ml6509 Microsemi Corporation, ml6509 Datasheet
ml6509
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ml6509 Summary of contents
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... SCSI bus. The desired V-I characteristics for signal negation requires that the terminator source 0–24mA while maintaining 2.85V and for signal assertion preferably follow a linear slope of 110 . The ML6509 attempts to provide a V-I characteristic optimized to minimize the transmission line effects during both signal assertion and negation, using a MOSFET based architecture ...
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... ML6509 GENERAL DESCRIPTION One unique feature of the ML6509 is its support for a Low Power mode, for use in Notebook and portable computer applications, where it provides a 1mA (approximately 2.5K termination) for less than 6" cable lengths. This minimizes the battery drain significantly in such systems. PIN CONFIGURATION ...
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... L1 thru L9, DISCNKT = 0 2V 100kHz square wave applied P-P biased at 1V D.C. L1 thru L9, DISCNKT = 0 0.4V , 1MHz square wave applied P-P biased at 0.5V D.C. Sourcing 0–200mA Sinking 0–50mA L1–L9 = 0.2V 2.85V OUT Regulator output = 0V Regulator output = 5V ML6509 = 0°C to 70°C (Note 1) A MIN TYP MAX UNITS 3 225 250 mA 70 100 µA 1.0 ...
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... The ML6509 provides active termination for nine signal lines, thus accommodating basic SCSI which requires 18 lines to be terminated and wide SCSI which requires 27 lines to be terminated. The ML6509 integrates an accurate voltage reference (1V dropout voltage) and nine MOSFET based termination lines. A single internal resistor is trimmed to tune the V-I characteristic of the MOSFETs as shown in figure 1 ...
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... characteristic impedance of cable. O ML6509 TERMPWR VREF DISCNKT 0.1µF 10µF GND LPWR . . . SCSI XCVR SCSI XCVR Figure 2. Application Diagram Showing Typical SCSI Bus Configuration with the ML6509 V 285V 2. TERMPWR LINE 10µF SCSI CABLE V REG LINE LINE ...
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... This is a very important characteristic that the terminator helps overcome by increasing the noise margin and boosting the step as high as possible. This capability for the ML6509 implementation is illustrated in the attached simulation graphs which show the terminator performance under different cable impedance situations and a comparison is shown with the standard Boulay terminator, under identical conditions ...
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... ML6509 SCSI TERMINATOR DRIVER END 2V 0.8V TERMINATOR END 2V 0.8V 100ns TIME (SECONDS) BOULAY TERMINATOR DRIVER END 2V 0.8V TERMINATOR END 2V 0.8V 100ns TIME (SECONDS) Conditions Low Cable impedance of 110 (worst case 10ns D 10 segment distributed L-C, SCSI Bus Model Driver end of cable not terminated Figure 6. Signal Assertion/Negation Waveforms (Simulated) ...
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... END 2V 0.8V DRIVER END 2V 0.8V TERMINATOR END 2V 0.8V Conditions Figure 6a. Signal Assertion/Negation Waveforms (Simulated) 8 ML6509 SCSI TERMINATOR 100ns 200ns TIME (SECONDS) BOULAY TERMINATOR 100ns 200ns TIME (SECONDS) Low Cable impedance of 55 (worst case 10ns D 10 segment distributed L-C, SCSI Bus Model Driver end of cable not terminated ...
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... PHYSICAL DIMENSIONS 0.251 - 0.262 (6.38 - 6.65) 20 PIN 0.026 BSC (0.65 BSC) 0.008 - 0.012 0.033 - 0.037 (0.20 - 0.30) (0.84 - 0.94) inches (millimeters) Package: T20 20-Pin TSSOP 0.169 - 0.177 0.246 - 0.258 (4.29 - 4.50) (6.25 - 6.55) 0.043 MAX (1.10 MAX) 0º - 8º 0.020 - 0.028 0.002 - 0.006 SEATING PLANE (0.51 - 0.71) (0.05 - 0.15) ML6509 0.004 - 0.008 (0.10 - 0.20) 9 ...
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... ORDERING INFORMATION PART NUMBER ML6509CS ML6509CT (EOL) © Micro Linear 1997 is a registered trademark of Micro Linear Corporation Products described herein may be covered by one or more of the following patents: 4,897,611; 4,964,026; 5,027,116; 5,281,862; 5,283,483; 5,418,502; 5,508,570; 5,510,727; 5,523,940; 5,546,017; 5,559,470; 5,565,761; 5,594,376. Other patents are pending. ...