t9 10 10 ns min DIN set-up time prior to SCLK falling edge t10 5 5 ns min DIN hold time after SCLK falling edge t11 20 20 ns min Sixteenth SCLK falling edge to CS high t12 1 1 µs max Power-Up time from full power-down/auto shutdown mode 1 Sample tested at 25°C to ensure compliance. All input signals are specified with tR = tF = 5 ns (10% to 90% of AVDD) and timed from a voltage level of 1.6 V. See Figure 2. The 3 V operating range spans from 2.7 V to 3.6 V. The 5 V operating range spans from 4.75 V to 5.25 V. 2 The mark/space ratio for the SCLK input is 40/60 to 60/40. 3 Measured with the load circuit of Figure 2 and defined as the time required for the output to cross 0.4 V or 0.7 × VDRIVE. 4 t8 is derived from the measured time taken by the data outputs to change 0.5 V when loaded with the circuit of Figure 2. The measured number is then extrapolated back to remove the effects of charging or discharging the 50 pF capacitor. This means that the time, quoted in the timing characteristics t8, is the true bus relinquish time of the part and is independent of the bus loading.
200
µ
A IOL TO OUTPUT 1.6V PIN CL 50pF 200
µ
A IOH
03086-002 Figure 2. Load Circuit for Digital Output Timing Specification Rev. D | Page 5 of 24 Document Outline Specifications Timing Specifications Absolute Maximum Ratings ESD Caution Pin Configuration and Function Description Typical Performance Characteristics Terminology Control Register Descriptions Sequencer Operation Theory of Operation 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 (PM1 = 1, PM0 = 0) Auto Shutdown (PM1 = 0, PM0 = 1) Powering Up the AD7923 Power vs. Throughput Rate Serial Interface Writing Between Conversions Microprocessor Interfacing AD7923-to-TMS320C541 AD7923-to-ADSP-21xx AD7923-to-DSP563xx Application Hints Grounding and Layout Outline Dimensions Ordering Guide Automotive Products