1 MSPS, 14-Bit, Simultaneous Sampling SAR ADC with PGA and Four Comparators

The AD7264 is a dual, 14-bit, high speed, low power, successive approximation ADC that operates from a single 5 V power supply and features throughput rates of up to 1 MSPS per on-chip ADC. Two complete ADC functions allow simultaneous sampling and conversion of two channels. Each ADC is preceded by a true differential analog input with a PGA. There are 14 gain settings available: ×1, ×2, ×3, ×4, ×6, ×8, ×12, ×16, ×24, ×32, ×48, ×64, ×96, and ×128.

The AD7264 contains four comparators. Comparator A and Comparator B are optimized for low power, whereas Comparator C and Comparator D have fast propagation delays. The AD7264 features a calibration function to remove any device offset error and programmable gain adjust registers to allow input path (for example, sensor) offset and gain compensation. The AD7264 has an on-chip 2.5 V reference that can be disabled if an external reference is preferred. The AD7264 is available in 48-lead LFCSP and LQFP packages.

The AD7264 is ideally suited for monitoring small amplitude signals from a variety of sensors. The devices include all the functionality needed for monitoring the position feedback signals from a variety of analog encoders used in motor control systems.

Product Highlights

* Integrated PGA with a variety of flexible gain settings to allow detection and conversion of low level analog signals.

* Each PGA is followed by a dual simultaneous sampling ADC, featuring throughput rates of 1 MSPS per ADC. The conversion result of both ADCs is simultaneously available on separate data lines or in succession on one data line if only one serial port is available.

* Four integrated comparators that can be used to count signals from pole sensors in motor control applications.

* Internal 2.5 V reference.

* Dual, simultaneous sampling, 14-bit, 2-channel ADC

* True differential analog inputs

* Programmable gain stage: ×1, ×2, ×3, ×4, ×6, ×8, ×12, ×16, ×24, ×32, ×48, ×64, ×96, ×128

* Throughput rate per ADC

* 1 MSPS for AD7264

* Analog input impedance: >1 GΩ

* Wide input bandwidth

* −3 dB bandwidth: 1.7 MHz at gain = 2

* 4 on-chip comparators

* SNR: 78 dB typical at gain = 2, 71 dB typical at gain = 32

* Device offset calibration

* System gain calibration

* On-chip reference: 2.5 V

* −40°C to +105°C operation

* High speed serial interface

* Compatible with SPI, QSPI™, MICROWIRE™, and DSP

* 48-lead LFCSP and LQFP packages