MAX1160

19-1189; Rev 0; 3/97 KIT ATION EVALU BLE AVAILA 10-Bit, 20Msps, TTL-Output ADC ____________________________Features o Monolithic 20Msps Converter o On-Chip Track/Hold o Bipolar, ±2V Analog Input o 60dB SNR at 1MHz Input o 5pF Input Capacitance o TTL Outputs _______________General Description The MAX1160 10-bit, monolithic analog-to-digital converter (ADC) is capable of 20Msps minimum word rates. An on-board track/hold ensures excellent dynamic performance without the need for external components. A 5pF input capacitance minimizes drive requirement problems. Inputs and outputs are TTL compatible. An overrange output is provided to indicate overflow conditions. Output data format is straight binary. Power dissipation is low at only 1W with +5V and -5.2V power-supply voltages. The MAX1160 also accepts wide ±2V input voltages. The MAX1160 is available in 28-pin DIP and SO packages in the commercial temperature range. MAX1160 ________________________Applications Medical Imaging Professional Video Radar Receivers Instrumentation Digital Communications ______________Ordering Information PART MAX1160ACPI MAX1160BCPI MAX1160ACWI MAX1160BCWI TEMP. RANGE 0°C to +70°C 0°C to +70°C 0°C to +70°C 0°C to +70°C PIN-PACKAGE 28 Wide Plastic DIP 28 Wide Plastic DIP 28 SO 28 SO ________________Functional Diagram ANALOG INPUT 4 COARSE ADC ANALOG PRESCALER __________________Pin Configuration TOP VIEW TOP VIEW DGND D0 D1 D2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 DVCC 27 VEE 26 AGND 25 VCC DECODING NETWORK T/H AMPLIFIER BANK D3 DIGITAL OUTPUT D4 D5 D6 D7 D8 D9 D10 DGND DVCC MAX1160 24 VFB 23 VSB 22 VRM 21 VIN 20 VST 19 VFT 18 VCC 17 AGND 16 VEE 15 CLK 10 SUCCESSIVE INTERPOLATION STAGE i SUCCESSIVE INTERPOLATION STAGE i + 1 . . . . SUCCESSIVE INTERPOLATION STAGE N DIP/SO 1 ________________________________________________________________ Maxim Integrated Products For the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800 10-Bit, 20Msps, TTL-Output ADC MAX1160 ABSOLUTE MAXIMUM RATINGS VCC ..........................................................................................................6V VEE .........................................................................................................-6V Analog Input ......................................................VFB ≤ VIN ≤ VFT VFT, VFB ...........................................................................3V, -3V Reference-Ladder Current..................................................12mA CLK Input...............................................................................VCC Digital Outputs.....................................................30mA to -30mA Continuous Power Dissipation (TA = +70°C) Plastic DIP ......................................................................1.14W SO .......................................................................................1W Operating Temperature Range...............................0°C to +70°C Junction Temperature .....................................................+150°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10sec). ............................+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 (VCC = +5.0V, VEE = -5.2V, DVCC = +5.0V, VIN = ±2.0V, VSB = -2.0V, VST = +2.0V, fCLK = 20MHz, 50% clock duty cycle, TA = TMIN to TMAX, unless otherwise noted.) PARAMETER Resolution DC ACCURACY (± full scale, 250kHz sample rate, TA = +25°C) Integral Nonlinearity Differential Nonlinearity No Missing Codes ANALOG INPUT Input Voltage Range Input Bias Current Input Bias Current Input Resistance Input Resistance Input Capacitance Input Bandwidth Positive Full-Scale Error Negative Full-Scale Error REFERENCE INPUT Reference-Ladder Resistance Reference-Ladder Tempco TIMING CHARACTERISTICS Maximum Conversion Rate Overvoltage Recovery Time Pipeline Delay (Latency) Output Delay Aperture Delay Time Aperture Jitter Time Acquisition Time 2 TA = +25°C TA = +25°C TA = +25°C TA = +25°C VI V VI V V V V 14 1 5 20 20 20 1 18 14 1 5 20 20 20 1 18 MHz ns Clock Cycle ns ns ps-RMS ns VI V 500 800 0.8 500 800 0.8 Ω Ω/°C 3dB small signal TA = -55°C to +125°C VIN = 0V TA = -55°C to +125°C VI VI VI VI VI V V V V 100 75 300 300 5 120 ±2.0 ±2.0 ±2.0 30 60 75 100 75 300 300 5 120 ±2.0 ±2.0 ±2.0 30 60 75 V µA µA kΩ kΩ pF MHz LSB LSB I I ±1.0 ±0.5 Guaranteed ±1.5 ±0.75 Guaranteed LSB LSB CONDITIONS TEST LEVEL MAX1160A TYP MAX MAX1160B TYP MAX UNITS Bits MIN 10 MIN 10 _______________________________________________________________________________________ 10-Bit, 20Msps, TTL-Output ADC ELECTRICAL CHARACTERISTICS (continued) (VCC = +5.0V, VEE = -5.2V, DVCC = +5.0V, VIN = ±2.0V, VSB = -2.0V, VST = +2.0V, fCLK = 20MHz, 50% clock duty cycle, TA = TMIN to TMAX, unless otherwise noted.) PARAMETER DYNAMIC PERFORMANCE Effective Number of Bits (ENOB) fIN = 1MHz fIN = 3.58MHz fIN = 10MHz TA = +25°C fIN = 1MHz Signal-to-Noise Ratio (without harmonics) (SNR) TA = 0°C to +70°C, TA = -25°C to +85°C TA = +25°C fIN = 3.58MHz TA = 0°C to +70°C, TA = -25°C to +85°C TA = +25°C fIN = 10MHz TA = 0°C to +70°C, TA = -25°C to +85°C TA = +25°C fIN = 1MHz TA = 0°C to +70°C, TA = -25°C to +85°C TA = +25°C fIN = 3.58MHz TA = 0°C to +70°C, TA = -25°C to +85°C TA = +25°C fIN = 10MHz TA = 0°C to +70°C, TA = -25°C to +85°C TA = +25°C fIN = 1MHz Signal-to-Noise and Distortion Ratio (SINAD) TA = 0°C to +70°C, TA = -25°C to +85°C TA = +25°C fIN = 3.58MHz TA = 0°C to +70°C, TA = -25°C to +85°C TA = +25°C fIN = 10MHz Spurious-Free Dynamic Range (SFDR) Differential Phase Differential Gain TA = 0°C to +70°C, TA = -25°C to +85°C TA = +25°C TA = +25°C TA = +25°C I IV I IV I IV I IV I IV I IV I IV I IV I IV V V V 57 55 56 54 50 47 57 54 56 53 46 45 55 52 54 51 44 43 67 0.2 0.5 47 55 9.2 8.8 7.5 60 58 58 56 53 50 60 57 58 55 48 47 57 54 52 53 51 47 44 54 51 53 50 43 42 52 49 51 48 41 40 67 0.2 0.7 dB Degrees % 44 52 dB 8.7 8.3 7.0 57 55 55 53 49 46 57 54 55 52 45 44 54 dB dB Bits CONDITIONS TEST LEVEL MAX1160A MIN TYP MAX MAX1160B MIN TYP MAX UNITS MAX1160 Total Harmonic Distortion (THD) fIN = 1MHz fIN = 3.58MHz and 4.35MHz fIN = 3.58MHz and 4.35MHz _______________________________________________________________________________________ 3 10-Bit, 20Msps, TTL-Output ADC MAX1160 ELECTRICAL CHARACTERISTICS (continued) (VCC = +5.0V, VEE = -5.2V, DVCC = +5.0V, VIN = ±2.0V, VSB = -2.0V, VST = +2.0V, fCLK = 20MHz, 50% clock duty cycle, TA = TMIN to TMAX, unless otherwise noted.) PARAMETER DIGITAL INPUTS Logic 1 Voltage Logic 0 Voltage Maximum Input Current Low Maximum Input Current High Pulse Width Low (CLK) Pulse Width High (CLK) DIGITAL OUTPUTS Logic 1 Voltage Logic 0 Voltage POWER-SUPPLY REQUIREMENTS VCC Voltages DVCC -VEE ICC Currents Power Dissipation Power-Supply Rejection TEST LEVEL CODES CONDITIONS TEST LEVEL V V MAX1160A MIN TYP MAX 2.4 4.5 0.8 0 0 20 20 2.4 0.6 4.75 4.75 5.0 118 40 40 1.0 1.0 -4.95 -5.2 5.25 5.25 145 55 57 1.3 300 5 5 20 20 MAX1160B MIN TYP MAX 2.4 4.0 0.8 0 0 20 20 2.4 0.6 4.75 4.75 5.0 118 40 40 1.0 1.0 5.25 5.25 -5.45 145 55 57 1.3 300 5 5 20 20 UNITS V V µA µA ns ns V V TA = +25°C TA = +25°C IV IV IV IV IV IV IV IV IV VI VI VI VI V V -5.45 -4.95 -5.2 DICC -IEE VCC = 5V ±0.25V, VEE = -5.2V ±0.25V TEST LEVEL I II III IV V VI mA W LSB All electrical characteristics are subject to the following conditions: All parameters having min/max specifications are guaranteed. The Test Level column indicates the specific device testing actually performed during production and Quality Assurance inspection. Any blank section in the data column indicates that the specification is not tested at the specified condition. Unless otherwise noted, all tests are pulsed; therefore, Tj = TC = TA. TEST PROCEDURE 100% production tested at the specified temperature. 100% production tested at TA = +25°C, and sample tested at the specified temperatures. QA sample tested only at the specified temperatures. Parameter is guaranteed (but not tested) by design and characterization data. Parameter is a typical value for information purposes only. 100% production tested at TA = +25°C. Parameter is guaranteed over specified temperature range. ______________________________________________________________Pin Description PIN 1, 13 2 3–10 11 12 14, 28 15 16, 27 NAME DGND D0 D1–D8 D9 D10 DVCC CLK VEE FUNCTION Digital Ground TTL Output (LSB) TTL Outputs TTL Output (MSB) TTL Output Overrange +5V Supply (digital) Clock -5.2V Supply (analog) PIN 17, 26 18, 25 19 20 21 22 23 24 NAME AGND VCC VFT VST VIN VRM VSB VFB FUNCTION Analog Ground +5V Supply (analog) Force for Top of Reference Ladder Sense for Top of Reference Ladder Analog Input Middle of Voltage Reference Ladder Sense for Bottom of Reference Ladder Force for Bottom of Reference Ladder 4 _______________________________________________________________________________________ 10-Bit, 20Msps, TTL-Output ADC __________________________________________Typical Operating Characteristics (TA = +25°C, unless otherwise noted.) MAX1160 SIGNAL-TO-NOISE RATIO vs. INPUT FREQUENCY MAX1160-01 TOTAL HARMONIC DISTORTION vs. INPUT FREQUENCY MAX1160-02 SIGNAL-TO-NOISE AND DISTORTION vs. INPUT FREQUENCY fS = 20Msps 70 60 50 40 30 20 MAX1160-03 80 fS = 20Msps 70 60 SNR (dB) 80 fS = 20Msps 70 60 THD (dB) 50 40 30 20 80 50 40 30 20 1 10 INPUT FREQUENCY (MHz) 100 1 10 INPUT FREQUENCY (MHz) 100 SINAD (dB) 1 10 INPUT FREQUENCY (MHz) 100 SNR, THD, SINAD vs. SAMPLE RATE fIN = 1MHz 70 SNR, THD, SINAD (dB) 60 50 40 30 20 1 10 SAMPLE RATE (Msps) 100 SNR, THD MAX1160-04 SNR, THD, SINAD vs. TEMPERATURE MAX1160-06 SPECTRAL RESPONSE SNR fS = 20Msps fIN = 1MHz -30 AMPLITUDE (dB) MAX1160-05 80 65 SNR SNR, THD, SINAD (dB) 60 55 THD SINAD 50 THD 0 SINAD -60 45 fS = 20Msps fIN = 1MHz 40 -25 0 25 50 75 TEMPERATURE (°C) -90 -120 0 1 2 3 4 5 6 7 8 9 10 INPUT FREQUENCY (MHz) ______________Detailed Description The MAX1160 requires few external components to achieve the stated operation and performance. Figure 2 shows the typical interface requirements when using the MAX1160 in normal circuit operation. The following section provides a description of the pin functions, and outlines critical performance criteria to consider for achieving the optimal device performance. Power Supplies and Grounding The MAX1160 requires -5.2V and +5V analog supply voltages. The +5V supply is common to analog VCC and digital DVCC. A ferrite bead in series with each supply line reduces the transient noise injected into the analog V CC . Connect these beads as close to the device as possible. The connection between the beads and the MAX1160 should not be shared with any other device. Bypass each power-supply pin as close to the device as possible. Use 0.1µF for VEE and VCC, and 0.01µF for DVCC (chip capacitors are recommended). _______________________________________________________________________________________ 5 10-Bit, 20Msps, TTL-Output ADC MAX1160 N tpwH tpwL N+1 N+2 CLK td CLK td OUTPUT N-2 DATA DATA VALID N DATA VALID N+1 N-1 OUTPUT DATA DATA VALID Figure 1a. Timing Diagram Figure 1b. Single-Event Clock Table 1. Timing Parameters PARAMETER td tpwH tpwL DESCRIPTION CLK to Data Valid Propagation Delay CLK High Pulse Width CLK Low Pulse Width 20 20 MIN TYP 14 MAX 18 300 UNITS ns ns ns The MAX1160 has two grounds: AGND and DGND. These internal grounds are isolated on the device. Use ground planes for optimum device performance. Use DGND for the DVCC return path (typically 40mA) and for the return path for all digital output logic interfaces. Separate AGND and DGND from each other, connecting them together only through a ferrite bead at the device. Connect a Schottky or hot carrier diode between AGND and VEE. The use of separate power supplies between VCC and DVCC is not recommended due to potential power-supply-sequencing latchup conditions. For optimum performance, use the recommended circuit shown in Figure 2. Voltage Reference The MAX1160 requires the use of two voltage references: VFT and VFB. VFT is the force for the top of the voltage-reference ladder (typically +2.5V); VFB (typically -2.5V) is the force for the bottom of the voltage-reference ladder. Both voltages are applied across an 800Ω internal reference-ladder resistance. The +2.5V voltage source for reference VFT must be current limited to 20mA (max) if a different driving circuit is used in place of the recommended reference circuit shown in Figures 2 and 3. In addition, there are three reference-ladder taps (VST, VRM, and VSB). VST is the sense for the top of the reference ladder (+2V), VRM is the midpoint of the ladder (typically 0V), and VSB is the sense for the 6 bottom of the reference ladder (-2V). The voltages at VST and VSB are the device’s true full-scale input voltages when VFT and VFB are driven to the recommended voltages (typically +2.5V and -2.5V, respectively). These points should be used to monitor the device’s actual full-scale input range. When not being used, a decoupling capacitor of 0.01µF (chip capacitor preferred) connected to AGND from each tap is recommended to minimize high-frequency noise injection. Figure 2 shows an example of a recommended reference-driver circuit. IC1 is a MAX6225, a 2.5V reference with an accuracy of 0.2%. The 10kΩ potentiometer R1 supports a minimum adjustable range of 0.6%. Use an OP07 or equivalent device for IC2. R2 and R3 must be matched to within 0.1% with good TC tracking to maintain 0.3LSB matching between VFT and VFB. If 0.1% matching is not met, then R4 can be used to adjust the VFB voltage to the desired level. Adjust VFT and VFB such that VST and VSB are exactly +2V and -2V, respectively. The analog input range scales proportionally with respect to the reference voltage if a different input range is required. The maximum scaling factor for device operation is ±20% of the recommended reference voltages of VFT and VFB. However, because the device is laser trimmed to optimize performance with ±2.5V references, its accuracy degrades if operated beyond a ±2% range. _______________________________________________________________________________________ 10-Bit, 20Msps, TTL-Output ADC The following errors are defined: +FS error = top of ladder offset voltage = ∆(+FS - VST + 1LSB) -FS error = bottom of ladder offset voltage = ∆(-FS - VSB - 1LSB) where the +FS (full-scale) input voltage is defined as the output transition between 11 1111 1110 and 11 1111 1111, and the -FS input voltage is defined as the output transition between 00 0000 0000 and 00 0000 0001 (Table 2). The analog input’s drive requirements are minimal when compared to conventional flash converters. This is due to the MAX1160’s extremely low (5pF) input capacitance and very high (300kΩ) input resistance. For example, for an input signal of ±2Vp-p with a 10MHz input frequency, the peak output current required for the driving circuit is only 628µA. MAX1160 Clock Input The MAX1160 is driven from a single-ended TTL input (CLK). The CLK pulse width (t pwH ) must be kept between 20ns and 300ns to ensure proper operation of the internal track/hold amplifier (Figure 1a). When operating the MAX1160 at sampling rates above 3Msps, it is recommended that the clock input duty cycle be kept at Analog Input VIN is the analog input. The full-scale input range will be 80% of the reference voltage, or ±2V with VFB = -2.5V and VFT = +2.5V. CLK (TTL) VIN (±2V) +5V 1µF CLK R5 100Ω ±2.5V MAX 2 VIN 6 IC1 VOUT 2.5V R1 10k 5 R2 30k -5.2V 4 0.01µF 76 -2.5V 1µF = AGND = DGND C5 0.01µF DGND DGND AGND AGND DVCC DVCC VCC VCC VEE VEE VFB R3 30k C4 0.01µF 1µF C1 0.01µF C2 0.01µF VIN VFT R VST 2R C3 0.01µF 2R VRM 2R 2R R SUCCESSIVE INTERPOLATION STAGE N ANALOG PRESCALER DECODING NETWORK COARSE ADC 4 D10 (OVERRANGE) D9 (MSB) D8 D7 D6 D5 D4 D3 D2 D1 D0 (LSB) DIGITAL OUTPUTS MAX1160 4 GND MAX6225 VTRIM 3 1 R4 10k +5V 0.01µF 8 2 IC2 OP07 SUCCESSIVE INTERPOLATION STAGE 1 VSB NOTES: 1) D1 = SCHOTTKY OR HOT CARRIER DIODE 2) FB = FERRITE BEAD, FAIR RITE #2743001111 TO BE MOUNTED AS CLOSELY TO THE DEVICE AS POSSIBLE. THE FERRITE BEAD TO ADC CONNECTION SHOULD NOT BE SHARED WITH ANY OTHER DEVICE. 3) C1–C11 = CHIP CAPACITOR (RECOMMENDED) MOUNTED AS CLOSE TO DEVICE'S PIN AS POSSIBLE. 4) USE OF A SEPARATE SUPPLY FOR VCC AND DVCC IS NOT RECOMMENDED. 5) R5 PROVIDES CURRENT LIMITING TO 45mA. C6 0.1µF C7 0.1µF C8 0.1µF C9 0.1µF FB FB C10 0.01µF C11 0.01µF FB D1 10µF -5.2V 10µF +5V Figure 2. Typical Operating Circuit _______________________________________________________________________________________ 7 10-Bit, 20Msps, TTL-Output ADC MAX1160 Table 2. Output Data Information ANALOG INPUT > +2V + 1/2LSB +2V - 1LSB 0V -2V + 1LSB < 2V OVERRANGE D10 1 0 0 0 0 OUTPUT CODE D9–D0 11 1111 1111 11 ØØ 00 00 1111 ØØØØ 0000 0000 111Ø ØØØØ 000Ø 0000 The digital outputs’ rise and fall times are not symmetrical. Typical propagation delay is 14ns for the rise time and 6ns for the fall time (Figure 4). The nonsymmetrical rise and fall times create approximately 8ns of invalid data. Overrange Output The overrange output (D10) is an indication that the analog input signal has exceeded the positive full-scale input voltage by 1LSB. When this condition occurs, D10 will switch to logic 1. All other data outputs (D0–D9) will remain at logic 1 as long as D10 remains at logic 1. This feature makes it possible to include the MAX1160 in higher-resolution systems. (Ø indicates the flickering bit between logic 0 and 1.) 50% to optimize performance, but performance will not be degraded if kept within the 40% to 60% range. The analog input signal is latched on the rising edge of CLK. The clock input must be driven from fast TTL logic (VIH ≤ 4.5V, tRISE < 6ns). In the event the clock is driven from a high current source, use a 100Ω resistor (R5) in series to limit current to approximately 45mA. Evaluation Board The MAX1160 EV kit is available to help designers demonstrate the MAX1160’s full performance. This board includes a reference circuit, a clock-driver circuit, output data latches, and an on-board reconstruction of the digital data. A separate data sheet describing the operation of this board is also available. Contact the factory for price and availability. Digital Outputs The format of the output data (D0–D9) is straight binary (Table 2). The outputs are latched on the rising edge of CLK with a typical propagation delay of 14ns. There is a one-clock-cycle latency between CLK and the valid output data (Figure 1a). VCC N N+1 CLK IN 2.4V 6ns VIN ANALOG PRESCALER typ VFT tRISE 6ns 3.5V DATA 2.4V OUT (ACTUAL) 0.8V 0.5V (N - 2) INVALID DATA tpd1 14ns typ (N - 1) INVALID DATA N VEE DATA OUT (EQUIVALENT) (N - 2) INVALID DATA (N - 1) INVALID DATA N Figure 3. Analog Equivalent Input Circuit Figure 4. Digital Output Characteristics 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. 8 ___________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 (408) 737-7600 © 1997 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.