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FST16245
16-Bit Bus Switch
FST16245 16-Bit Bus Switch
April 2001
Revised April 2001
General Description
The Fairchild Switc h FST16245 provides 16-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.
The device is organized as a 16- bit switch. There are two
8-bit switches with separ ate output enable inputs. When
OE
is LOW, the switch is ON and Port a is connected to
Port B. When OE
impedance state exists between the A and B Ports.
is HIGH, the switch is OFF an d a high
Features
■ 4Ω switch connection between two ports.
■ Minimal propagation delay through the switch.
■ Low l
■ Zero bounce in flow-through mode.
■ Control inputs compatible with TTL level.
.
CC
Ordering Code:
Order Number Package Number Package Description
FST16245MTD MTD48 48-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 6.1mm Wide
Devices also availab le in Tape and Reel. Specify by appending the suffix letter “X” to the o rdering code.
Connection Diagram
Logic Diagram
Pin Descriptions
Pin Name Description
OE
n
, 2An, 3An, 4A
1A
n
1B
, 2Bn, 3Bn, 4B
n
NC No Internal Connection
© 2001 Fairchild Semiconductor Corporation DS500419 www.fairchildsemi.com
Output Enable Input (Active LOW)
n
n
Bus A
Bus B
Truth Table
Inputs Outputs
OE
LA Port
H = HIGH Voltage Level
L = LOW Voltage Level
Z = High Impedance
HZ
x
A, B
= B Port
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Absolute Maximum Ratings(Note 1) Recommended Operating
Supply Voltage (VCC) −0.5V to +7.0V
DC Switch Voltage (V
FST16245
DC Input Voltage (V
DC Input Diode Current (l
DC Output Current (I
DC V
/GND Current (ICC/I
CC
Storage Temperature Range (T
) (Note 2) −0.5V to +7.0V
S
) (Note 3) −0.5V to +7.0V
IN
) VIN < 0V −50mA
IK
)128mA
OUT
) ±100mA
GND
) −65°C to +150 °C
STG
Conditions
Power Supply Operating (V
Input Voltage (V
Output Voltage (V
Input Rise and Fall Time (t
Switch Control Input 0 ns/V to 5 ns/V
Switch I/O 0 ns/V to DC
Free Air Operating Temperature (T
Note 1: The “Absolute Maximum Ratings” are those values bey ond which
the safety of the d evice cannot be guaranteed. The device sh ould not be
operated at these limit s. The parametric values defin ed in the Electrical
Characteristics tables are not guaranteed at the absolute maximum rating.
The “Recomme nded O perat ing Co ndition s” table will defin e the condition s
for actual device operation.
is the volt age observed/applied at either the A or B Ports a c ross
Note 2: V
S
the switch.
Note 3: The input and output ne gative vo ltage ra tings may be excee ded if
the input and output diode current ratings are observed.
Note 4: Unused control inputs m ust be held HIGH o r LOW. They may no t
float.
(Note 4)
CC)
)0V to 5.5V
IN
)0V to 5.5V
OUT
, tf)
r
)-40 °C to +85 °C
A
DC Electrical Characteristics
TA = −40°C to +85°C
Symbol Parameter
V
IK
V
IH
V
IL
I
I
I
OZ
R
ON
I
CC
∆ I
Note 5: Typi c al values are at VCC = 5.0V and TA = +25°C
Note 6: Measured by the volta ge drop between A an d B pins at the indicated c urrent through the switch. On Resistance is determined by the lower of the
voltages on the two (A or B) pins.
Clamp Diode Voltage 4.5 −1.2 V IIN = −18mA
HIGH Level Input Voltage 4.0–5.5 2.0 V
LOW Level Input Voltage 4.0–5.5 0.8 V
Input Leakage Current 5.5 ±1.0 µA0 ≤ VIN ≤ 5.5V
OFF-STATE Leakage Current 5.5 ±1.0 µA0 ≤ A, B ≤ V
Switch On Resistance 4.5 4 7 Ω VIN = 0V, IIN = 64 mA
(Note 6) 4.5 4 7 Ω V
Quiescent Supply Current 5.5 3 µAVIN = VCC or GND, I
Increase in I
CC
per Input 5.5 2.5 mA One Input at 3.4V
CC
CC
(V) (Note 5)
0 ±10 µAV
4.5 7 12 Ω V
4.0 11 20 Ω VIN = 2.4V, IIN = 15 mA
Min Typ Max
Units ConditionsV
= 5.5V
IN
= 0V, IIN = 30 mA
IN
= 2.4V, IIN = 15 mA
IN
Other Inputs at VCC or GND
CC
4.0V to 5.5V
= 0
OUT
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AC Electrical Characteristics
TA = −40 °C to +85 °C,
= 50pF, RU = RD = 500Ω Figure
C
Symbol Parameter
L
V
= 4.5 – 5.5V VCC = 4.0V Number
CC
Units Conditions
Min Max Min Max
t
, t
PHL
t
PZH
t
PHZ
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 sw it c h and the 50pF load capa citance, when drive n by an ideal voltage sourc e (zero output impe dance).
Propagation Delay Bus-to-Bus
PLH
(Note 7)
, t
Output Enable Time 1.0 5.6 6.1 ns VI = 7V for t
PZL
, t
Output Disable Time 1.0 5.5 5.9 ns VI = 7V for t
PLZ
0.25 0.25 ns VI = OPEN Figures
VI = OPEN for t
PZL
= OPEN for t
I
PLZ
V
PZH
PHZ
Figures
Figures
Capacitance (Note 8)
Symbol Parameter Typ Max Units Conditions
C
IN
C
I/O
Note 8: TA = +25°C, f = 1 MHz, Ca pacitance is charac te riz ed but not tested.
Control Pin Input Capacitance 3 pF VCC = 5.0V, VIN = 0V
Input/Output Capacitance “OFF State” 6pFV
, OE = 5.0V, VIN = 0V
CC
AC Loading and Waveforms
FST16245
1, 2
1, 2
1, 2
Note: Input driven by 50Ω source terminated in 50Ω
includes load and stray capacitance
Note: C
L
Note: Input PRR = 1.0 MHz, t
= 500 ns
W
FIGURE 1. AC Test Circuit
FIGURE 2. AC Waveforms
3 www.fairchildsemi.com
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Physical Dimensions inches (millimeters) unless otherwise noted
FST16245 16-Bit Bus Switch
48-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 6.1mm Wide
Package Number MTD48
Technology Description
The Fairchild Switch family derives from and embodies Fairchild’s proven s witch technolog y used for several years i n its
74LVX3L384( FST3384) bus switch product.
Fairchild does not assume any responsibility for use of any circuitr y described, no circuit patent licenses are implied a nd
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:
1. Life support devices or systems are device s or syste ms
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 inju ry to the
user.
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2. A critical component in any compon ent of a l ife supp ort
device or system whose failu re to perform can be reasonably expected to cause the failure of the li fe su pp ort
device or system, or to affect its safety or effectiveness.
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