Datasheet AD5749 (Analog Devices) - 9

Data Sheet AD5749 Pin No. Mnemonic Description
10 AD1/R2 Device Addressing Bit (AD1). In software mode, this pin, in conjunction with AD0 and AD2, allows up to eight devices to be addressed on one bus. Range Decode Bit (R2). In hardware mode, this pin, in conjunction with R0, R1, and R3, selects the output current range setting on the part. 11 AD0/R3 Device Addressing Bit (AD0). In software mode, this pin, in conjunction with AD1 and AD2, allows up to eight devices to be addressed on one bus. Range Decode Bit (R3). In hardware mode, this pin, in conjunction with R0, R1, and R2, selects the output current range setting on the part. 12, 13 REXT2, REXT1 A 15 kΩ external current setting resistor can be connected between the REXT1 and REXT2 pins to improve the IOUT temperature drift performance. 14 VREF Buffered Reference Input. 15 VIN Buffered Analog Input (0 V to 4.096 V). 16 GND Ground Connection. 17 AVDD Positive Analog Supply. 18 IOUT Current Output. 19, 20, 23, 24 DNC Do not connect to these pins. 21, 22 GND Ground Connection. 25, 26, 27, 28 NC No Connect. Can be tied to GND. 29 HW SELECT This part is used to configure the part to hardware or software mode. HW SELECT = 0 selects software control. HW SELECT = 1 selects hardware control. 30 RESET In software mode, this pin resets the part to its power-on state. Active low. In hardware mode, there is no reset. If using the part in hardware mode, the RESET pin should be tied high. 31 FAULT/TEMP Fault Alert (FAULT). In software mode, this pin acts as a general fault alert pin. It is asserted low when an open-circuit, overtemperature error, or PEC interface error is detected. This pin is an open-drain output and must be connected to a pull-up resistor. Overtemperature Fault (TEMP). In hardware mode, this pin acts as an overtemperature fault pin. It is asserted low when an overtemperature error is detected. This pin is an open-drain output and must be connected to a pull-up resistor. 32 NC/IFAULT No Connect (NC). In software mode, this pin is a no connect. Instead, tie this pin to GND. Open-Circuit Fault Alert (IFAULT). In hardware mode, this pin acts as an open-circuit fault alert pin. It is asserted low when an open-circuit error is detected. This pin is an open-drain output and must be connected to a pull-up resistor. 33 (EPAD) EPAD The exposed paddle is tied to GND. Rev. E | Page 9 of 28 Document Outline FEATURES APPLICATIONS FUNCTIONAL BLOCK DIAGRAM GENERAL DESCRIPTION REVISION HISTORY TIMING CHARACTERISTICS Timing Diagrams ESD CAUTION SOFTWARE MODE CURRENT OUTPUT ARCHITECTURE DRIVING INDUCTIVE LOADS POWER-ON STATE OF THE AD5749 DEFAULT REGISTERS AT POWER-ON RESET FUNCTION OUTEN SOFTWARE CONTROL Input Shift Register Status Bit Read Operation HARDWARE CONTROL TRANSFER FUNCTION OUTPUT FAULT ALERT—SOFTWARE MODE OUTPUT FAULT ALERT—HARDWARE MODE ASYNCHRONOUS CLEAR (CLEAR) EXTERNAL CURRENT SETTING RESISTOR PROGRAMMABLE OVERRANGE MODES PACKET ERROR CHECKING TRANSIENT VOLTAGE PROTECTION THERMAL CONSIDERATIONS LAYOUT GUIDELINES GALVANICALLY ISOLATED INTERFACE MICROPROCESSOR INTERFACING ORDERING GUIDE