AD7808 Analog Devices, AD7808 Datasheet
AD7808
Specifications of AD7808
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AD7808 Summary of contents
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... CONTROL REG SYSTEM CONTROL REG FSIN INPUT SHIFT CLKIN REGISTER & CONTROL LOGIC SDIN CLR LDAC **ONLY AD7804 SHOWN FOR CLARITY **SHOWS ADDITIONAL CHANNELS ON THE AD7808 **PIN ON THE AD7808 ONLY AV DV AGND DGND DD DD POWER ON REFOUT 1.23V REF RESET AD7805/ AD7809 ...
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... AD7804/AD7805/AD7808/AD7809 AD7804/AD7805–SPECIFICATIONS Reference = Internal Reference 100 pF Parameter B Grade STATIC PERFORMANCE MAIN DAC Resolution 10 Relative Accuracy Gain Error 2 Bias Offset Error –80/+40 3 –V Zero-Scale Error Monotonicity 9 Minimum Load Resistance 2 SUB DAC Resolution 8 Differential Nonlinearity OUTPUT CHARACTERISTICS 3 Output Voltage Range V V Voltage Output Settling Time to 10 Bits ...
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... Temperature range is – + Can be minimized using the Sub DAC the center of the output voltage swing and can be V BIAS Specifications subject to change without notice. REV. A AD7804/AD7805/AD7808/AD7809 (AV and GND. Sub DAC at Midscale. All specifications ...
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... DB0 Figure 1. Timing Diagram for AD7804 and AD7808 –4– 10 10%; AGND = DGND = 0 V; Reference = Description CLKIN Cycle Time CLKIN High Time CLKIN Low Time FSIN Setup Time Data Setup Time Data Hold Time LDAC Hold Time ...
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... DATA 1 LDAC 2 LDAC CLR 1 TIMING REQUIREMENTS FOR SYNCHRONOUS LDAC UPDATE OR LDAC MAY BE TIED PERMANENTLY LOW IF REQUIRED. 2 TIMING REQUIREMENTS FOR ASYNCHRONOUS LDAC UPDATE. Figure 2. Timing Diagram for AD7805/AD7809 Parallel Write REV. A AD7804/AD7805/AD7808/AD7809 3 unless otherwise noted.) MIN MAX , T MIN MAX ...
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... OUT Input Current to Any Pin Except Supplies Operating Temperature Range AD7804/AD7805 Commercial Plastic (B, C Versions – +85 C AD7808/AD7809 Commercial Plastic (B, C Versions – +85 C Storage Temperature Range . . . . . . . . . . . . – +150 C Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . . . +150 C SOIC (R-16) Package, Power Dissipation . . . . . . . . . 450 mW Thermal Impedance . . . . . . . . . . . . . . . . . . . . . . 75 C/W ...
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... SDIN 7 DGND 8 REV. A AD7804/AD7808 PIN FUNCTION DESCRIPTION Description Ground reference point for analog circuitry. Analog output voltage from the DACs. Reference Output. This is a bandgap reference and is typically 1.23 V. Active low input used to put the part into low power mode reducing current consumption ...
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... AD7804/AD7805/AD7808/AD7809 AD7805 AD7809 Pin No. Pin No. Mnemonic 1, 11, 13 39, 40 AGND OUT OUT 4 43 REFOUT 5–10 DB9–DB2 12, 13 10, 15, 23 19, 20 24, 26 DB1, DB0 OUT OUT LDAC DGND ...
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... Figure 1. Two mode bits (MD1 and MD0) which are DB13 and DB14 of the serial word written to the AD7804/AD7808 are used to deter- mine whether writing is to the DAC data registers or the control registers of the device. These parts contain a system control ...
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... DB15 (MSB) X MD0 = 1 MD1 = 0 A2 Don’t Care *Applicable to the AD7808 Only, and Are Don’t Care Conditions when Operating the AD7804 . Figure 5. AD7804/AD7808 Channel Control Register Loading Sequence DB15 (MSB) MAIN/SUB MD0 = X MD1 = 1 A2 Don’t Care *Applicable to the AD7808 Only, and Are Don’t Care Conditions when Operating the AD7804 . ...
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... Table IIa. DAC Selection Table for the AD7804 Function DAC A Selected DAC B Selected DAC C Selected DAC D Selected Table IIb. DAC Selection Table for the AD7808 Function DAC A Selected DAC B Selected DAC C Selected DAC D Selected ...
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... DAC and the final 10 bits contain the data. To write half scale to channel A Sub DAC, then A200 should be written to the input register. The flowchart in Figure 10 shows in graphic form the steps required in communicating with the AD7804/AD7808. MX0 0 0 Figure 10. Flowchart for Controlling the DAC Following ...
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... The external mode pin must be taken high to allow data to be written to the DAC data registers. Figure 14 shows the bit allo- cations when 10-bit parallel operation is selected in the system control register. REV. A AD7804/AD7805/AD7808/AD7809 DB9 /16. BIAS DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 X = Don’ ...
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... AD7804/AD7805/AD7808/AD7809 Table IVb. AD7809 DAC Data/Control Register Selection Table MODE ...
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... Main DAC, and when high, writing is to the Sub DAC data register. In the 8+2 mode the channel con- trol register does not have to be accessed to switch between writing to the Main and Sub DACs as in the 10-bit parallel REV. A AD7804/AD7805/AD7808/AD7809 WRITE TO CHANNEL CONTROL REGISTER WRITE TO MAIN DAC DATA REGISTER ...
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... LDAC input has two operating modes, a synchronous mode and an asynchronous mode. The LDAC input condition is sampled on the sixteenth falling edge on the AD7804/AD7808 and is sampled on the rising edge of write on the AD7805/AD7809. If LDAC is low on the sixteenth falling clock edge or on the rising edge of WR, an automatic or synchronous update will take place ...
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... NA ranges from –512 to +511 and NB ranges from –128 to +127. Figure 28 shows a pictorial view of the transfer function for any DAC. REV. A AD7804/AD7805/AD7808/AD7809 Configuring the AD7805/AD7809 for Twos Complement Coding Figure 24 shows a typical configuration for the AD7805/AD7809. The circuit can be used for either 3 operation and uses the internal V lel interfacing is used ...
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... AD7804/AD7805/AD7808/AD7809 Table VI and Figure 22 show the analog outputs available for the above configuration. The following is the procedure re- quired if the complete transfer function needs to be offset around the V point. Table VII and Figure 23 show the ana- BIAS log output variations available from the Sub DAC. ...
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... F 1/256 127/256 SERIAL INTERFACE DV DD Figure 27. Typical Configuration for AD7804/AD7808 Using an AD589 1.23 V Reference for the AD7804/AD7808 System Control Register Serial Write: Write 0060 Hex Mode bits select system control register Channel Control Register Serial Write Write 4210 Hex Main DAC Data Register Serial Write: ...
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... The external REFIN pin should also be shielded with analog ground from the digital pins located next to it. The same precautions should be taken with the reference pins on the AD7804/AD7808 to reduce the risk of noise pickup and feedthrough. Reference Settling Time With the REFOUT on the AD7804/AD7805/AD7808/AD7809 decoupled with a 0 ...
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... Typical Performance Characteristics–AD7804/AD7805/AD7808/AD7809 0.150000 MAIN DAC = ZERO SCALE SUB DAC = MID SCALE 0.125000 BIAS + 0.100000 V = 5.5V DD 0.075000 0.050000 DD 0.025000 SOURCE CURRENT SINK CURRENT 0.000000 –0.5 –0.4 –0.3 –0.2 –0.1 0.0 CURRENT – mA Figure 29. Sink and Source Current with Zero Scale Loaded to DAC ...
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... Data is trans- mitted MSB first. In order to load data to the AD7804/AD7808, PC7 is left low after the first eight bits are transferred and a second serial write operation is performed to the DAC and then PC7 is taken high at the end of this procedure ...
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... D0 **ADDITIONAL PINS OMITTED FOR CLARITY **A2 CONTAINED ON THE AD7809 ONLY Figure 39. AD7805/AD7809–TMS32020 Interface REV. A AD7804/AD7805/AD7808/AD7809 Again fast interface timing allows the AD7805/AD7809 inter- face directly to the processor. Data is loaded to the AD7805/ AD7809 input latch using the following instruction: OUT DAC, D. DAC = Decoded DAC Address. ...
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... DGND Figure 41. AD7804/AD7808 Opto-Isolated Interface Decoding Multiple AD7808s The FSIN pin on the AD7808s can be used in applications to decode a number of DACs. In this application all DACs in the system receive the same serial clock and serial data, but only the FSIN to one of the DACs will be active at any one time allowing access to eight channels in this thirty-two channel system ...
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... DGND REV. A AD7804/AD7805/AD7808/AD7809 Dual External Reference Input Capability It is possible to operate the AD7804/AD7805/AD7808/AD7809 with two externally applied references. Figure 45 shows the connections for the AD7804. Reference one, the AD589, is connected to the REFIN pin of the part; the second reference, the AD780, is used to overdrive the internal VDD/2 reference which is provided at the COMP pin of the device ...
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... AD7804/AD7805/AD7808/AD7809 PAGE INDEX (AD7804/AD7808 SERIAL INTERFACE PART) Topic Functional Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2, 3 Timing Information Timing Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Timing Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . 6 Ordering Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Pin Function Description . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Terminology Relative Accuracy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Differential Nonlinearity . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Bias Offset Error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Gain Error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Zero-Scale Error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Digital-to-Analog Glitch Impulse ...
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... AD7804/AD7805/AD7808/AD7809 Plastic DIP (N-16) 0.840 (21.33) 0.745 (18.93 0.280 (7.11) 0.240 (6.10 0.060 (1.52) PIN 1 0.015 (0.38) MAX 0.130 (3.30) MIN 0.100 0.070 (1.77) SEATING 0.022 (0.558) PLANE (2 ...
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... AD7804/AD7805/AD7808/AD7809 Plastic DIP (N-24 PIN 1.275 (32.30) 1.125 (28.60) 0.210 (5.33) MAX 0.160 (4.06) 0.115 (2.92) 0.022 (0.558) 0.100 (2.54) 0.070 (1.77) 0.014 (0.356) BSC 0.045 (1.15) SOIC (R-24) 0.614 (15.6) 0.598 (15. 0.299 (7.6) 0.291 (7. PIN 1 0.104 (2.65) 0.093 (2.35) 0.012 (0.3) 0.0500 (1.27) 0.019 (0.49) SEATING 0.013 (0.32) BSC PLANE 0.004 (0.1) 0.014 (0.35) 0.009 (0.25) OUTLINE DIMENSIONS Dimensions shown in inches and (mm) ...