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ROHM Semiconductor |
Mulimedia ICs
SCSI active terminator
BH9595FP-Y / BH9596FP-Y
These SCSI active terminators, developed as a substitute for conventional discrete terminators, maintain good con-
sistency between VM level (2.85V) and GND level (0V) and between VM level and VDD level, and have extremely
low power consumption, dropping to a maximum of 90 milliwatts at standby (compared to the maximum of 990 milli-
watts used by conventional resistance terminators). These SCSI active terminators electrically control SCSI lines,
connecting and disengaging the terminating resistor by electrically controlling the enable pin. (The enable pin is
enabled at the HIGH level and switched to the High-Z state by the LOW level in the BH9595 and by the HIGH level in
the BH9596, completely disconnecting the SCSI line from the SCSI terminator.)
These SCSI active terminators allow for the configuration of flexible, energy-saving SCSI networks, and are ideal for
notebook computers, hard disk drives and a wide range of other products with SCSI capabilities.
•Applications
Compact disk drives, optical disk drives, CD-ROM dri-
ves, tape drives, personal computers (including laptop
computers and notebook computers), workstations,
mainframes, laser printers, plotters
•Features
1) Internal 2.85V power supply and push-pull opera-
tion, for good consistency at all signal levels.
2) Enable pin for terminator enabling and disconnect-
ing, facilitating SCSI network construction.
3) Low power consumption, ideal for energy-saving
systems.
Power consumption during standby : 90mW (com-
pared to 990mW for conventional resistor termina-
tors)Power consumption at 25% duty : 614mW
(compared to 1,360mW for convention resistor ter-
minators)Significant reductions in power consump-
tion are possible.
4) Wide operating range.
TERM power : 4.0 ~ 5.5V (Transient : 6.0V)
5) Thin, microminiature design, ideal for space-saving
applications.
Package body size : 13.6 × 5.4 × 1.9mm
6) Active termination of 18-line SCSI.
7) Internal thermal shutdown circuit.
8) Compatibility with SCSI-I and SCSI-II.
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Mulimedia ICs
BH9595FP-Y / BH9596FP-Y
•Absolute maximum ratings (Ta = 25°C)
Parameter
Symbol
Limits
Unit
Power supply voltage
DC Output current ∗1
DC Output current ∗2
VDD1
ISLD
ISLS
– 0.3 ~ + 7.0
– 30
35
V
mA
mA
Input voltage
Power dissipation ∗3
Vi
– 0.6 ~ (VDD1 + 0.6)
V
Pd 1.45 W
Operating temperature
Topr
0 ~ + 75
°C
Storage temperature
Tstg – 55 ~ + 125
∗1 Drain Current (from Module to SCSI Line) / Line
∗2 Sink Current (from SCSI Line to Module) / Line
∗3 When mounted to a 90 × 50 × 1.6 mm glass epoxy board
•Recommended operating conditions (Ta = 25°C)
°C
Parameter
Power supply voltage
Symbol Min. Typ. Max.
VDD1
4.0 4.5 5.5∗
Unit
V
Input voltage
VIH VDD1 – 0.6 — VDD1 + 0.6
V
Input voltage
VIL – 0.3 — 0.8
V
SCSI Line voltage
•∗ Transient 6V
Block diagram
VSLX
– 0.3
— VDD1 + 0.3
V
Not to be used
∗ (N.C.) 1
“H”: ENABLE
“L”: DISCONNECT 2
EN
SCSI LINE 15 3
SCSI LINE 16 4
POW
TSD
MODE
CONTROL
to SW
POW
POW
25 TSD
24 VM
23 SCSI LINE 14
22 SCSI LINE 13
SCSI LINE 17 5
21 SCSI LINE 12
SCSI LINE 18 6
GND
POW
(PUSH - PULL)
POW
(PUSH - PULL)
20 SCSI LINE 11
GND
GND 7
SCSI LINE 1 8
SCSI LINE 2 9
110Ω
Resistors
POW
(PUSH - PULL)
POW
(PUSH - PULL)
19 SCSI LINE 10
18 SCSI LINE 9
SCSI LINE 3 10
17 SCSI LINE 8
SCSI LINE 4 11
SCSI LINE 5 12
VDD1 13
(PUSH - PULL)
2.85V SUPPLY
POW
2.85V GENERATER
POW
(PUSH - PULL)
BH9595FP-Y
16 SCSI LINE 7
15 SCSI LINE 6
14 VDD1
(TRMPWR)
0.1µ
Schottky barrier diodes
SYSTEM POWER
5.0V
+
2.2µ
–
∗For BH9596
“L”: ENABLE
“H”: DISCONNECT
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