ADS-112

® ® 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 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. 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. PIN 1 2 3 4 5 6 7 8 9 10 11 12 INPUT/OUTPUT CONNECTIONS FUNCTION 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) PIN 24 23 22 21 20 19 18 17 16 15 14 13 FUNCTION –15V SUPPLY ANALOG GROUND +15V SUPPLY +10V REFERENCE BIPOLAR ANALOG INPUT COMP BIN ENABLE (1-12) START CONVERT EOC DIGITAL GROUND +5V SUPPLY 17 ENABLE (1-12) DAC 12 BIT 1 (MSB) +10V REF. 21 S2 S/H S1 BIPOLAR 20 RE GIS TER BUFFER FLASH ADC REF DIGITAL CORRECTION LOGIC 3-S TATE OUTPUT RE GIS TER 11 BIT 2 10 BIT 3 9 8 7 6 5 4 3 2 1 BIT 4 BIT 5 BIT 6 BIT 7 BIT 8 BIT 9 BIT 10 BIT 11 BIT 12 (LSB) ANALOG INPUT 19 – + COMP BIN 18 START CONVERT 16 EOC 15 TIMING AND CONTROL LOGIC 13 +5V SUPPLY 14 DIGITAL GROUND 22 +15V SUPPLY RE GIS TER 23 ANALOG GROUND 24 –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) LIMITS 0 to +18 0 to –18 0 to +6 –0.3 to +VDD +0.3 –9 to +15 +300 UNITS Volts Volts Volts Volts Volts °C DYNAMIC PERF. (cont) Signal-to-Noise Ratio (wo/distort., –0.5dB) dc to 100kHz 100kHz to 500kHz Signal-to-Noise Ratio  (& 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 DIGITAL OUTPUTS Output Coding Pin 18 High Pin 18 Low Logic Level Logic "1" Logic "0" Logic Loading "1" Logic Loading "0" POWER REQUIREMENTS Power Supply Ranges Ž +15V Supply –15V Supply +5V Supply Power Supply Current +15V Supply –15V Supply +5V Supply Power Dissipation Power Supply Rejection PHYSICAL/ENVIRONMENTAL — — +9.98 — — ±0.1 ±0.3 +10.0 ±5 — ±0.38 ±0.60 +10.02 ±30 1.5 % % Volts ppm/°C mA Operating Temp. Range, Case ADS-112MC ADS-112MM, 883 Storage Temperature Range Package Type Weight Œ See Table 3 also  Effective bits is equal to: (SNR + Distortion) – 1.76 + 20 log 6.02 Full Scale Amplitude Actual Input Amplitude MIN. TYP. MAX. UNITS 68 67 66 66 — — 8 6 — — — — — — 160 1 1 1 72 71 70 70 –88 –68 10 8 ±150 — — — — — 250 — — — — — — — –80 –65 — — — 20 16 15 ±50 1000 280 — — — dB dB dB dB dB dB MHz MHz V/µs ns ns ps ps ns ns MHz MHz MHz FUNCTIONAL SPECIFICATIONS (TA = +25°C, ±VCC = ±15V, +VDD =+5V, 1MHz sampling rate, and a minimum 1 minute warmup unless otherwise specified.) ANALOG INPUTS Input Voltage Range Œ Bipolar Unipolar Input Impedence Input Capacitance DIGITAL INPUTS Logic Levels Logic "1" Logic "0" Logic Loading "1" Logic Loading "0" 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 DYNAMIC PERFORMANCE In-Band Harmonics (–0.5dB) dc to 100kHz 100kHz to 500kHz Total Harm. Distort. (–0.5dB) dc to 100kHz 100kHz to 500kHz † See Tech Note 1 — — — — –81 –75 –78 –73 –75 –70 –75 –68 dB dB dB dB 12 Bits Over the operating temperature range — — — — — — — — — — — — — — — ±1/4 ±1/4 ±1/2 ±1/4 ±1/4 ±1/2 ±0.13 ±0.15 ±0.25 ±0.074 ±0.224 ±0.074 ±0.124 ±0.1 ±0.3 ±3/4 ±3/4 ±1.5 ±3/4 ±3/4 ±1 ±0.25 ±0.44 ±0.78 ±0.265 ±0.43 ±0.166 ±0.210 ±0.38 ±0.60 LSB LSB LSB LSB LSB LSB %FSR %FSR %FSR %FSR %FSR %FSR %FSR %FSR %FSR +2.0 — — — — — — — — +0.8 +10 –600 Volts Volts µA µA MIN. — — 4.5 — TYP. ±5 0 to +10 5 6 MAX. — — — 15 UNITS Volts Volts kΩ pF 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 +24 –40 +80 1.3 — +15.75 –15.75 +5.25 +35 –48 +95 1.7 ±0.07 Volts Volts Volts mA mA mA Watts %FSR%V 0 — +70 °C –55 — +125 °C –65 — +150 °C 24-pin, metal-sealed, ceramic DDIP 0.42 ounces (12 grams) Ž For ±12V, +5V operation, contact DATEL 2 ® ® ADS-112 TECHNICAL NOTES 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. 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. 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). 4. Obtain straight binary/offset binary output coding by tying COMP BIN (pin 18) to +5V or leaving it open. The device 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. 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). 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. 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. N START CONVERT 150ns, ±25ns N+1 10ns min. 20ns max. INTERNAL S/H Hold Acquisition Time 250ns 20ns max. EOC Conversion Time 600ns max. 60ns max. 35ns max. OUTPUT DATA DATA N-1 VALID 800ns min. INVALID DATA 200ns max. DATA N VALID INVALID DATA Note: Scale is approximately 50ns per division. Figure 2. ADS-112 Timing Diagram 3 ® ® ADS-112 CALIBRATION PROCEDURE 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. 2. Zero Adjustments 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). 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). 3. Full-Scale Adjustment 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. Table 1. Input Range Selection R2 Œ R1 SIGNAL INPUT Œ +15V 5kΩ 50Ω GAIN ADJUST 5kΩ 10kΩ ZERO/ OFFSET ADJUST –15V To Pin19 of ADS-112 Œ For values of R1 and R2 refer to Table 3. Figure 4. Optional Calibration Circuit Table 2. Zero and Gain Adjust Input Range 0 to +10V ±5V Zero Adjust +1/2 LSB +1.22mV +1.22mV Gain Adjust +FS – 1 1/2 LSB +9.9963V +4.9963V Table 3. Input Range (using external calibration) INPUT RANGE 0 to 10V, ±5 0 to 5V, ±2.5V 0 to +2.5V, ±1.25V R1 2 2 2 R2 2 6 14 UNIT kΩ kΩ kΩ INPUT RANGE ±5v 0 to +10V INPUT PIN Pin 19 Pin 19 TIE TOGETHER Pin 20 to Pin 21 Pin 20 to Ground BIPOLAR OPERATION 20 21 UNIPOLAR OPERATION 20 21 +10V REF. + 0.1µF 4.7µF –15V 4.7µF 4.7µF +15V +5V 4.7µF + 0.1µF + 0.1µF 24 ADS-112 23 22 13 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 + 0.1µF 14 COMP BIN 18 Note: Always bypass pin 21 to ground +5V Figure 3. Typical ADS-112 Connection Diagram 4 ® ® ADS-112 Table 4. Output Coding STRAIGHT BIN. UNIPOLAR SCALE INPUT RANGE 0 to +10V COMP. BINARY LSB INPUT RANGE ±5V BIPOLAR SCALE OUTPUT CODING MSB LSB MSB +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 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 0000 1111 1111 1111 1111 1111 1111 1111 0000 1111 1111 1111 1111 1111 1110 1111 +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 OFF. BINARY COMP. OFF. BIN. 0 –10 Amplitude Relative to Full Scale (dB) –20 –30 –40 –50 –60 –70 –80 –90 –100 –110 –120 –130 0 50 100 150 200 250 300 350 400 450 500 Frequency (kHz) (fs = 1MHz, fin = 485kHz, Vin = –0.5dB, 4,096-point FFT) Figure 5. FFT Analysis of ADS-112 5 ® ® ADS-112 MECHANICAL DIMENSIONS INCHES (mm) 1.31 MAX. (33.27) Dimension Tolerances (unless otherwise indicated): 2 place decimal (.XX) ±0.010 (±0.254) 3 place decimal (.XXX) ±0.005 (±0.127) 0.80 MAX. (20.32) 1 12 Lead Material: Kovar alloy Lead Finish: 50 microinches (minimum) gold plating over 100 microinches (nominal) nickel plating 24 13 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) 0.018 ±0.002 (0.457) 0.100 (2.540) 0.040 (1.016) +0.002 –0.001 SEATING PLANE 0.025 (0.635) 0.600 ±0.010 (15.240) 0.100 (2.540) ORDERING INFORMATION MODEL NUMBER ADS-112MC ADS-112MM ADS-112/883 OPERATING TEMP. RANGE 0 to +70°C –55 to +125°C –55 to +125°C ACCESSORIES ADS-EVAL4 HS-32 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 10/96 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:sales@datel.com Data Sheet Fax Back: (508) 261-2857 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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