HP7501 Datasheet, PDF (4/9 Pages) List of Unclassifed Manufacturers – Ultra320 LVD/SE SCSI Terminator

HP7501
Ultra320 LVD/SE SCSI Terminator
PIN DESCRIPTION ( for 36pin SSOP)
PIN
SYMBOL
36
TPWR
1
2,3
8,9,10
26,27,28
4,6,11,13,15
22,24,29,31
5,7,12,14,16
23,25,30,32
17
VREF
NC
HGND
RxP
RxN
ISO
18
GND
19
MST/SLV
20
DIFFSENSE
21
DIF_CAP
33
SE
34
LVD
35
HVD
DESCRIPTION
2.7V to 5.25V power input pin. Connect to SCSI bus power line. A 4.7µF
capacitor and a 0.1µF high frequency capacitor are recommended between
TPWR and ground
Reference Voltage. Must be decoupled with a 4.7uF as shown in Figure 1.
Do not connect any signal to this pin.
Heat Sink Ground. Connect to large area PC board ground trace in order to
increase power dissipation.
Termination lines. These lines switch to hard ground in SE mode and are the
positive lines for LVD mode. All lines are in high impedance when HVD is
detected.
Termination lines. These lines switch to the active lines in SE mode and are the
negative lines for LVD mode. All lines are in high impedance when HVD is
detected.
Isolation pin. This pin is used to shut down the terminator if the terminator is
not connected at the end of the bus. Connect the pin to ground will activate the
terminator in normal operation. The terminator will be disabled when the pin is
in high state. An internal pull-down resistor assures that the HP7501 will
operate as normal if the ISO pin is left floating.
Signal Ground.
Mode select pin. When pull high, master mode will enable the DIFFSEN drive
SCSI bus. The DIFFSENSE driver is off when this pin is connected to ground.
This signal will drive 1.3V to the SCSI bus during the Master mode in order to
detect which type of device is connected to the SCSI bus. On power up, the
HP7501 will try to deliver LVD level to the DIFFSENSE line. If only LVD SCSI
devices are on the bus, the DIFFSENSE signal will be successfully driven to
1.3V and the terminator will configure the system for LVD operation. If any SE
device is on the bus, it will present a grounding level to the DIFFSENSE line.
This will indicate HP7501 to configure into SE operation. HP7501 will be in shut
down mode if DIFFSENSE detects a high voltage level.
This pin should be connected to a 0.1uF capacitor to ground and 20K resistor
to SCSI bus DIFFSENS line for DIFFSEN filter.
Single ended. Indicates SE device is on the SCSI bus when this pin is active.
Low Voltage Differential. Indicates the terminator is in LVD operation.
High Voltage Differential. Indicates the HVD device is detected and terminator
is in shut down mode.
PIN DESCRIPTION ( for 28pin TSSOP)
PIN
27,28
1
6,22
2,4,7,9,11
18,20,23,25
3,5,8,10,12
19,21,24,26
13
SYMBOL
TPWR
VREF
HGND
RxP
RxN
ISO
DESCRIPTION
2.7V to 5.25V power input pin. Connect to SCSI bus power line. A 4.7µF
capacitor and a 0.1µF high frequency capacitor are recommended between
TPWR and ground.
Reference Voltage. Must be decoupled with a 4.7uF as shown in Figure 1.
Heat Sink Ground. Connect to large area PC board ground trace in order to
increase power dissipation.
Termination lines. These lines switch to hard ground in SE mode and are the
positive lines for LVD mode. All lines are in high impedance when HVD is
detected.
Termination lines. These lines switch to the active lines in SE mode and are the
negative lines for LVD mode. All lines are in high impedance when HVD is
detected.
Isolation pin. This pin is used to shut down the terminator if the terminator is
not connected at the end of the bus. Connect the pin to ground will activate the
terminator in normal operation. The terminator will be disabled when the pin is
in high state. An internal pull-down resistor assures that the HP7501 will
operate as normal if the ISO pin is left floating.
2003/05/12 Ver. 0.0
4
HIMARK TECHNOLOGY INC.