FAIRCHILD FSTU162211MTD

Preliminary
Revised June 2001
FSTU162211
24-Bit Bus Switch with −2V Undershoot Protection
and 25Ω Series Resistors in Outputs (Preliminary)
General Description
Features
The Fairchild Switch FSTU162211 provides 24-bits of highspeed 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.
■ Undershoot hardened to −2V (A and B Ports)
The device is organized as a 12-bit or 24-bit bus switch.
When OE1 is LOW, the switch is ON and Port 1A is connected to Port 1B. When OE2 is LOW, Port 2A is connected
to Port 2B. The A and B Ports are protected against undershoot to support an extended range to 2.0V below ground.
Fairchild’s integrated Undershoot Hardened Circuit
(UHC) senses undershoot at the I/O and responds by
preventing voltage differentials from developing and turning the switch on.
■ Slower output enable times to prevent signal disruption
■ 25Ω switch connection between two ports
■ Minimal propagation delay through the switch
■ Low lCC
■ Zero bounce in flow-through mode
■ Control inputs compatible with TTL level
■ See Applications Note AN-5008 for details
The FSTU162211 has equivalent 25Ω series resistors to
reduce signal-reflection noise, eliminating the need for
external terminating resistors.
Ordering Code:
Order Number
Package Number
Package Description
FSTU162211MTD
MTD56
56-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.
UHC is a trademark of Fairchild Semiconductor Corporation.
© 2001 Fairchild Semiconductor Corporation
DS500064
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FSTU162211 24-Bit Bus Switch with −2V Undershoot Protection and 25Ω Series Resistors in Outputs
(Preliminary)
June 2001
FSTU162211
Preliminary
Logic Diagram
Connection Diagram
Truth Table
Pin Descriptions
Inputs
OE1
Inputs/Outputs
OE2
Pin Name
Description
1A, 1B
2A, 2B
OE1, OE2
Bus Switch Enables
Bus A
L
L
1A = 1B
2A = 2B
1A, 2A
L
H
1A = 1B
Z
1B, 2B
Bus B
H
L
Z
2A = 2B
NC
No Connect
H
H
Z
Z
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Preliminary
Supply Voltage (VCC)
−0.5V to +7.0V
DC Switch Voltage (VS) (Note 2)
−0.5V to +7.0V
Recommended Operating
Conditions (Note 4)
Power Supply Operating (VCC)
DC Input Control
Pin Voltage (VIN) (Note 3)
−0.5V to +7.0V
DC Input Diode Current (lIK) VIN < 0V
−50 mA
DC Output Current (IOUT)
Storage Temperature Range (TSTG)
0V to 5.5V
Output Voltage (VOUT)
0V to 5.5V
Input Rise and Fall Time (tr, tf)
128 mA
Switch Control Input
+/− 100 mA
DC VCC/GND Current (ICC/IGND)
4.0V to 5.5V
Input Voltage (VIN)
0 ns/V to 5 ns/V
Switch I/O
−65°C to +150 °C
0 ns/V to DC
-40 °C to +85 °C
Free Air Operating Temperature (TA)
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
Symbol
Parameter
VCC
(V)
TA = −40 °C to +85 °C
Min
Typ
(Note 5)
Max
−1.2
Units
Conditions
IIN = −18 mA
VIK
Clamp Diode Voltage
VIH
HIGH Level Input Voltage
4.0–5.5
VIL
LOW Level Input Voltage
4.0–5.5
0.8
V
II
Input Leakage Current
5.5
±1.0
µA
0 ≤ VIN ≤ 5.5V
0
10
µA
VIN = 5.5V
±1.0
µA
0 ≤ A, B ≤ VCC
VIN = 0V, IIN = 64 mA
4.5
2.0
V
V
IOZ
OFF-STATE Leakage Current
5.5
RON
Switch On Resistance
4.5
20
26
38
Ω
(Note 6)
4.5
20
27
40
Ω
VIN = 0V, IIN = 30 mA
4.5
20
28
48
Ω
VIN = 2.4V, IIN = 15 mA
4.0
20
30
VIN = 2.4V, IIN = 15 mA
48
Ω
ICC
Quiescent Supply Current
5.5
3
µA
VIN = VCC or GND, IOUT = 0
∆ ICC
Increase in ICC per Input
5.5
2.5
mA
One Input at 3.4V
VIKU
Voltage Undershoot
5.5
−2.0
V
Other Inputs at VCC or GND
0.0 mA ≥ IIN ≥ −50 mA
OE1,2 = 5.5v
Note 5: Typical values are at VCC = 5.0V and TA = +25°C
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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FSTU162211
Absolute Maximum Ratings(Note 1)
FSTU162211
Preliminary
AC Electrical Characteristics
TA = −40 °C to +85 °C,
Symbol
CL = 50pF, RU = RD = 500Ω
Parameter
VCC = 4.5 – 5.5V
Min
tPHL, tPLH
Propagation Delay Bus to Bus
(Note 7)
tPZH, tPZL
Output Enable Time
1.5
VCC = 4.0V
Max
Min
Units
Max
1.25
1.25
ns
VI = OPEN
Figures 2,
3
6.0
6.5
ns
VI = 7V for tPZL
Figures 2,
3
VI = OPEN for tPZH
tPHZ, tPLZ
Output Disable Time
1.5
Figure
Number
Conditions
7.0
7.2
VI = 7V for tPLZ
ns
VI = OPEN for tPHZ
Figures 2,
3
Note 7: This parameter is guaranteed by design but is not tested. The bus switch contributes no propagation delay other than the RC delay of the typical On
Resistance of the switch and the 50pF load capacitance, when driven by an ideal voltage source (zero output impedance).
Capacitance
Symbol
(Note 8)
Parameter
Typ
Max
Units
Conditions
CIN
Control Pin Input Capacitance
3
pF
VCC = 5.0V
CI/O
Input/Output Capacitance
6
pF
VCC, OE = 5.0V
Note 8: TA = +25°C, f = 1 MHz, Capacitance is characterized but not tested.
Undershoot Characteristic
Symbol
VOUTU
Parameter
Output Voltage During Undershoot
Min
Typ
2.5
VOH − 0.3
Max
Units
Conditions
V
Note 9: This test is intended to characterize the device’s protective capabilities by maintaining output signal integrity during an input transient voltage undershoot event.
FIGURE 1.
Device Test Conditions
Parameter
Value
VIN
see Waveform
V
R1 = R2
100K
Ω
VTRI
11.0
V
VCC
5.5
V
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Transient
Input Voltage (VIN) Waveform
Units
4
Preliminary
FSTU162211
AC Loading and Waveforms
Note: Input driven by 50 Ω source terminated in 50 Ω
Note: C L includes load and stray capacitance
Note: Input PRR = 1.0 MHz, tW = 500 ns
FIGURE 2. AC Test Circuit
FIGURE 3. AC Waveforms
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FSTU162211 24-Bit Bus Switch with −2V Undershoot Protection and 25Ω Series Resistors in Outputs
(Preliminary)
Preliminary
Physical Dimensions inches (millimeters) unless otherwise noted
56-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 6.1mm Wide
Package Number MTD56
Technology Description
The Fairchild Switch family derives from and embodies Fairchild’s proven switch technology used for several years in its
74LVX3L384 (FST3384) bus switch product.
Fairchild does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and
Fairchild reserves the right at any time without notice to change said circuitry and specifications.
LIFE SUPPORT POLICY
FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD
SEMICONDUCTOR CORPORATION. As used herein:
2. A critical component in any component of a life support
device or system whose failure to perform can be reasonably expected to cause the failure of the life support
device or system, or to affect its safety or effectiveness.
1. Life support devices or systems are devices or systems
which, (a) are intended for surgical implant into the
body, or (b) support or sustain life, and (c) whose failure
to perform when properly used in accordance with
instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the
user.
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