19-0537; Rev 0; 4/06 KIT ATION EVALU E L B A AVAIL 1.8V, Low-Power, 12-Bit, 250Msps ADC for Broadband Applications The MAX1215N is a monolithic, 12-bit, 250Msps analog-to-digital converter (ADC) optimized for outstanding dynamic performance at high-IF frequencies beyond 300MHz. The product operates with conversion rates up to 250Msps while consuming only 886mW. At 250Msps and an input frequency of 100MHz, the MAX1215N achieves an 84.7dBc spurious-free dynamic range (SFDR) with e6.7dB signal-to-noise ratio (SNR) that remains flat (within 2dB) for input tones up to 250MHz. This makes it ideal for wideband applications such as communications receivers, cable-head end receivers, and power-amplifier predistortion in cellular base-station transceivers (BTS). The MAX1215N operates from a single 1.8V power supply. The analog input is designed for AC-coupled differential or single-ended operation. The ADC also features a selectable on-chip divide-by-2 clock circuit that accepts clock frequencies as high as 500MHz. A low-voltage differential signal (LVDS) sampling clock is recommended for best performance. The converter provides LVDS-compatible digital outputs with data format selectable to be either two’s complement or offset binary. The MAX1215N is available in a 68-pin QFN package with exposed paddle (EP) and is specified over the industrial (-40°C to +85°C) temperature range. See the Pin-Compatible Versions table for a complete selection of 8-bit, 10-bit, and 12-bit high-speed ADCs in this family. Features 250Msps Conversion Rate Excellent Low-Noise Characteristics SNR = 66.7dB at fIN = 100MHz SNR = 65.6dB at fIN = 250MHz Excellent Dynamic Range SFDR = 84.7dBc at fIN = 100MHz SFDR = 80dBc at fIN = 250MHz Single 1.8V Supply 886mW Power Dissipation at fSAMPLE = 250Msps and fIN = 100MHz On-Chip Track-and-Hold Amplifier Internal 1.25V-Bandgap Reference On-Chip Selectable Divide-by-2 Clock Input LVDS Digital Outputs with Data Clock Output MAX1215NEVKIT Available Ordering Information PART TEMP RANGE MAX1215NEGK-D MAX1215NEGK+D PINPACKAGE PKG CODE -40°C to +85°C 68 QFN-EP* G6800-4 -40°C to +85°C 68 QFN-EP* G6800-4 *EP = Exposed paddle. +Denotes lead-free package. D = Dry pack. Applications Base-Station Power-Amplifier Linearization Cable-Head End Receivers Pin-Compatible Versions Wireless and Wired Broadband Communications Communications Test Equipment RESOLUTION (BITS) SPEED GRADE (Msps) ON-CHIP BUFFER MAX1121 8 250 Yes MAX1122 10 170 Yes MAX1123 10 210 Yes MAX1124 10 250 Yes MAX1213 12 170 Yes MAX1214 12 210 Yes MAX1215 12 250 Yes MAX1213N 12 170 No MAX1214N 12 210 No MAX1215N 12 250 No PART Radar and Satellite Subsystems Pin Configuration appears at end of data sheet. ________________________________________________________________ Maxim Integrated Products 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. 1 MAX1215N General Description MAX1215N 1.8V, Low-Power, 12-Bit, 250Msps ADC for Broadband Applications ABSOLUTE MAXIMUM RATINGS ESD on All Pins (Human Body Model).............................±2000V Current into Any Pin..........................................................±50mA Continuous Power Dissipation (TA = +70°C, multilayer board) 68-Pin QFN-EP (derate 41.7mW/°C above +70°C)....3333mW Operating Temperature Range ...........................-40°C to +85°C Junction Temperature .....................................................+150°C Storage Temperature Range ............................-60°C to +150°C Lead Temperature (soldering,10s) ..................................+300°C AVCC to AGND ......................................................-0.3V to +2.1V OVCC to OGND .....................................................-0.3V to +2.1V AVCC to OVCC .......................................................-0.3V to +2.1V AGND to OGND ....................................................-0.3V to +0.3V Analog Inputs to AGND ...........................-0.3V to (AVCC + 0.3V) All Digital Inputs to AGND........................-0.3V to (AVCC + 0.3V) REFIO, REFADJ to AGND ........................-0.3V to (AVCC + 0.3V) All Digital Outputs to OGND ....................-0.3V to (OVCC + 0.3V) 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 (AVCC = OVCC = 1.8V, AGND = OGND = 0, fSAMPLE = 250MHz, differential clock input drive, 0.1µF capacitor on REFIO, internal reference, digital output pins differential RL = 100Ω. Limits are for TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS -3 ±0.8 +3 LSB ±0.4 +1.3 LSB DC ACCURACY Resolution 12 Integral Nonlinearity (Note 2) INL fIN = 10MHz Differential Nonlinearity (Note 2) DNL No missing codes -1.0 Transfer Curve Offset VOS (Note 2) -3.5 Bits +3.5 Offset Temperature Drift mV ±20 µV/°C 1385 mVP-P ±60 ppm/°C ANALOG INPUTS (INP, INN) Full-Scale Input Voltage Range VFS 1250 Full-Scale Range Temperature Drift Common-Mode Input Voltage VCM Differential Input Capacitance CIN Differential Input Resistance Full-Power Analog Bandwidth Internally self-biased 0.7 V 2.5 pF RIN 1.8 kΩ FPBW 700 MHz REFERENCE (REFIO, REFADJ) Reference Output Voltage VREFIO REFADJ = AGND 1.18 1.25 Reference Temperature Drift REFADJ Input High Voltage 90 VREFADJ Used to disable the internal reference AVCC - 0.3 1.30 V ppm/°C V SAMPLING CHARACTERISTICS Maximum Sampling Rate fSAMPLE Minimum Sampling Rate fSAMPLE Clock Duty Cycle 250 MHz 20 40 to 60 % Aperture Delay tAD Figures 5, 11 620 ps Aperture Jitter tAJ Figure 11 0.15 psRMS 2 Set by clock-management circuit MHz ________________________________________________________________________________________ 1.8V, Low-Power, 12-Bit, 250Msps ADC for Broadband Applications (AVCC = OVCC = 1.8V, AGND = OGND = 0, fSAMPLE = 250MHz, differential clock input drive, 0.1µF capacitor on REFIO, internal reference, digital output pins differential RL = 100Ω. Limits are for TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 200 500 mVP-P 1.15 ±0.25 V CLOCK INPUTS (CLKP, CLKN) Differential Clock Input Amplitude (Note 3) Clock Input Common-Mode Voltage Range Internally self-biased Clock Differential Input Resistance RCLK 11 ±25% kΩ Clock Differential Input Capacitance CCLK 5 pF DYNAMIC CHARACTERISTICS (at AIN = -1dBFS) Signal-to-Noise Ratio SNR fIN = 10MHz 64.5 67 fIN = 100MHz 64.3 66.7 fIN = 200MHz fIN = 250MHz Signal-to-Noise and Distortion SINAD Spurious-Free Dynamic Range SFDR Worst Harmonics (HD2 or HD3) Two-Tone Intermodulation Distortion TTIMD dB 66.1 65.6 fIN = 10MHz 63.5 fIN = 100MHz 63.3 66.8 66.4 fIN = 200MHz 65.9 fIN = 250MHz 65.4 fIN = 10MHz 70 86 fIN = 100MHz 70 84.7 fIN = 200MHz dB dBc 83.4 fIN = 250MHz 80 fIN = 10MHz -86 -70 fIN = 100MHz -84.7 -70 fIN = 200MHz -83.4 fIN = 250MHz -80 fIN1 = 99MHz at AIN1 = -7dBFS, fIN2 = 101MHz at AIN2 = -7dBFS -86.9 dBc dBc LVDS DIGITAL OUTPUTS (D0P/N–D11P/N, ORP/N) Differential Output Voltage |VOD| RL = 100Ω 280 440 mV Output Offset Voltage OVOS RL = 100Ω 1.11 1.37 V _______________________________________________________________________________________ 3 MAX1215N ELECTRICAL CHARACTERISTICS (continued) MAX1215N 1.8V, Low-Power, 12-Bit, 250Msps ADC for Broadband Applications ELECTRICAL CHARACTERISTICS (continued) (AVCC = OVCC = 1.8V, AGND = OGND = 0, fSAMPLE = 250MHz, differential clock input drive, 0.1µF capacitor on REFIO, internal reference, digital output pins differential RL = 100Ω. Limits are for TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS LVCMOS DIGITAL INPUTS (CLKDIV, T/B) Digital Input-Voltage Low VIL Digital Input-Voltage High VIH 0.2 x AVCC 0.8 x AVCC V V TIMING CHARACTERISTICS CLK-to-Data Propagation Delay CLK-to-DCLK Propagation Delay DCLK-to-Data Propagation Delay tPDL Figure 5 tCPDL Figure 5 tCPDL - tPDL Figure 5 (Note 3) 2.23 ns 3.77 1.47 1.54 ns 1.63 ns LVDS Output Rise Time tRISE 20% to 80%, CL = 5pF 155 ps LVDS Output Fall Time tFALL 20% to 80%, CL = 5pF 145 ps Figure 5 11 Clock cycles Output Data Pipeline Delay tLATENCY POWER REQUIREMENTS Analog Supply Voltage Range AVCC 1.7 1.9 V Digital Supply Voltage Range OVCC 1.8 1.9 V Analog Supply Current IAVCC fIN = 100MHz 428 480 mA Digital Supply Current IOVCC fIN = 100MHz 64 74 mA Analog Power Dissipation PDISS fIN = 100MHz 886 965 Offset 1.7 mV/V Gain 4.5 %FS/V Power-Supply Rejection Ratio (Note 4) PSRR 1.7 1.8 mW Note 1: TA ≥ +25°C guaranteed by production test, TA < +25°C guaranteed by design and characterization. Typical values are at TA = +25°C Note 2: Static linearity and offset parameters are computed from an endpoint curve fit. Note 3: Parameter guaranteed by design and characterization: TA = -40°C to +85°C. Note 4: PSRR is measured with both analog and digital supplies connected to the same potential. 4 ________________________________________________________________________________________ 1.8V, Low-Power, 12-Bit, 250Msps ADC for Broadband Applications 20 40 60 80 100 ANALOG INPUT FREQUENCY (MHz) 120 0 35 0 MAX1215N toc04 fSAMPLE = 250MHz fIN = 248.627MHz AIN = -0.933dBFS SNR = 65.4dB SINAD = 65.185dB THD = -78dBc SFDR = 82.7dBc HD2 = -82.7dBc HD3 = -83.1dBc -25 -75 SNR 70 65 50 100 150 200 fIN (MHz) 250 25 50 75 100 58 52 125 0 300 MAX1215N toc08 -52 -56 -60 -64 -68 -72 -76 -80 -84 -88 -92 -96 -100 HD2 HD3 0 50 100 150 200 fIN (MHz) 250 300 50 100 150 200 fIN (MHz) 250 300 SNR/SINAD vs. ANALOG INPUT AMPLITUDE (fSAMPLE = 250MHz, fIN = 65.033MHz) SNR/SINAD (dB) 75 SINAD 61 HD2/HD3 vs. ANALOG INPUT FREQUENCY (fSAMPLE = 250MHz, AIN = -1dBFS) 80 0 64 ANALOG INPUT FREQUENCY (MHz) HD2/HD3 (dBc) 85 120 55 0 MAX1215N toc07 90 20 40 60 80 100 ANALOG INPUT FREQUENCY (MHz) 67 -125 SFDR vs. ANALOG INPUT FREQUENCY (fSAMPLE = 250MHz, AIN = -1dBFS) MAX1215N toc03 MAX1215N toc02 -50 120 4 70 -100 20 40 60 80 100 ANALOG INPUT FREQUENCY (MHz) fSAMPLE = 250MHz fIN = 199.249MHz AIN = -1.004dBFS SNR = 66dB SINAD = 65.9dB THD = -81dBc SFDR = 82.7dBc HD2 = -90.9dBc HD3 = -82.7dBc 3 2 SNR/SINAD vs. ANALOG INPUT FREQUENCY (fSAMPLE = 250MHz, AIN = -1dBFS) 4 0 SFDR (dBc) fSAMPLE = 250MHz fIN1 = 99MHz fIN2 = 101MHz IMD = -86dBc 5 0 120 SNR/SINAD (dB) 2 20 40 60 80 100 ANALOG INPUT FREQUENCY (MHz) TWO-TONE IMD PLOT (32,768-POINT DATA RECORD) AMPLITUDE (dBFS) AMPLITUDE (dBS) 0 2 5 4 FFT PLOT (8192-POINT DATA RECORD) -10 -20 -30 -40 -50 -60 -70 -80 -90 -100 -110 -120 AMPLITUDE (dBS) 3 0 -10 -20 -30 -40 -50 -60 -70 -80 -90 -100 -110 -120 70 65 60 55 50 45 40 35 30 25 20 15 10 MAX1215N toc09 0 5 4 fSAMPLE = 250MHz fIN = 65.033MHz AIN = -1.008dBFS SNR = 67dB SINAD = 66.9dB THD = -83.6dBc SFDR = 87dBc HD2 = -87dBc HD3 = -81.8dBc -10 -20 -30 -40 -50 -60 -70 -80 -90 -100 -110 -120 MAX1215N toc05 3 2 0 MAX1215N toc01 fSAMPLE = 250MHz fIN = 11.566MHz AIN = -0.982dBFS SNR = 67.1dB SINAD = 66.953dB THD = -82.5dBc SFDR = 84.7dBc HD2 = -94.9dBc HD3 = -84.7dBc AMPLITUDE (dBFS) AMPLITUDE (dBFS) 0 -10 -20 -30 -40 -50 -60 -70 -80 -90 -100 -110 -120 FFT PLOT (8192-POINT DATA RECORD) FFT PLOT (8192-POINT DATA RECORD) MAX1215N toc06 FFT PLOT (8192-POINT DATA RECORD) SNR SINAD -55 -50 -45 -40 -35 -30 -25 -20 -15 -10 -5 ANALOG INPUT AMPLITUDE (dBFS) _______________________________________________________________________________________ 0 5 MAX1215N Typical Operating Characteristics (AVCC = OVCC = 1.8V, AGND = OGND = 0, fSAMPLE = 250MHz, AIN = -1dBFS, see each TOC for detailed information on test conditions, differential input drive, differential sine-wave clock input drive, 0.1µF capacitor on REFIO, internal reference, digital output pins differential RL = 100Ω, TA = +25°C.) Typical Operating Characteristics (continued) (AVCC = OVCC = 1.8V, AGND = OGND = 0, fSAMPLE = 250MHz, AIN = -1dBFS, see each TOC for detailed information on test conditions, differential input drive, differential sine-wave clock input drive, 0.1µF capacitor on REFIO, internal reference, digital output pins differential RL = 100Ω, TA = +25°C.) HD2/HD3 vs. ANALOG INPUT AMPLITUDE (fSAMPLE = 250MHz, fIN = 65.033MHz) HD2/HD3 (dBc) 60 55 50 45 40 35 -55 -50 -45 -40 -35 -30 -25 -20 -15 -10 -5 ANALOG INPUT AMPLITUDE (dBFS) HD2 60 -72 -76 82 80 78 76 -80 50 100 150 fSAMPLE (MHz) 200 250 TOTAL POWER DISSIPATION vs. SAMPLE FREQUENCY (fIN = 65.033MHz, AIN = -1dBFS) 0.900 0.875 HD3 0.850 PDISS (W) HD2/HD3 (dBc) 84 SFDR (dBc) 0 MAX1215N toc14 86 0 HD2/HD3 vs. SAMPLE FREQUENCY (fIN = 65MHz, AIN = -1dBFS) MAX1215N toc13 88 SINAD 64 62 SFDR vs. SAMPLE FREQUENCY (fIN = 65MHz, AIN = -1dBFS) 90 66 HD3 -55 -50 -45 -40 -35 -30 -25 -20 -15 -10 -5 ANALOG INPUT AMPLITUDE (dBFS) 0 SNR 68 -84 -88 0.825 0.800 -92 74 -96 72 0.775 HD2 -100 70 0 0.750 0 25 50 75 100 125 150 175 200 225 250 fSAMPLE (MHz) INTEGRAL NONLINEARITY vs. DIGITAL OUTPUT CODE 100 150 fSAMPLE (MHz) 200 250 0 DIFFERENTIAL NONLINEARITY vs. DIGITAL OUTPUT CODE 0.2 100 150 fSAMPLE (MHz) 200 0 -0.5 -1.0 250 -1.5 0 GAIN (dB) DNL (LSB) -0.3 50 GAIN BANDWIDTH PLOT (fSAMPLE = 250MHz, NORMALIZED TO 0dB) MAX1215N toc17 0.2 MAX1215N toc16 0.7 50 MAX1215 toc18 SFDR (dBc) 65 70 MAX1215N toc12 70 -30 -35 -40 -45 -50 -55 -60 -65 -70 -75 -80 -85 -90 -95 -100 MAX1215N toc15 75 SNR/SINAD (dB) MAX1215N toc10 80 SNR/SINAD vs. SAMPLE FREQUENCY (fIN = 65MHz, AIN = -1dBFS) MAX1215N toc11 SFDR vs. ANALOG INPUT AMPLITUDE (fSAMPLE = 250MHz, fIN = 65.033MHz) INL (LSB) MAX1215N 1.8V, Low-Power, 12-Bit, 250Msps ADC for Broadband Applications -0.2 -2.0 -2.5 -3.0 -3.5 -4.0 -4.5 -0.8 -0.5 0 1365 2730 DIGITAL OUTPUT CODE 6 4095 -5.0 0 1365 2729 DIGITAL OUTPUT CODE 4094 10 100 ANALOG INPUT FREQUENCY (MHz) ________________________________________________________________________________________ 1000 1.8V, Low-Power, 12-Bit, 250Msps ADC for Broadband Applications 88 86 -72 HD2/HD3 (dBc) SFDR (dBc) SINAD 80 78 76 -80 -84 -88 -92 74 62 -100 70 60 -15 10 35 TEMPERATURE (°C) 60 85 -40 -15 10 35 TEMPERATURE (°C) 60 85 10 35 TEMPERATURE (°C) 60 85 MAX1215N to23 SNR 68 -15 90 MAX1215N toc22 70 -40 SFDR vs. SUPPLY VOLTAGE (fIN = 65.033MHz, AIN = -1dBFS) SNR/SINAD vs. SUPPLY VOLTAGE (fIN = 65.033MHz, AIN = -1dBFS) 88 86 84 66 SFDR (dBc) SNR/SINAD (dB) SINAD 64 82 80 78 76 62 74 72 60 1.70 1.75 1.80 1.85 SUPPLY VOLTAGE (V) 1.70 1.90 HD2/HD3 vs. SUPPLY VOLTAGE (fIN = 65.033MHz, AIN = -1dBFS) -80 1.90 1.254 MAX1215N toc25 -75 1.75 1.80 1.85 SUPPLY VOLTAGE (V) REFERENCE vs. SUPPLY VOLTAGE (fIN = 65.033MHz, AIN = -1dBFS) MAX1215N toc24 1.253 1.252 HD2 -85 VREFIO (V) -40 HD3 -96 72 HD2/HD3 (dBc) SNR/SINAD (dB) 64 82 HD2 -76 84 66 MAX1215N toc21 MAX1215N toc20 SNR 68 90 MAX1215N toc19 70 HD2/HD3 vs. TEMPERATURE (fIN = 65MHz, AIN = -1dBFS) SFDR vs. TEMPERATURE (fIN = 65MHz, AIN = -1dBFS) SNR/SINAD vs. TEMPERATURE (fIN = 65MHz, AIN = -1dBFS) -90 1.251 1.250 1.249 1.248 -95 HD3 1.247 -100 1.246 1.70 1.75 1.80 1.85 SUPPLY VOLTAGE (V) 1.90 1.70 1.75 1.80 1.85 SUPPLY VOLTAGE (V) 1.90 _______________________________________________________________________________________ 7 MAX1215N Typical Operating Characteristics (continued) (AVCC = OVCC = 1.8V, AGND = OGND = 0, fSAMPLE = 250MHz, AIN = -1dBFS, see each TOC for detailed information on test conditions, differential input drive, differential sine-wave clock input drive, 0.1µF capacitor on REFIO, internal reference, digital output pins differential RL = 100Ω, TA = +25°C.) MAX1215N 1.8V, Low-Power, 12-Bit, 250Msps ADC for Broadband Applications Pin Description PIN NAME FUNCTION 1, 6, 11–14, 20, 25, 62, 63, 65 AVCC Analog Supply Voltage. Bypass AVCC to AGND with a parallel combination of 0.1µF and 0.22µF capacitors for best decoupling results. Connect all AVCC inputs together. See the Grounding, Bypassing, and Layout Considerations section. 2, 5, 7, 10, 15, 16, 18, 19, 21, 24, 64, 66, 67 AGND Analog Converter Ground. Connect all AGND inputs together. 3 REFIO Reference Input/Output. Pull REFADJ high to allow REFIO to accept an external reference. Pull REFADJ low to activate the internal 1.25V-bandgap reference. Connect a 0.1µF capacitor from REFIO to AGND for both internal and external reference. 4 REFADJ Reference Adjust Input. REFADJ allows for FSR adjustments by placing a resistor or trim potentiometer between REFADJ and AGND (decreases FSR) or REFADJ and REFIO (increases FSR). Connect REFADJ to AVCC to override the internal reference with an external source connected to REFIO. Connect REFADJ to AGND to allow the internal reference to determine the FSR of the data converter. See the FSR Adjustment Using the Internal Reference section. 8 INP Positive Analog Input Terminal. Internally self-biased to 0.7V. 9 INN Negative Analog Input Terminal. Internally self-biased to 0.7V. 8 Clock Divider Input. CLKDIV controls the sampling frequency relative to the input clock frequency. CLKDIV has an internal pulldown resistor. CLKDIV = 0: Sampling frequency is at one-half the input clock frequency. CLKDIV = 1: Sampling frequency is equal to the input clock frequency. 17 CLKDIV 22 CLKP True Clock Input. Apply an LVDS-compatible input level to CLKP. Internally self-biased to 1.15V. 23 CLKN Complementary Clock Input. Apply an LVDS-compatible input level to CLKN. Internally selfbiased to 1.15V. 26, 45, 61 OGND Digital Converter Ground. Ground connection for digital circuitry and output drivers. Connect all OGND inputs together. 27, 28, 41, 44, 60 OVCC Digital Supply Voltage. Bypass OVCC with a 0.1µF capacitor to OGND. Connect all OVCC inputs together. See the Grounding, Bypassing, and Layout Considerations section. 29 D0N Complementary Output Bit 0 (LSB) 30 D0P True Output Bit 0 (LSB) 31 D1N Complementary Output Bit 1 32 D1P True Output Bit 1 33 D2N Complementary Output Bit 2 34 D2P True Output Bit 2 35 D3N Complementary Output Bit 3 36 D3P True Output Bit 3 ________________________________________________________________________________________ 1.8V, Low-Power, 12-Bit, 250Msps ADC for Broadband Applications PIN NAME FUNCTION 37 D4N 38 D4P True Output Bit 4 39 D5N Complementary Output Bit 5 40 D5P True Output Bit 5 42 DCLKN Complementary Clock Output. This output provides an LVDS-compatible output level and can be used to synchronize external devices to the converter clock. 43 DCLKP True Clock Output. This output provides an LVDS-compatible output level and can be used to synchronize external devices to the converter clock. 46 D6N 47 D6P True Output Bit 6 48 D7N Complementary Output Bit 7 Complementary Output Bit 4 Complementary Output Bit 6 49 D7P True Output Bit 7 50 D8N Complementary Output Bit 8 51 D8P True Output Bit 8 52 D9N Complementary Output Bit 9 53 D9P True Output Bit 9 54 D10N Complementary Output Bit 10 55 D10P True Output Bit 10 56 D11N Complementary Output Bit 11 (MSB) 57 D11P True Output Bit 11 (MSB) 58 ORN Complementary Out-of-Range Control Bit Output. If an out-of-range condition is detected, bit ORN flags this condition by transitioning low. 59 ORP True Out-of-Range Control Bit Output. If an out-of-range condition is detected, bit ORP flags this condition by transitioning high. 68 T/B Output Format Select Input. This LVCMOS-compatible input controls the digital output format of the MAX1215N. T/B has an internal pulldown resistor. T/B = 0: Two’s-complement output format. T/B = 1: Binary output format. — EP Exposed Paddle. The exposed paddle is located on the backside of the chip and must be connected to AGND. _______________________________________________________________________________________ 9 MAX1215N Pin Description (continued) MAX1215N 1.8V, Low-Power, 12-Bit, 250Msps ADC for Broadband Applications OVCC AVCC INP 12-BIT PIPELINE ADC T/H MAX1215N INN 900Ω 900Ω DCLKP DCLKN COMMONMODE BUFFER REFIO REFERENCE REFADJ DIV1/DIV2 D0P/N CLOCK MANAGEMENT D1P/N LVDS DATA PORT D2P/N D11P/N CLKP ORP/ORN CLKN CLKDIV T/B AGND OGND Figure 1. Block Diagram Detailed Description— Theory of Operation The MAX1215N uses a fully differential pipelined architecture that allows for high-speed conversion, optimized accuracy, and linearity while minimizing power consumption. Both positive (INP) and negative analog input terminals (INN) are centered around a 0.7V common-mode voltage, and accept a differential analog input voltage swing of ±VFS / 4 each, resulting in a typical 1.385VP-P differential full-scale signal swing. Inputs INP and INN are sampled when the differential sampling clock signal transitions high. When using the clock-divide mode, the analog inputs are sampled at every other high transition of the differential sampling clock. Each pipeline converter stage converts its input voltage to a digital output code. At every stage, except the last, the error between the input voltage and the digital output code is multiplied and passed along to the next pipeline stage. Digital error correction compensates for 10 ADC comparator offsets in each pipeline stage and ensures no missing codes. The result is a 12-bit parallel digital output word in user-selectable two’s-complement or offset binary output formats with LVDS-compatible output levels. See Figure 1 for a more detailed view of the MAX1215N architecture. Analog Inputs (INP, INN) INP and INN are the fully differential inputs of the MAX1215N. Differential inputs usually feature good rejection of even-order harmonics, which allows for enhanced AC performance as the signals are progressing through the analog stages. The MAX1215N analog inputs are self-biased at a 0.7V common-mode voltage and allow a 1.385VP-P differential input voltage swing (Figure 2). Both inputs are self-biased through 900Ω resistors, resulting in a typical differential input resistance of 1.8kΩ. Drive the analog inputs of the MAX1215N in AC-coupled configuration to achieve best dynamic performance. See the TransformerCoupled, Differential Analog Input Drive section. ______________________________________________________________________________________ 1.8V, Low-Power, 12-Bit, 250Msps ADC for Broadband Applications MAX1215N AVCC T/H MAX1215N INP CP 900Ω CS 12-BIT PIPELINE ADC 900Ω CS INN CP FROM CLOCKMANAGEMENT BLOCK TO COMMON MODE CS IS THE SAMPLING CAPACITANCE CP IS THE PARASITIC CAPACITANCE ~ 1pF VCM + VFS / 4 INP VCM INN VCM - VFS / 4 GND +VFS / 2 GND 1.385V DIFFERENTIAL FSR INP - INN -VFS / 2 Figure 2. Simplified Analog Input Architecture and Allowable Input Voltage Range ______________________________________________________________________________________ 11 MAX1215N 1.8V, Low-Power, 12-Bit, 250Msps ADC for Broadband Applications On-Chip Reference Circuit The MAX1215N also features an internal clock-management circuit (duty-cycle equalizer) that ensures the clock signal applied to inputs CLKP and CLKN is processed to provide a 50% duty-cycle clock signal that desensitizes the performance of the converter to variations in the duty cycle of the input clock source. Note that the clock duty-cycle equalizer cannot be turned off externally and requires a minimum 20MHz clock frequency to allow the device to meet data sheet specifications. The MAX1215N features an internal 1.25V-bandgap reference circuit (Figure 3), which, in combination with an internal reference-scaling amplifier, determines the FSR of the MAX1215N. Bypass REFIO with a 0.1µF capacitor to AGND. To compensate for gain errors or increase/decrease the ADC’s FSR, the voltage of this bandgap reference can be indirectly adjusted by adding an external resistor (e.g., 100kΩ trim potentiometer) between REFADJ and AGND or REFADJ and REFIO. See the Applications Information section for a detailed description of this process. Data Clock Outputs (DCLKP, DCLKN) The MAX1215N features a differential clock output, which can be used to latch the digital output data with an external latch or receiver. Additionally, the clock output can be used to synchronize external devices (e.g., FPGAs) to the ADC. DCLKP and DCLKN are differential outputs with LVDS-compatible voltage levels. There is a 3.77ns delay time between the rising (falling) edge of CLKP (CLKN) and the rising (falling) edge of DCLKP (DCLKN). See Figure 5 for timing details. To disable the internal reference, connect REFADJ to AVCC. Apply an external, stable reference at REFIO to set the converter’s full scale. To enable the internal reference, connect REFADJ to AGND. Clock Inputs (CLKP, CLKN) Drive the clock inputs of the MAX1215N with an LVDS- or LVPECL-compatible clock to achieve the best dynamic performance. The clock signal source must be of high quality and low phase noise to avoid any degradation in the noise performance of the ADC. The clock inputs (CLKP, CLKN) are internally biased to 1.15V, accept a typical 500mVP-P differential signal swing (Figure 4). See the Differential, AC-Coupled LVPECL-Compatible Clock Input section for more circuit details on how to drive CLKP and CLKN appropriately. Although not recommended, the clock inputs also accept a single-ended input signal. Divide-by-2 Clock Control (CLKDIV) The MAX1215N offers a clock control line (CLKDIV), which supports the reduction of clock jitter in a system. Connect CLKDIV to OGND to enable the ADC’s internal divide-by-2 clock divider. Data is now updated at onehalf the ADC’s input clock rate. CLKDIV has an internal pulldown resistor and can be left open for applications that require this divide-by-2 mode. Connecting CLKDIV to OVCC disables the divide-by-2 mode. REFT ADC FULL SCALE = REFT - REFB 1V G REFERENCESCALING AMPLIFIER REFB REFERENCE BUFFER REFIO 0.1µF REFADJ* CONTROL LINE TO DISABLE REFERENCE BUFFER 100Ω* MAX1215N AVCC AVCC / 2 REFT: TOP OF REFERENCE LADDER. REFB: BOTTOM OF REFERENCE LADDER. Figure 3. Simplified Reference Architecture 12 _______________________________________________________________________________________ *REFADJ MAY BE SHORTED TO AGND DIRECTLY 1.8V, Low-Power, 12-Bit, 250Msps ADC for Broadband Applications Digital outputs D0P/N–D11P/N, DCLKP/N, and ORP/N are LVDS compatible, and data on D0P/N–D11P/N is presented in either binary or two’s-complement format (Table 1). The T/B control line is an LVCMOS-compatible input, which allows the user to select the desired output format. Pulling T/B low outputs data in two’s complement, and pulling it high presents data in offset binary format on the 12-bit parallel bus. T/B has an internal pulldown resistor and may be left unconnected in applications using only two’s-complement output format. All LVDS outputs provide a typical 360mV voltage swing around a 1.24V common-mode voltage, and must be terminated at the far end of each transmission line pair (true and complementary) with 100Ω. Apply a 1.7V to 1.9V voltage supply at OVCC to power the LVDS outputs. The MAX1215N offers an additional differential output pair (ORP, ORN) to flag out-of-range conditions, where out-of-range is above positive or below negative full scale. An out-of-range condition is identified with ORP (ORN) transitioning high (low). 2.89kΩ CLKP 5.35kΩ 5.35kΩ CLKN 5.35kΩ AGND Figure 4. Simplified Clock Input Architecture System Timing Requirements Figure 5 depicts the relationship between the clock input and output, analog input, sampling event, and data output. The MAX1215N samples on the rising (falling) edge of CLKP (CLKN). Output data is valid on the next rising (falling) edge of the DCLKP (DCLKN) clock, but has an internal latency of 11 clock cycles. SAMPLING EVENT SAMPLING EVENT Note: Although a differential LVDS output architecture reduces single-ended transients to the supply and ground planes, capacitive loading on the digital outputs should still be kept as low as possible. Using LVDS buffers on the digital outputs of the ADC when driving larger loads may improve overall performance and reduce system-timing constraints. SAMPLING EVENT SAMPLING EVENT SAMPLING EVENT INP INN tAD CLKN N N+1 N + 10 N + 11 CLKP tCH N + 12 tCL tCPDL DCLKN N-11 N-10 N-1 N N+1 DCLKP D0P/D0N– D11P/D11N ORP/N tLATENCY tPDL N - 11 N - 10 N-9 N-1 N N+1 tCPDL - tPDL~ 0.4 x tSAMPLE WITH tSAMPLE = 1 / fSAMPLE NOTE: THE ADC SAMPLES ON THE RISING EDGE OF CLKP. THE RISING EDGE OF DCLKP CAN BE USED TO EXTERNALLY LATCH THE OUTPUT DATA. Figure 5. System and Output Timing Diagram ______________________________________________________________________________________ 13 MAX1215N Digital Outputs (D0P/N–D11P/N, DCLKP/N, ORP/N) and Control Input T/B AVDD MAX1215N 1.8V, Low-Power, 12-Bit, 250Msps ADC for Broadband Applications Table 1. MAX1215N Digital Output Coding INP ANALOG INPUT VOLTAGE LEVEL INN ANALOG INPUT VOLTAGE LEVEL OUT-OF-RANGE ORP (ORN) BINARY DIGITAL OUTPUT CODE (D11P/N–D0P/N) TWO’S-COMPLEMENT DIGITAL OUTPUT CODE (D11P/N–D0P/N) > VCM + VFS / 4 < VCM - VFS / 4 1 (0) 1111 1111 1111 (exceeds +FS, OR set) 0111 1111 1111 (exceeds +FS, OR set) VCM + VFS / 4 VCM - VFS / 4 0 (1) 1111 1111 1111 (+FS) 0111 1111 1111 (+FS) VCM VCM 0 (1) 1000 0000 0000 or 0111 1111 1111 (FS/2) 0000 0000 0000 or 1111 1111 1111 (FS/2) VCM - VFS / 4 VCM + VFS / 4 0 (1) 0000 0000 0000 (-FS) 1000 0000 0000 (-FS) 1 (0) 0000 0000 0000 (exceeds -FS, OR set) 1000 0000 0000 (exceeds -FS, OR set) < VCM + VFS / 4 > VCM - VFS / 4 CONFIGURATION TO INCREASE THE FSR OF THE MAX1215N CONFIGURATION TO DECREASE THE FSR OF THE MAX1215N REFERENCESCALING AMPLIFIER ADC FULL SCALE = REFT - REFB REFT REFERENCESCALING AMPLIFIER ADC FULL SCALE = REFT - REFB REFT G G REFERENCE REFB BUFFER REFERENCE REFB BUFFER 1V 1V REFIO REFIO 0.1µF REFADJ 0.1µF 13kΩ TO 1MΩ REFADJ CONTROL LINE TO DISABLE REFERENCE BUFFER MAX1215N AVCC CONTROL LINE TO DISABLE REFERENCE BUFFER MAX1215N AVCC / 2 AVCC 13kΩ TO 1MΩ AVCC / 2 REFT: TOP OF REFERENCE LADDER. REFB: BOTTOM OF REFERENCE LADDER. Figure 6a. Circuit Suggestions to Adjust the ADC’s Full-Scale Range Applications Information FSR Adjustments Using the Internal Bandgap Reference The MAX1215N supports a 10% (±5%) full-scale adjustment range. To decrease the full-scale signal range, add an external resistor value ranging from 13kΩ to 1MΩ between REFADJ and AGND. Adding a variable resistor, potentiometer, or predetermined resis14 tor value between REFADJ and REFIO increases the FSR of the data converter. Figure 6a shows the two possible configurations and their impact on the overall full-scale range adjustment of the MAX1215N. Do not use resistor values of less than 13kΩ to avoid instability of the internal gain regulation loop for the bandgap reference. See Figure 6b for the resulting FSR for a series of resistor values. _______________________________________________________________________________________ 1.8V, Low-Power, 12-Bit, 250Msps ADC for Broadband Applications The MAX1215N dynamic performance depends on the use of a very clean clock source. The phase noise floor of the clock source has a negative impact on the SNR performance. Spurious signals on the clock signal source also affect the ADC’s dynamic range. The preferred method of clocking the MAX1215N is differentially with LVDS- or LVPECL-compatible input levels. The fast data transition rates of these logic families minimize the clock-input circuitry’s transition uncertainty, thereby improving the SNR performance. To accomplish this, a 50Ω reverse-terminated clock signal source with low phase noise is AC-coupled into a fast differential receiver such as the MC100LVEL16 (Figure 7). The receiver produces the necessary LVPECL output levels to drive the clock inputs of the data converter. FS VOLTAGE vs. ADJUST RESISTOR 1.34 1.32 RESISTOR VALUE APPLIED BETWEEN REFADJ AND REFIO INCREASES VFS 1.30 VFS (V) 1.28 1.26 1.24 1.22 RESISTOR VALUE APPLIED BETWEEN REFADJ AND AGND DECREASES VFS 1.20 1.18 1.16 1.14 0 100 200 300 400 500 600 700 800 900 1000 FS ADJUST RESISTOR (kΩ) Transformer-Coupled, Differential Analog Input Drive The MAX1215N provides the best SFDR and THD with fully differential input signals and it is not recommended to drive the ADC inputs in single-ended configuration. In differential input mode, even-order harmonics are usually lower since INP and INN are balanced, and Figure 6b. FS Adjustment Range vs. FS Adjustment Resistor VCLK 0.1µF 10kΩ SINGLE-ENDED INPUT TERMINAL 8 0.1µF 0.1µF 2 7 150Ω 50Ω MC100LVEL16D 0.1µF 6 3 510Ω 150Ω 510Ω AVCC OVCC 4 5 0.01µF INP CLKN CLKP D0P/N–D11P/N, 0RP/N MAX1215N INN 12 AGND OGND Figure 7. Differential, AC-Coupled, LVPECL-Compatible Clock Input Configuration ______________________________________________________________________________________ 15 MAX1215N Differential, AC-Coupled, LVPECL-Compatible Clock Input MAX1215N 1.8V, Low-Power, 12-Bit, 250Msps ADC for Broadband Applications each of the ADC inputs only requires half the signal swing compared to a single-ended configuration. Wideband RF transformers provide an excellent solution to convert a single-ended signal to a fully differential signal, required by the MAX1215N to reach its optimum dynamic performance. Apply a secondaryside termination of a 1:1 transformer (e.g., Mini-Circuit’s ADT1-1WT) into two separate 24.9Ω resistors. Higher source impedance values can be used at the expense of degradation in dynamic performance. Use resistors with tight tolerance (0.5%) to minimize effects of imbalance, maximizing the ADC’s dynamic range. This configuration optimizes THD and SFDR performance of the ADC by reducing the effects of transformer parasitics. However, the source impedance combined with the shunt capacitance provided by a PC board and the ADC’s parasitic capacitance limit the ADC’s full-power input bandwidth. To further enhance SFDR performance at high input frequencies (> 100MHz), place a second transformer (Figure 8) in series with the single-ended-to-differential conversion transformer. This transformer reduces the increase of even-order harmonics at high frequencies. Single-Ended, AC-Coupled Analog Inputs Although not recommended, the MAX1215N can be used in single-ended mode (Figure 9). AC-couple the analog signals to the positive input INP through a 0.1µF capacitor terminated with a 49.9Ω resistor to AGND. Terminate the negative input INN with a 49.9Ω resistor in series with a 0.1µF capacitor to AGND. In single-ended mode, the input range is limited to approximately half of the FSR of the device, and dynamic performance usually degrades. AVCC SINGLE-ENDED INPUT TERMINAL OVCC 0.1µF 0.1µF INP 1 ADT1-1WT 4 3 ADT1-1WT 6 24.9Ω 5 2 5 2 3 6 1 4 D0P/N–D11P/N, 0RP/N 10Ω 1% MAX1215N 24.9Ω 10Ω 1% 12 INN 0.1µF OGND AGND Figure 8. Analog Input Configuration with Back-to-Back Transformers and Secondary-Side Termination AVCC SINGLE-ENDED INPUT TERMINAL 0.1µF OVCC INP D0P/N–D11P/N, 0RP/N 49.9Ω 1% 0.1µF MAX1215N INN 12 49.9Ω 1% AGND OGND Figure 9. Single-Ended AC-Coupled Analog Input Configuration 16 _______________________________________________________________________________________ 1.8V, Low-Power, 12-Bit, 250Msps ADC for Broadband Applications The MAX1215N requires board layout design techniques suitable for high-speed data converters. This ADC provides separate analog and digital power supplies. The analog and digital supply voltage pins accept 1.7V to 1.9V input voltage ranges. Although both supply types can be combined and supplied from one source, it is recommended to use separate sources to cut down on performance degradation caused by digital switching currents, which can couple into the analog supply network. Isolate analog and digital supplies (AVCC and OVCC) where they enter the PC board with separate networks of ferrite beads and capacitors to their corresponding grounds (AGND, OGND). To achieve optimum performance, provide each supply with a separate network of a 47µF tantalum capacitor and parallel combinations of 10µF and 1µF ceramic capacitors. Additionally, the ADC requires each supply pin to be bypassed with separate 0.1µF ceramic capacitors (Figure 10). Locate these capacitors directly at the ADC supply pins or as close as possible to the MAX1215N. Choose surface-mount capacitors, whose preferred location should be on the same side as the converter to save space and minimize the inductance. If close placement on the same side is not possible, these bypassing capacitors may be routed through vias to the bottom side of the PC board. Multilayer boards with separated ground and power planes produce the highest level of signal integrity. Consider the use of a split ground plane arranged to match the physical location of analog and digital ground on the ADC’s package. The two ground planes should be joined at a single point so the noisy digital ground currents do not interfere with the analog ground plane. The dynamic currents that may need to travel long distances before they are recombined at a common-source ground, resulting in large and undesirable ground loops, are a major concern with this approach. Ground loops can degrade the input noise by coupling back to the analog front-end of the converter, resulting in increased spurious activity, leading to decreased noise performance. Alternatively, all ground pins could share the same ground plane, if the ground plane is sufficiently isolated from any noisy, digital systems ground. To minimize the coupling of the digital output signals from the analog input, segregate the digital output bus carefully from the analog input circuitry. To further minimize the effects of digital noise coupling, ground return vias can be positioned throughout the layout to divert digital switching currents away from the sensitive analog sections of the ADC. This approach does not require split ground planes, but can be accomplished by placing substantial ground connections between the analog front-end and the digital outputs. The MAX1215N is packaged in a 68-pin QFN-EP package (package code: G6800-4), providing greater design flexibility, increased thermal dissipation, and optimized AC performance of the ADC. The exposed paddle (EP) must be soldered down to AGND. In this package, the data converter die is attached to an EP lead frame with the back of this frame exposed BYPASSING—ADC LEVEL BYPASSING—BOARD LEVEL OVCC AVCC 0.1µF AVCC 0.1µF 1µF AGND 10µF 47µF ANALOG POWERSUPPLY SOURCE 10µF 47µF DIGITAL/OUTPUT DRIVER POWERSUPPLY SOURCE OGND D0P/N–D11P/N, 0RP/N OVCC MAX1215N 12 1µF AGND OGND NOTE: EACH POWER-SUPPLY PIN (ANALOG AND DIGITAL) SHOULD BE DECOUPLED WITH AN INDIVIDUAL 0.1µF CAPACITOR AS CLOSE AS POSSIBLE TO THE ADC. Figure 10. Grounding, Bypassing, and Decoupling Recommendations for the MAX1215N ______________________________________________________________________________________ 17 MAX1215N Grounding, Bypassing, and Board Layout Considerations MAX1215N 1.8V, Low-Power, 12-Bit, 250Msps ADC for Broadband Applications at the package bottom surface, facing the PC board side of the package. This allows a solid attachment of the package to the board with standard infrared (IR) flow soldering techniques. Thermal efficiency is one of the factors for selecting a package with an exposed pad for the MAX1215N. The exposed pad improves thermal efficiency and ensures a solid ground connection between the ADC and the PC board’s analog ground layer. Considerable care must be taken when routing the digital output traces for a high-speed, high-resolution data converter. Keep trace lengths at a minimum and place minimal capacitive loading (less than 5pF) on any digital trace to prevent coupling to sensitive analog sections of the ADC. It is recommended running the LVDS output traces as differential lines with 100Ω matched impedance from the ADC to the LVDS load device. Static Parameter Definitions Integral Nonlinearity (INL) Integral nonlinearity is the deviation of the values on an actual transfer function from a straight line. This straight line can be either a best straight-line fit or a line drawn between the end points of the transfer function, once offset and gain errors have been nullified. The static linearity parameters for the MAX1215N are measured using the histogram method with a 10MHz input frequency. Differential Nonlinearity (DNL) Differential nonlinearity is the difference between an actual step width and the ideal value of 1 LSB. A DNL error specification of less than 1 LSB guarantees no missing codes and a monotonic transfer function. The MAX1215N’s DNL specification is measured with the histogram method based on a 10MHz input tone. Dynamic Parameter Definitions Aperture Delay Aperture delay (tAD) is the time defined between the rising edge of the sampling clock and the instant when an actual sample is taken (Figure 11). Signal-to-Noise Ratio (SNR) For a waveform perfectly reconstructed from digital samples, the theoretical maximum SNR is the ratio of the fullscale analog input (RMS value) to the RMS quantization error (residual error). The ideal, theoretical minimum analog-to-digital noise is caused by quantization error only and results directly from the ADC’s resolution (N bits): SNR[max] = 6.02 x N + 1.76 In reality, other noise sources such as thermal noise, clock jitter, signal phase noise, and transfer function nonlinearities are also contributing to the SNR calculation and should be considered when determining the signal-to-noise ratio in ADC. Signal-to-Noise Plus Distortion (SINAD) SINAD is computed by taking the ratio of the RMS signal to all spectral components excluding the fundamental and the DC offset. In the case of the MAX1215N, SINAD is computed from a curve fit. CLKP CLKN ANALOG INPUT tAD tAJ SAMPLED DATA (T/H) Aperture Jitter Figure 11 depicts the aperture jitter (tAJ), which is the sample-to-sample variation in the aperture delay. T/H TRACK HOLD TRACK Figure 11. Aperture Jitter/Delay Specifications 18 _______________________________________________________________________________________ 1.8V, Low-Power, 12-Bit, 250Msps ADC for Broadband Applications The fundamental input tone amplitudes (V1 and V2) are at -7dBFS. The intermodulation products are the amplitudes of the output spectrum at the following frequencies: • Second-order intermodulation products: fIN1 + fIN2, fIN2 - fIN1 • Third-order intermodulation products: 2 x fIN1 - fIN2, 2 x fIN2 - fIN1, 2 x fIN1 + fIN2, 2 x fIN2 + fIN1 Intermodulation Distortion (IMD) • Fourth-order intermodulation products: 3 x fIN1 - fIN2, 3 x fIN2 - fIN1, 3 x fIN1 + fIN2, 3 x fIN2 + fIN1 IMD is the ratio of the RMS sum of the intermodulation products to the RMS sum of the two fundamental input tones. This is expressed as: ⎛ VIM12 + VIM22 + ...... + VIM32 + VIMn2 IMD = 20 × log⎜ ⎜ V12 + V22 ⎝ • Fifth-order intermodulation products: 3 x fIN1 - 2 x fIN2, 3 x fIN2 - 2 x fIN1, 3 x fIN1 + 2 x fIN2, 3 x fIN2 + 2 x fIN1 ⎞ ⎟ ⎟ ⎠ Full-Power Bandwidth A large -1dBFS analog input signal is applied to an ADC and the input frequency is swept up to the point where the amplitude of the digitized conversion result has decreased by 3dB. The -3dB point is defined as the full-power input bandwidth frequency of the ADC. Pin Configuration AVCC 1 AGND 2 REFIO 3 REFADJ 63 62 61 60 59 58 D9P D9N D10N D10P D11N D11P ORN ORP OVCC OGND AVCC 67 66 65 64 AVCC AGND 68 AVCC AGND AGND T/B TOP VIEW 57 56 55 54 53 52 51 D8P 50 D8N 49 D7P 4 48 D7N AGND 5 47 D6P AVCC 6 46 D6N AGND 7 45 OGND INP 8 44 OVCC INN 9 43 DCLKP AGND 10 42 DCLKN AVCC 11 41 OVCC AVCC 12 40 D5P AVCC 13 39 D5N D4P EP MAX1215N AVCC 14 38 AGND 15 37 D4N AGND 16 36 D3P 35 D3N CLKDIV 17 D2P D2N D1P D1N D0P D0N OVCC OVCC AVCC OGND AGND CLKN CLKP AGND AVCC AGND AGND 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 QFN EP = EXPOSED PADDLE. ______________________________________________________________________________________ 19 MAX1215N Spurious-Free Dynamic Range (SFDR) SFDR is the ratio of RMS amplitude of the carrier frequency (maximum signal component) to the RMS value of the next-largest noise or harmonic distortion component. SFDR is usually measured in dBc with respect to the carrier frequency amplitude or in dBFS with respect to the ADC’s full-scale range. Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.) For the MAX1215N, the package code is G6800-4. 68L QFN.EPS MAX1215N 1.8V, Low-Power, 12-Bit, 250Msps ADC for Broadband Applications PACKAGE OUTLINE, 68L QFN, 10x10x0.9 MM 1 C 21-0122 2 20 _______________________________________________________________________________________ 1.8V, Low-Power, 12-Bit, 250Msps ADC for Broadband Applications PACKAGE OUTLINE, 68L QFN, 10x10x0.9 MM 1 C 21-0122 2 Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 21 © 2006 Maxim Integrated Products Freed Printed USA is a registered trademark of Maxim Integrated Products, Inc. MAX1215N Package Information (continued) (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.)