MAX1422CCM

19-1899; Rev 1; 5/04 12-Bit, 20Msps, 3.3V, Low-Power ADC with Internal Reference General Description The MAX1422 3.3V, 12-bit analog-to-digital converter (ADC) features a fully differential input, pipelined, 12stage ADC architecture with wideband track-and-hold (T/H) and digital error correction incorporating a fully-differential signal path. The MAX1422 is optimized for lowpower, high dynamic performance applications in imaging and digital communications. The converter operates from a single 3.3V supply, consuming only 137mW while delivering a 67dB (typ) signal-to-noise ratio (SNR) at a 5MHz input frequency and a 20Msps sampling frequency. The fully-differential input stage has a small signal -3dB bandwidth of 400MHz and may be operated with single-ended inputs. An internal 2.048V precision bandgap reference sets the ADCs full-scale range. A flexible reference structure accommodates an internally or externally applied buffered or unbuffered reference for applications requiring increased accuracy or a different input voltage range. In addition to low operating power, the MAX1422 features two power-down modes, a reference power-down, and a shutdown mode. In reference power-down, the internal bandgap reference is deactivated, resulting in a 2mA (typ) supply current reduction. For idle periods, a full shutdown mode is available to maximize power savings. The MAX1422 provides parallel, offset binary, CMOScompatible three-state outputs. The MAX1422 is available in a 7mm ✕ 7mm ✕ 1.4mm, 48-pin TQFP package and is specified over the commercial (0°C to +70°C) and extended industrial (-40°C to +85°C) temperature ranges. Pin-compatible higher-speed versions of the MAX1422 are also available. Please refer to the MAX1421 data sheet for 40Msps and the MAX1420 data sheet for 60Msps. ♦ Single 3.3V Power Supply ♦ 67dB SNR at fIN = 5MHz ♦ Internal 2.048V Precision Bandgap Reference ♦ Differential Wideband Input T/H Amplifier ♦ Power-Down Modes 130mW (Reference Shutdown Mode) 10µW (Shutdown Mode) ♦ Space-Saving 48-Pin TQFP Package Features MAX1422 Ordering Information PART MAX1422CCM MAX1422ECM TEMP RANGE 0°C to +70°C -40°C to +85°C PIN-PACKAGE 48 TQFP 48 TQFP Pin Configuration AGND AVDD CML REFN REFP REFIN AVDD AGND PD OE D11 D10 48 47 46 45 44 43 42 41 40 39 38 37 ________________________Applications Medical Ultrasound Imaging CCD Pixel Processing Data Acquisition Radar IF and Baseband Digitization AGND AVDD AVDD AGND AGND INP INN AGND AGND AVDD AVDD AGND 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 36 35 34 33 32 31 30 29 28 27 26 25 D9 D8 D7 D6 DVDD DVDD DGND DGND D5 D4 D3 D2 MAX1422 Functional Diagram appears at end of data sheet. ________________________________________________________________ Maxim Integrated Products AGND AVDD AVDD AGND CLK CLK AGND AVDD DVDD DGND D0 D1 TQFP 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 12-Bit, 20Msps, 3.3V, Low-Power ADC with Internal Reference MAX1422 ABSOLUTE MAXIMUM RATINGS AVDD, DVDD to AGND ..............................................-0.3V to +4V DVDD, AVDD to DGND..............................................-0.3V to +4V DGND to AGND.....................................................-0.3V to +0.3V INP, INN, REFP, REFN, REFIN, CML,CLK, CLK, ....................(AGND - 0.3V) to (AVDD + 0.3V) D0–D11, OE, PD .......................(DGND - 0.3V) to (DVDD + 0.3V) Continuous Power Dissipation (TA = +70°C) 48-Pin TQFP (derate 21.7mW/°C above +70°C)........1739mW Operating Temperature Ranges MAX1422CCM ....................................................0°C to +70°C MAX1422ECM .................................................-40°C to +85°C Maximum Junction Temperature .....................................+150°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10s) .................................+300°C Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (VAVDD = VDVDD = 3.3V, AGND = DGND = 0, VIN = ±1.024V, differential input voltage at -0.5dBFS, internal reference, fCLK = 20MHz (50% duty cycle); digital output load CL = 10pF, ≥+25°C guaranteed by production test,