ADS79XX Serial Interface ADCs

By Texas Instruments 238

ADS79XX Serial Interface ADCs

Texas Instruments' ADS79XX is a 12/10/8-bit multichannel analog-to-digital converter family. The devices include a capacitor based SAR A/D converter with inherent sample and hold. 

The ADS795x devices accept a wide analog supply range from 2.7 V to 5.25 V. Very low power consumption makes these devices suitable for battery-powered and isolated power supply applications. A wide 1.7 V to 5.25 V I/O supply range facilitates a glue-less interface with the most commonly used CMOS digital hosts.

The serial interface is controlled by CS and SCLK for easy connection with microprocessors and DSP.

The input signal is sampled with the falling edge of CS. It uses SCLK for conversion, serial data output, and reading serial data in. The devices allow auto sequencing of preselected channels or manual selection of a channel for the next conversion cycle. There are two software selectable input ranges (0 V - 2.5 V and 0 V -5 V), four individually configurable GPIOs, and two programmable alarm thresholds per channel. These features make the devices suitable for most data acquisition applications.

The devices offer an attractive power-down feature. This is extremely useful for power saving when the device is operated at lower conversion speeds.

The 16-/12-channel devices from this family are available in a 38-pin TSSOP package and the 4/8-channel devices are available in a 30-pin TSSOP package.

  • 1 MHz sample rate serial devices
  • Product family of 12-/10-/8-bit resolution
  • Zero latency
  • 20 MHz serial interface
  • Analog supply range: 2.7 V to 5.25 V
  • I/O supply range: 1.7 V to 5.25 V
  • Two SW selectable unipolar, input ranges: 0 to 2.5 V and 0 to 5 V
  • Auto and manual modes for channel selection
  • 12-, 8-, and 4-channel devices can share 16 channel device footprint
  • Two programmable alarm levels per channel
  • Four individually configurable GPIOs
  • Typical power dissipation: 14.5 mW (+VA = 5 V, +VBD = 3 V) at 1 MSPS
  • Power-down current (1 µA)
  • Input bandwidth (47 at 3dB)
  • 30-pin and 38-pin TSSOP packages
  • SINAD(dB): 49, 60, and 69
  • SNR(dB): 49, 60, and 70
  • SNR(typ.)(dB): 49.8, 61.7, and 71.7
  • SFDR(dB): 78, 82, and 84
  • DNL(max.)(±LSB): 0.3, 0.5, and 1
  • INL(max.)(±LSB): 0.3, 0.5, and 1
  • ENOB(bits): 7.85, 9.66, and 11.29
  • Architecture: SAR
  • Power Consumption(typ.)(mW): 11.5
  • No. of supplies: 2
  • PLC / IPC
  • Battery powered systems
  • Medical instrumentation
  • Digital power supplies
  • Touch screen controllers
  • High-speed data acquisition systems
  • High-speed closed-loop systems