DS2120 Dallas Semiconducotr, DS2120 Datasheet
DS2120
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DS2120 Summary of contents
Page 1
... The DS2120 Ultra3 LVD SCSI terminator is a low-voltage differential (LVD) terminator. If the device is connected in an LVD-only bus, the DS2120 uses LVD termination. If any single-ended (SE) or high- voltage differential (HVD) devices are connected to the bus, the DS2120 disconnects from the bus. This is accomplished inside the part automatically by sensing the voltage on the SCSI bus DIFFSENS line ...
Page 2
... TERMPWR and V and a 0.01 F high- frequency capacitor are recommended between TPWR and ground and placed as close as possible to the DS2120. The DS2120 should be placed as close as possible to the SCSI connector to minimize signal and power trace length, thereby lessening input capacitance and reflections that can degrade the bus signals ...
Page 3
... DIFFSENS control line, thereby eliminating erroneous switching between modes. This filter eliminates the need for the external capacitor and resistor, which previously performed this function. The external filter can be used in addition to the digital filter if the DS2120 and DS2118M or DS2119M are to be used interchangeably. ...
Page 4
... Figure 1. BLOCK DIAGRAM 2.15V DIFF CAP 0.6V THERMAL SHUTDOWN ISO MSTR/SLV Mode Change Delay/Filter 1.30V CONTROL LOGIC I_GEN 2.15V REFERENCE 1.30V GENERATOR 0.6V 1.25V VREF DS2120 LVD DIFFSENSE R1N R1P R9N R9P ...
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... Figure 2. SCSI BUS CONFIGURATION DS2120 ...
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... Table 1. PIN DESCRIPTION DS2120E 28-Pin TSSOP PIN NAME 1 VREF 2–5, 7–12, RxP, RxN 18–21, 23– HS_GND 13 ISO 14 GND 15 MSTR/SLV 16 DIFFSENSE 17 DIFF_CAP 27, 28 TPWR DS2120B 36-Pin SSOP PIN NAME 1 VREF 4–7, 11–16, RxP, RxN 22–25, 29–32 8–10, 26–28 ...
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... MAX UNITS 110 ? 190 ? 125 mV 1.375 MAX UNITS µA 1.0 µA -1 1 200 µA +125 µA +6.5 µA 150 °C DS2120 NOTES 13 13 NOTES NOTES 2, 3 14 10, 11 ...
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... RC time constant formed by the resistor connected from DIFFSENSE to CD DIFF_CAP and the capacitor connected from DIFF_CAP to ground. 13) MSTR/SLV and ISO pins. 14) Terminator pins only. 15) DIFFCAP pin only. SYMBOL MIN TYP LI 1.0 REG LO 1.3 REG I LIM I SINK DS2120 MAX UNITS NOTES 2.0 % 3.5 % 200 mA 200 mA ...
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... DS2120E 28-PIN TSSOP PACKAGE DIM MIN MAX A - 1. 0.75 1.05 c 0.09 0.20 L 0.50 0.75 e1 0.65 BSC b 0.18 0.30 D 9.60 9.80 E1 4.40 BSC E 6.20 6.60 Dimensions are in millimeters (mm). NOTES: 1) Dimension D does not include mold mismatch, flash, or protrusions. Mold mismatch, flash, and protrusions shall not exceed 0.15 per side. 2) Dimension B does not include dambar protrusion. Dambar protrusion shall not be located on the lower radius of the foot ...
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... DS2120B 36-PIN SSOP PACKAGE DIM MIN MAX A 2.44 2. 0.29 0.43 c 0.23 0.32 D 15.20 15.54 E 10.11 10.52 E1 7.40 7.60 e 0.80 BSC h 0.25 0.71 L 0.51 1.02 Dimensions are in millimeters (mm). NOTES: 1) Dimensions D and E1 include mold mismatch, but do not include mold flash, protrusions, or gate burrs. Mold flash, protrusions or gate burrs shall not exceed 0.254mm per side. ...