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Fairchild Semiconductor |
Preliminary
May 2001
Revised May 2001
FST162244
16-Bit Bus Switch with 25Ω Series Resistor in Outputs
(Preliminary)
General Description
The Fairchild Switch FST162244 provides 16-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.
The device is organized as a 16-bit switch. There are four
4-bit switches with separate output enable inputs. When
OE is LOW, the switch in ON and Port A is connected to
Port B. When OE is HIGH, the switch OFF and a high
impedance state exists between the A and B Ports. The
FST162244 has an equivalent 25Ω series resistors to
reduce signal-reflection noise, eliminating the need for
external terminating resistors.
Features
s 25Ω switch connection between two ports.
s Minimal propagation delay through the switch.
s Low lCC.
s Zero bounce in flow-through mode.
s Control inputs compatible with TTL level.
Ordering Code:
Order Number Package Number
Package Description
FST162244MTD
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
OEn
1An, 2An, 3An, 4An
1Bn, 2Bn, 3Bn, 4Bn
Description
Output Enable Input (Active LOW)
Bus A
Bus B
Truth Table
Inputs
Outputs
OEx
A, B
L A Port = B Port
HZ
H = HIGH Voltage Level L = LOW Voltage Level Z = High Impedance
© 2001 Fairchild Semiconductor Corporation DS500430
www.fairchildsemi.com
Preliminary
Absolute Maximum Ratings(Note 1)
Supply Voltage (VCC)
DC Switch Voltage (VS) (Note 2)
DC Input Voltage (VIN) (Note 3)
DC Input Diode Current (lIK) VIN < 0V
DC Output Current (IOUT)
DC VCC/GND Current (ICC/IGND)
Storage Temperature Range (TSTG)
−0.5V to +7.0V
−0.5V to +7.0V
−0.5V to +7.0V
−50 mA
128 mA
±100 mA
−65°C to +150 °C
Recommended Operating
Conditions (Note 4)
Power Supply Operating (VCC)
Input Voltage (VIN)
Output Voltage (VOUT)
Input Rise and Fall Time (tr, tf)
Switch Control Input
4.0V to 5.5V
0V to 5.5V
0V to 5.5V
0 ns/V to 5 ns/V
Switch I/O
0 ns/V to DC
Free Air Operating Temperature (TA)
-40°C to +85°C
Note 1: The “Absolute Maximum Ratings” are those values beyond which
the safety of the device cannot be guaranteed. The device should not be
operated at these limits. The parametric values defined in the Electrical
Characteristics tables are not guaranteed at the absolute maximum rating.
The “Recommended Operating Conditions” table will define the conditions
for actual device operation.
Note 2: VS is the voltage observed/applied at either the A or B Ports across
the switch.
Note 3: The input and output negative voltage ratings may be exceeded if
the input and output diode current ratings are observed.
Note 4: Unused control inputs must be held HIGH or LOW. They may not
float.
DC Electrical Characteristics
TA = −40°C to +85°C
Symbol
Parameter
VCC Typ Units
Min Max
(V) (Note 5)
Conditions
VIK
VIH
VIL
II
IOZ
RON
ICC
∆ ICC
Clamp Diode Voltage
HIGH Level Input Voltage
LOW Level Input Voltage
Input Leakage Current
OFF-STATE Leakage Current
Switch On Resistance
(Note 6)
Quiescent Supply Current
Increase in ICC per Input
4.5
4.0–5.5
4.0–5.5
5.5
0
5.5
4.5
4.5
4.5
4.0
5.5
5.5
Note 5: Typical values are at VCC = 5.0V and TA = +25°C
2.0
20
20
20
20
−1.2
V IIN = −18mA
V
0.8 V
±1.0
µA 0 ≤ VIN ≤ 5.5V
±10 µA VIN = 5.5V
±1.0
µA 0 ≤ A, B ≤ VCC
26 38
Ω VIN = 0V, IIN = 64 mA
27 40
Ω VIN = 0V, IIN = 30 mA
28 48
Ω VIN = 2.4V, IIN = 15 mA
30 48
Ω VIN = 2.4V, IIN = 15 mA
3 µA VIN = VCC or GND, IOUT = 0
2.5 mA One Input at 3.4V
Other Inputs at VCC or GND
Note 6: Measured by the voltage drop between A and B pins at the indicated current through the switch. On Resistance is determined by the lower of the
voltages on the two (A or B) pins.
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