ADS-916 14-Bit, 500kHz, Low-Power Sampling A/D Converters PRODUCT OVERVIEW The ADS-916 is a high-performance, 14-bit, 500kHz sampling A/D converter. This device samples input signals up to Nyquist frequencies with no missing codes. The ADS-916 features outstanding dynamic performance including a THD of –90dB. Housed in a small 24-pin DDIP or SMT (gullwing) package, the functionally complete ADS-916 contains a fast-settling sample-hold amplifier, a subranging (two-pass) A/D converter, a precise voltage reference, timing/control logic, and error- FEATURES 14-bit resolution correction circuitry. Digital input and output levels are TTL. Requiring ±15V (or ±12V) and +5V supplies, the ADS-916 dissipates 1.8W (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, and graphic/medical imaging. PIN FUNCTION INPUT/OUTPUT CONNECTIONS PIN FUNCTION 1 BIT 14 (LSB) 24 –12V/–15V SUPPLY 500kHz sampling rate 2 BIT 13 23 ANALOG GROUND Functionally complete; No missing codes 3 BIT 12 22 +12V/+15V SUPPLY 4 BIT 11 21 +10V REFERENCE OUT 5 BIT 10 20 ANALOG INPUT Small 24-pin DDIP or SMT package 6 BIT 9 19 ANALOG GROUND Low power, 1.8 Watts maximum 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 Edge-triggered; No pipeline delays Operates from ±15V or ±12V supplies & +5V supply Unipolar 0 to +10V input range (for bipolar ±5V see ADS-926) BLOCK DIAGRAM DAC 18 BIT 1 (MSB) 17 BIT 2 +10V REF. OUT 21 REF REGISTER S2 FLASH ADC S/H ANALOG INPUT 20 S1 DIGITAL CORRECTION LOGIC 12 BIT 3 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-916 Functional Block Diagram DATEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151 USA • Tel: (508) 339-3000 • www.datel.com • e-mail: [email protected] 24 Jul 2015 MDA_ADS-916.C02 Page 1 of 9 ADS-916 14-Bit, 500kHz, 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-916MC, GC, MC-C, GC-C 0 — +70 °C ADS-916ME, GE, ME-C, GE-C –40 — +100 °C ADS-916MM, GM, MM-C, GM-C –55 — +125 °C ADS-916MM-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, 500kHz sampling rate, and a minimum 1 minute warmup ➀ unless otherwise specified.) +25°C 0 TO +70°C –55 TO +125°C ANALOG INPUT Input Voltage Range ➁ Input Resistance Input Capacitance MIN. — — — TYP. 0 to +10 1 7 MAX. — — 15 MIN. — — — TYP. 0 to +10 1 7 MAX. — — 15 MIN. — — — TYP. 0 to +10 1 7 MAX. — — 15 UNITS Volts kΩ pF DIGITAL INPUT Logic Levels Logic "1" Logic "0" Logic Loading "1" Logic Loading "0" Start Convert Positive Pulse Width ➂ +2.0 — — — 50 — — — — 200 — +0.8 +20 –20 — +2.0 — — — 50 — — — — 200 — +0.8 +20 –20 — +2.0 — — — 50 — — — — 200 — +0.8 +20 –20 — Volts Volts μA μA ns — — –0.95 — — — 14 14 ±0.5 ±0.5 ±0.05 ±0.1 ±0.1 — — — +0.95 ±0.1 ±0.2 ±0.25 — — — –0.95 — — — 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 ±0.4 ±0.4 — Bits LSB LSB %FSR %FSR % Bits — — –91 –84 –86 –79 — — –91 –84 –86 –79 — — –90 –82 –82 –76 dB dB — — –90 –82 –85 –77 — — –90 –82 –85 –77 — — –87 –80 –81 –74 dB dB 77 75 81 80 — — 77 75 81 80 — — 76 74 80 78 — — dB dB 77 72 80 78 — — 77 72 80 78 — — 75 70 78 76 — — dB dB — — –86 310 — — — — –86 310 — — — — –86 360 — — dB μVrms — — — — — — 7 3 84 ±40 ±20 5 — — — — — — — — — — — — 7 3 84 ±40 ±20 5 — — — — — — — — — — — — 7 3 84 ±40 ±20 5 — — — — — — MHz MHz dB V/μs ns ps rms 1530 — 500 1570 1400 — 1610 2000 — 1530 — 500 1570 1400 — 1610 2000 — 1530 — 500 1570 1400 — 1610 2000 — ns ns kHz 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) DYNAMIC PERFORMANCE Peak Harmonics (–0.5dB) dc to 100kHz 100kHz to 250kHz Total Harmonic Distortion (–0.5dB) dc to 100kHz 100kHz to 250kHz Signal-to-Noise Ratio (w/o distortion, –0.5dB) dc to 100kHz 100kHz to 250kHz Signal-to-Noise Ratio ➃ (& distortion, –0.5dB) dc to 100kHz 100kHz to 250kHz Two-tone Intermodulation Distortion (fin = 100kHz, 240kHz, fs = 500kHz –0.5dB) Noise Input Bandwidth (–3dB) Small Signal (–20dB input) Large Signal (–0.5dB input) Feedthrough Rejection (fin = 250 kHz) 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 • e-mail: [email protected] 24 Jul 2015 MDA_ADS-916.C02 Page 2 of 9 ADS-916 14-Bit, 500kHz, 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 ±12V Power Dissipation ±15V 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 –40 +70 1.6 — +70 –50 +85 1.8 ±0.01 — — — — — +50 –40 +70 1.6 — +70 –50 +85 1.8 ±0.01 — — — — — +50 –40 +70 1.6 — +70 –50 +85 1.8 ±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 1.6 — +70 –50 +80 1.6 1.9 ±0.01 — — — — — — +50 –40 +70 1.4 1.6 — +70 –50 +80 1.6 1.9 ±0.01 — — — — — — +50 –40 +70 1.4 1.6 — +70 –50 +80 1.6 1.9 ±0.01 mA mA mA Watts Watts %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 500 kHz clock with a 200ns wide start convert pulse is used for all production testing. Only the rising edge of the start convert pulse is required for the device to operate (edge-triggered). See Timing Diagram for more details. (SNR + Distortion) – 1.76 + 20 log 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 1. Obtaining fully specified performance from the ADS-916 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. 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. 3. When operating the ADS-916 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 in parallel with 0.1μF ceramic capacitors. Locate the bypass capacitors as close to the unit as possible. If the userinstalled offset and gain adjusting circuit shown in Figure 2 is used, also locate it as close to the ADS-916 as possible. 2. The ADS-916 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 Full Scale Amplitude Actual Input Amplitude 4. Applying a start convert pulse while a conversion is in progress (EOC = logic "1") initiates a new and inaccurate conversion cycle. Data for the interrupted and subsequent conversions will be invalid. • Tel: (508) 339-3000 • www.datel.com • e-mail: [email protected] 24 Jul 2015 MDA_ADS-916.C02 Page 3 of 9 ADS-916 14-Bit, 500kHz, 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-916'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. 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. 2. Apply +305μV to the ANALOG INPUT (pin 20). For the ADS-916, 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 +½LSB (+305μV). 2. Adjust the gain potentiometer until the output bits are all 1's and the LSB flickers between 1 and 0. 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). Table 1. Zero and Gain Adjust +15V ZERO/ OFFSET ADJUST 20k7 –15V SIGNAL INPUT 2k7 200k7 GAIN ADJUST INPUT VOLTAGE RANGE ZERO ADJUST +½ LSB GAIN ADJUST +FS –1½ LSB 0 to +10V +305μV +9.999085V Table 2. Output Coding +15V 1.98k7 To Pin 20 of ADS-916 507 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-916 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-916 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-916 Connection Diagram DATEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151 USA • Tel: (508) 339-3000 • www.datel.com • e-mail: [email protected] 24 Jul 2015 MDA_ADS-916.C02 Page 4 of 9 ADS-916 14-Bit, 500kHz, Low-Power Sampling A/D Converters THERMAL REQUIREMENTS 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 devices do not N+1 N START CONVERT 200ns typ. 10ns typ. INTERNAL S/H Acquisition Time Hold 430ns typ. 1570ns ±40ns 70ns ±10ns 90ns typ. EOC Conversion Time 420ns ±20ns 35ns max. 74ns max. OUTPUT DATA Data N Valid (1926ns min.) Data (N – 1) Valid Invalid Data Notes: 1. fs = 500kHz. 2. The ADS-916 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 50nsec. All production testing is performed at a 500kHz sampling rate with 200nsec wide start pulses. For lower sampling rates, wider start pulses may be used, however, a minimum pulse width low of 50nsec must be maintained. Figure 4. ADS-916 Timing Diagram DATEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151 USA • Tel: (508) 339-3000 • www.datel.com • e-mail: [email protected] 24 Jul 2015 MDA_ADS-916.C02 Page 5 of 9 ADS-916 Figure 5. ADS-916 Evaluation Board Schematic 14-Bit, 500kHz, 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] 24 Jul 2015 MDA_ADS-916.C02 Page 6 of 9 ADS-916 14-Bit, 500kHz, Low-Power Sampling A/D Converters 0 –10 Amplitude Relative to Full Scale (dB) –20 –30 –40 –50 –60 –70 –80 –90 –100 –110 –120 –130 –140 –150 –160 –170 0 25 50 75 100 125 150 175 200 225 250 Frequency (kHz) (fs = 500kHz, fin = 240kHz, Vin = –0.5dB, 16,384-point FFT) Figure 6. ADS-916 FFT Analysis +0.34 DNL (LSB's) Number of Occurrences 0 –0.33 0 0 16,384 Digital Output Code 16,384 Digital Output Code Figure 7. ADS-916 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] 24 Jul 2015 MDA_ADS-916.C02 Page 7 of 9 ADS-916 14-Bit, 500kHz, Low-Power Sampling A/D Converters MECHANICAL DIMENSIONS INCHES (mm) 24-Pin DDIP Versions ADS-916MC ADS-916ME ADS-916MM ADS-916MM-QL ADS-916/883 ADS-916MC-C ADS-916ME-C ADS-916MM-C ADS-916-C/883 1.31 MAX. (33.27) 24 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) 0.100 (2.540) 0.600 ±0.010 (15.240) SEATING PLANE 0.025 (0.635) 0.040 (1.016) 0.018 ±0.002 (0.457) +0.002 –0.001 1.31 MAX. (33.02) 24-Pin Surface Mount Versions ADS-916GC ADS-916GE ADS-916GM ADS-916G/883 ADS-916GC-C ADS-916GE-C ADS-916GM-C ADS-916G-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 0.80 MAX. (20.32) 1 0.190 MAX. (4.826) Lead Material: Kovar alloy Lead Finish: 50 microinches (minimum) gold plating over 100 microinches (nominal) nickel plating 12 0.020 TYP. (0.508) 0.060 TYP. (1.524) 0.100 (2.540) 0.100 TYP. (2.540) 0.015 (0.381) MAX. radius for any pin 0.130 TYP. (3.302) PIN 1 INDEX 0.020 (0.508) 0.010 TYP. (0.254) 0.040 (1.016) DATEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151 USA • Tel: (508) 339-3000 • www.datel.com • e-mail: [email protected] 24 Jul 2015 MDA_ADS-916.C02 Page 8 of 9 ADS-916 14-Bit, 500kHz, Low-Power Sampling A/D Converters ORDERING GUIDE MODEL NUMBER ADS-916MC ADS-916MC-C ADS-916ME ADS-916ME-C ADS-916MM ADS-916MM-C ADS-916MM-QL ADS-916MM-QL-C ADS-916/883 ADS-916-C/883 ADS-916GC ADS-916GC-C ADS-916GE ADS-916GE-C ADS-916GM ADS-916GM-C ADS-916G/883 ADS-916G-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-926 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] 24 Jul 2015 MDA_ADS-916.C02 Page 9 of 9