® ® ADS-112 12-Bit, 1MHz, Low-Power Sampling A/D Converters FEATURES • • • • • • • • 12-bit resolution No missing codes 1MHz minimum sampling rate Functionally complete Small 24-pin DDIP Low-power, 1.3 Watts Three-state output buffers Samples to Nyquist frequencies GENERAL DESCRIPTION INPUT/OUTPUT CONNECTIONS DATEL’s ADS-112 is a 12-bit, functionally complete, sampling A/D converter that is packaged in a space-saving 24-pin DDIP. Requiring ±15V and +5V supplies, a minimum sampling rate of 1MHz is achieved while only dissipating 1.3 Watts. The ADS-112 digitizes signals up to Nyquist frequencies. Models are available for use in either commercial (0 to + 70°C) or military (–55 to +125°C) operating temperature ranges. PIN FUNCTION PIN FUNCTION 1 2 3 4 5 6 7 8 9 10 11 12 BIT 12 (LSB) BIT 11 BIT 10 BIT 9 BIT 8 BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 (MSB) 24 23 22 21 20 19 18 17 16 15 14 13 –15V SUPPLY ANALOG GROUND +15V SUPPLY +10V REFERENCE BIPOLAR ANALOG INPUT COMP BIN ENABLE (1-12) START CONVERT EOC DIGITAL GROUND +5V SUPPLY Typical applications include spectrum, transient, vibration and waveform analysis. This device is also ideally suited for radar, sonar, video digitization, medical instrumentation and highspeed data acquisition systems. 17 ENABLE (1-12) DAC 12 BIT 1 (MSB) REF S/H S1 BUFFER ANALOG INPUT 19 REGISTER BIPOLAR 20 – + 3-STATE OUTPUT REGISTER FLASH ADC DIGITAL CORRECTION LOGIC S2 11 BIT 2 REGISTER +10V REF. 21 10 BIT 3 9 BIT 4 8 BIT 5 7 BIT 6 6 BIT 7 5 BIT 8 4 BIT 9 3 BIT 10 2 BIT 11 1 BIT 12 (LSB) COMP BIN 18 START CONVERT 16 TIMING AND CONTROL LOGIC EOC 15 13 14 22 23 24 +5V SUPPLY DIGITAL GROUND +15V SUPPLY ANALOG GROUND –15V SUPPLY Figure 1. ADS-112 Functional Block Diagram DATEL, Inc., 11 Cabot Boulevard, Mansfield, MA 02048-1151 (U.S.A.) • Tel: (508) 339-3000 Fax: (508) 339-6356 • For immediate assistance: (800) 233-2765 ® ® ADS-112 ABSOLUTE MAXIMUM RATINGS PARAMETERS +15V Supply (Pin 22) –15V Supply (Pin 24) +5V Supply (Pin 13) Digital Inputs (Pin 16, 17, 18) Analog Input (Pin 19) Lead Temp. (10 seconds) DYNAMIC PERF. (cont) LIMITS UNITS 0 to +18 0 to –18 0 to +6 –0.3 to +VDD +0.3 –9 to +15 +300 Volts Volts Volts Volts Volts °C Signal-to-Noise Ratio (wo/distort., –0.5dB) dc to 100kHz 100kHz to 500kHz Signal-to-Noise Ratio ➁ (& distort., –0.5dB) dc to 100kHz 100kHz to 500kHz Two-tone Intermodulation Distortion (fin = 75kHz, 105kHz, fs = 1MHz, –0.7dB) Two-tone Intermodulation Distortion (fin = 480kHz, 490kHz, fs = 1MHz, –0.7dB) Input Bandwith (–3dB) Small Signal (–20dB input) Large Signal (–0.5dB input) Slew Rate Apperture Delay TIme Effect. Aperture Delay Time Apperture Uncertainity (Jitter) RMS Peak Overvoltage Recovery Time S/H Acquisition Time Conversion Rate (Changing Inputs) +25°C 0°C to +70°C –55°C to +125°C FUNCTIONAL SPECIFICATIONS (TA = +25°C, ±VCC = ±15V, +VDD =+5V, 1MHz sampling rate, and a minimum 1 minute warmup unless otherwise specified.) ANALOG INPUTS MIN. TYP. MAX. UNITS Input Voltage Range ➀ Bipolar Unipolar Input Impedence Input Capacitance — — 4.5 — ±5 0 to +10 5 6 — — — 15 Volts Volts kΩ pF DIGITAL INPUTS Logic Levels Logic "1" Logic "0" Logic Loading "1" Logic Loading "0" +2.0 — — — — — — — — +0.8 +10 –600 Volts Volts µA µA PERFORMANCE Resolution No Missing Codes (12 Bits; fin = 1MHz) Integral Non-Linearity +25°C 0°C to +70°C –55°C to +125°C Differential Non-Linearity +25°C 0°C to +70°C –55°C to +125°C Full Scale Absolute Accuracy +25°C 0°C to +70°C –55°C to +125°C Unipolar Zero Error † 0°C to +70°C –55°C to +125°C Bipolar Zero Error † 0°C to +70°C –55°C to +125°C Bipolar Offset Error † 0°C to +70°C –55°C to +125°C Gain Error † 0°C to +70°C –55°C to +125°C Internal Reference Voltage, +25°C Drift External Current 12 Bits TYP. MAX. UNITS 68 67 72 71 — — dB dB 66 66 70 70 — — dB dB — –88 –80 dB — –68 –65 dB 8 6 — — — 10 8 ±150 — — — — — 20 16 MHz MHz V/µs ns ns — — — 160 — — — 250 15 ±50 1000 280 ps ps ns ns 1 1 1 — — — — — — MHz MHz MHz DIGITAL OUTPUTS Over the operating temperature range — — — ±1/4 ±1/4 ±1/2 ±3/4 ±3/4 ±1.5 LSB LSB LSB — — — ±1/4 ±1/4 ±1/2 ±3/4 ±3/4 ±1 LSB LSB LSB — — — ±0.13 ±0.15 ±0.25 ±0.25 ±0.44 ±0.78 %FSR %FSR %FSR — — ±0.074 ±0.224 ±0.265 ±0.43 %FSR %FSR — — ±0.074 ±0.124 ±0.166 ±0.210 %FSR %FSR — — ±0.1 ±0.3 ±0.38 ±0.60 %FSR %FSR — — +9.98 — — ±0.1 ±0.3 +10.0 ±5 — ±0.38 ±0.60 +10.02 ±30 1.5 % % Volts ppm/°C mA — — –81 –75 –75 –70 dB dB — — –78 –73 –75 –68 dB dB Output Coding Pin 18 High Pin 18 Low Logic Level Logic "1" Logic "0" Logic Loading "1" Logic Loading "0" Staight binary/Offset binary Complementary binary Complementary offset binary +2.4 — — — — — — — — +0.4 –160 +6.4 Volts Volts µA mA +14.25 –14.25 +4.75 +15.0 –15.0 +5.0 +15.75 –15.75 +5.25 Volts Volts Volts — — — — — +24 –40 +80 1.3 — +35 –48 +95 1.7 ±0.07 mA mA mA Watts %FSR%V POWER REQUIREMENTS Power Supply Ranges ➂ +15V Supply –15V Supply +5V Supply Power Supply Current +15V Supply –15V Supply +5V Supply Power Dissipation Power Supply Rejection PHYSICAL/ENVIRONMENTAL Operating Temp. Range, Case ADS-112MC ADS-112MM, 883 Storage Temperature Range Package Type Weight DYNAMIC PERFORMANCE In-Band Harmonics (–0.5dB) dc to 100kHz 100kHz to 500kHz Total Harm. Distort. (–0.5dB) dc to 100kHz 100kHz to 500kHz MIN. 0 — +70 °C –55 — +125 °C –65 — +150 °C 24-pin, metal-sealed, ceramic DDIP 0.42 ounces (12 grams) ➀ See Table 3 also ➁ Effective bits is equal to: (SNR + Distortion) – 1.76 + Full Scale Amplitude 20 log 6.02 † See Tech Note 1 ➂ For ±12V, +5V operation, contact DATEL 2 Actual Input Amplitude ® ® ADS-112 TECHNICAL NOTES has an internal pull-up resistor on this pin. To obtain complementary binary or complementary offset binary output coding, tie pin 18 to ground. The pin 18 signal is compatible with CMOS/TTL logic levels for those users desiring dynamic control of this function. 1. Applications which are unaffected by endpoint errors or remove them through software will use the typical connections shown in Figure 3. Remove system errors or adjust the small initial errors of the ADS-112 to zero using the optional external circuitry shown in Figure 4. The external adjustment circuit has no effect on the throughput rate. 5. To enable the three-state outputs, connect ENABLE (pin 17) to a logic "0" (low). To disable, connect pin 17 to a logic "1" (high). 2. For best performance, always connect the analog and digital ground pins to a ground plane beneath the converter. The analog and digital grounds are not connected to each other internally. 6. Do not change the status of pin 18 when EOC is high. 7. Re-initiating the START CONVERT (pin 16) while EOC is a logic "1" (high) will result in a new conversion sequence. 3. Bypass the analog and digital supplies and the +10V reference (pin 21) to ground with 4.7µF, 25V tantalum electrolytic capacitors in parallel with 0.1µF ceramic capacitors. Bypass the +10V reference (pin 21) to analog ground (pin 23). TIMING Figure 2 shows the relationship between the various input signals. The timing shown applies over the operating temperature range and over the operating power supply range. These times are guaranteed by design. 4. Obtain straight binary/offset binary output coding by tying COMP BIN (pin 18) to +5V or leaving it open. The device N N+1 START CONVERT 150ns, ±25ns 10ns min. 20ns max. Acquisition Time INTERNAL S/H 250ns Hold 20ns max. EOC 60ns max. Conversion Time 600ns max. 35ns max. OUTPUT DATA DATA N-1 VALID 800ns min. DATA N VALID INVALID DATA 200ns max. Note: Scale is approximately 50ns per division. Figure 2. ADS-112 Timing Diagram 3 INVALID DATA ® ® ADS-112 CALIBRATION PROCEDURE R2 ➀ 1. Connect the converter per Figures 3 and 4 and Tables 1 and 3 for the appropriate input range. Apply a pulse of 150 nanoseconds to the START CONVERT input (pin 16) at a rate of 250kHz. This rate is chosen to reduce the flicker if LED’s are used on the outputs for calibration purposes. +15V ➀ R1 SIGNAL INPUT 2. Zero Adjustments To Pin19 of ADS-112 5kΩ 50Ω GAIN ADJUST Apply a precision voltage reference source between the amplifier’s analog input and ground. Adjust the output of the reference source per Table 2. For unipolar, adjust the zero trimming potentiometer so that the output code flickers equally between 0000 0000 0000 and 0000 0000 0001 with COMP BIN (pin 18) tied high (straight binary) or between 1111 1111 1111 and 1111 1111 1110 with pin 18 tied low (complementary binary). –15V 5kΩ 10kΩ ZERO/ OFFSET ADJUST ➀ For values of R1 and R2 refer to Table 3. For bipolar operation, adjust the potentiometer such that the code flickers equally between 1000 0000 0000 and 1000 0000 0001 with pin 18 tied high (offset binary) or between 0111 1111 1111 and 0111 1111 1110 with pin 18 tied low (complementary offset binary). Figure 4. Optional Calibration Circuit 3. Full-Scale Adjustment Table 2. Zero and Gain Adjust Set the output of the voltage reference used in step 2 to the value shown in Table 2. Adjust the gain trimming potentiometer so that the output code flickers equally between 1111 1111 1110 and 1111 1111 1111 for pin 18 tied high or between 0000 0000 0001 and 0000 0000 0000 for pin 18 tied low. To confirm proper operation of the device, vary the precision reference voltage source to obtain the output coding listed in Table 4. Zero Adjust +1/2 LSB Gain Adjust +FS – 1 1/2 LSB 0 to +10V ±5V +1.22mV +1.22mV +9.9963V +4.9963V Table 3. Input Range (using external calibration) Table 1. Input Range Selection INPUT RANGE INPUT RANGE INPUT PIN TIE TOGETHER ±5v 0 to +10V Pin 19 Pin 19 Pin 20 to Pin 21 Pin 20 to Ground BIPOLAR OPERATION Input Range 20 21 +10V REF. 21 + 0.1µF 4.7µF 24 –15V 4.7µF + 0.1µF + 0.1µF ADS-112 23 4.7µF +15V 22 + 4.7µF UNIT 2 2 2 2 6 14 kΩ kΩ kΩ 12 BIT 1 (MSB) 11 BIT 2 10 BIT 3 9 BIT 4 8 BIT 5 7 BIT 6 6 BIT 7 5 BIT 8 4 BIT 9 3 BIT 10 2 BIT 11 1 BIT 12 (LSB) 15 EOC 17 ENABLE (1-12) 16 START CONVERT 19 ANALOG INPUT 13 +5V R2 0 to 10V, ±5 0 to 5V, ±2.5V 0 to +2.5V, ±1.25V UNIPOLAR OPERATION 20 R1 0.1µF COMP BIN 18 14 Note: Always bypass pin 21 to ground Figure 3. Typical ADS-112 Connection Diagram 4 +5V ® ® ADS-112 Table 4. Output Coding STRAIGHT BIN. UNIPOLAR SCALE INPUT RANGE 0 to +10V +FS – 1 LSB +7/8 FS +3/4 FS +1/2 FS +1/4 FS +1/8 FS +1 LSB 0 +9.9976 +8.7500 +7.5000 +5.0000 +2.5000 +1.2500 +0.0024 0.0000 COMP. BINARY OUTPUT CODING MSB LSB MSB 1111 1110 1100 1000 0100 0010 0000 0000 1111 0000 0000 0000 0000 0000 0000 0000 1111 0000 0000 0000 0000 0000 0001 0000 0000 0001 0011 0111 1011 1101 1111 1111 OFF. BINARY LSB 0000 1111 1111 1111 1111 1111 1111 1111 0000 1111 1111 1111 1111 1111 1110 1111 INPUT RANGE ±5V BIPOLAR SCALE +4.9976 +3.7500 +2.5000 0.0000 –2.5000 –3.7500 –4.9976 –5.0000 +FS –1 LSB +3/4FS +1/2FS 0 –1/2FS –3/4FS –FS+1LSB –FS COMP. OFF. BIN. 0 Amplitude Relative to Full Scale (dB) –10 –20 –30 –40 –50 –60 –70 –80 –90 –100 –110 –120 –130 0 50 100 150 200 250 300 350 400 Frequency (kHz) (fs = 1MHz, fin = 485kHz, Vin = –0.5dB, 4,096-point FFT) Figure 5. FFT Analysis of ADS-112 5 450 500 ® ® ADS-112 MECHANICAL DIMENSIONS INCHES (mm) 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 Lead Material: Kovar alloy 0.80 MAX. (20.32) 1 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) SEATING PLANE 0.025 (0.635) 0.040 (1.016) 0.018 ±0.002 (0.457) +0.002 –0.001 0.100 (2.540) 0.600 ±0.010 (15.240) ORDERING INFORMATION MODEL NUMBER ADS-112MC ADS-112MM ADS-112/883 ACCESSORIES OPERATING TEMP. RANGE ADS-EVAL4 HS-32 0 to +70°C –55 to +125°C –55 to +125°C Evaluation Board (without ADS-112) Heat Sink for all ADS-112 models For MIL-STD-883 product specification or availability of surface-mount packaging, contact DATEL. Receptacles for PC mounting can be ordered through AMP Inc., Part # 3-331272-8 (Component Lead Socket), 24 required. ® ® ISO 9001 R E G I S T E R E D DS-0149F DATEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151 Tel: (508) 339-3000 (800) 233-2765 Fax: (508) 339-6356 Internet: www.datel.com E-mail:[email protected] Data Sheet Fax Back: (508) 261-2857 10/96 DATEL (UK) LTD. Tadley, England Tel: (01256)-880444 DATEL S.A.R.L. Montigny Le Bretonneux, France Tel: 1-34-60-01-01 DATEL GmbH München, Germany Tel: 89-544334-0 DATEL KK Tokyo, Japan Tel: 3-3779-1031, Osaka Tel: 6-354-2025 DATEL 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. 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