® ® ADS-917 14-Bit, 1MHz, Low-Power Sampling A/D Converters FEATURES • • • • • • • • 14-bit resolution 1MHz sampling rate Functionally complete; No missing codes Edge-triggered; No pipeline delays Small 24-pin DDIP or SMT package Low power, 1.9 Watts maximum Operates from ±15V or ±12V supplies Unipolar 0 to +10V input range GENERAL DESCRIPTION INPUT/OUTPUT CONNECTIONS 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 errorcorrection 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) or military (–55 to +125°C) operating temperature ranges. Applications include radar, sonar, spectrum analysis, and graphic/medical imaging. PIN FUNCTION PIN 1 2 3 4 5 6 7 8 9 10 11 12 BIT 14 (LSB) BIT 13 BIT 12 BIT 11 BIT 10 BIT 9 BIT 8 BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 24 23 22 21 20 19 18 17 16 15 14 13 FUNCTION –12V/–15V SUPPLY ANALOG GROUND +12V/+15V SUPPLY +10V REFERENCE OUT ANALOG INPUT ANALOG GROUND BIT 1 (MSB) BIT 2 START CONVERT EOC DIGITAL GROUND +5V SUPPLY DAC 18 BIT 1 (MSB) 17 BIT 2 +10V REF. OUT 21 REF REGISTER S2 FLASH ADC S/H ANALOG INPUT 20 S1 BUFFER – REGISTER + DIGITAL CORRECTION LOGIC 12 BIT 3 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 (U.S.A.) • Tel: (508) 339-3000 Fax: (508) 339-6356 • For immediate assistance: (800) 233-2765 ® ® ADS-917 ABSOLUTE MAXIMUM RATINGS PARAMETERS +12V/+15V Supply (Pin 22) –12V/–15V Supply (Pin 24) +5V Supply (Pin 13) Digital Input (Pin 16) Analog Input (Pin 20) Lead Temperature (10 seconds) PHYSICAL/ENVIRONMENTAL LIMITS UNITS 0 to +16 0 to –16 0 to +6 –0.3 to +VDD +0.3 –4 to +17 +300 Volts Volts Volts Volts Volts °C PARAMETERS Operating Temp. Range, Case ADS-917MC, GC ADS-917MM, GM Thermal Impedance θjc θca Storage Temperature Package Type Weight MIN. TYP. MAX. UNITS 0 –55 — — +70 +125 °C °C 6 °C/Watt 24 °C/Watt –65 — +150 °C 24-pin, metal-sealed, ceramic DDIP or SMT 0.42 ounces (12 grams) FUNCTIONAL SPECIFICATIONS (TA = +25°C, ±VCC = ±15V (or ±12V), +VDD = +5V, 1MHz sampling rate, and a minimum 1 minute warmup ➀ unless otherwise specified.) +25°C ANALOG INPUT Input Voltage Range ➁ Input Resistance Input Capacitance 0 to +70°C MIN. TYP. MAX. — — — 0 to +10 1 7 — — 15 +2.0 — — — 20 — — — — 200 — — — — — — 14 MIN. –55 to +125°C TYP. MAX. — — — 0 to +10 1 7 — — 15 — +0.8 +20 –20 — +2.0 — — — 20 — — — — 200 14 ±0.5 ±0.5 ±0.05 ±0.1 ±0.1 — — — ±0.95 ±0.1 ±0.2 ±0.25 — — — — — — — 14 — — –87 –81 –82 –76 — — –85 –80 75 73 MIN. TYP. MAX. UNITS — — — 0 to +10 1 7 — — 15 Volts kΩ pF — +0.8 +20 –20 — +2.0 — — — 20 — — — — 200 — +0.8 +20 –20 — Volts Volts µA µA ns 14 ±0.75 ±0.5 ±0.1 ±0.1 ±0.1 — — — ±0.95 ±0.2 ±0.2 ±0.25 — — — –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 — — –87 –81 –82 –76 — — –85 –79 –80 –74 dB dB –82 –76 — — –85 –80 –82 –76 — — –84 –79 –80 –74 dB dB 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 DIGITAL INPUT Logic Levels Logic "1" Logic "0" Logic Loading "1" Logic Loading "0" Start Convert Positive Pulse Width ➂ 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 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, 240kHz, 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 2 ® ® ADS-917 +25°C 0 to +70°C ANALOG OUTPUT MIN. TYP. MAX. Internal Reference Voltage Drift External Current +9.95 — — +10.0 ±5 — +10.05 — 1.5 +2.4 — — — — — — — — MIN. –55 to +125°C TYP. MAX. MIN. TYP. MAX. UNITS +9.95 — — +10.0 ±5 — +10.05 — 1.5 +9.95 — — +10.0 ±5 — +10.05 — 1.5 Volts ppm/°C mA — +0.4 –4 +4 +2.4 — — — — — — — — +0.4 –4 +4 +2.4 — — — — — — — — +0.4 –4 +4 Volts Volts mA mA — 35 — — Straight Binary 35 — — 35 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 — +65 –50 +85 1.9 ±0.01 — — — — — +50 –41 +70 1.7 — +65 –50 +85 1.9 ±0.01 — — — — — +50 –41 +70 1.7 — +65 –50 +85 1.9 ±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 — — — — — +50 –40 +70 1.4 — +65 –48 +80 1.6 ±0.01 — — — — — +50 –40 +70 1.4 — +65 –48 +80 1.6 ±0.01 mA mA mA Watts %FSR/%V 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 Footnotes: ➃ Effective bits is equal to: 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. (SNR + Distortion) – 1.76 + 20 log Full Scale Amplitude Actual Input Amplitude 6.02 ➁ See Ordering Information for availability of ±5V input range. Contact DATEL for availability of other input voltage ranges. ➄ This is the time required before the A/D output data is valid after the analog input is back within the specified range. ➂ A 1MHz clock with a 200ns wide start convert pulse is used for all production testing. See Timing Diagram for more details. TECHNICAL NOTES need for external calibration. If required, the device's small initial offset and gain errors 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, as well as 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 user-installed offset and gain adjusting circuit shown in Figure 2 is used, also locate it as close to the ADS-917 as possible. 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. 2. The ADS-917 achieves its specified accuracies without the 3 ® ® ADS-917 CALIBRATION PROCEDURE Zero/Offset Adjust Procedure (Refer to Figures 2 and 3) 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. 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. 2. Apply +305µV to the ANALOG INPUT (pin 20). 3. Adjust the offset potentiometer until the output bits are all 0's and the LSB flickers between 0 and 1. 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. Gain Adjust Procedure 1. Apply +9.999085V to the ANALOG INPUT (pin 20). 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. 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 INPUT VOLTAGE RANGE For the ADS-919, 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). 0 to +10V 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) . 20kΩ –15V SIGNAL INPUT 200kΩ GAIN ADJUST +FS –1½ LSB +305µV +9.999085V Table 2. Output Coding INPUT VOLTAGE (0 to +10V) +9.999390 +7.500000 +5.000000 +2.500000 +0.000610 0.000000 +15V ZERO/ OFFSET ADJUST ZERO ADJUST +½ LSB 2kΩ GAIN ADJUST +15V UNIPOLAR SCALE +FS – 1LSB +3/4 FS +1/2 FS +1/4 FS +1LSB 0 DIGITAL OUTPUT MSB LSB 11 11 10 01 00 00 1.98kΩ Coding is straight binary; 1LSB = 610µV. To Pin 20 of ADS-917 50Ω –15V Figure 2. ADS-917 Calibration Circuit 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 0.1µF 19, 23 6 BIT 9 5 BIT 10 4 BIT 11 ANALOG GROUND 0.1µF + 22 +12V/+15V 3 BIT 12 2 BIT 13 ANALOG 20 INPUT 0 to +10V 1 BIT 14 (LSB) 15 EOC 21 +10V REF. OUT 0.1µF + START 16 CONVERT 4.7µF Figure 3. Typical ADS-917 Connection Diagram 4 8 BIT 7 7 BIT 8 1111 0000 0000 0000 0000 0000 1111 1111 0000 0000 0000 0000 0000 0000 0000 0001 0000 0000 ® ® ADS-917 THERMAL REQUIREMENTS 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. 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. In more severe ambient conditions, the package/junction temperature of a given device can be reduced dramatically (typically 35%) by using one of DATEL's HS Series heat sinks. See Ordering Information for the assigned part number. See page 1-183 of the DATEL Data Acquisition Components Catalog for more information on the HS Series. Request DATEL Application Note AN-8, "Heat Sinks for DIP Data Converters", or contact DATEL directly, for additional information. These devices do not normally require heat sinks, however, standard precautionary design and layout procedures should be used to ensure 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. 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 926ns min. Invalid Data 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 5 +15V 5 7 9 6 8 10 SG1 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 1 3 2 4 P1 C19 2.2MF ANALOG INPUT P4 -15V 20K 6 C21 0.1MF +15V -15V +5V SEE NOTE 1 START CONVERT C20 0.1MF J5 7 U6 + 3 2 XTAL Y1 8 14 J1 +15V C11 2.2MF P3 1 3 2 10K 0.1% R7 C22 2.2 -15V MF 4 7 R6 2K 0.1% 0.1% R4 1.98K OP-77 50 GAIN ADJ R1 C1 0.1MF R3 200K 5% + +5V J2 C23 0.1MF 0.1% R8 10K C18 0.1MF + 2.2MF C24 2 1 -15V C12 0.1MF C10 0.1MF 6 AD845 C6 2.2MF 4 -15V U5 7 C4 2.2MF +15V C5 0.1MF C3 0.1MF 24 23 22 21 20 19 18 17 16 15 14 13 C8 2.2MF 11 5 4 74LS86 U4 ADS-916/917/919/929 12 +5V B3 11 DGND B4 10 EOC B5 9 ST. CONV B6 8 B2 B7 7 U1 B1 B8 6 AGND B9 5 INPUT B10 4 +10VREF B11 3 +15V B12 2 AGND B13 1 -15V B14 C7 0.1MF 74LS86 U4 1. SG1 SHOULD BE OPEN. SG2 & SG3 SHOULD BE CLOSED. 2. FOR ADS-916 Y1 IS 500 KHZ. FOR ADS-917 Y1 IS 1 MHZ. FOR ADS-919/929 Y1 IS 2 MHZ. 74LS86 3 NOTES: C14 2.2MF +5V 13 12 6 Figure 5. ADS-917 Evaluation Board Schematic 7 U4 14 +5V C13 0.1MF C15 0.1MF C9 2.2MF R5 2K .1% + R2 + OFFSET ADJ + + C2 15pF COG + + 6 + + +15V 10 9 2G 19 17 15 13 11 8 6 4 2 10 8 1G 2Y4 2Y3 2Y2 2Y1 1Y4 1Y3 1Y2 1Y1 20 74LS86 U4 2G 2A4 2A3 2A2 2A1 1A4 1A3 1A2 1A1 74LS240 B5 B6 9 7 1 3 J4 8 B13 1 3 5 7 17 9 7 11 13 15 LSB 5 P2 19 21 23 25 27 ST.CONV. 1 J3 34 ENABLE 2 4 EOC 3 6 10 B12 B14 12 B11 14 16 18 20 22 24 26 B10 9 31 33 28 MSB 29 30 32 12 B9 B8 SG3 SG2 14 16 18 B7 B4 12 5 B3 B2 B1 14 16 18 C17 0.1MF 10 1G 2Y4 2Y3 2Y2 +5V 2A4 2A3 2A2 2Y1 1Y4 1A4 2A1 1Y3 1Y2 1Y1 20 C16 0.1MF 1A3 1A2 1A1 U3 19 17 15 13 11 8 6 4 2 74LS240 U2 +5V ® ® ADS-917 ® ® ADS-917 0 –20 –30 –40 –50 –60 –70 –80 –90 –100 –110 –120 –130 –140 0 50 100 150 200 250 300 350 400 450 Frequency (kHz) (fs = 1MHz, fin = 480kHz, Vin = –0.5dB, 16,384-point FFT) Figure 6. ADS-917 FFT Analysis DNL (LSB's) +0.41 Number of Occurrences Amplitude Relative to Full Scale (dB) –10 0 –0.33 0 0 Digital Output Code 16,384 Digital Output Code Figure 7. ADS-917 Histogram and Differential Nonlinearity 7 16,384 500 ® ® ADS-917 MECHANICAL DIMENSIONS INCHES (mm) 1.31 MAX. (33.27) 24-Pin DDIP Versions 24 ADS-917MC ADS-917MM ADS-927MC ADS-927MM ADS-927/883 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) 0.600 ±0.010 (15.240) SEATING PLANE 0.025 (0.635) 0.040 (1.016) +0.002 –0.001 0.100 (2.540) 1.31 MAX. (33.02) 24-Pin Surface Mount Versions Dimension Tolerances (unless otherwise indicated): 2 place decimal (.XX) ±0.010 (±0.254) 3 place decimal (.XXX) ±0.005 (±0.127) 13 24 ADS-917GC ADS-917GM ADS-927GC ADS-927GM 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) 0.130 TYP. (3.302) PIN 1 INDEX 0.100 (2.540) 0.100 TYP. (2.540) 0.020 (0.508) 0.015 (0.381) MAX. radius for any pin 0.010 TYP. (0.254) 0.040 (1.016) ORDERING INFORMATION MODEL NUMBER ADS-917MC ADS-917MM ADS-917GC ADS-917GM ADS-927MC ADS-927MM ADS-927GC ADS-927GM ADS-927/883 ® OPERATING TEMP. RANGE 0 to +70°C –55 to +125°C 0 to +70°C –55 to +125°C 0 to +70°C –55 to +125°C 0 to +70°C –55 to +125°C –55 to +125°C ® ANALOG INPUT Unipolar (0 to +10V) Unipolar (0 to +10V) Unipolar (0 to +10V) Unipolar (0 to +10V) Bipolar (±5V)* Bipolar (±5V)* Bipolar (±5V)* Bipolar (±5V)* Bipolar (±5V)* ACCESSORIES ADS-B916/917 HS-24 Receptacles for PC board mounting can be ordered through AMP Inc. Part #3-331272-8 (Component Lead Socket), 24 required. For MIL-STD-883 product specifications, contact DATEL. * For information, see ADS-927 data sheet. ISO 9001 R 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 E G Evaluation Board (without ADS-917) Heat Sinks for all ADS-917/927 DDIP models I S T E R E D DS-0293B 11/96 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. The DATEL logo is a registered DATEL, Inc. trademark.