DS21T06 Datasheet, PDF (1/6 Pages) Dallas Semiconductor – SCSI Terminator

www.dalsemi.com
FEATURES
Fully compliant with SCSI-1, Fast SCSI and
Ultra SCSI
Functional drop in replacement for the
DS2106
Complimentary part to DS21T07 for wide
SCSI
Provides active termination for 18 signal lines
5% tolerance on termination resistors and
voltage regulator
5% tolerance on termination current
Low power down capacitance of 3 pF
Onboard thermal shutdown circuitry
SCSI bus hot plug compatible
Fully supports actively negated SCSI signals
DS21T06
SCSI Terminator
PIN ASSIGNMENT
PD 1
R1 2
R2 3
R3 4
R4 5
R5 ₆
HS-GND 7
HS-GND 8
NC 9
R6 10
R7 11
R8 12
R9 13
TPWR 14
28 GND
27 R18
26 R17
25 R16
24 R15
23 ^R14
22 NC
21 HS-GND
20 NC
19 R13
18 R12
17 R11
16 R10
15 V_REF
DS21T06S 28-Pin SOIC (300-mil)
DESCRIPTION
Fast SCSI and Ultra SCSI require the use of active terminations at both ends of every cable segment in a
SCSI system with single-ended drivers and receivers. Ultra SCSI requires support of active negation and
hot plugging. The DS21T06 is fully compliant with these standards.
The DS21T06 integrates a low dropout regulator and 18 precise switched 110 ohms termination resistors
into a 28-pin 300-mil SOIC package.
Active termination provides greater immunity to voltage drops on the TERMPWR (TERMination
PoWeR) line, enhanced high-level noise immunity, intrinsic TERMPWR decoupling, and very low
quiescent current consumption. One DS21T06 can be used to terminate the Narrow SCSI bus, or a
DS21T07 can be used with a DS21T06 for termination of a Wide SCSI bus.
REFERENCE DOCUMENTS
SCSI-2 (X3.131-1994)
SCSI-3 Parallel Interface (X3T10/855D)
SCSI-3 Fast–20 (X3T10/1071D)
Available from: Global Engineering Documents
15 Inverness Way East
Englewood, CO 80112-5704
Phone: [phone]
Fax: [phone]
1 of 6
112099