SN74CB3Q3345 Datasheet, PDF (2/11 Pages) Texas Instruments – 8 BIT FET BUS SWITCH 2.5V/3.3V LOW VOLTAGE HIGH BANDWIDTH BUS SWITCH

SN74CB3Q3345
8ĆBIT FET BUS SWITCH
2.5ĆV/3.3ĆV LOWĆVOLTAGE HIGHĆBANDWIDTH BUS SWITCH
SCDS144A − OCTOBER 2003 − REVISED NOVEMBER 2003
description/ordering information
The SN74CB3Q3345 is a high-bandwidth FET bus switch utilizing a charge pump to elevate the gate voltage
of the pass transistor, providing a low and flat ON-state resistance (r_on). The low and flat ON-state resistance
allows for minimal propagation delay and supports rail-to-rail switching on the data input/output (I/O) ports. The
device also features low data I/O capacitance to minimize capacitive loading and signal distortion on the data
bus. Specifically designed to support high-bandwidth applications, the SN74CB3Q3345 provides an optimized
interface solution ideally suited for broadband communications, networking, and data-intensive computing
systems.
The SN74CB3Q3384A is organized as an 8-bit bus switch with two output-enable (OE, OE) inputs. When OE
is high or OE is low, the bus switch is ON, and the A port is connected to the B port, allowing bidirectional data
flow between ports. When OE is low and OE is high, the bus switch is OFF, and a high-impedance state exists
between the A and B ports.
This device is fully specified for partial-power-down applications using I_off. The I_off circuitry prevents damaging
current backflow through the device when it is powered down. The device has isolation during power off.
To ensure the high-impedance state during power up or power down, OE should be tied to V_CC through a pullup
resistor and OE should be tied to GND through a pulldown resistor; the minimum value of the resistor is
determined by the current-sinking/current-sourcing capability of the driver.
ORDERING INFORMATION
TA
PACKAGE†
ORDERABLE
PART NUMBER
TOP-SIDE
MARKING
QFN − RGY
Tape and reel SN74CB3Q3345RGYR BU345
SSOP (QSOP) − DBQ Tape and reel SN74CB3Q3345DBQR CB3Q3345
−40°C to 85°C
TSSOP − PW
Tube
Tape and reel
SN74CB3Q3345PW
SN74CB3Q3345PWR
BU345
TVSOP − DGV
Tape and reel SN74CB3Q3345DGVR BU345
† _{Package drawings, standard packing quantities, thermal data, symbolization, and PCB design guidelines are}
available at www.ti.com/sc/package.
INPUTS
OE
OE
H
X
X
L
L
H
FUNCTION TABLE
INPUT/OUTPUT
A
FUNCTION
B
A port = B port
B
A port = B port
Z
Disconnect
logic diagram (positive logic)
2
A1
18
SW
B1
9
A8
1
OE
19
OE
11
SW
B8
2
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