ADS-917 14-Bit, 1MHz, Low-Power Sampling A/D Converters PRODUCT OVERVIEW The ADS-917 is a high-performance, 14-bit, 1MHz sampling A/D converter. This device samples input signals up to Nyquist frequencies with no missing codes. The ADS-917 features outstanding dynamic performance including a THD of –80dB. Housed in a small 24-pin DDIP or SMT (gull-wing) package, the functionally complete ADS-917 contains a fast-settling sample-hold amplifier, a subranging (two-pass) A/D converter, a precise voltage reference, timing/control logic, and error-correction circuitry. Digital input and output levels are TTL. Requiring ±15V (or ±12V) and +5V supplies, the ADS-917 dissipates 1.9W (1.6W for ±12V) maximum. The unit is offered with a unipolar input (0 to +10V). Models are available for use in either commercial (0 to +70°C), industrial (–40 to +100°C), or HI-REL (–55 to +125°C) operating temperature ranges. Applications include radar, sonar, spectrum analysis, instrumentation, and graphic/medical imaging. FEATURES 14-bit resolution PIN FUNCTION INPUT/OUTPUT CONNECTIONS PIN FUNCTION 1MHz sampling rate 1 BIT 14 (LSB) 24 –12V/–15V SUPPLY Functionally complete; No missing codes 2 BIT 13 23 ANALOG GROUND Edge-triggered; No pipeline delays 3 BIT 12 22 +12V/+15V SUPPLY 4 BIT 11 21 +10V REFERENCE OUT Small 24-pin DDIP or SMT package 5 BIT 10 20 ANALOG INPUT Low power, 1.9 Watts maximum 6 BIT 9 19 ANALOG GROUND 7 BIT 8 18 BIT 1 (MSB) 8 BIT 7 17 BIT 2 9 BIT 6 16 START CONVERT 10 BIT 5 15 EOC 11 BIT 4 14 DIGITAL GROUND 12 BIT 3 13 +5V SUPPLY Operates from ±15V or ±12V supplies & +5V supply Unipolar 0 to +10V input range (for bipolar ±5V input range see ADS-927) BLOCK DIAGRAM DAC 18 BIT 1 (MSB) 17 BIT 2 +10V REF. OUT 21 REF DIGITAL CORRECTION LOGIC 12 BIT 3 REGISTER S2 FLASH ADC S/H ANALOG INPUT 20 S1 BUFFER – REGISTER + 11 BIT 4 10 BIT 5 9 BIT 6 8 BIT 7 7 BIT 8 6 BIT 9 5 BIT 10 4 BIT 11 3 BIT 12 2 BIT 13 1 BIT 14 (LSB) START CONVERT 16 TIMING AND CONTROL LOGIC EOC 15 13 14 22 19, 23 24 +5V SUPPLY DIGITAL GROUND +12V/+15V SUPPLY ANALOG GROUND –12V/–15V SUPPLY Figure 1. ADS-917 Functional Block Diagram DATEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151 USA • Tel: (508) 339-3000 • www.datel.com • e-mail: [email protected] MDA_ADS-917.C02 Page 1 of 9 ADS-917 14-Bit, 1MHz, Low-Power Sampling A/D Converters ABSOLUTE MAXIMUM RATINGS PARAMETERS LIMITS +12V/+15V Supply (Pin 22) 0 to +16 –12V/–15V Supply (Pin 24) 0 to –16 +5V Supply (Pin 13) 0 to +6 Digital Input (Pin 16) –0.3 to +VDD +0.3 Analog Input (Pin 20) –4 to +17 Lead Temperature (10 seconds) +300 PHYSICAL/ENVIRONMENTAL PARAMETERS MIN. TYP. MAX. UNITS Operating Temp. Range, Case ADS-917MC, GC, MC-C, GC-C 0 — +70 °C ADS-917ME, GE, ME-C, GE-C –40 — +100 °C ADS-917MM, GM, MM-C, GM-C –55 — +125 °C ADS-917MM-QL, 883, MM-QL-C, 883-C –55 — +125 °C Thermal Impedance θjc — 6 — °C/Watt θca — 24 — °C/Watt Storage Temperature Range –65 — +150 °C Package Type 24-pin, metal-sealed, ceramic DDIP or SMT Weight 0.42 ounces (12 grams) UNITS Volts Volts Volts Volts Volts °C FUNCTIONAL SPECIFICATIONS (TA = +25°C, ±VCC = ±15V (or ±12V), +VDD = +5V, 1MHz sampling rate, and a minimum 1 minute warmup ➀ unless otherwise specified.) ANALOG INPUT Input Voltage Range ➁ Input Resistance Input Capacitance MIN. — — — +25°C TYP. 0 to +10 1 7 MAX. — — 15 MIN. — — — 0 TO +70°C TYP. 0 to +10 1 7 MAX. — — 15 MIN. — — — DIGITAL INPUT Logic Levels Logic "1" Logic "0" Logic Loading "1" Logic Loading "0" Start Convert Positive Pulse Width ➂ +2.0 — — — 20 — — — — 200 — +0.8 +20 –20 — +2.0 — — — 20 — — — — 200 — +0.8 +20 –20 — +2.0 — — — 20 — — — — 200 — +0.8 +20 –20 — Volts Volts μA μA ns STATIC PERFORMANCE Resolution Integral Nonlinearity (fin = 10kHz) Differential Nonlinearity (fin = 10kHz) Full Scale Absolute Accuracy Unipolar Offset Error (Tech Note 2) Gain Error (Tech Note 2) No Missing Codes (fin = 10kHz) — — — — — — 14 14 ±0.5 ±0.5 ±0.05 ±0.1 ±0.1 — — — +0.95 ±0.1 ±0.2 ±0.25 — — — — — — — 14 14 ±0.75 ±0.5 ±0.1 ±0.1 ±0.1 — — — ±0.95 ±0.2 ±0.2 ±.025 — — — -0.95 — — — 14 14 ±1.5 ±0.75 ±0.15 ±0.15 ±0.25 — — — +1.25 ±0.4 ±0.3 ±0.4 — Bits LSB LSB %FSR %FSR % Bits — — –87 –81 –82 –76 — — –87 –81 –82 –76 — — –85 –79 –80 –74 dB dB — — –85 –80 –82 –76 — — –85 –80 –82 –76 — — –84 –79 –80 –74 dB dB 75 73 79 78 — — 75 73 79 78 — — 73 72 77 76 — — dB dB 74 72 77 76 — — 74 72 77 76 — — 72 71 76 75 — — dB dB — — –87 300 — — — — –86 400 — — — — –85 600 — — dB μVrms — — — — — — 7 5 84 ±60 ±20 5 — — — — — — — — — — — — 7 5 84 ±60 ±20 5 — — — — — — — — — — — — 7 5 84 ±60 ±20 5 — — — — — — MHz MHz dB V/μs ns ps rms 530 — 1 570 400 — 610 1000 — 530 — 1 570 400 — 610 1000 — 530 — 1 570 400 — 610 1000 — ns ns MHz DYNAMIC PERFORMANCE Peak Harmonics (–0.5dB) dc to 100kHz 100kHz to 500kHz Total Harmonic Distortion (–0.5dB) dc to 100kHz 100kHz to 500kHz Signal-to-Noise Ratio (w/o distortion, –0.5dB) dc to 100kHz 100kHz to 500kHz Signal-to-Noise Ratio ➃ (& distortion, –0.5dB) dc to 100kHz 100kHz to 500kHz Two-tone Intermodulation Distortion (fin = 100kHz, 500kHz, fs = 1MHz –0.5dB) Noise Input Bandwidth (–3dB) Small Signal (–20dB input) Large Signal (–0.5dB input) Feedthrough Rejection (fin = 500kHz) Slew Rate Aperture Delay Time Aperture Uncertainty S/H Acquisition Time (to ±0.003%FSR, 10V step) Overvoltage Recovery Time ➄ A/D Conversion Rate DATEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151 USA • Tel: (508) 339-3000 • www.datel.com • –55 TO +125°C TYP. MAX. 0 to +10 — 1 — 7 15 UNITS Volts kΩ pF e-mail: [email protected] MDA_ADS-917.C02 Page 2 of 9 ADS-917 14-Bit, 1MHz, Low-Power Sampling A/D Converters +25°C ANALOG OUTPUT Internal Reference Voltage Drift External Current DIGITAL OUTPUTS Logic Levels Logic "1" Logic "0" Logic Loading "1" Logic Loading "0" Delay, Falling Edge of EOC to Output Data Valid Output Coding POWER REQUIREMENTS , ±15V Power Supply Ranges +15V Supply –15V Supply +5V Supply Power Supply Currents +15V Supply –15V Supply +5V Supply Power Dissipation Power Supply Rejection POWER REQUIREMENTS, ±12V Power Supply Ranges +12V Supply –12V Supply +5V Supply Power Supply Currents +12V Supply –12V Supply +5V Supply Power Dissipation Power Supply Rejection Power Supply Rejection 0 TO +70°C –55 TO +125°C MIN. TYP. MAX. MIN. TYP. MAX. MIN. TYP. MAX. UNITS +9.95 — — +10.0 ±5 — +10.05 — 1.5 +9.95 — — +10.0 ±5 — +10.05 — 1.5 +9.95 — — +10.0 ±5 — +10.05 — 1.5 Volts ppm/°C mA +2.4 — — — — — — — — — — +0.4 –4 +4 35 +2.4 — — — — +2.4 — — — — — — — — — — +0.4 –4 +4 35 Volts Volts mA mA ns +14.5 –14.5 +4.75 +15.0 –15.0 +5.0 +15.5 –15.5 +5.25 +14.5 –14.5 +4.75 +15.0 –15.0 +5.0 +15.5 –15.5 +5.25 +14.5 –14.5 +4.75 +15.0 –15.0 +5.0 +15.5 –15.5 +5.25 Volts Volts Volts — — — — — +50 –41 +70 1.7 — +70 –50 +85 1.98 ±0.01 — — — — — +50 –41 +70 1.7 — +70 –50 +85 1.98 ±0.01 — — — — — +50 –41 +70 1.7 — +70 –50 +85 1.98 ±0.01 mA mA mA Watts %FSR/%V +11.5 –11.5 +4.75 +12.0 –12.0 +5.0 +12.5 –12.5 +5.25 +11.5 –11.5 +4.75 +12.0 –12.0 +5.0 +12.5 –12.5 +5.25 +11.5 –11.5 +4.75 +12.0 –12.0 +5.0 +12.5 –12.5 +5.25 Volts Volts Volts — — — — — — +50 –40 +70 1.4 — — +65 –48 +80 1.6 ±0.01 ±0.01 — — — — — — +50 –40 +70 1.4 — — +65 –48 +80 1.6 ±0.01 ±0.01 — — — — — — +50 –40 +70 1.4 — — +65 –48 +80 1.6 ±0.01 ±0.01 mA mA mA Watts %FSR/%V %FSR/%V — — — +0.4 — –4 — +4 — 35 Straight Binary ➃ Effective bits is equal to: Footnotes: ➀ All power supplies must be on before applying a start convert pulse. All supplies and the clock (START CONVERT) must be present during warmup periods. The device must be continuously converting during this time. There is a slight degradation in performance when using ±12V supplies. ➁ See Ordering Information for availability of ±5V input range. Contact DATEL for availability of other input voltage ranges. ➂ A 1MHz clock with a 200ns wide start convert pulse is used for all production testing. See Timing Diagram for more details. (SNR + Distortion) – 1.76 + 20 log Full Scale Amplitude Actual Input Amplitude 6.02 ➄ This is the time required before the A/D output data is valid once the analog input is back within the specified range. TECHNICAL NOTES can be reduced to zero using the input circuit of Figure 2. When using this circuit, or any similar offset and gain-calibration hardware, make adjustments following warmup. To avoid interaction, always adjust offset before gain. 1. Obtaining fully specified performance from the ADS-917 requires careful attention to pc-card layout and power supply decoupling. The device's analog and digital ground systems are connected to each other internally. For optimal performance, tie all ground pins (14, 19 and 23) directly to a large analog ground plane beneath the package. 3. When operating the ADS-917 from ±12V supplies, do not drive external circuitry with the REFERENCE OUTPUT. The reference's accuracy and drift specifications may not be met, and loading the circuit may cause accuracy errors within the converter. Bypass all power supplies and the REFERENCE OUTPUT (pin 21) to ground with 4.7μF tantalum capacitors. Locate the bypass capacitors as close to the unit as possible. If the user-installed offset and gain adjusting circuit shown in Figure 2 is used, also locate it as close to the ADS-917 as possible. 2. The ADS-917 achieves its specified accuracies without the need for external calibration. If required, the device's small initial offset and gain errors DATEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151 USA 4. Applying a start convert pulse while a conversion is in progress (EOC = logic "1") initiates a new and inaccurate conversion cycle. Data from the interrupted and subsequent conversions will be invalid. • Tel: (508) 339-3000 • www.datel.com • e-mail: [email protected] MDA_ADS-917.C02 Page 3 of 9 ADS-917 14-Bit, 1MHz, Low-Power Sampling A/D Converters CALIBRATION PROCEDURE (Refer to Figures 2 and 3) Gain adjusting is accomplished when all bits are 1's and the LSB just changes from a 1 to a 0. This transition ideally occurs when the analog input is at +full scale minus 1½ LSB's (+9.999085V). Any offset and/or gain calibration procedures should not be implemented until devices are fully warmed up. To avoid interaction, offset must be adjusted before gain. The ranges of adjustment for the circuit of Figure 2 are guaranteed to compensate for the ADS-917's initial accuracy errors and may not be able to compensate for additional system errors. Zero/Offset Adjust Procedure All fixed resistors in Figure 2 should be metal-film types, and multiturn potentiometers should have TCR’s of 100ppm/°C or less to minimize drift with temperature. 2. Apply +305μV to the ANALOG INPUT (pin 20). 1. Apply a train of pulses to the START CONVERT input (pin 16) so the converter is continuously converting. If using LED's on the outputs, a 200kHz conversion rate will reduce flicker. A/D converters are calibrated by positioning their digital outputs exactly on the transition point between two adjacent digital output codes. This can be accomplished by connecting LED's to the digital outputs and adjusting until certain LED's "flicker" equally between on and off. Other approaches employ digital comparators or microcontrollers to detect when the outputs change from one code to the next. For the ADS-917, offset adjusting is normally accomplished at the point where the output bits are 0's and the LSB just changes from a 0 to a 1. This digital output transition ideally occurs when the applied analog input is +½ LSB (+305μV). 3. Adjust the offset potentiometer until the output bits are all 0's and the LSB flickers between 0 and 1. Gain Adjust Procedure 1. Apply +9.999085V to the ANALOG INPUT (pin 20). 2. Adjust the gain potentiometer until the output bits are all 1's and the LSB flickers between 1 and 0. Table 1. Zero and Gain Adjust +15V ZERO/ OFFSET ADJUST 20kΩ –15V SIGNAL INPUT 200kΩ 2kΩ INPUT VOLTAGE RANGE ZERO ADJUST +½ LSB GAIN ADJUST +FS –1½ LSB 0 to +10V +305μV +9.999085V Table 2. Output Coding GAIN ADJUST +15V 1.98kΩ To Pin 20 of ADS-917 50Ω DIGITAL OUTPUT INPUT VOLTAGE (0 TO +10V) UNIPOLAR SCALE +9.999390 +FS –1LSB 11 1111 1111 1111 +7.500000 +3/4 FS 11 0000 0000 0000 +5.000000 +1/2 FS 10 0000 0000 0000 +2.500000 +1/4 FS 01 0000 0000 0000 +0.000610 +1LSB 00 0000 0000 0001 0.000000 0 00 0000 0000 0000 –15V Figure 2. ADS-917 Calibration Circuit OFFSET MSB BINARY LSB Coding is straight binary; 1LSB = 610μV. 18 BIT 1 (MSB) +5V 4.7μF + 13 17 BIT 2 12 BIT 3 14 DIGITAL GROUND 11 BIT 4 10 BIT 5 9 BIT 6 0.1μF ADS-917 24 –12V/–15V 4.7μF 4.7μF +12V/+15V + + 0.1μF ANALOG 19, 23 GROUND 6 BIT 9 5 BIT 10 4 BIT 11 22 3 BIT 12 2 BIT 13 0.1μF ANALOG 20 INPUT 0 to +10V 0.1μF 8 BIT 7 7 BIT 8 4.7μF + 1 BIT 14 (LSB) 15 EOC 21 +10V REF. OUT START 16 CONVERT Figure 3. Typical ADS-917 Connection Diagram DATEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151 USA • Tel: (508) 339-3000 • www.datel.com • e-mail: [email protected] MDA_ADS-917.C02 Page 4 of 9 ADS-917 14-Bit, 1MHz, Low-Power Sampling A/D Converters THERMAL REQUIREMENTS devices do not overheat. The ground and power planes beneath the package, as well as all pcb signal runs to and from the device, should be as heavy as possible to help conduct heat away from the package. All DATEL sampling A/D converters are fully characterized and specified over operating temperature (case) ranges of 0 to +70°C and –55 to +125°C. All room-temperature (TA = +25°C) production testing is performed without the use of heat sinks or forced-air cooling. Thermal impedance figures for each device are listed in their respective specification tables. Electrically-insulating, thermally-conductive "pads" may be installed underneath the package. Devices should be soldered to boards rather than "socketed," and of course, minimal air flow over the surface can greatly help reduce the package temperature. These devices do not normally require heat sinks, however, standard precautionary design and layout procedures should be used to ensure N START CONVERT N+1 200ns typ. 10ns typ. INTERNAL S/H Acquisition Time Hold 430ns typ. 570ns ±40ns 70ns ±10ns 90ns typ. EOC Conversion Time 420ns ±20ns 35ns max. 74ns max. OUTPUT DATA Data (N – 1) Valid 926ns min. Data N Valid Invalid Data Invalid Data 926ns min. Notes: 1. fs = 500kHz. 2. The ADS-917 is an edge-triggered device. All internal operations are triggered by the rising edge of the start convert pulse, which may be as narrow as 20nsec. All production testing is performed at a 1MHz sampling rate with 200nsec wide start pulses. For lower sampling rates, wider start pulses may be used, however, a minimum pulse width low of 20nsec must be maintained. Figure 4. ADS-917 Timing Diagram DATEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151 USA • Tel: (508) 339-3000 • www.datel.com • e-mail: [email protected] MDA_ADS-917.C02 Page 5 of 9 ADS-917 Figure 5. ADS-917 Evaluation Board Schematic 14-Bit, 1MHz, Low-Power Sampling A/D Converters DATEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151 USA • Tel: (508) 339-3000 • www.datel.com • e-mail: [email protected] MDA_ADS-917.C02 Page 6 of 9 ADS-917 14-Bit, 1MHz, Low-Power Sampling A/D Converters 0 Amplitude Relative to Full Scale (dB) –10 –20 –30 –40 –50 –60 –70 –80 –90 –100 –110 –120 –130 –140 0 50 100 150 200 250 300 350 400 450 500 Frequency (kHz) (fs = 1MHz, fin = 480kHz, Vin = –0.5dB, 16,384-point FFT) Figure 6. ADS-917 FFT Analysis Number of Occurrences DNL (LSB's) +0.41 0 –0.33 0 0 16,384 Digital Output Code 16,384 Digital Output Code Figure 7. ADS-917 Histogram and Differential Nonlinearity DATEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151 USA • Tel: (508) 339-3000 • www.datel.com • e-mail: [email protected] MDA_ADS-917.C02 Page 7 of 9 ADS-917 14-Bit, 1MHz, Low-Power Sampling A/D Converters MECHANICAL DIMENSIONS INCHES (mm) 1.31 MAX. (33.27) 24-Pin DDIP Versions 24 ADS-917MC ADS-917ME ADS-917MM ADS-917/883 ADS-917MC-C ADS-917ME-C ADS-917MM-C ADS-917-C/883 Dimension Tolerances (unless otherwise indicated): 2 place decimal (.XX) ±0.010 (±0.254) 3 place decimal (.XXX) ±0.005 (±0.127) 13 0.80 MAX. (20.32) 1 Lead Material: Kovar alloy Lead Finish: 50 microinches (minimum) gold plating over 100 microinches (nominal) nickel plating 12 0.100 TYP. (2.540) 1.100 (27.940) 0.235 MAX. (5.969) PIN 1 INDEX 0.200 MAX. (5.080) 0.010 (0.254) 0.190 MAX. (4.826) 0.100 (2.540) 0.018 ±0.002 (0.457) 0.100 (2.540) 0.600 ±0.010 (15.240) SEATING PLANE 0.025 (0.635) 0.040 (1.016) +0.002 –0.001 1.31 MAX. (33.02) 24-Pin Surface Mount Versions ADS-917GC ADS-917GE ADS-917GM ADS-917G/883 ADS-917GC-C ADS-917GE-C ADS-917GM-C ADS-917G-C/883 Dimension Tolerances (unless otherwise indicated): 2 place decimal (.XX) ±0.010 (±0.254) 3 place decimal (.XXX) ±0.005 (±0.127) 13 24 Lead Material: Kovar alloy 0.80 MAX. (20.32) 1 0.190 MAX. (4.826) Lead Finish: 50 microinches (minimum) gold plating over 100 microinches (nominal) nickel plating 12 0.020 TYP. (0.508) 0.060 TYP. (1.524) PIN 1 INDEX 0.100 (2.540) 0.100 TYP. (2.540) DATEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151 USA 0.015 (0.381) MAX. radius for any pin 0.130 TYP. (3.302) 0.020 (0.508) 0.010 TYP. (0.254) 0.040 (1.016) • Tel: (508) 339-3000 • www.datel.com • e-mail: [email protected] MDA_ADS-917.C02 Page 8 of 9 ADS-917 14-Bit, 1MHz, Low-Power Sampling A/D Converters ORDERING GUIDE MODEL NUMBER ADS-917MC ADS-917MC-C ADS-917ME ADS-917ME-C ADS-917MM ADS-917MM-C ADS-917MM-QL ADS-917MM-QL-C ADS-917/883 ADS-917-C/883 ADS-917GC ADS-917GC-C ADS-917GE ADS-917GE-C ADS-917GM ADS-917GM-C ADS-917G/883 ADS-917G-C/883 OPERATING TEMPERATURE RANGE 0 to +70°C 0 to +70°C –40 to +100°C –40 to +100°C –55 to +125°C –55 to +125°C –55 to +125°C –55 to +125°C –55 to +125°C –55 to +125°C 0 to +70°C 0 to +70°C –40 to +100°C –40 to +100°C –55 to +125°C –55 to +125°C –55 to +125°C –55 to +125°C PACKAGE ROHS DDIP DDIP DDIP DDIP DDIP DDIP DDIP DDIP DDIP DDIP SMT SMT SMT SMT SMT SMT SMT SMT No Yes No Yes No Yes No Yes No Yes No Yes No Yes No Yes No Yes For bipolar analog input ±5V see ADS-927 data sheet. DATEL is a registered trademark of DATEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151 USA DATEL, Inc. makes no representation that the use of its products in the circuits described herein, or the use of other technical information contained herein, will not infringe upon existing or future patent rights. The descriptions contained herein do not imply the granting of licenses to make, use, or sell equipment constructed in accordance therewith. Specifications are subject to change without notice. ITAR and ISO 9001/14001 REGISTERED © 2015 DATEL, Inc. www.datel.com • e-mail: [email protected] MDA_ADS-917.C02 Page 9 of 9