SN74CB3T3384_15 Datasheet, PDF (2/19 Pages) Texas Instruments – 10-BIT FET BUS SWITCH 2.5-V/3.3-V LOW-VOLTAGE BUS SWITCH WITH 5-V-TOLERANT LEVEL SHIFTER

SN74CB3T3384
10ĆBIT FET BUS SWITCH
2.5ĆV/3.3ĆV LOWĆVOLTAGE BUS SWITCH WITH 5ĆVĆTOLERANT LEVEL SHIFTER
SCDS159B − OCTOBER 2003 − REVISED MARCH 2004
description/ordering information (continued)
The SN74CB3T3384 is a high-speed TTL-compatible FET bus switch with low ON-state resistance (r_on),
allowing for minimal propagation delay. The device fully supports mixed-mode signal operation on all data I/O
ports by providing voltage translation that tracks V_CC. The SN74CB3T3384 supports systems using 5-V TTL,
3.3-V LVTTL, and 2.5-V CMOS switching standards, as well as user-defined switching levels (see Figure 1).
VCC
5.5 V
VCC
≈VCC − 1 V
IN
OUT
CB3T
≈VCC
≈VCC − 1 V
0V
0V
Input Voltages
Output Voltages
NOTE A: If the input high voltage (VIH) level is greater than or equal to VCC − 1 V, and less than or equal to 5.5 V, the output high
voltage (VOH) level will be equal to approximately the VCC voltage level.
Figure 1. Typical DC-Voltage-Translation Characteristics
The SN74CB3T3384 is organized as two 5-bit bus switches with separate ouput-enable (1OE, 2OE) inputs. It
can be used as two 5-bit bus switches or as one 10-bit bus switch. When OE is low, the associated 5-bit bus
switch is ON, and the A port is connected to the B port, allowing bidirectional data flow between ports. When
OE is high, the associated 5-bit 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 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, OE 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.
INPUT
OE
L
H
FUNCTION TABLE
(each 5-bit bus switch)
INPUT/OUTPUT
A
FUNCTION
B
A port = B port
Z
Disconnect
2
• POST OFFICE BOX 655303 DALLAS, TEXAS 75265