SN74CBT6800C Datasheet, PDF (2/15 Pages) Texas Instruments – 10-BIT FET BUS SWITCH WITH PRECHARGED OUTPUTS 5-V BUS WITCH WITH-2-V UNDERSHOOT PROTECTION

SN74CBT6800C
10ĆBIT FET BUS SWITCH WITH PRECHARGED OUTPUTS
5ĆV BUS SWITCH WITH -2ĆV UNDERSHOOT PROTECTION
SCDS138 − OCTOBER 2003
description/ordering information (continued)
The SN74CBT6800C is a 10-bit bus switch with a single output-enable (ON) input. When ON is low, the 10-bit
bus switch is ON, and the A port is connected to the B port, allowing bidirectional data flow between ports. When
ON is high, the 10-bit bus switch is OFF, and a high-impedance state exists between the A and B ports. The
B port is precharged to BIASV through the equivalent of a 10-kΩ resistor when ON is high, or if the device is
powered down (V_CC = 0 V).
During insertion (or removal) of a card into (or from) an active bus, the card’s output voltage may be close to
GND. When the connector pins make contact, the card’s parasitic capacitance tries to force the bus signal to
GND, creating a possible glitch on the active bus. This glitching effect can be reduced by using a bus switch
with precharged bias voltage (BIASV) of the bus switch equal to the input threshold voltage level of the receivers
on the active bus. This method will ensure that any glitch produced by insertion (or removal) of the card will not
cross the input threshold region of the receivers on the active bus, minimizing the effects of live-insertion noise.
This device is fully specified for partial-power-down applications using I_off. The I_off feature ensures that
damaging current will not 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, ON should be tied to V_CC through a pullup
resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.
ORDERING INFORMATION
TA
PACKAGE†
ORDERABLE
PART NUMBER
TOP-SIDE
MARKING
SOIC − DW
Tube
Tape and reel
SN74CBT6800CDW
SN74CBT6800CDWR
CBT6800C
−40°C to 85°C
SSOP − DB
SSOP (QSOP) − DBQ
Tube
Tape and reel
Tape and reel
SN74CBT6800CDB
SN74CBT6800CDBR
SN74CBT6800CDBQR
CT6800C
CBT6800C
TSSOP − PW
Tube
Tape and reel
SN74CBT6800CPW
SN74CBT6800CPWR
CT6800C
TVSOP − DGV
Tape and reel
SN74CBT6800CDGVR CT6800C
† _{Package drawings, standard packing quantities, thermal data, symbolization, and PCB design guidelines are}
available at www.ti.com/sc/package.
INPUT
ON
L
H
FUNCTION TABLE
INPUT/OUTPUT
A
FUNCTION
B
A port = B port
Z
Disconnect
B port = BIASV
2
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