® ® ADS-943 14-Bit, 3MHz, Low-Distortion Sampling A/D Converters FEATURES • • • • • • • • • 14-bit resolution 3MHz minimum sampling rate Ideal for both frequency and time-domain applications Excellent peak harmonics, –83dB Excellent signal-to-noise ratio, 79dB No missing codes over full military temperature range ±5V supplies, 1.7 Watts Small, 24-pin ceramic DDIP or SMT Low cost INPUT/OUTPUT CONNECTIONS GENERAL DESCRIPTION The low-cost ADS-943 is a 14-bit, 3MHz sampling A/D converter optimized to meet the demanding dynamic-range and sampling-rate requirements of contemporary digital telecommunications applications. The ADS-943's outstanding dynamic performance is evidenced by a peak harmonic specification of –83dB and a signal-to-noise ratio (SNR) of 79dB. Additionally, the ADS-943 easily achieves the 2.2MHz minimum sampling rate required by digital receivers in certain ADSL, HDSL and ATM applications. The ADS-943 also addresses size and power constraints normally associated with these types of applications. This device requires just ±5V supplies, dissipates 1.7 Watts, and is packaged in a very small 24-pin DDIP. Although optimized for frequency-domain applications, the ADS-943's DNL and noise specifications are also outstanding, thereby making it an equally impressive device for time-domain applications (graphic and medical imaging, process control, etc.). In fact, the ADS-943 guarantees no missing codes to the 14-bit level over the full military operating temperature range. The functionally complete ADS-943 contains a fast-settling sample-hold amplifier, a subranging (two-pass) A/D converter, an internal reference, timing/control logic, and error-correction circuitry. Digital input and output levels are TTL. The unit is PIN FUNCTION PIN 1 2 3 4 5 6 7 8 9 10 11 12 BIT1 (MSB) BIT 2 BIT 3 BIT 4 BIT 5 BIT 6 BIT 7 BIT 8 BIT 9 BIT 10 BIT 11 BIT 12 24 23 22 21 20 19 18 17 16 15 14 13 FUNCTION ANALOG GROUND OFFSET ADJUST +5V ANALOG SUPPLY ANALOG INPUT –5V SUPPLY ANALOG GROUND START CONVERT EOC BIT 14 (LSB) BIT 13 DIGITAL GROUND +5V DIGITAL SUPPLY edge-triggered, requiring only the rising edge of a start convert pulse to initiate a conversion. The device is offered with a bipolar input range of ±2V. Models are available for use in either commercial (0 to +70°C) or military (–55 to +125°C) operating temperature ranges. A proprietary, auto-calibrating, error-correcting circuit allows the device to achieve specified performance over the full military temperature range. OFFSET ADJUST 23 BUFFER 16 BIT 14 (LSB) FLASH ADC 1 + POWER AND GROUNDING REF 22 +5V DIGITAL SUPPLY 13 DIGITAL GROUND 14 –5V SUPPLY 20 ANALOG GROUND DAC Σ 19, 24 AMP START CONVERT 18 EOC 17 FLASH ADC 2 REGISTER +5V ANALOG SUPPLY 15 BIT 13 12 BIT 12 11 BIT 11 OUTPUT REGISTER S/H DIGITAL CORRECTION LOGIC – REGISTER ANALOG INPUT 21 10 BIT 10 9 BIT 9 8 BIT 8 7 BIT 7 6 BIT 6 5 BIT 5 4 BIT 4 3 BIT 3 2 BIT 2 1 BIT 1 (MSB) TIMING AND CONTROL LOGIC Figure 1. ADS-943 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-943 ABSOLUTE MAXIMUM RATINGS PARAMETERS +5V Supply (Pins 13, 22) –5V Supply (Pin 20) Digital Input (Pin 18) Analog Input (Pin 21) Lead Temperature (10 seconds) PHYSICAL/ENVIRONMENTAL LIMITS UNITS 0 to +6 0 to –6 –0.3 to +VDD +0.3 –5 to +5 +300 Volts Volts Volts Volts °C PARAMETERS MIN. TYP. MAX. UNITS 0 –55 — — +70 +125 °C °C Operating Temp. Range, Case ADS-943MC, GC ADS-943MM, GM, 883, G/883 Thermal Impedance θjc θca Storage Temperature Range Package Type Weight — 6 — °C/Watt — 23 — °C/Watt –65 — +150 °C 24-pin,metal-sealed, ceramic DDIP or SMT 0.42 ounces (12 grams) FUNCTIONAL SPECIFICATIONS (TA = +25°C, ±VDD = ±5V, 3MHz sampling rate, and a minimum 3 minute warmup ➀ unless otherwise specified.) +25°C ANALOG INPUT Input Voltage Range ➁ Input Resistance Input Capacitance 0 to +70°C –55 to +125°C MIN. TYP. MAX. MIN. TYP. MAX. MIN. TYP. MAX. UNITS — — — ±2 280 6 — — 15 — — — ±2 280 6 — — 15 — — — ±2 280 6 — — 15 Volts Ω pF +2.0 — — — 10 — — — — 20 — +0.8 +20 –20 — +2.0 — — — 10 — — — — 20 — +0.8 +20 –20 — +2.0 — — — 10 — — — — 20 — +0.8 +20 –20 — Volts Volts µA µA ns — — –0.95 — — — 14 14 ±0.75 ±0.5 ±0.15 ±0.1 ±0.2 — — — +1.25 ±0.4 ±0.3 ±0.5 — — — –0.95 — — — 14 14 ±0.75 ±0.5 ±0.15 ±0.1 ±0.2 — — — +1.25 ±0.4 ±0.3 ±0.5 — — — –0.95 — — — 14 14 ±1 ±0.75 ±0.4 ±0.3 ±0.4 — — — +1.5 ±0.6 ±0.6 ±1.25 — Bits LSB LSB %FSR %FSR % Bits — — — –83 –83 –83 –77 –77 –77 — — — –83 –83 –83 –77 –77 –77 — — — –81 –81 –81 –75 –75 –75 dB dB dB — — — –80 –80 –80 –76 –76 –76 — — — –80 –80 –80 –76 –76 –76 — — — –78 –77 –77 –74 –73 –73 dB dB dB 76 76 75 79 79 78 — — — 76 76 75 79 79 78 — — — 75 74 74 78 77 77 — — — dB dB dB 73 73 73 — 77 77 77 125 — — — — 73 73 73 — 77 77 77 125 — — — — 71 71 71 — 75 75 74 125 — — — — dB dB dB µVrms — –82 — — –82 — — –82 — dB — — — — — — 30 10 85 ±400 +5 2 — — — — — — — — — — — — 30 10 85 ±400 +5 2 — — — — — — — — — — — — 30 10 85 ±400 +5 2 — — — — — — MHz MHz dB V/µs ns ps rms 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 Bipolar Zero Error (Tech Note 2) Gain Error (Tech Note 2) No Missing Codes (fin = 10kHz) DYNAMIC PERFORMANCE Peak Harmonics (–0.5dB) dc to 500kHz 500kHz to 1MHz 1MHz to 1.5MHz Total Harmonic Distortion (–0.5dB) dc to 500kHz 500kHz to 1MHz 1MHz to 1.5MHz Signal-to-Noise Ratio (w/o distortion, –0.5dB) dc to 500kHz 500kHz to 1MHz 1MHz to 1.5MHz Signal-to-Noise Ratio ➃ (& distortion, –0.5dB) dc to 500kHz 500kHz to 1MHz 1MHz to 1.5MHz Noise Two-Tone Intermodulation Distortion (fin = 975kHz, 1.2MHz, fs = 3MHz, –0.5dB) Input Bandwidth (–3dB) Small Signal (–20dB input) Large Signal (–0dB input) Feedthrough Rejection (fin = 1.5MHz) Slew Rate Aperture Delay Time Aperture Uncertainty 2 ® ® ADS-943 +25°C DYNAMIC PERFORMANCE cont. 0 to +70°C –55 to +125°C MIN. TYP. MAX. MIN. TYP. MAX. MIN. TYP. MAX. — — 3 208 100 — 215 333 — — — 3 208 100 — 215 333 — — — 3 208 100 — 215 333 — ns ns MHz +2.4 — — — — — — — — +0.4 –4 +4 +2.4 — — — +2.4 — — — — — — — — +0.4 –4 +4 Volts Volts mA mA +4.75 –4.75 +5.0 –5.0 +5.25 –5.25 +4.75 –4.75 +5.0 –5.0 +5.25 –5.25 +4.9 –4.9 +5.0 –5.0 +5.25 –5.25 Volts Volts — — — — +210 –125 1.7 — +230 –145 1.9 ±0.05 — — — — +210 –125 1.7 — +230 –145 1.9 ±0.05 — — — — +210 –125 1.7 — +230 –145 1.9 ±0.05 mA mA Watts %FSR/%V S/H Acquisition Time ( to ±0.003%FSR, 4V step) Overvoltage Recovery Time ➄ A/D Conversion Rate UNITS DIGITAL OUTPUTS Logic Levels Logic "1" Logic "0" Logic Loading "1" Logic Loading "0" Output Coding — — — +0.4 — –4 — +4 Offset Binary POWER REQUIREMENTS Power Supply Ranges ➅ +5V Supply –5V Supply Power Supply Currents +5V Supply –5V Supply Power Dissipation Power Supply Rejection Footnotes: ➀ All power supplies should be on before applying a start convert pulse. All supplies and the clock (start convert pulses) must be present during warmup periods. The device must be continuously converting during this time. ➃ Effective bits is equal to: (SNR + Distortion) – 1.76 + ➁ Contact DATEL for other input voltage ranges. 20 log Full Scale Amplitude Actual Input Amplitude 6.02 ➂ A 3MHz clock with a 20nsec positive pulse width is used for all production testing. When sampling at 3MHz, the start convert pulse must be between 10 and 110nsec wide or between 160 and 300nsec wide. The falling edge must not occur between 110 and 160nsec. For lower sampling rates, wider start pulses may be used. ➄ This is the time required before the A/D output data is valid once the analog input is back within the specified range. This time is only guaranteed if the input does not exceed ±2.2V (S/H Saturation Voltage). ➅ The minimum supply voltages of +4.9V and –4.9V for ±VDD are required for –55°C operation only. The minumum limits are +4.75V and –4.75V when operating at +125°C. TECHNICAL NOTES 3. Applying a start convert pulse while a conversion is in progress (EOC = logic "1") will initiate a new and inaccurate conversion cycle. Data for the interrupted and subsequent conversions will be invalid. 1. Obtaining fully specified performance from the ADS-943 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 24) directly to a large analog ground plane beneath the package. 4. A passive bandpass filter is used at the input of the A/D for all production testing. Bypass all power supplies 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. 2k Ω 2. The ADS-943 achieves its specified accuracies without the need for external calibration. If required, the device's small initial offset and gain errors can be reduced to zero using the adjustment circuitry shown in Figures 2 and 3. GAIN ADJUST +5V SIGNAL INPUT When using this circuitry, or any similar offset and gaincalibration hardware, make adjustments following warmup. To avoid interaction, always adjust offset before gain. 1.98kΩ To Pin21 of ADS-943 50Ω –5V Figure 2. Optional ADS-943 Gain Adjust Calibration Circuit 3 ® ® ADS-943 CALIBRATION PROCEDURE Gain Adjust Procedure 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 circuits in Figures 2 and 3 are guaranteed to compensate for the ADS-943's initial accuracy errors and may not be able to compensate for additional system errors. 1. Apply +1.99963V to the ANALOG INPUT (pin 21). 2. Adjust the gain potentiometer until all output bits are 1's and the LSB flickers between 1 and 0. 3. To confirm proper operation of the device, vary the input signal to obtain the output coding listed in Table 2. 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. Table 1. Gain and Zero Adjust INPUT VOLTAGE RANGE ±2V Offset adjusting for the ADS-943 is normally accomplished at the point where the MSB is a 1 and all other 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 (+122µV). 2. Apply +122µV to the ANALOG INPUT (pin 21). 3. Adjust the offset potentiometer until the output bits are 10 0000 0000 0000 and the LSB flickers between 0 and 1. 4.7µF + 4.7µF 4.7µF + + 0.1µF 0.1µF 20 24 0.1µF 22, 13 21 +5V ADS-943 20kΩ –5V START CONVERT +1.99976 +1.50000 +1.00000 0.00000 –1.00000 –1.50000 1.99976 –2.00000 +5V ➀ –5V 23 INPUT VOLTAGE (±2V RANGE) +FS – 1 LSB +3/4FS +1/2FS 0 –1/2 FS –3/4 FS –FS +1 LSB –FS 1. Apply a train of pulses to the START CONVERT input (pin 18) so the converter is continuously converting. ZERO/ OFFSET ADJUST +122µV BIPOLAR SCALE Zero/Offset Adjust Procedure ANALOG INPUT GAIN ADJUST +FS –1½ LSB +1.99963V Table 2. Output Coding for Bipolar Operation 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 (+1.99963V). 19 ZERO ADJUST +1/2 LSB 18 14 1 2 3 4 5 6 7 8 9 10 11 12 15 16 17 BIT 1 (MSB) BIT 2 BIT 3 BIT 4 BIT 5 BIT 6 BIT 7 BIT 8 BIT 9 BIT 10 BIT 11 BIT 12 BIT 13 BIT 14 (LSB) EOC ➀ A single +5V supply should be used for both the +5V analog and +5V digital. If separate supplies are used, the difference between the two cannot exceed 100mV. Figure 3. Connection Diagram 4 OFFSET BINARY MSB LSB 11 11 11 10 01 00 00 00 1111 1000 0000 0000 0000 1000 0000 0000 1111 0000 0000 0000 0000 0000 0000 0000 1111 0000 0000 0000 0000 0000 0001 0000 ® ® ADS-943 THERMAL REQUIREMENTS 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. 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 20ns typ. 333nsec 10ns typ. INTERNAL S/H 125ns typ. Hold 35ns typ. EOC 130ns Acquisition Time 208ns typ. 215ns max. 125ns typ. Conversion Time 120ns min., 130ns typ., 140ns max. 10ns max. OUTPUT DATA Data N-1 Valid 30ns typ. Invalid Data Data N Valid 283ns typ. Data N+1 Valid 50ns typ. Note: 1. Scale is approximately 20ns per division. Sampling rate = 3MHz. 2. The start convert positive pulse width must be between either 10 and 110nsec or 160 and 300nsec (when sampling at 3MHz) to ensure proper operation. For sampling rates lower than 3MHz, the start pulse can be wider than 300nsec, however a minimum pulse width low of 30nsec should be maintained. A 3MHz clock with a 20nsec positive pulse width is used for all production testing. Figure 4. ADS-943 Timing Diagram 5 SG10 SG3 SG2 SG1 P2 26 24 22 20 18 16 14 12 10 8 6 4 2 25 23 21 19 17 15 13 11 9 7 5 3 1 ANA. IN 20µH L7 20µH L6 20µH L5 20µH L4 20µH L3 20µH L2 20µH L1 C8 0.01µF C9 0.01µF C1 2.2µF C2 2.2µF +5VF C11 0.01µF C12 0.01µF 2.2µF C5 2.2µF 0.01µF 2.2µF C4 C10 C3 2.2µF C7 0.01µF 2.2µF 0.01µF C14 C13 C6 –5V +5VA +15V –15V –5VA +5V 5 +15V 10 12 11 13 -15V SG8 U6 HCT7474 Q 9 8 5 4 13 12 SPARE GATES 0.1µF 11 U5 6 7 14 8 HCT7474 7 ADS-943 AGND BIT1 1 OFFSET BIT2 2 +5VA BIT3 3 AIN BIT4 4 -5V BIT5 5 AGND BIT6 6 TRIG BIT7 7 EOC BIT8 8 BIT14 BIT9 9 BIT13 BIT10 10 DGND BIT11 11 +5VD BIT12 12 U1 3.2k 2.2µF 14 4 JPR1 PR 5 2 D U6 Q 6 3 1 2 3 CK Q 1 R3 CLR 0.1µF C24 + C23 START CONVERT 24 23 22 21 20 19 18 17 16 15 14 13 +5V 15pF C25 +5VA –5V X1 SG9 +5VF 2.2µF C27 74HCT86 0.1µF C15 7 GND U5 14 +5VF ANA. IN SG4 0.1µF C26 3MHz CRYSTAL +5VF 10 9 P3 U5 Figure 5. ADS-943 Evaluation Board Schematic 0.1µF (Optional) C19 (Optional) -15V C20 PR D CK CLR 2 R1 C18 0.1µF (Optional) SG6 20k CLC402 HI2541 10 +5VA OFFSET ADJUST -5VA SG7 6 U4 11 +5VF + (Optional) 4 – R2 SG5 +15V + P4 ANA. IN + + + + + + 6 + OPTION U5 + 0.1µF 2.2µF C16 C22 3 2 3 4 5 6 7 8 9 11 2 3 4 5 6 7 8 9 11 74HCT573 C21 74HCT573 19 18 17 16 15 14 13 12 1 +5VF 19 18 17 16 15 14 13 12 1 2.2µF Q1 1D 2D Q2 Q3 3D 4D Q4 U2 Q5 5D 6D Q6 Q7 7D Q8 8D OE CE 10 20 10 C17 0.1µF Q1 1D 2D Q2 Q3 3D 4D Q4 5D U3 Q5 6D Q6 Q7 7D Q8 8D OE CE 20 + +5VF 3. SEE DATEL DWG A-24546 FOR ADDITIONAL INFORMATION ON ADS-B946 EVALUATION BOARD. 2. CLOSE SG1-SG3, SG9, SG10. C1 - C7 ARE 20V. ALL RESISTORS ARE IN OHMS. 1. UNLESS OTHERWISE SPECIFIED ALL CAPACITORS ARE 50V. NOTES: 74HCT86 8 74HCT86 2 1 START CONV. 2 3 JPR2 1 CE B14 B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 TRIG 2 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 P1 1 33 31 29 27 25 23 21 19 17 15 13 11 9 7 5 3 ® ® ADS-943 ® ® ADS-943 0 –20 –30 –40 –50 –60 –70 –80 –90 –100 –110 –120 –130 –140 –150 0 150 kHz 300 kHz 450 kHz 600 kHz 750 kHz 900 kHz 1.05 MHz 1.20 MHz Frequency (fs = 3MHz, fin = 1.485MHz, Vin = –0.5dB, 16,384-point FFT) Figure 6. FFT Analysis of ADS-943 +0.60 DNL (LSB's) 0.00 –0.58 Number of Occurences Amplitude Relative to Full Scale (dB) –10 0 16,384 Digital Output Code 0 Digital Output Code 16,384 Figure 7. ADS-943 Histogram and Differential Nonlinearity 7 1.35 MHz 1.5 MHz ® ® ADS-943 MECHANICAL DIMENSIONS INCHES (mm) 1.31 MAX. (33.27) 24-Pin DDIP Versions 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) ADS-943MC ADS-943MM ADS-943/883 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) 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 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 Lead Material: Kovar alloy 0.80 MAX. (20.32) ADS-943GC ADS-943GM ADS-943G/883 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) 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 OPERATING TEMP. RANGE 24-PIN PACKAGE ADS-943MC ADS-943MM ADS-943/883 ADS-943GC ADS-943GM ADS-943G/883 0 to +70°C –55 to +125°C –55 to +125°C 0 to +70°C –55 to +125°C –55 to +125°C DDIP DDIP DDIP SMT SMT SMT ACCESSORIES ADS-B943 HS-24 Evaluation Board (without ADS-943) Heat Sink for all ADS-943 DDIP models 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 specifcation, contact DATEL. ® ® ISO 9001 R E 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 G I S T E R E D DS-0333A 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.