Dual, 8-Bit, 100Msps, 3.3V, Low-Power ADC with Internal Reference and Parallel Outputs

The MAX1198 is a 3.3V, dual, 8-bit analog-to-digital converter (ADC) featuring fully differential wideband track-and-hold (T/H) inputs, driving two ADCs. The MAX1198 is optimized for low power, small size, and high-dynamic performance for applications in imaging, instrumentation, and digital communications. This ADC operates from a single 2.7V to 3.6V supply, consuming only 264mW, while delivering a typical signal-to-noise and distortion (SINAD) of 48.1dB at an input frequency of 50MHz and a sampling rate of 100Msps. The T/H-driven input stages incorporate 400MHz (-3dB) input amplifiers. The converters may also be operated with single-ended inputs. In addition to low operating power, the MAX1198 features a 3.2mA sleep mode, as well as a 0.15µA power-down mode to conserve power during idle periods.

An internal 2.048V precision bandgap reference sets the full-scale range of the ADC. A flexible reference structure allows the use of this internal or an externally applied reference, if desired, for applications requiring increased accuracy or a different input voltage range.

The MAX1198 features parallel, CMOS-compatible three-state outputs. The digital output format can be set to two's complement or straight offset binary through a single control pin. The device provides for a separate output power supply of 1.7V to 3.6V for flexible interfacing with various logic families. The MAX1198 is available in a 7mm x 7mm, 48-pin TQFP package, and is specified for the extended industrial (-40°C to +85°C) temperature range.

For a 10-bit, pin-compatible upgrade, refer to the MAX1180 data sheet. With the N.C. pins of the MAX1198 internally pulled down to ground, this ADC becomes a drop-in replacement for the MAX1180.

Applications

* Baseband I/Q Sampling

* Battery-Powered Applications

* Instrumentation

* MMDS Modems

* Multichannel IF Sampling

* Set-Top Boxes

* Ultrasound and Medical Imaging

* VSAT Terminals

* WLAN, WWAN, WLL,

* Single 2.7V to 3.6V Operation

* Excellent Dynamic Performance

* 48.1dB/47.6dB SINAD at fIN = 50MHz/200MHz

* 66dBc/61.5dBc SFDR at fIN = 50MHz/200MHz

* -72dB Interchannel Crosstalk at fIN = 50MHz

* Low Power

* 264mW (Normal Operation)

* 10.6mW (Sleep Mode)

* 0.5µW (Shutdown Mode)

* 0.05dB Gain and ±0.1° Phase Matching

* Wide ±1VP-P Differential Analog Input Voltage Range

* 400MHz -3dB Input Bandwidth

* On-Chip 2.048V Precision Bandgap Reference

* User-Selectable Output Format—Two's Complement or Offset Binary

* Pin-Compatible 8-Bit and 10-Bit Upgrades Available