DS2117MB Maxim Integrated Products, DS2117MB Datasheet - Page 3

• Manufacturer Part Number: DS2117MB
• Description: IC TERM SCSI LVD/SE ULT-3 36SSOP
• Manufacturer: Maxim Integrated Products
• Type: SCSI, LVD, SEr

Specifications of DS2117MB

• Number Of Terminations: 9
• Voltage - Supply: 4 V ~ 5.5 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 36-SSOP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

DS2117M
To ensure proper operation, the TPWR pin should be connected to the SCSI bus TERMPWR line. As
with all analog circuitry, the TERMPWR and V
lines should be bypassed locally. A 2.2µF capacitor
DD
and a 0.01µF high frequency capacitor are recommended between TPWR and ground and placed as close
as possible to the DS2117M. The DS2117M should be placed as close as possible to the SCSI connector
to minimize signal and power trace length, thereby resulting in less input capacitance and reflections
which can degrade the bus signals.
To maintain the specified regulation, a 4.7µF capacitor is required between the V
pin (VREF) and
REF
ground of each DS2117M. A high frequency cap (0.1µF ceramic recommended) can also be placed on the
V
pin in applications that use fast rise/fall time drivers. A typical SCSI bus configuration is shown in
REF
Figure 2.
DIFFSENS NOISE FILTERING
The DS2117M incorporates a digital filter to remove high-frequency transients on the DIFFSENS control
line, thereby eliminating erroneous switching between modes. This filter eliminates the need for the
external capacitor and resistor, which heretofore performed this function. The external filter can be used
in addition to the digital filter if the DS2117M and DS2118M are to be used interchangeably.
NOTE:
DIFFSENS—Refers to the SCSI bus signal.
DIFFSENSE—Refers to the DS2117M pin name and internal circuitry capable of driving the DIFFSENS
line.
DIFF_CAP—Refers to the DS2117M pin name and internal circuitry relating to monitoring the
DIFFSENS line.
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