FAIRCHILD FSTU32160

Revised March 2000
FSTU32160
16-Bit to 32-Bit Multiplexer/Demultiplexer Bus Switch
with −2V Undershoot Protection
General Description
Features
The Fairchild Switch FSTU32160 is a 16-bit to 32-bit highspeed CMOS TTL-compatible multiplexer/demultiplexer
bus switch. 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 can be used in applications where two buses
need to be addressed simultaneously. The FSTU32160 is
designed so that the A Port demultiplexes into B1 or B2 or
both. The A and B Ports are “undershoot hardened” with
UHC protection to support an extended range to 2.0V
below ground. Fairchild’s integrated Undershoot Hardened
Circuit, UHC senses undershoot at the I/O’s, and responds
by preventing voltage differentials from developing and
turning on the switch.
■ Slower Output Enable times prevent signal disruption
■ 4Ω 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
Two select (SEL1, SEL 2) inputs provide switch enable control. When SEL1, SEL2 are HIGH, the device precharges
the B Port to a selectable bias voltage (Bias V) to minimize
live insertion noise.
Ordering Code:
Order Number
Package Number
Package Description
FSTU32160MTD
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.
© 2000 Fairchild Semiconductor Corporation
DS500244
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FSTU32160 16-Bit to 32-Bit Multiplexer/Demultiplexer Bus Switch with −2V Undershoot Protection
May 1999
FSTU32160
Connection Diagram
Pin Descriptions
Pin Name
Description
SEL1, SEL2
Select Inputs
A
Bus A
B1 , B2
Bus B
Truth Table
Inputs
SEL2
L
H
x A = x B1
H
L
x A = x B2
L
L
x A = x B1 and x B2
H
H
x B1, x B2 = BiasV
Logic Diagram
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Function
SEL1
Recommended Operating
Conditions (Note 4)
Supply Voltage (VCC)
−0.5V to +7.0V
DC Switch Voltage (VS) (Note 2)
−2.0V to +7.0V
Power Supply Operating (VCC)
BiasV Voltage Range
−0.5V to +7.0V
Precharge Supply (BiasV)
1.5 to VCC
Input Voltage (VIN)
0V to 5.5V
Output Voltage (VOUT)
0V to 5.5V
DC Input Control Pin Voltage
−0.5V to +7.0V
(VIN) (Note 3)
DC Input Diode Current (lIK) VIN < 0V
−50 mA
DC Output Current (IOUT)
Storage Temperature Range (TSTG)
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
0nS/V to 5nS/V
Switch I/O
−65°C to +150 °C
0nS/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
TA = −40 °C to +85 °C
Symbol
Parameter
VCC
Min
Typ
(V)
Max
Units
Conditions
(Note 5)
−1.2
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
IO
Output Current
4.5
4.5
2.0
V
IIN = −18mA
VIK
V
0.25
mA
BiasV = 2.4V, SELX = 2.0V
BX = 0
IOZH, IOZL
OFF-STATE Leakage Current
5.5
±1.0
µA
0 ≤ A, ≤ VCC, V
IOZH, IOZL
OFF-STATE Leakage Current
5.5
±1.0
µA
0 ≤ B, ≤ VCC, V
RON
Switch On Resistance
4.5
4
7
Ω
(Note 6)
4.5
4
7
Ω
VIN = 0V, IIN = 30 mA
4.5
8
14
Ω
VIN = 2.4V, IIN = 15 mA
4.0
11
VIN = 2.4V, IIN = 15 mA
BiasV1 = BiasV2 = 5.5V
BiasV1 = BiasV2 = FLOATING
VIN = 0V, IIN = 64 mA
20
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
IBIAS
Bias Pin Leakage Current
5.5
±1.0
µA
SEL1, SEL2 = 0V
VIKU
Voltage Undershoot
5.5
−2.0
V
Other inputs at VCC or GND
BX = 0V, BiasVX = 5.5V
0.0 mA ≥ IIN ≥ −50 mA
SEL1, SEL2 = 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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FSTU32160
Absolute Maximum Ratings(Note 1)
FSTU32160
AC Electrical Characteristics
TA = −40 °C to +85 °C,
Symbol
Parameter
CL = 50 pF, RU= RD = 500Ω
VCC = 4.5 − 5.5V
Min
tPHL, tPLH
A or B, to B or A (Note 7)
tPZH
Output Enable Time,
SEL to A, B
tPZL
Output Enable Time,
SEL to A, B
tPHZ
Output Disable Time,
SEL to A, B
tPLZ
Output Disable Time,
SEL to A, B
VCC = 4.0V
Max
Min
Units
Conditions
Figure No.
VI = OPEN
Figure 2
Figure 3
VI = OPEN for tPZH
Figure 2
Figure 3
Max
0.25
0.25
ns
7.0
30.0
35.0
ns
7.0
30.0
35.0
ns
1.0
6.9
7.3
ns
1.0
7.7
7.7
ns
BiasV = GND
VI = 7V for tPZL
Figure 2
Figure 3
BiasV = 3V
VI = OPEN for tPHZ
BiasV = GND
VI = 7V for tPLZ ,
Figure 2
Figure 3
Figure 2
Figure 3
BiasV = 3V
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
4
pF
VCC = 5.0V
CI/O OFF
Input/Output Capacitance “OFF State”
8
pF
VCC = 5.0V, Switch OFF
Note 8: TA = +25°C, f = 1 MHz, Capacitance is characterized but not tested.
Undershoot Characteristic (Note 9)
Symbol
VOUTU
Parameter
Output Voltage During Undershoot
Min
Typ
2.5
VOH − 0.3
Max
Units
V
Conditions
Figure 1
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
Transient
Input Voltage (VIN) Waveform
Parameter
Value
VIN
see Waveform
V
R1 = R2
100K
Ω
VTRI
11.0
V
VCC
5.5
V
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Units
4
FSTU32160
AC Loading and Waveforms
Note: Input driven by 50Ω source terminated in 50Ω
Note: C L includes load and stray capacitance, CL = 50 pF
Note: Input PRR = 1.0 MHz, tW = 500 ns
FIGURE 2. AC Test Circuit
FIGURE 3. AC Waveforms
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FSTU32160 16-Bit to 32-Bit Multiplexer/Demultiplexer Bus Switch with −2V Undershoot Protection
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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