Datasheet AD9731 (Analog Devices) - 5

AD9731 PIN FUNCTION DESCRIPTIONS Pin No. Mnemonic Function
1 D9(MSB) Most significant data bit of digital input word 2–9 D8–D1 Eight bits of 10-bit digital input word 10 D0(LSB) Least significant data bit of digital input word 11 CLOCK TTL-compatible edge-triggered latch enable signal for on-board registers 12, 13 NC No internal connection to this pin 14 DIGITAL +VS 5 V supply voltage for digital circuitry 15, 18, 28 GND Converter ground 16 DIGITAL –VS –5.2 V supply voltage for digital circuitry 17 RSET Connection for external reference set resistor; nominal 1.96 kW. Full-scale output current = 32 (control amp in V/RSET). 19 ANALOG RETURN Analog return. This point and the reference side of the DAC load resistors should be connected to the same potential (nominally ground). 20 IOUT Analog current output; full-scale current occurs with a digital word input of all “1s.” With
OBSOLETE
external load resistor, output voltage = IOUT (RLOAD储RINTERNAL). RINTERNAL is nominally 240 W. 21 IOUTB Complementary analog current output; full-scale current occurs with a digital word input of all “0s.” 22 ANALOG –VS Negative analog supply, nominally –5.2 V 23 REF IN Normally connected to CONTROL AMP OUT (Pin 24). Direct line to DAC current source network. Voltage changes (noise) at this point have a direct effect on the full-scale output current of the DAC. Full-scale current output = 32 (CONTROL AMP IN/RSET) when using the internal amplifier. DAC load is virtual ground. 24 CONTROL AMP OUT Normally connected to REF IN (Pin 23). Output of internal control amplifier that provides a reference for the current switch network. 25 REF OUT Normally connected to CONTROL AMP IN (Pin 26). Internal voltage reference, nominally –1.25 V. 26 CONTROL AMP IN Normally connected to REF Out (Pin 25) if not connected to external reference. 27 DIGITAL –VS Negative digital supply, nominally –5.2 V.
PIN CONFIGURATION D9(MSB) 1 28 GND D8 2 27 DIGITAL –VS D7 3 26 CONTROL AMP IN D6 4 25 REF OUT D5 5 24 CONTROL AMP OUT D4 6 23 REF IN AD9731 D3 7 22 ANALOG –V TOP VIEW S D2 (Not to Scale) 8 21 IOUTB D1 9 20 IOUT D0(LSB) 10 19 ANALOG RETURN CLOCK 11 18 GND NC 12 17 RSET NC 13 16 DIGITAL –VS DIGITAL +V 14 15 GND S NC = NO CONNECT
REV. B –5– Document Outline FEATURES APPLICATIONS FUNCTIONAL BLOCK DIAGRAM GENERAL DESCRIPTION SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS EXPLANATION OF TEST LEVELS ORDERING GUIDE PIN FUNCTION DESCRIPTIONS PIN CONFIGURATION Typical Performance Characteristics THEORY AND APPLICATIONS Digital Inputs/Timing Input Clock and Data Timing Relationship References Analog Output EVALUATION BOARD OUTLINE DIMENSIONS Revision History