UCC5610

18LINE 3-5 VOLT LOW CAPACITANCE SCSI

ACTIVE TERMINATOR

SLUS362A − FEBRUARY 1997 − REVISED NOVEMBER 2000

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POST OFFICE BOX 655303

Disconnect

Negation Drivers

Protection

description

The UCC5610 provides 18 lines of active termination for a SCSI (small computer systems interface) parallel

bus. The SCSI standard recommends active termination at both ends of the cable.

The UCC5610 is ideal for high performance 3.3-V SCSI systems. The key features contributing to such low

operating voltage are the 0.1-V drop-out regulator and the 2.75-V reference. During disconnect the supply

current is typically only 0.5

µA, which makes the IC attractive for battery powered systems.

The UCC5610 is designed with an ultralow-channel capacitance of 1.8 pF, which eliminates effects on signal

integrity from disconnected terminators at interim points on the bus.

The UCC5610 can be programmed for either a 110-

Ω or 2.5-kΩ termination. The 110-Ω termination is used for

standard SCSI bus lengths and the 2.5-k

Ω termination is typically used in short bus applications. When driving

the TTL compatible DISCNCT pin directly, the 110-

Ω termination is connected when the DISCNCT pin is driven

low, and disconnected when driven high. When the DISCNCT pin is driven through an impedance between

80 k

Ω and 150 kΩ, the 2.5-kΩ termination is connected when the DISCNCT pin is driven low, and disconnected

when driven high.

block diagram

UDG-94128-1

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Copyright

 2000, Texas Instruments Incorporated

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of Texas Instruments

standard warranty. Production processing does not necessarily include

testing of all parameters.

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.