MAX1422 19-1899 Rev 1 5/04 12-Bit, 20Msps, 3.3V, Low-Power ADC with Internal Reference General Description Features The MAX1422 3.3V, 12-bit analog-to-digital converter Single 3.3V Power Supply (ADC) features a fully differential input, pipelined, 12- 67dB SNR at f = 5MHz stage ADC architecture with wideband track-and-hold IN (T/H) and digital error correction incorporating a fully-dif- Internal 2.048V Precision Bandgap Reference ferential signal path. The MAX1422 is optimized for low- power, high dynamic performance applications in Differential Wideband Input T/H Amplifier imaging and digital communications. The converter Power-Down Modes operates from a single 3.3V supply, consuming only 130mW (Reference Shutdown Mode) 137mW while delivering a 67dB (typ) signal-to-noise ratio (SNR) at a 5MHz input frequency and a 20Msps 10W (Shutdown Mode) sampling frequency. The fully-differential input stage Space-Saving 48-Pin TQFP Package 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 Ordering Information buffered or unbuffered reference for applications requiring increased accuracy or a different input volt- PART TEMP RANGE PIN-PACKAGE age range. MAX1422CCM 0C to +70C 48 TQFP In addition to low operating power, the MAX1422 features MAX1422ECM -40C to +85C 48 TQFP 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. Pin Configuration The MAX1422 provides parallel, offset binary, CMOS- compatible three-state outputs. The MAX1422 is available in a 7mm 7mm 1.4mm, 48-pin TQFP package and is specified over the com- mercial (0C to +70C) and extended industrial (-40C to +85C) temperature ranges. Pin-compatible higher-speed versions of the MAX1422 AGND 1 36 D9 are also available. Please refer to the MAX1421 data AV 2 35 D8 DD sheet for 40Msps and the MAX1420 data sheet for AV 3 34 D7 DD 60Msps. AGND 4 33 D6 Applications AGND 5 32 DV DD INP DV 6 31 DD Medical Ultrasound Imaging MAX1422 INN 7 30 DGND CCD Pixel Processing AGND 8 29 DGND AGND 9 28 D5 Data Acquisition AV 10 27 D4 DD Radar AV D3 11 26 DD AGND 12 25 D2 IF and Baseband Digitization Functional Diagram appears at end of data sheet. TQFP Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com. AGND 13 48 AGND AV 14 47 AV DD DD AV 15 46 CML DD 45 AGND 16 REFN CLK 17 44 REFP CLK 18 43 REFIN AGND 19 42 AV DD AV 20 41 AGND DD DV 21 40 PD DD DGND 22 39 OE D0 23 38 D11 D1 24 37 D1012-Bit, 20Msps, 3.3V, Low-Power ADC with Internal Reference ABSOLUTE MAXIMUM RATINGS AV , DV to AGND..............................................-0.3V to +4V 48-Pin TQFP (derate 21.7mW/C above +70C)........1739mW DD DD DV , AV to DGND..............................................-0.3V to +4V Operating Temperature Ranges DD DD DGND to AGND.....................................................-0.3V to +0.3V MAX1422CCM ....................................................0C to +70C INP, INN, REFP, REFN, REFIN, MAX1422ECM .................................................-40C to +85C CML,CLK, CLK, ....................(AGND - 0.3V) to (AV + 0.3V) Maximum Junction Temperature .....................................+150C DD D0D11, OE, PD .......................(DGND - 0.3V) to (DV + 0.3V) Storage Temperature Range .............................-65C to +150C DD Continuous Power Dissipation (T = +70C) Lead Temperature (soldering, 10s) .................................+300C A 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 (V = V = 3.3V, AGND = DGND = 0, V = 1.024V, differential input voltage at -0.5dBFS, internal reference, f = 20MHz (50% AVDD DVDD IN CLK duty cycle) digital output load C = 10pF, +25C guaranteed by production test, <+25C guaranteed by design and characterization. L Typical values are at T = +25C.) A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DC ACCURACY Resolution RES 12 Bits T = +25C, no missing codes -1 1 A Differential Nonlinearity DNL LSB T = T to T 0.5 A MIN MAX Integral Nonlinearity INL T = T to T 2 LSB A MIN MAX Mid-scale Offset MSO -3 .75 3 %FSR Mid-scale Offset Temperature - 4 MSOTC 3 10 %/C Coefficient Internal reference (Note 1) -5 0.1 5 External reference applied to REFIN, (Note 2) -5 0.2 5 Gain Error GE %FSR External reference applied to REFP, CML, -1.5 1.5 and REFN (Note 3) Gain Error Temperature External reference applied to REFP, CML, - 6 GETC 15 10 %/C Coefficient and REFN (Note 3) DYNAMIC PERFORMANCE (f = 20MHz, 4096-point FFT) CLK Signal-to-Noise Ratio SNR f = 5MHz, T = +25C6367 dB IN A Spurious-Free Dynamic Range SFDR f = 5MHz, T = +25C 64 74 dBc IN A Total Harmonic Distortion THD f = 5MHz, T = +25C -72 -63 dBc IN A Signal-to-Noise and Distortion SINAD f = 5MHz, T = +25C6065 dB IN A Effective Number of Bits ENOB f = 5MHz IN 10.5 Bits Two-Tone Intermodulation IMD f = 7.028MHz, f = 8.093MHz (Note 4) -77 dBc IN1 IN2 Distortion Differential Gain DG 1% Degrees Differential Phase DP 0.25 ANALOG INPUTS (INP, INN, CML) Input Resistance R Either input to ground 61 k IN Input Capacitance C Either input to ground 4 pF IN Common-Mode Input Level V AVDD V V CML (Note 5) 0.5 2 MAX1422