The AD7291 is a 12-bit, low power, 8-channel, successive approximation analog-to-digital converter (ADC) with an internal temperature sensor. The part operates from a single 3.3 V power supply and features an I2C-compatible interface. The part contains a 9-channel multiplexer and a track-and-hold amplifier than can handle frequencies up to 30 MHz. The device has an on-chip 2.5 V reference that can be disabled to allow the use of an external reference. The AD7291 provides a 2-wire serial interface compatible with I2C interfaces. The I2C interface supports standard and fast I2C interface modes. The AD7291 normally remains in a partial power-down state while not converting and powers up for conversions. The conversion process can be controlled by a command mode where conversions occur across I2C write operations or an autocycle mode selected through software control. The AD7291 includes a high accuracy band gap temperature sensor, which is monitored and digitized by the 12-bit ADC to give a resolution of 0.25°C. The AD7291 offers a programmable sequencer, which enables the selection of a preprogrammable sequence of channels for conversion. On-chip limit registers can be programmed with high and low limits for the conversion results; an out-of-range indicator output (ALERT) becomes active when the programmed high or low limits are violated by the conversion result. This output can be used as an interrupt. Product Highlights * Ideally suited to monitoring system variables in a variety of systems including telecommunications, process control, and industrial control. * I2C-compatible serial interface. Standard and fast modes. * Automatic partial power-down while not converting to maximize power efficiency. * Channel sequencer operation. * Integrated temperature sensor with 0.25°C resolution. * Out of range indicator that can be software disabled or enabled. * 12-bit SAR ADC * 8 single-ended analog input channels * Analog input range: 0 V to 2.5 V * 12-bit temperature-to-digital converter * Temperature sensor accuracy of ±1°C typical * Channel sequencer operation * Specified for VDD of 2.8 V to 3.6 V * Logic voltage VDRIVE = 1.65 V to 3.6 V * Internal 2.5 V reference * See data sheet for additional features https://elecena.pl/product/1332656/8-channel-ic-12-bit-sar-adc-with-temperature-sensor 2011-01-27 https://elecena.pl/product/1332656/8-channel-ic-12-bit-sar-adc-with-temperature-sensor 2018-03-29 https://elecena.pl/product/1332656/8-channel-ic-12-bit-sar-adc-with-temperature-sensor 2025-01-18