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 drives, optical disk drives, CD-ROM dri-
Compact disk
ves, tape drives, personal computers (including laptop
computers and notebook computers), workstations,
mainframes, laser printers, plotters
•
Features 2.85V power supply and push-pull opera-
1) Internal
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.
1
Mulimedia ICs
BH9595FP-Y / BH9596FP-Y
•
Pin descriptions
Pin No.
1
2
3
4
5
6
—
7
8
9
10
11
12
13
Pin name
(N.C.) Not to be used
EN (Output enable)
SCSI Line 15
SCSI Line 16
SCSI Line 17
SCSI Line 18
GND
GND
SCSI Line 1
SCSI Line 2
SCSI Line 3
SCSI Line 4
SCSI Line 5
V
DD1
Pin No.
14
15
16
17
18
19
—
20
21
22
23
24
25
V
DD1
SCSI Line 6
SCSI Line 7
SCSI Line 8
SCSI Line 9
SCSI Line 10
GND
SCSI Line 11
SCSI Line 12
SCSI Line 13
SCSI Line 14
VM
TSD (TSD signal output)
Pin name
•
Electrical characteristics otherwise noted, Ta = 25°C)
DC characteristics (unless
Parameter
Input leakage current
SCSI line leakage current
SCSI line short current
∗
1
SCSI line short current
∗
2
VM voltage
Standby current
∗
1
SCSI total sink current
SCSI total drain current
SCSI equivalent resistance
Pin capacity
∗
3
Symbol
I
IL
I
IH
I
SLZ
I
SLD
I
SLS
V
M
I
DDSTB
I
SLS
I
SLD
R
SL
PC
Min.
50
–1
–1
15
7
2.700
—
300
300
105
—
Typ.
110
—
—
25
20
2.85
1.0
—
—
—
5.0
Max.
200
1
1
30
30
3.000
2.0
550
550
115
6.0
Unit
µA
µA
µA
mA
mA
V
mA
mA
mA
Ω
pF
Conditions
Vi = GND, V
DD1
= 5.5V
Vi = V
DD1
, V
DD1
= 5.5V
EN = ENABLE
∗
4
, V
DD1
= 5.5V
EN = DISABLE
∗
5
, SCSI Line = GND,
4.0 V
DD1
5.5V
EN = DISABLE
∗
5
, SCSI Line = V
DD1
4.0 V
DD1
5.5V
4.0
V
DD1
5.5V
V
DD1
5.5V
EN = ENABLE
∗
4
, 4.0V
EN = DISABLE
∗
5
, 18 SCSI Line = GND
4.0 V
DD1
5.5V
EN = DISABLE
∗
5
, 18 SCSI Line = V
DD1
4.0 V
DD1
5.5V
EN = DISABLE
∗
5
, SCSI Line: V
DD1
= 4.7V
EN = ENABLE
∗
4
∗
1 Drain Current (from Module to SCSI Line) / Line
∗
2 Sink Current (from SCSI Line to Module) / Line
∗
3 Guaranteed performance
∗
4 BH9595FP-Y: EN = GND, BH9595FP-Y: EN = V
DD1
∗
5 BH9696FP-Y: EN = V
DD1
, BH9696FP-Y: EN = GND
3
Mulimedia ICs
Transient characteristics (unless otherwise noted, Ta = 25°C)
Parameter
Load Transient Voltage
2.85V→GND
Load Transient 1 / 10 decay Time
2.85V→GND
Load Transient Voltage
GND→2.85V
Load Transient 1 / 10 decay Time
GND→2.85V
Load Transient Voltage
2.85V→V
DD1
Load Transient Voltage
2.85V→V
DD1
Load Transient Voltage
V
DD1
→2.85V
Load Transient Voltage
V
DD1
→2.85V
Symbol
∆VM
TD1
τ
TD1
∆VM
TD2
τ
TD2
∆VM
TS1
τ
TS1
∆VM
TS2
τ
TS2
Min.
– 100
—
– 100
—
– 100
—
– 100
—
Max.
100
100
100
100
100
100
100
100
Unit
mV
µs
mV
µs
mV
µs
mV
µs
BH9595FP-Y / BH9596FP-Y
Conditions
EN = DISABLE
∗
, 4.0 V
DD1
5.5V
All SCSI Lines: 2.85V→GND Level
EN = DISABLE
∗
, 4.0 V
DD1
5.5V
All SCSI Lines: 2.85V→GND Level
EN = DISABLE
∗
, 4.0 V
DD1
5.5V
All SCSI Lines: GND→2.85V Level
EN = DISABLE
∗
, 4.0 V
DD1
5.5V
All SCSI Lines: GND→2.85V Level
EN = DISABLE
∗
, 4.0 V
DD1
5.5V
All SCSI Lines: 2.85V→V
DD1
Level
EN = DISABLE
∗
, 4.0 V
DD1
5.5V
All SCSI Lines: 2.85V→V
DD1
Level
EN = DISABLE
∗
, 4.0 V
DD1
5.5V
All SCSI Lines: V
DD1
→2.85V
Level
EN = DISABLE
∗
, 4.0 V
DD1
5.5V
All SCSI Lines: V
DD1
→2.85V
Level
∗
BH9595FP-Y: EN = V
DD1
, BH9596FP-Y: GND
The transient characteristics are guaranteed design values.
SCSI
Line
Potential
V
DD1
Level
2.85V
GND Level
tτ = 50ns
– 5.5V
– 2.85V
0 V
∆VM
TD1
∆VM
TD2
∆VM
TS1
∆VM
TS2
VM
τ
TD1
τ
TD2
τ
TS1
τ
TS1
V
DD1
SCSI Line
#1
SCSI
Active
Terminator
+
#18
–
Same Voltage
as V
DD1
–
+
VM
Fig. 1 Measurement of transient characteristics
4
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