LAMBDA ADVANCED ANALOG INC. λ AFL12000S Series Single Output, Hybrid - High Reliability DC/DC Converters DESCRIPTION FEATURES Lambda Advanced requirements. The AFL Series of DC/DC converters feature high power density with no derating over the full military temperature range. This series is offered as part of a complete family of converters providing single and dual output voltages and operating from nominal +28, +50, +120 or +270 volt inputs and output power ranging from 80 to 120 watts. For applications requiring higher output power, individual converters can be operated in parallel. The internal current sharing circuits assure accurate current distribution among the paralleled converters. This series incorporates Lambda Advanced Analog's proprietary magnetic pulse feedback technology providing optimum dynamic line and load regulation response. This feedback system samples the output voltage at the pulse width modulator fixed clock frequency, nominally 550 KHz. Multiple converters can be synchronized to a system clock in the 500 KHz to 700 KHz range or to the synchronization output of one converter. Undervoltage lockout, primary and secondary referenced inhibit, soft-start and load fault protection are provided on all models. These converters are hermetically packaged in two enclosure variations, utilizing copper core pins to minimize resistive DC losses. Three lead styles are available, each fabricated with Lambda Advanced Analog's rugged ceramic lead-to-package seal assuring long term hermeticity in the most harsh environments. Manufactured in a facility fully qualified to MIL-PRF38534, these converters are available in four screening grades to satisfy a wide range of requirements. The CH grade is fully compliant to the requirements of MIL-PRF-38534 for class H. The HB grade is fully processed and screened to the class H requirement, may not necessarily meet all of the other MIL-PRF-38534 requirements, e.g., element evaluation and Periodic Inspections (PI) not required. Both grades are tested to meet the complete group "A" test specification over the full military temperature range without output power deration. Two grades with more limited screening are also available for use in less demanding applications. Variations in electrical, mechanical and screening can be accommodated. Contact 1 Analog with specific n 80 To 160 Volt Input Range n 5, 8, 9, 12, 15, 24 and 28 Volt Outputs Available n High Power Density - up to 84 W / in3 n Up To 120 Watt Output Power n Parallel Operation with Stress and Current Sharing n Low Profile (0.380") Seam Welded Package n Ceramic Feedthru Copper Core Pins n High Efficiency - to 87% n Full Military Temperature Range n Continuous Short Circuit and Overload Protection n Remote Sensing Terminals n Primary and Secondary Referenced Inhibit Functions n Line Rejection > 50 dB - DC to 50 KHz n External Synchronization Port n Fault Tolerant Design n Dual Output Versions Available n Standard Military Drawings Available SPECIFICATIONS AFL120XXS ABSOLUTE MAXIMUM RATINGS Input Voltage Soldering Temperature Case Temperature Static Characteristics -0.5V to 180V 300°C for 10 seconds Operating -55°C to +125°C Storage -65°C to +135°C -55°C ≤ TCASE ≤ +125°C, 80V ≤ VIN ≤ 160V unless otherwise specified. Parameter Group A Subgroups Test Conditions INPUT VOLTAGE Note 6 OUTPUT VOLTAGE VIN = 120 Volts, 100% Load AFL12005S AFL12008S AFL12009S AFL12012S AFL12015S AFL12024S AFL12028S 1 1 1 1 1 1 1 AFL12005S AFL12008S AFL12009S AFL12012S AFL12015S AFL12024S AFL12028S 2, 3 2, 3 2, 3 2, 3 2, 3 2, 3 2, 3 OUTPUT CURRENT Min Nom Max Unit 80 120 160 V 4.95 7.92 8.91 11.88 14.85 23.76 27.72 5.00 8.00 9.00 12.00 15.00 24.00 28.00 5.05 8.08 9.09 12.12 15.15 24.24 28.28 V V V V V V V 5.10 8.16 9.18 12.24 15.30 24.48 28.56 V V V V V V V 4.90 7.84 8.82 11.76 14.70 23.52 27.44 VIN = 80, 120, 160 Volts - Note 6 AFL12005S AFL12008S AFL12009S AFL12012S AFL12015S AFL12024S AFL12028S OUTPUT POWER 16.0 10.0 10.0 9.0 8.0 4.0 4.0 A A A A A A A 80 80 90 108 120 96 112 W W W W W W W µfd Note 6 AFL12005S AFL12008S AFL12009S AFL12012S AFL12015S AFL12024S AFL12028S MAXIMUM CAPACITIVE LOAD Note 1 10,000 OUTPUT VOLTAGE TEMPERATURE COEFFICIENT VIN = 120 Volts, 100% Load - Note 1, 6 -0.015 +0.015 %/°C No Load, 50% Load, 100% Load VIN = 80, 120, 160 Volts -70.0 -20.0 +70.0 +20.0 mV mV -1.0 +1.0 % OUTPUT VOLTAGE REGULATION AFL12028S Line All Others Line Load 1, 2, 3 1, 2, 3 1, 2, 3 2 Static Characteristics (Continued) Parameter Group A Subgroups OUTPUT RIPPLE VOLTAGE AFL12005S AFL12008S AFL12009S AFL12012S AFL12015S AFL12024S AFL12028S 1, 2, 3 1, 2, 3 1, 2, 3 1, 2, 3 1, 2, 3 1, 2, 3 1, 2, 3 INPUT CURRENT No Load Inhibit 1 Inhibit 2 INPUT RIPPLE CURRENT AFL12005S AFL12008S AFL12009S AFL12012S AFL12015S AFL12024S AFL12028S CURRENT LIMIT POINT As a percentage of full rated load LOAD FAULT POWER DISSIPATION Overload or Short Circuit 1 2, 3 1, 2, 3 1, 2, 3 Min Nom VIN = 80, 120, 160 Volts, 100% Load, BW = 10MHz VIN = 120 Volts IOUT = 0 Pin 4 Shorted to Pin 2 Pin 12 Shorted to Pin 8 Max Unit 30 40 40 45 50 80 100 mVpp mVpp mVpp mVpp mVpp mVpp mVpp 30 40 3 5 mA mA mA mA 60 60 70 70 80 80 80 mApp mApp mApp mApp mApp mApp mApp 125 115 140 % % % 32 W VIN = 120 Volts, 100% Load, BW = 10MHz 1, 2, 3 1, 2, 3 1, 2, 3 1, 2, 3 1, 2, 3 1, 2, 3 1, 2, 3 1 2 3 VOUT = 90% VNOM , VIN = 120 Volts Note 5 115 105 125 VIN = 120 Volts 1, 2, 3 EFFICIENCY VIN = 120 Volts, 100% Load AFL12005S AFL12008S AFL12009S AFL12012S AFL12015S AFL12024S AFL12028S ENABLE INPUTS (Inhibit Function) Converter Off Sink Current Converter On Sink Current SWITCHING FREQUENCY SYNCHRONIZATION INPUT Frequency Range Pulse Amplitude, Hi Pulse Amplitude, Lo Pulse Rise Time Pulse Duty Cycle ISOLATION Test Conditions 1, 2, 3 1, 2, 3 1, 2, 3 1, 2, 3 1, 2, 3 1, 2, 3 1, 2, 3 1, 2, 3 1, 2, 3 78 79 80 82 83 82 82 Logical Low on Pin 4 or Pin 12 Note 1 Logical High on Pin 4 and Pin 12 - Note 9 Note 1 -0.5 2.0 1, 2, 3 500 1, 2, 3 1, 2, 3 1, 2, 3 500 2.0 -0.5 Note 1 Note 1 1 82 83 84 85 87 85 85 550 20 Input to Output or Any Pin to Case (except Pin 3). Test @ 500VDC DEVICE WEIGHT Slight Variations with Case Style MTBF MIL-HDBK-217F, AIF @ TC = 40°C 3 100 0.8 100 50 100 V µA V µA 600 KHz 700 10 0.8 100 80 KHz V V nSec % MΩ 85 300 % % % % % % % gms KHrs Dynamic Characteristics Parameter -55°C ≤ TCASE ≤ +125°C, VIN = 120 Volts unless otherwise specified. Group A Subgroups LOAD TRANSIENT RESPONSE AFL12005S AFL12008S AFL12009S AFL12012S AFL12015S AFL12024S AFL12028S Test Conditions Min Nom Unit Note 2, 8 Amplitude Recovery 4, 5, 6 4, 5, 6 Load Step 50% ⇔ 100% -450 450 200 mV µSec Amplitude Recovery 4, 5, 6 4, 5, 6 Load Step 10% ⇔ 50% -450 450 400 mV µSec Amplitude Recovery 4, 5, 6 4, 5, 6 Load Step 50% ⇔ 100% -500 500 200 mV µSec Amplitude Recovery 4, 5, 6 4, 5, 6 Load Step 10% ⇔ 50% -500 500 400 mV µSec Amplitude Recovery 4, 5, 6 4, 5, 6 Load Step 50% ⇔ 100% -600 600 200 mV µSec Amplitude Recovery 4, 5, 6 4, 5, 6 Load Step 10% ⇔ 50% -600 600 400 mV µSec Amplitude Recovery 4, 5, 6 4, 5, 6 Load Step 50% ⇔ 100% -750 750 200 mV µSec Amplitude Recovery 4, 5, 6 4, 5, 6 Load Step 10% ⇔ 50% -750 750 400 mV µSec Amplitude Recovery 4, 5, 6 4, 5, 6 Load Step 50% ⇔ 100% -900 900 200 mV µSec Amplitude Recovery 4, 5, 6 4, 5, 6 Load Step 10% ⇔ 50% -900 900 400 mV µSec Amplitude Recovery 4, 5, 6 4, 5, 6 Load Step 50% ⇔ 100% -900 900 200 mV µSec Amplitude Recovery 4, 5, 6 4, 5, 6 Load Step 10% ⇔ 50% -900 900 400 mV µSec Amplitude Recovery 4, 5, 6 4, 5, 6 Load Step 50% ⇔ 100% -1200 1200 200 mV µSec Amplitude Recovery 4, 5, 6 4, 5, 6 Load Step 10% ⇔ 50% -1200 1200 400 mV µSec -500 500 500 mV µSec 250 120 mV mSec LINE TRANSIENT RESPONSE Note 1, 2, 3 VIN Step = 80 ⇔ 160 Volts Amplitude Recovery TURN-ON CHARACTERISTICS Overshoot Delay Note 4 4, 5, 6 4, 5, 6 Enable 1, 2 on. (Pins 4, 12 high or open) LOAD FAULT RECOVERY Same as Turn On Characteristics. LINE REJECTION MIL-STD-461D, CS101, 30Hz to 50KHz Note 1 50 75 50 60 Notes to Specifications: 1. 2. 3. 4. 5. 6. 7. 8. 9. Max Parameters not 100% tested but are guaranteed to the limits specified in the table. Recovery time is measured from the initiation of the transient to where VOUT has returned to within ±1% of VOUT at 50% load. Line transient transition time ≥ 100 µSec. Turn-on delay is measured with an input voltage rise time of between 100 and 500 volts per millisecond. Current limit point is that condition of excess load causing output voltage to drop to 90% of nominal. Parameter verified as part of another test. All electrical tests are performed with the remote sense leads connected to the output leads at the load. Load transient transition time ≥ 10 µSec. Enable inputs internally pulled high. Nominal open circuit voltage ≈ 4.0VDC. 4 dB AFL12000S Case Outlines Case X Case W Pin Variation of Case Y 3.000 ø 0.128 0.050 2.760 0.050 1 12 0.250 1.000 Ref 0.200 Typ Non-cum 1.000 6 7 1.260 1.500 0.250 Pin ø 0.040 Pin ø 0.040 0.220 2.500 0.220 2.800 2.975 max 0.525 0.238 max 0.42 0.380 Max 0.380 Max Case Y Case Z Pin Variation of Case Y 0.300 1.150 ø 0.140 0.25 typ 0.050 0.050 0.250 1 12 0.250 1.000 Ref 1.000 Ref 0.200 Typ Non-cum 6 7 1.500 1.750 2.00 Pin ø 0.040 1.750 0.375 Pin ø 0.040 0.220 0.220 2.500 0.36 2.800 2.975 max 0.525 0.238 max 0.380 Max 0.380 Max 5 AFL12000S Pin Designation Pin No. Designation 1 Positive Input 2 Input Return 3 Case 4 Enable 1 5 Sync Output 6 Sync Input 7 Positive Output 8 Output Return 9 Return Sense 10 Positive Sense 11 Share 12 Enable 2 Available Screening Levels and Process Variations for AFL 12000S Series. Requirement MIL-STD-883 Method Temperature Range No Suffix ES Suffix HB Suffix CH Suffix -20°C to +85°C -55°C to +125°C -55°C to +125°C -55°C to +125°C Element Evaluation MIL-H-38534 ü ü ü 1010 Cond B Cond C Cond C Constant Acceleration 2001, 500g Cond A Cond A Burn-in 1015 96hrs @ 125°C 160hrs @ 125°C 160hrs @ 125°C Internal Visual 2017 Temperature Cycle Final Electrical (Group A) ¬ MIL-PRF-38534 25°C 25°C -55, +25, +125°C -55, +25, +125°C Seal, Fine & Gross 1014 Cond A Cond A, C Cond A, C Cond A, C External Visual 2009 ¬ ü ü ü ¬ per Commercial Standards Part Numbering AFL120 05 S X / CH Model Input Voltage Screening Case Style 28= 28 V, 50= 50 V 120=120 V, 270= 270 V W, X, Y, Z Output Voltage Outputs 03.3= 3.3 V, 05= 5 V 08= 8 V, 09= 9 V 12= 12 V, 15= 15 V 24= 24 V, 28= 28 V S = Single D = Dual 6 – , ES HB, CH AFL12000S Circuit Description Figure I. AFL Single Output Block Diagram DC Input 1 Enable 1 4 Input Filter Output Filter Primary Bias Supply 7 +Output 10 +Sense Current Sense Sync Output 5 Sync Input 6 Case Control Share Amplifier Error Amp & Ref FB 3 11 Share 12 Enable 2 Sense Amplifier Input Return 2 9 -Sense 8 Output Return load when their physical separation could cause undesirable voltage drop. This connection allows regulation to the placard voltage at the point of application. When the remote sensing feature is not used, the sense leads should be connected to their respective output terminals at the converter. Figure III. illustrates a typical remotely sensed application. Circuit Operation and Application Information The AFL series of converters employ a forward switched mode converter topology. (refer to Figure I.) Operation of the device is initiated when a DC voltage whose magnitude is within the specified input limits is applied between pins 1 and 2. If pin 4 is enabled (at a logical 1 or open) the primary bias supply will begin generating a regulated housekeeping voltage bringing the circuitry on the primary side of the converter to life. A power MOSFET is used to chop the DC input voltage into a high frequency square wave, applying this chopped voltage to the power transformer at the nominal converter switching frequency. Maintaining a DC voltage within the specified operating range at the input assures continuous generation of the primary bias voltage. Inhibiting Converter Output As an alternative to application and removal of the DC voltage to the input, the user can control the converter output by providing TTL compatible, positive logic signals to either of two enable pins (pin 4 or 12). The distinction between these two signal ports is that enable 1 (pin 4) is referenced to the input return (pin 2) while enable 2 (pin 12) is referenced to the output return (pin 8). Thus, the user has access to an inhibit function on either side of the isolation barrier. Each port is internally pulled "high" so that when not used, an open connection on both enable pins permits normal converter operation. When their use is desired, a logical "low" on either port will shut the converter down. The switched voltage impressed on the secondary output transformer winding is rectified and filtered to generate the converter DC output voltage. An error amplifier on the secondary side compares the output voltage to a precision reference and generates an error signal proportional to the difference. This error signal is magnetically coupled through the feedback transformer into the controller section of the converter varying the pulse width of the square wave signal driving the MOSFET, narrowing the width if the output voltage is too high and widening it if it is too low, thereby regulating the output voltage. Figure II. Enable Input Equivalent Circuit +5.6V Pin 4 or Pin 12 1N4148 100K Disable 290K Remote Sensing 2N3904 Connection of the + and - sense leads at a remotely located load permits compensation for excessive resistance between the converter output and the 150K Pin 2 or Pin 8 7 Internally, these ports differ slightly in their function. In use, a low on Enable 1 completely shuts down all circuits in the converter while a low on Enable 2 shuts down the secondary side while altering the controller duty cycle to near zero. Externally, the use of either port is transparent save for minor differences in standby current. (See specification table). requires transition times less than 100 ns, maximum low level of +0.8 volts and a minimum high level of +2.0 volts. The sync output of another converter which has been designated as the master oscillator provides a convenient frequency source for this mode of operation. When external synchronization is not required, the sync in pin should be left open (unconnected) thereby permitting the converter to operate at its' own internally set frequency. Synchronization of Multiple Converters The sync output signal is a continuous pulse train set at 550 ±50 KHz, with a duty cycle of 15 ±5%. This signal is referenced to the input return and has been tailored to be compatible with the AFL sync input port. Transition times are less than 100 ns and the low level output impedance is less than 50 ohms. This signal is active when the DC input voltage is within the specified operating range and the converter is not inhibited. This output has adequate drive reserve to synchronize at least five additional converters. A typical connection is illustrated in Figure III. When operating multiple converters, system requirements often dictate operation of the converters at a common frequency. To accommodate this requirement, the AFL series converters provide both a synchronization input and a synchronization output. The sync input port permits synchronization of an AFL converter to any compatible external frequency source operating between 500 and 700 KHz. This input signal should be referenced to the input return and have a 10% to 90% duty cycle. Compatibility Figure III. Preferred Connection for Parallel Operation Power Input 1 12 Vin Enable 2 Rtn Share Case Enable 1 Optional Synchronization Connection AFL + Sense - Sense Sync Out Return Sync In + Vout 6 7 1 12 Share Bus Enable 2 Vin Share Rtn Case Enable 1 AFL + Sense - Sense Sync Out Return Sync In + Vout to Load 7 6 1 12 Enable 2 Vin Rtn Share Case Enable 1 AFL + Sense - Sense Sync Out Return Sync In + Vout 7 6 (Other Converters) Parallel Operation — Current and Stress Sharing permits equal sharing among the members of a set where total load current exceeds the capacity of an individual AFL. An important feature of the AFL series operating in the parallel mode is that in addition to sharing the current, the stress induced by Figure III. illustrates the preferred connection scheme for operation of a set of AFL converters with outputs operating in parallel. Use of this connection 8 under the trade name of Sil-Pad 4001. This particular product is an insulator but electrically conductive versions are also available. Use of these materials assures maximum surface contact with the heat dissipater thereby compensating for any minor surface variations. While other available types of heat conductive materials and thermal compounds provide similar effectiveness, these alternatives are often less convenient and are frequently messy to use. temperature will also be shared. Thus if one member of a paralleled set is operating at a higher case temperature, the current it provides to the load will be reduced as compensation for the temperature induced stress on that device. When operating in the shared mode, it is important that symmetry of connection be maintained as an assurance of optimum load sharing performance. Thus, converter outputs should be connected to the load with equal lengths of wire of the same gauge and sense leads from each converter should be connected to a common physical point, preferably at the load along with the converter output and return leads. All converters in a paralleled set must have their share pins connected together. This arrangement is diagrammatically illustrated in Figure III. showing the outputs and sense pins connected at a star point which is located close as possible to the load. A conservative aid to estimating the total heat sink surface area (AHEAT SINK) required to set the maximum case temperature rise (∆T) above ambient temperature is given by the following expression: . ∆T −143 − 3.0 A HEAT SINK ≈ 80P 0.85 where As a consequence of the topology utilized in the current sharing circuit, the share pin may be used for other functions. In applications requiring only a single converter, the voltage appearing on the share pin may be used as a "current monitor". The share pin open circuit voltage is nominally +1.00v at no load and increases linearly with increasing output current to +2.20v at full load. ∆T = Case temperature rise above ambient 1 P = Device dissipation in Watts = POUT − 1 Eff As an example, it is desired to maintain the case temperature of an AFL12015S at ≤ +85°C while operating in an open area whose ambient temperature is held at a constant +25°C; then Thermal Considerations ∆T = 85 - 25 = 60°C. Because of the incorporation of many innovative technological concepts, the AFL series of converters is capable of providing very high output power from a package of very small volume. These magnitudes of power density can only be obtained by combining high circuit efficiency with effective methods of heat removal from the die junctions. This requirement has been effectively addressed inside the device; but when operating at maximum loads, a significant amount of heat will be generated and this heat must be conducted away from the case. To maintain the case temperature at or below the specified maximum of 125°C, this heat must be transferred by conduction to an appropriate heat dissipater held in intimate contact with the converter base-plate. If the worst case full load efficiency for this device is 83%; then the power dissipation at full load is given by 1 P = 120 • − 1 = 120 • ( 0.205) = 24.6W .83 and the required heat sink area is −1.43 60 A HEAT SINK = − 3.0 = 71 in 2 80 • 24.6 0.85 Thus, a total heat sink surface area (including fins, if any) of 71 in2 in this example, would limit case rise to 60°C above ambient. A flat aluminum plate, 0.25" thick and of approximate dimension 4" by 9" (36 in2 per side) would suffice for this application in a still air environment. Note that to meet the criteria in this example, both sides of the plate require unrestricted exposure to the ambient air. Because effectiveness of this heat transfer is dependent on the intimacy of the baseplate-heatsink interface, it is strongly recommended that a high thermal conductivity heat transferring medium is inserted between the baseplate and heatsink. The material most frequently utilized at the factory during all testing and burn-in processes is sold 1Sil-Pad is a registered Trade Mark of Bergquist, Minneapolis, MN 9 Input Filter Finding a resistor value for a particular output voltage, is simply a matter of substituting the desired output voltage and the nominal device voltage into the equation and solving for the corresponding resistor value. The AFL12000S series converters incorporate a LC input filter whose elements dominate the input load impedance characteristic at turn-on. The input circuit is as shown in Figure IV. Figure V. Connection for VOUT Adjustment Figure IV. Input Filter Circuit Enable 2 16.8uH Share RADJ Pin 1 AFL120xxS + Sense - Sense 0.78uF Return To Load + Vout Pin 2 Note: Radj must be set ≥ 500Ω Attempts to adjust the output voltage to a value greater than 120% of nominal should be avoided because of the potential of exceeding internal component stress ratings and subsequent operation to failure. Under no circumstance should the external setting resistor be made less than 500Ω. By remaining within this specified range of values, completely safe operation fully within normal component derating limits is assured. Undervoltage Lockout A minimum voltage is required at the input of the converter to initiate operation. This voltage is set to 75 ± 3 volts. To preclude the possibility of noise or other variations at the input falsely initiating and halting converter operation, a hysteresis of approximately 4 volts is incorporated in this circuit. Thus if the input voltage drops to 71 ± 3 volts, the converter will shut down and remain inoperative until the input voltage returns to ≈75 volts. Examination of the equation relating output voltage and resistor value reveals a special benefit of the circuit topology utilized for remote sensing of output voltage in the AFL12000S series of converters. It is apparent that as the resistance increases, the output voltage approaches the nominal set value of the device. In fact the calculated limiting value of output voltage as the adjusting resistor becomes very large is ≈ 25mV above nominal device voltage. Output Voltage Adjust In addition to permitting close voltage regulation of remotely located loads, it is possible to utilize the converter sense pins to incrementally increase the output voltage over a limited range. The adjustments made possible by this method are intended as a means to “trim” the output to a voltage setting for some particular application, but are not intended to create an adjustable output converter. These output voltage setting variations are obtained by connecting an appropriate resistor value between the +sense and -sense pins while connecting the sense pin to the output return pin as shown in Figure V. below. The range of adjustment and corresponding range of resistance values can be determined by use of the following equation. Radj The consequence is that if the +sense connection is unintentionally broken, an AFL120xxS has a failsafe output voltage of Vout + 25mV, where the 25mV is independent of the nominal output voltage. It can be further demonstrated that in the event of both the + and - sense connections being broken, the output will be limited to Vout + 440mV. This 440 mV is also essentially constant independent of the nominal output voltage. General Application Information The AFL12000 series of converters are capable of providing large transient currents to user loads on demand. Because the nominal input voltage range in this series is relatively low, the resulting input current demands will be correspondingly large. It is important therefore, that the line impedance be kept very low to prevent steady state and transient input currents from degrading the supply voltage between VNOM = 100 • VOUT - VNOM -.025 Where VNOM = device nominal output voltage, and VOUT = desired output voltage 10 Incorporation of a 100 µfd capacitor at the input terminals is recommended as compensation for the dynamic effects of the parasitic resistance of the input cable reacting with the complex impedance of the converter input, and to provide an energy reservoir for transient input current requirements. the voltage source and the converter input. In applications requiring high static currents and large transients, it is recommended that the input leads be made of adequate size to minimize resistive losses, and that a good quality capacitor of approximately 100µfd be connected directly across the input terminals to assure an adequately low impedance at the input terminals. Table I relates nominal resistance values and selected wire sizes. Table I. Nominal Resistance Of Cu Wire Wire Size, AWG Resistance per ft 24 Ga 22 Ga 20 Ga 18 Ga 16 Ga 14 Ga 12 Ga 25.7 mΩ 16.2 mΩ 10.1 mΩ 6.4 mΩ 4.0 mΩ 2.5 mΩ 1.6 mΩ Figure VI. Problems of Parasitic Resistance in Input Leads (See text) Rp Iin 100 µfd esource Rp IRtn Vin eRtn Rtn Case Enable 1 System Ground Sync Out Sync In 11 Lambda Advanced Analog The information in this data sheet has been carefully checked and is believed to be accurate; however no responsibility is assumed for possible errors. These specifications are subject to change without notice. LAMBDA ADVANCED ANALOG INC. λ MIL-PRF-38534 Qualified ISO9001 Registered 12 981027 2270 Martin Avenue Santa Clara CA 95050-2781 (408) 988-4930 FAX (408) 988-2702