IMP5226
1
D
ATA
C
OMMUNICATIONS
18-Line Plug and Play
SCSI Terminator
The 18-channel IMP5226 SCSI terminator is part of IMP's family of high-
performance SCSI terminators that deliver true UltraSCSI performance.
The BiCMOS design offers superior performance over first generation
linear regulator/resistor based terminators.
IMP's new architecture employs high-speed adaptive elements for each
channel, thereby providing the fastest response possible - typically
35MHz, which is 100 times faster than the older linear regulator termi-
nator approach. The bandwidth of terminators based on the older
regulator/resistor terminator architecture is limited to 500kHz since a
large output stabilization capacitor is required.
The IMP architecture eliminates the external output compensation
capacitor and the need for transient output capacitors while maintaining
pin compatibility with first generation designs. Reduced component
count is inherent with the IMP5226.
The IMP5226 architecture tolerates marginal system designs. A key
improvement offered by the IMP5226 lies in its ability to insure reliable,
error-free communications even in systems which do not adhere to rec-
ommended SCSI hardware design guidelines, such as improper cable
lengths and impedance. Frequently, this situation is not controlled by the
peripheral or host designer.
The IMP5226 can be placed in a sleep mode with a high logic signal. In
the sleep mode the outputs are in a high impedance state. Quiescent cur-
rent is less than 150µA when disabled.
The IMP5226 is a superior pin-for-pin replacement for the LX5226,
LX5207, UC5601/5602 and the UCC5610.
Key Features
x
Ultra-Fast response for Fast-20 SCSI
x
35MHz channel bandwidth
x
Sleep-mode current less than 150µA
— Disconnects terminator from lows
x
NO external compensation capacitors
x
Compatible with active negation drivers
x
Compatible with passive and active terminations
x
Approved for use with SCSI 1, 2, 3 and
Ultra SCSI
x
Hot-swap compatible
x
Pin-for-pin compatible with LX5226, LX5207
and UCC5610
IMP SCSI Terminators
Part
IMP5111
IMP5112
IMP5115
IMP5121
IMP5218
IMP5219
IMP5225
IMP5226
IMP5241
IMP5242
Channels
9
9
9
27
9
9
18
18
8
8
Type
SE
SE
SE
SE
SE
SE
SE
SE
SE/LVD
SE/LVD
5226_t06.eps
Block Diagrams
Term Power
Thermal
Limiting
Circuit
V
TERM
Current
Biasing
Circuit
24mA Current
Limiting Circuit
DATA OUTPUT
PIN DB (0)
2.85V
DISCONNECT
–
1 of 18 Channels
+
1.4V
5226_01.eps
A1PROS [ A1 PROS CO., LTD. ]
