AD7782

a FEATURES 2-Channel, 24-Bit ⌺- ⌬ ADC Pin Configurable (No Programmable Registers) Pin Selectable Input Channels Pin Programmable Input Ranges (؎2.56 V or ؎160 mV) Fixed 19.79 Hz Update Rate Simultaneous 50 Hz and 60 Hz Rejection 24-Bit No Missing Codes 18.5-Bit p-p Resolution (؎2.56 V Range) 16.5-Bit p-p Resolution (؎160 mV Range) INTERFACE Master or Slave Mode of Operation Slave Mode 3-Wire Serial SPI™, QSPI™, MICROWIRE™, and DSP-Compatible Schmitt Trigger on SCLK POWER Specified for Single 3 V and 5 V Operation Normal: 1.3 mA @ 3 V Power-Down: 9 ␮ A ON-CHIP FUNCTIONS Rail-Rail Input Buffer and PGA APPLICATIONS Sensor Measurement Industrial Process Control Temperature Measurement Pressure Measurements Weigh Scales Portable Instrumentation Read Only, Pin Configured 24-Bit ⌺-⌬ ADC AD7782 FUNCTIONAL BLOCK DIAGRAM VDD GND REFIN(+) REFIN(–) XTAL1 XTAL2 AD7782 OSCILLATOR AND PLL AIN1(+) AIN1(–) AIN2(+) AIN2(–) MUX BUF PGA 24-BIT ⌺-⌬ ADC SERIAL INTERFACE AND CONTROL LOGIC DOUT/RDY SCLK MODE CS CH1/CH2 RANGE BASIC CONNECTION DIAGRAM POWER SUPPLY VDD AD7782 ANALOG INPUT ANALOG INPUT REFERENCE INPUT AIN1(+) AIN1(–) AIN2(+) AIN2(–) REFIN(+) REFIN(–) GND CS DOUT/RDY SCLK XTAL1 XTAL2 32.768kHz CRYSTAL DIGITAL INTERFACE GENERAL DESCRIPTION The AD7782 is a complete analog front end for low-frequency measurement applications. The 24-bit sigma-delta ADC contains two fully differential analog input channels that can be configured with a gain of 1 or 16 allowing full-scale input ...