Low-Power, 90Msps, Dual 6-Bit ADC

The MAX1003 is a dual, 6-bit analog-to-digital converter (ADC) that combines high-speed, low-power operation with a user-selectable input range, an internal reference, and a clock oscillator. The dual parallel ADCs are designed to convert in-phase (I) and quadrature (Q) analog signals into two 6-bit, offset-binary-coded digital outputs at sampling rates up to 90Msps. The ability to directly interface with baseband I and Q signals makes the MAX1003 ideal for use in direct-broadcast satellite, VSAT, and QAM16 demodulation applications.

The MAX1003 input amplifiers feature true differential inputs, a -0.5dB analog bandwidth of 55MHz, and user-programmable input full-scale ranges of 125mVp-p, 250mVp-p, or 500mVp-p. With an AC-coupled input signal, matching performance between input channels is typically better than 0.1dB gain, 1/4LSB offset, and 0.5° phase. Dynamic performance is 5.85 effective number of bits (ENOB) with a 20MHz analog input signal, or 5.7 ENOB with a 50MHz signal.

The MAX1003 operates with +5V analog and +3.3V digital supplies for easy interfacing to +3.3V-logic-compatible digital signal processors and microprocessors. It comes in a 36-pin SSOP package.

Applications

* Cable Television Set-Top Boxes * Direct-Broadcast Satellite (DBS) Receiver * VSAT Receivers * Wide Local Area Networks (WLANs)

* Two Matched 6-Bit ADCs

* High Sampling Rate: 90Msps per ADC

* Low Power Dissipation: 350mW

* Excellent Dynamic Performance:

* 5.85 ENOB with 20MHz Analog Input

* 5.7 ENOB with 50MHz Analog Input

* ±1/4LSB INL and DNL (typ)

* Internal Bandgap Voltage Reference

* Internal Oscillator with Overdrive Capability

* 55MHz (-0.5dB) Bandwidth Input Amplifiers with True Differential Inputs

* User-Selectable Input Full-Scale Range (125mVp-p, 250mVp-p, or 500mVp-p)

* 1/4LSB Channel-to-Channel Offset Matching (typ)

* 0.1dB Gain and 0.5° Phase Matching (typ)

* Single-Ended or Differential Input Drive

* Flexible, 3.3V, CMOS-Compatible Digital Outputs