® ® INNOVATION and EXCELLENCE Single Output UNR Series Non-Isolated, 1.8/2.5/3.3VOUT 3.6-10W DC/DC Converters Features Low cost! High reliability! 1" x 1" SMT, 1" x 1" Through-hole packages Gull-wing leads; Standard reflow Complete; No external components Outputs: 1.8V/2A, 2.5V/2A, 3.3V/3A Inputs: 4.75-5.5V, 10.8-13.6V Guaranteed efficiencies to 87% Output noise as low as 30mVp-p Transient response as quick as 20µsec –40 to +70°C operation with no derating On/off control; EMC compliant IEC950/EN60950/UL1950 approvals Modifications and customs for OEM's DATEL's 3.6-10W UNR Series consists of non-isolated, 5V-to-1.8V (2A), 5V-to2.5V (2A), 5V-to-3.3V (3A), and 12V-to-3.3V (3A) DC/DC converters in miniature, 1" x 1" surface-mount and through-hole packages. The "gull-wing" packages (with metal shells and non-conductive plastic baseplates) weigh a mere 17 grams and can withstand temperatures up to +235°C. They are compatible with virtually all contemporary pick-and-place and solder-reflow processes. The true benefits of distributed power will ultimately be realized only when every low-voltage, high-current CPLD, ASIC, DSP, etc. has its own "power plant" right next to it. With isolated DC/DC converters inevitably residing at the edges of boards in proximity with backplanes and power buses, the "on-board" proliferation of distributed power will continue with more cost-effective, non-isolated devices. The low-cost, easy-to-use (no external components required), highly reliable (100% fully automated SMT construction) 3.6-10W UNR Series makes this power processing at the concluding point of use a practical reality today. These versatile DC/DC's are fully line and load regulated. They feature useroptional on/off control (for power-sequencing requirements), output current limiting, and short-circuit protection (foldback technique with auto-recovery). Additionally, the 12V-to-3.3V model offers input undervoltage lockout (at 9.6V). Their impressive guaranteed efficiencies enable all models to deliver their fully rated output power from –40 to +70°C (ambient) without heat sinking or forced-air cooling. If you've already considered and rejected the use of inefficient, step-down, linear regulators, take a look at one of these new switching buck regulators. Their high efficiency, ease-of-use, long-term reliability, and overall cost effectiveness will impress you. Safety agency approvals are currently in progress. +VOUT +VIN ➁ OUTPUT RETURN INPUT RETURN ➀ LOGIC GROUND CURRENT LIMITING & S.C. SHUTDOWN UNDERVOLTAGE SHUTDOWN ON/OFF CONTROL PWM CONTROLLER REFERENCE & ERROR AMP Figure 1. Simplified Schematic ➀ "D5" models do not have input undervoltage shutdown. ➁ "D5" models employ a more traditional buck-regulator design in which this FET is replaced with a power Schottky diode. DATEL, Inc., Mansfield, MA 02048 (USA) • Tel: (508)339-3000, (800)233-2765 Fax: (508)339-6356 • Email: [email protected] • Internet: www.datel.com UNR Series N O N - I S O L AT E D , 3 . 6 - 1 0 W D C / D C C O N V E R T E R S Performance Specifications and Ordering Guide ➀ Input Output VOUT (Volts) Model R/N (mVp-p) ➁ Typ. Max. IOUT (Amps) Regulation (Max.) Load ➂ Line VIN Nom. (Volts) Efficiency Min. Typ. IIN ➃ (mA) Range (Volts) Package (Case, Pinout) UNR-1.8/2-D5 1.8 2 40 75 ±0.35% ±0.5% 5 4.75-5.5 30/900 77% 79% C7A, P9 UNR-1.8/2-D5SM 1.8 2 40 75 ±0.35% ±0.5% 5 4.75-5.5 30/900 77% 79% C17, P24 UNR-2.5/2-D5 ➄ 2.5 2 30 50 ±0.25% ±0.5% 5 4.75-5.5 40/1180 83% 85% C7A, P9 UNR-2.5/2-D5SM ➄ 2.5 2 30 50 ±0.25% ±0.5% 5 4.75-5.5 40/1180 83% 85% C17, P24 UNR-3.3/3-D5 ➄ ➅ 3.3 3 30 45 ±0.4% ±0.5% 5 4.75-5.5 40/2250 86% 88% C7A, P9 UNR-3.3/3-D5SM ➄ ➅ 3.3 3 30 45 ±0.4% ±0.5% 5 4.75-5.5 40/2250 86% 88% C17, P24 UNR-3.3/3-D12 ➁ 3.3 3 100 150 ±0.25% ±0.5% 12 10.8-13.6 40/930 87% 89% C7A, P9 UNR-3.3/3-D12SM ➁ 3.3 3 100 150 ±0.25% ±0.5% 12 10.8-13.6 40/930 87% 89% C17, P24 ➀ Typical at TA = +25°C under nominal line voltage and full-load conditions, unless otherwise noted. The UNR-1.8/2-D5SM/-D5SM models require an external 15kΩ pull-up resistor between VIN and On/Off Control for normal operation. See On/Off Control for details. ➁ Ripple/Noise (R/N) measured over a 20MHz bandwidth. The UNR-3.3/3-D12/-D12SM models are specified with an external 22µF input capacitor. All other models are specified with no external I/O capacitors. Output noise on the "D12" model can be reduced significantly with the addition of external output capacitors. See I/O Filtering. ➂ D5/D5SM models require a minimum 300mA load current to maintain regulation. The D12/D12SM model has no mimimum load requirement. Listed specs apply from 300mA to full load for D5/D5SM models and from no load to full load for the D12/D12SM models. ➃ Nominal line voltage, no-load/full-load conditions. ➄ Internal circuit design of "D5" models mandates that no voltages greater than 1.2V are present on the output pins at power-up. Failure to comply may result in start-up problems. ➅ Circuit design of 3.3V -D5/D5SM models mandates that no voltages greater than 1.0V are present on the output pins at power-up. Failure to comply may result in start-up problems. M E C H A N I C A L S P E C I F I C AT I O N S 1.00 (25.40) 0.45 (11.43) 1.22 (30.99) 0.100 (2.54) STANDOFFS 0.020 (0.51) Case C7A 4 9 8 3 7 0.500 (12.70) 0.040 ±0.002 DIA. (1.016 ±0.051) 0.20 MIN (5.08) 0.800 (20.32) 2 0.300 (7.62) 6 1.00 (25.40) 5 1 0.10 (2.54) 0.800 (20.32) 4 EQ. SP.@ 0.200 (5.08) TOP VIEW 0.10 (2.54) Case C17 0.100 (2.54) 3 0.800 1.00 (20.32) (25.40) 4 2 5 0.200 (5.08) 0.060 (1.52) 0.47 (11.94) 6 BOTTOM VIEW 0.200 (5.08) 0.10 (2.54) INSULATED BASE METAL CASE PLASTIC CASE WITH AN INSULATED BASE N U M B E R I/O Connections S T R U C T U R E Pin 1 2 3 4 5 6 7 8 9 U NR - 2.5 / 2 - D5 SM Output Configuration: U = Unipolar Non-Isolated Nominal Output Voltage: 1.8, 2.5 or 3.3 Volts Maximum Output Current in Amps 0.015 (0.38) DIMENSIONS ARE IN INCHES (MM) DIMENSIONS ARE IN INCHES (MM) P A R T 0.110 (2.79) 1.00 (25.40) 0.400 (10.16) 1 Surface-Mount Packaging Input Voltage Range: D5 = 4.75-5.5 Volts (5V nominal) ➀ D12 = 10.8-13.6 Volts (12V nominal) 2 Function P9 Logic Ground On/Off Control +Output Output Return Input Return +Input No Pin No Pin No Pin Function P24 N.C. Logic Ground On/Off Control N.C. +Output N.C. Output Return Input Return +Input 0.05 (1.4 UNR Models N O N - I S O L AT E D , 3 . 6 - 1 0 W D C / D C C O N V E R T E R S Performance/Functional Specifications Typical @ TA = +25°C under nominal line voltage and full-load conditions with no external filtering; specifications apply to both surface-mount and through-hole models, unless otherwise noted. ➀ Input Physical Input Voltage Range: D5 Models: 1.8VOUT 2.5VOUT, 3.3VOUT ➆ D12 Models 4.75-5.5 Volts (5V nominal) 4.75-5.5 Volts (5V nominal) 10.8-13.6 Volts (12V nominal) Overvoltage Shutdown None Start-Up Threshold: D12 Models ➁ 10.2V typical, 10.8V maximum Undervoltage Shutdown: D12 Models ➁ ➆ 9.6V typical, 8.2V minimum Input Current: Normal Operating Conditions Standby Mode (Off or undervoltage): 1.8VOUT 2.5VOUT, 3.3VOUT D5 Models 3.3VOUT D12 Models 20mA typical, 30mA maximum 10mA typical, 20mA maximum 5mA typical, 10mA maximum Input Ripple Current: 1.8VOUT, 3.3VOUT D12 Models 2.5VOUT, 3.3VOUT D5 Models 50mArms 150mArms None TTL high (or open) = on, low = off ±1.5% (±27mV) maximum ±1.75% (±43.8mV) maximum ±1.5% (±50mV) maximum ±1% (±33mV) maximum Temperature Coefficient ±0.02% per °C Ripple/Noise (20MHz BW) ➃ See Ordering Guide Line/Load Regulation See Ordering Guide Efficiency See Ordering Guide Current Limiting ➄ Auto-recovery 5-sided NA Case Connection (Surface Mount) Input return Pin Material Surface Mount Through Hole Copper, tin plated Brass, solder coated Weight 0.6 ounces (17 grams) Absolute Maximum Ratings Dynamic Characteristics Transient Response (50% load step): 1.8VOUT 2.5VOUT, 3.3VOUT D12 Models 3.3VOUT D5 Models 20µsec to ±0.5% of final value 30µsec to ±1% of final value 40µsec to ±1% of final value Start-Up Time: ➅ ➆ ➇ VIN to VOUT : D5 Models D12 Models On/Off to VOUT: D5 Models D12 Models 100msec typical, 120msec maximum 13msec typical, 20msec maximum 60msec typical, 120msec maximum 13msec typical, 20msec maximum Switching Frequency 200kHz (±30kHz) Corrosion-resistant steel with non-conductive, epoxy-based, black enamel finish and plastic baseplate Diallyl phthalate, UL94V-0 rated ➀ D5 models require a minimum 300mA load current to maintain specified regulation. D12 models have no minimum load requirement. Operating D5 models under no-load conditions will not damage these devices, however they may not meet all listed specifications. The UNR-1.8/2-D5/-D5SM require an external 15Ω pull-up resistor between VIN and On/Off Control for normal operation. See On/Off Control for details. The UNR-3.3/3-D12/-D12SM are specifiied with an external 22µF input capacitor. See I/O Filtering for details. ➁ See Startup Threshold and Undervoltage Shutdown for details. ➂ See On/Off Control for details. ➃ The 22µF external input capacitor required for the UNR-3.3/3-D12/-D12SM should be minimally rated for 1.5Arms ripple current and 125mΩ ESR. Output noise for all models can be further reduced with the installation of external output capacitors. See See I/O Filtering for details. ➄ Current limiting initiates at approximately 30% above rated load. Under short-circuit conditions, output current folds back to approximately 150mA and input current drops to approximtely 50mA. Both remain at those levels until the short is removed. ➅ See Start-Up Time for details. ➆ Internal circuit design of the "D5" models mandates that no voltages greater than 1.2V are present on the output pins at power-up. Failure to comply may result in start-up problems. ➇ Circuit design of the 3.3VOUT models mandates that no voltages greater than 1.0V are present on the output pins at power-up. Failure to comply may result in start-up problems. Output VOUT Accuracy (50% load): 1.8VOUT 2.5VOUT 3.3VOUT D5 Models ➇ 3.3VOUT D12 Models Shielding (Surface Mount) Surface Mount Through Hole Through Hole Input Filter Type Capacitive On/Off Control (Pin 3) ➂ 1.5V typical logic threshold . 1" x 1" x 0.47" (25 x 25 x 11.9mm) 1" x 1" x 0.45" (25 x 25 x 11.4mm) Case Material Surface Mount See Ordering Guide Reverse-Polarity Protection Dimensions: Surface Mount Through Hole Input Voltage: Continuous: D5 Models D12 Models Transient (100msec): D5 Models D12 Models –40 to +70°C to +100°C (See Derating Curves) Storage Temperature –40 to +105°C 15 Volts 24 Volts Input Reverse-Polarity Protection None Output Overvoltage Protection None Output Current Current limited. Devices can withstand a sustained output short circuit without damage. Environmental Operating Temperature (Ambient): Without Derating With Derating 7 Volts 15 Volts Storage Temperature –40 to +105°C Lead Temperature (Soldering, 10 sec.) +300°C These are stress ratings. Exposure of devices to any of these conditions may adversely affect long-term reliability. Proper operation under conditions other than those listed in the Performance/Functional Specifications Table is not implied. 3 UNR Series N O N - I S O L AT E D , 3 . 6 - 1 0 W D C / D C C O N V E R T E R S Input Fusing T E M P E R AT U R E D E R AT I N G Certain applications and/or safety agencies may require the installation of fuses at the inputs of power conversion components. Fuses should also be used if the possibility of sustained, non-current-limited, input-voltage polarity reversals exists. For DATEL UNR SM Series 3.6-10 Watt DC/DC Converters, you should use slow-blow type fuses with values no greater than the following. Model Number Fuse Value UNR-1.8/2-D5/-D5SM 1.5 Amps UNR-2.5/2-D5/-D5SM 2 Amps UNR-3.3/3-D5/-D5SM 3 Amps UNR-3.3/3-D12/-D12SM 1.5 Amps 10 9 Output Power (Watts) 8 UNR-3.3/3-D5 UNR-3.3/3-D5SM UNR-3.3/3-D12 UNR-3.3/3-D12SM 7 6 UNR-2.5/2-D5SM UNR-2.5/2-D5SM 5 4 UNR-1.8/2-D5 UNR-1.8/2-D5SM 3 Start-Up Threshold and Undervoltage Shutdown (UNR-3.3/3-D12/-D12SM only) 2 1 0 –40 0 40 45 50 55 60 65 70 75 80 85 90 95 Under normal start-up conditions, UNR-3.3/3-D12/-D12SM devices will not begin to regulate until the ramping input voltage exceeds the Start-Up Threshold Voltage (typically 10.2V). Once operating, devices will not turn off until the input voltage drops below the Undervoltage Shutdown/Lockout limit (typically 9.6V). Subsequent re-start will not occur until the input is brought back up to the Start-Up Threshold. This built-in hysteresis obviously avoids any indeterminate on/off conditions at a single voltage. 100 Ambient Temperature (˚C) T E C H N I C A L N O T E S I/O Filtering and Noise Reduction Start-Up Time All "D5" models of UNR 3.6-10W Series DC/DC converters achieve their rated ripple and noise specifications without the use of external input/output capacitors. The UNR-3.3/3-D12/-D12SM models are tested and specified with a single, external 22µF input capacitor (minimally rated for 1.5Arms ripple current and 120mΩ ESR). For the three "D5" models (that do not have an input turn-on threshold), the VIN to VOUT Start-Up Time is the interval between the time a step input is applied to the device and the fully loaded output voltage enters and remains within its specified accuracy band. For the UNR-3.3/3-D12/-D12SM, VIN to VOUT Start-Up Time is the interval between the time at which a rapidly ramping input voltage crosses the turn-on threshold point and the fully loaded output voltage enters and remains within its specified accuracy band. Actual measured times will vary with input source impedance, external input capacitance, and the slew rate and final value of the input voltage as it appears to the converter. In critical applications, input/output ripple/noise may be further reduced by installing additional external I/O caps. Input capacitors, which function primarily as energy-storage elements, should be selected for bulk capacitance, low ESR and high rms-ripple-current ratings. Output capacitors, which function more as true filter elements, should be selected for bulk capacitance, low ESR, and appropriate frequency response. All caps should have appropriate voltage ratings and be mounted as close to the converters as possible. Temperature variations for all parameters should obviously be taken into consideration. The On/Off to VOUT Start-Up Time assumes the converter is turned off via the On/Off Control with the nominal input voltage already applied to the converter. The specification defines the interval between the time at which the converter is turned on and the fully loaded output voltage enters and remains within its specified accuracy band. The most effective combination of external I/O capacitors will be a function of your line voltage and source impedance, as well as your particular load and layout conditions. Our Applications Engineers will be happy to recommend potential solutions and can discuss the possibility of our modifying a given device’s internal filtering to meet your specific requirements. Contact our Applications Engineering Group for additional details. Internal circuit design of the 3.3VOUT models mandates that no voltages greater than 1.0V are present on the output pins at power-up. Failure to comply may result in start-up problems. Return Current Paths The Input Return (pin 8), Output Return (pin 7) and Logic Ground (pin 2) are all connected to each other internal to each device. To the extent possible, all load current should be returned through pin 7 (via low-impedance runs) and all input current returned through pin 8. Any control signals applied to pin 3 should be referenced to pin 2. The internal trace leading to pin 2 is not designed to carry high current. Devices should never be installed in a manner that results in high current flow through pin 2 (i.e., pins 7 and 8 should never be left open or attached via high-impedance connections). 4 UNR Models N O N - I S O L AT E D , 3 . 6 - 1 0 W D C / D C C O N V E R T E R S On/Off Control Solder Reflow The On/Off Control pin (pin 3) may be used for remote on/off operation. UNR SM Series converters are designed so that they are enabled when the control pin is pulled high or left open (normal mode) and disabled when the control pin is pulled low (to less than +0.8V relative to Logic Ground, pin 2). As shown in the figure and table below, each device has an internal pull-up resistor on its On/Off Control pin whose value and voltage vary with model. For UNR 3.6-10W Series devices, the packages' gull-wing leads are made of tin-plated (150 microinches) copper. The gull-wing configuration, as opposed to "J" leads, was selected to keep the solder joints out from under the package to minimize both heat conduction away from the leads (into the encapsulated package) and IR shadowing effects. Through a series of experiments, using 8 mil-thick, 63/37/2 (lead/tin/silver) solder paste and single-layer test boards, we have determined an optimal solder-reflow temperature profile as shown in Figure 2. Obviously, your optimal profile will be a function of many factors including paste thickness, board thickness, number of conductive layers, copper weight, the density of surrounding components, etc. Dynamic control of the on/off function is best accomplished with a mechanical relay or an open-collector/open-drain drive circuit (optically isolated if appropriate). The drive circuit should obviously be able to sink appropriate current when activated and withstand appropriate voltage when deactivated. e l b la i a v g A n i y r l . e t L d n l E e o DAT r S r Cu Hand tact for y. Con Onl The profile in Figure 3 should be used as a starting point for your own experiments. If you'd like, DATEL can provide you with complimentary "dummy" units to be used in such tests. Under no circumstances should the peak temperature exceed +235°C for an extended period of time. Applying an external voltage to pin 3 when no input power is applied to the converter can cause permanent damage to the converter. The on/off control function, however, is designed such that the converter can be disabled (pin 3 pulled low) while input power is ramping up and then "released" once the input has stabilized. The time duration between the point at which the converter is released and its fully loaded output voltage settles to within specified accuracy can be found in the Performance/Functional Specifications Table. As shown in Figure 4, our tests have determined the optimal landing-pad size to be 160 mils by 130 mils. 260 240 220 200 180 VIP Temperature (°C) 9 +INPUT REP RIP 3 SOLDER REFLOW PEAK TEMP. 235°C 160 140 120 100 80 ON/OFF CONTROL 60 40 2 LOGIC GROUND 20 PRE-HEAT AND TEMPERATURE SOAK 0 0 30 60 90 120 150 180 210 Time (Seconds) Figure 2. Driving the On/Off Control Pin Model UNR-1.8/2-D5/-D5SM UNR-2.5/2-D5/-D5SM UNR-3.3/3-D5/-D5SM UNR-3.3/3-D12/-D12SM Figure 3. Optimal Solder Reflow Profile Internal Pull-Up Resistor (RIP) External Pull-Up Resistor (REP) Internal Pull-Up Voltage (VIP) 1kΩ 1kΩ 1kΩ 10kΩ 15kΩ N.A. N.A. N.A. 1.8V 2.5V 3.3V VIN 0.015 (0.38) 0.130* (3.30) 0.110** (2.79) 0.100** (2.54) * PAD DIMENSION ** LEAD DIMENSION 0.160* (4.06) Figure 4. PC Board Land Pattern 5 240 270 300 UNR Series N O N - I S O L AT E D , 3 . 6 - 1 0 W D C / D C C O N V E R T E R S TYPICAL PERFORMANCE CURVES Efficiency vs. Output Current and Input Voltage UNR-3.3/3-D5/-D5SM (Guaranteed efficiency = 86% at VIN = 5V and IOUT = 3A) UNR-1.8/2-D5/-D5SM (Guaranteed efficiency = 77% at VIN = 5V and IOUT = 2A) 91 82 VIN = 4.75V 81 90 80 89 79 88 Efficiency (%) Efficiency (%) VIN = 5V 78 VIN = 4.5V VIN = 5.5V 77 87 VIN = 5V VIN = 5.5V 86 76 85 75 84 74 83 82 73 0.5 0.8 1.1 1.4 1.7 0.5 2 1 1.5 2 2.5 3 +3.3V Output Current (Amps) +1.8V Output Current (Amps) UNR-3.3/3-D12/-D12SM (Guaranteed efficiency = 87% at VIN = 12V and IOUT = 3A) UNR-2.5/2-D5/-D5SM (Guaranteed efficiency = 83% at VIN = 5V and IOUT = 2A) 87 92 VIN = 4.75V 86 89 85 86 84 83 Efficiency (%) Efficiency (%) VIN = 10.4V 83 VIN = 5V VIN = 5.5V 82 81 80 VIN = 13.6V 77 74 VIN = 12V 80 71 79 68 78 65 0.5 0.8 1.1 1.4 1.7 2 0.5 +2.5V Output Current (Amps) 1 1.5 2 +3.3V Output Current (Amps) 6 2.5 3 UNR Models N O N - I S O L AT E D , 3 . 6 - 1 0 W D C / D C C O N V E R T E R S EMI Radiated Emissions C U S TO M C A PA B I L I T I E S If you’re designing with EMC in mind, please note that all of DATEL’s 3.6-10 Watt UNR Series DC/DC Converters have been characterized for radiated and conducted emissions in our new EMI/EMC laboratory. Testing is conducted in an EMCO 5305 GTEM test cell utilizing EMCO automated EMC test software. Radiated emissions are tested to the limits of FCC Part 15, Class B and CISPR 22 (EN 55022), Class B. Correlation to other specifications can be supplied upon request. Radiated emissions plots to FCC and CISPR 22 for model UNR-3.3/3-D5SM appear below. Published EMC test reports are available for each model number. Contact DATEL's Applications Engineering Department for more details. DATEL’s world-class design, development and manufacturing team stands ready to work with you to deliver the exact power converter you need for your demanding, large volume, OEM applications. And ... we’ll do it on time and within budget! Our experienced applications and design staffs; quick-turn prototype capability; highly automated, SMT assembly facilities; and in-line SPC qualitycontrol techniques combine to give us the unique ability to design and deliver any quantity of power converters to the highest standards of quality and reliability. We have compiled a large library of DC/DC designs that are currently used in a variety of telecom, medical, computer, railway, aerospace and industrial applications. We may already have the converter you need. UNR-3.3/3-D5SM Radiated Emissions FCC Part 15 Class B, 3 Meters Converter Output = 3.3Vdc @ 2.7 Amps Contact us. Our goal is to provide you the highest-quality, most cost-effective power converters available. 80 Radiated Emissions (dBµV/M) 70 60 FCC Class B Limit 50 40 30 20 10 0 Radiated Emissions –10 –20 100 1000 Frequency (MHz) UNR-3.3/3-D5SM Radiated Emissions EN 55022 Class B, 10 Meters Converter Output = 3.3Vdc @ 2.7 Amps 80 Radiated Emissions (dBµV/M) 70 60 50 EN 55022 Class B Limit 40 30 20 10 0 Radiated Emissions –10 –20 100 1000 Frequency (MHz) ® ® INNOVATION and EXCELLENCE ISO 9001 REGISTERED DS-0442A 7/01 DATEL (UK) LTD. Tadley, England Tel: (01256)-880444 DATEL S.A.R.L. Montigny Le Bretonneux, France Tel: 01-34-60-01-01 DATEL GmbH München, Germany Tel: 89-544334-0 DATEL KK Tokyo, Japan Tel: 3-3779-1031, Osaka Tel: 6-6354-2025 DATEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151 Tel: (508) 339-3000 (800) 233-2765 Fax: (508) 339-6356 Internet: www.datel.com Email: [email protected] Data Sheet Fax Back: (508) 261-2857 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. 7