EVAL-CN0414-ARDZ Analog Devices

Circuit Note CN-0414 Devices Connected/Referenced Low Power, 24-Bit, Sigma-Delta ADC AD4111 with 10 V and 0 mA to 20 mA Inputs Low Power HART Modem with AD5700-1 Internal Oscillator Circuits from the Lab reference designs are engineered and tested for quick and easy system integration to help solve todays Quad-Channel Isolators with ADuM5411 analog, mixed-signal, and RF design challenges. For more Integrated DC-to-DC Converters information and/or support, visit 3.75 kV, 7-Channel, SPIsolator Digital ADuM3151 CN-0414 Circuit Note input path, including external signal conditioning circuitry. CIRCUIT DESCRIPTION This ADC comes in a small 6 mm 6 mm LFCSP package, Analog to Digital Converter making it ideal where space is a premium. The heart of the circuit is an AD4111 low power, low noise, The internal clock and precision 2.5 V reference minimize 24-bit, - analog-to-digital converter (ADC) with integrated external components and result in additional space savings. 10 V and 20 mA analog front ends. The two programmable general-purpose output pins (GPO0 The AD4111 is software configurable and allows four fully and GPO1) control auxiliary circuitry without using additional differential or eight single-ended voltage input channels with control lines from the processor/controller. open wire detection, and four current input channels offering great flexibility via an internal crosspoint multiplexer. CN-0414 uses GPO0 and GPO1 to enable/disable ADG704 multiplexers that allow a single AD5700-1 HART modem to The AD4111 has internal calibration registers that can be service all four current input channels. programmed to provide offset and gain corrections for the full +5V ISO +5V ISO ISOLATED SIDE PROCESSOR SIDE +7.5V AVDD IOVDD COMPA VIN0 9V TO 36V V+ CHANNEL 1 ADP2441 CH1 CH 1 VOLTAGE INPUT DC-TO-DC VOLTAGE V NETWORK VIN1 CONVERTER FIELD CIRCUIT SUPPLY COMPB AND PROTECTION I+ IIN0+ CHANNEL 1 CH1 CH 1 CURRENT INPUT CURRENT GND DGND DGND NETWORK IIN0 SDA EEPROM SCL AD4111 V+ CH 2 COMPA V +5V ISO VIO VIN6 ADuM5411 CH4 +5V ISO VOLTAGE VDD2 VDD1 VIN7 SCLK SCLK I+ COMPB CH 2 ADG704 DIN DIN GND CS CS IIN3+ DOUT DOUT CH4 CURRENT IIN3 +5V +5V ISO V+ SYNC CH 3 GPO0 VISO VDDP V GPO1 1 OF 4 AVSS DGND DECODER GNDISO GNDISO I+ GPIO2 CH 3 GND ISO GND ISO GPIO3 DGND GND GND ISO GND ISO GPO1 +5V ISO +5V ISO +5V ISO VIO V+ ADuM3151 AD5700-1 CH 4 VDD2 VDD1 HART V ADG704 OUTPUT HART OUT GPIO2 GPIO2 NETWORK GPIO3 GPIO3 SYNC SYNC HART I+ ADC IP RXD RXD OUTPUT CH 4 NETWORK TXD TXD GND RTS RTS CD CD REF 1 OF 4 GND2 GND1 AGND DGND DECODER GPIO2 GND ISO DGND DGND GND ISO GND ISO GPIO3 GND ISO GPO1 Figure 1. PLC/DCS Quad-Channel Voltage and Current Input Front End (Simplified Schematic: All Connections and Decoupling Not Shown) Rev. 0 Page 2 of 12 17134-001