Analog Devices Inc.

Category: Data Converters

The AD7997 / AD7998 are 8-channel, 10- and 12-bit, low power,successive approximation ADCs with an I2C-compatibleinterface. The parts operate from a single 2.7 V to 5.5 V powersupply and feature a 2 µs conversion time. The parts contain an8-channel multiplexer and track-and-hold amplifier that canhandle input frequencies up to 11 MHz.The AD7997 / AD7998 provide a 2-wire serial interface that iscompatible with I2C interfaces. Each part comes in two versions,AD7997-0 / AD7998-0 and AD7997-1 / AD7998-1, and eachversion allows at least two different I2C addresses. The I2C interface on the AD7997-0/AD7998-0 supports standard andfast I2C interface modes. The I2C interface on the AD7997-1 / AD7998-1 supports standard, fast, and high speed I2C interface modes.The AD7997 / AD7998 normally remain in a shutdown statewhile not converting, and power up only for conversions. Theconversion process can be controlled using the CONVST pin,by a command mode where conversions occur across I2C writeoperations or an automatic conversion interval mode selectedthrough software control. The AD7997 / AD7998 require an external reference that shouldbe applied to the REFIN pin and can be in the range of 1.2 V toVDD. This allows the widest dynamic input range to the ADC. On-chip limit registers can be programmed with high andlow limits for the conversion result, and an open-drain, out-of-range indicator output (ALERT) becomes active when theprogrammed high or low limits are violated by the conversionresult. This output can be used as an interrupt.PRODUCT HIGHLIGHTS 2 µs conversion time with low power consumption. I2C-compatible serial interface with pin-selectable addresses. Two AD7997/AD7998 versions allow five AD7997/AD7998 devices to be connected to the same serial bus. The parts feature automatic shutdown while not converting to maximize power efficiency. Current consumption is 1 µA max when in shutdown mode at 3V. Reference can be driven up to the power supply. Out-of-range indicator that can be software disabled or enabled. One-shot and automatic conversion rates. Registers store minimum and maximum conversion results.

$9.16 - * $16.02