AD7991 Datasheet | Analog Devices

FEATURES 4-Channel, 12-/10-/8-Bit ADC with I2Cpatible Interface in 8-Lead SOT23 AD7991/AD7995/AD7999 FUNCTIONAL BLOCK DIAGRAM 12-/10-/8-bit ADC with fast conversion time: 2 µs typ 4 Channel / 3 Channel with Reference input Specified for VDD of 2.7 V to 5.5 V Sequencer operation Temperature Range: -40 °C to 125 °C I2C®-patible serial interface supports standard, fast, and High-speed modes 2 versions allow 2 I2C addresses Low power consumption Shutdown mode: 1 µA max 8-lead SOT23 package VIN0 VIN1 VIN2 VIN3/Vref I/P MUX T/H 12-/10-/8-BIT SAR ADC CONTROL LOGIC & I2C INTERFACE SCL SDA AD7991/7995/7999 APPLICATIONS System Monitoring Battery Powered Systems Data Acquisition Medical Instruments Figure 1. GENERAL DESCRIPTION The AD7991/AD7995/AD7999 are 12-/10-/8-bit, low power, successive approximation ADCs with an I2C-patible interface. The parts operate from a single 2.7 V to 5.5 V power supply and feature a 2 µs conversion time. The part contains a 4-channel multiplexer and track-and-hold amplifier that can handle input frequencies up to 11 MHz. The AD7991/AD7995/AD7999 provides a 2-wire serial interface patible with I2C interfaces. The parts e in two versions with each part having an individual I2C address. This will allow two of the same devices be connected to the same I2C bus. Both parts support standard, fast and high-speed I2C interface modes The AD7991/AD7995/AD7999 normally remain in a shutdown state while not converting, and power up only for conversions. The conversion process is controlled by a mand mode, where every time an I2C read operation is executed on the AD7991/AD7995/AD7999, a conversion is performed and the result is returned on the I2C bus. The reference for the part is taken from VDD, this allows the widest dynamic input range to the ADC. Thus the analog input range to the ADC is 0V to VDD. An external reference may also be used with this part. The external reference may be applied through the Ain3 input. Rev. Pr B Information...