FSTD16861 Datasheet, PDF (1/5 Pages) Fairchild Semiconductor – 20-Bit Bus Switch with Level Shifting

May 2001
Revised May 2001
FSTD16861
20-Bit Bus Switch with Level Shifting
General Description
The Fairchild Switch FSTD16861 provides 20-bits of high-
speed CMOS TTL-compatible bus switching. The low On
Resistance of the switch allows inputs to be connected to
outputs without adding propagation delay or generating
additional ground bounce noise. A diode to V_CC has been
integrated into the circuit to allow for level shifting between
5V inputs and 3.3V outputs.
The device is organized as a 10-bit or 20-bit bus switch.
When OE₁ is LOW, the switch is ON and Port 1A is con-
nected to Port 1B. When OE₂ is LOW, Port 2A is connected
to Port 2B. When OE_X is HIGH, a high impedance state
exists between the A and B Ports.
Features
s 4Ω switch connection between two ports.
s Minimal propagation delay through the switch.
s Low l_CC.
s Zero bounce in flow-through mode.
s Control inputs compatible with TTL level.
s TruTranslation voltage translation from 5.0V inputs to
3.3V outputs
Ordering Code:
Order Number Package Number
Package Description
FSTD16861MTD
MTD48
48-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 6.1mm Wide
Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.
Connection Diagram
Logic Diagram
Pin Descriptions
Pin Name
OE₁, OE₂
1A_n, 2A_n
1B_n, 2B_n
Description
Bus Switch Enables
Bus A
Bus B
TruTranslation is trademark of Fairchild Semiconductor Corporation.
© 2001 Fairchild Semiconductor Corporation DS500421
Truth Table
Inputs
OE₁
OE₂
L
L
L
H
H
L
H
H
H = HIGH Voltage Level
L = LOW Voltage Level
Z = High Impedance
Inputs/Outputs
1A, 1B
1A = 1B
1A = 1B
Z
Z
2A, 2B
2A = 2B
Z
2A = 2B
Z
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