Fairchild FSTU3125QSC 4-bit bus switch with -2v undershoot protection Datasheet

Revised August 2001
FSTU3125
4-Bit Bus Switch with −2V Undershoot Protection
General Description
Features
The Fairchild Switch FSTU3125 provides four high-speed
CMOS TTL-compatible bus switches. 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 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.
■ Undershoot hardened to −2V (A and B Ports)
■ 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 application notes AN-5008 and AN-5021 for details
on undershoot
The device is organized as four 1-bit switches with separate OE inputs. When OE is LOW, the switch is ON and
Port A is connected to Port B. When OE is HIGH, the
switch is OPEN and a high-impedance state exists
between the two ports.
Ordering Code:
Order Number
FSTU3125M
Package Number
M14A
Package Description
14-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150" Narrow
FSTU3125QSC
MQA16
16-Lead Quarter Size Outline Package (QSOP), JEDEC MO-137, 0.150" Wide
FSTU3125MTC
MTC14
14-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide
Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.
Connection Diagrams
Pin Descriptions
Pin Assignment for SOIC and TSSOP
Pin Name
Description
OE1, OE2, OE3, OE4
Bus Switch Enables
1A, 2A, 3A, 4A
Bus A
1B, 2B, 3B, 4B
Bus B
NC
Not Connected
Truth Table
Inputs
Pin Assignment for QSOP
© 2001 Fairchild Semiconductor Corporation
DS500449
Inputs/Outputs
OE
A,B
L
A=B
H
Z
www.fairchildsemi.com
FSTU3125 4-Bit Bus Switch with −2V Undershoot Protection
June 2001
FSTU3125
Logic Diagram
www.fairchildsemi.com
2
Recommended Operating
Conditions (Note 3)
Supply Voltage (VCC)
−0.5V to +7.0V
DC Switch Voltage (VS)
−2.0V to +7.0V
Power Supply Operating (VCC)
DC Input Voltage (VIN)(Note 2)
−0.5V to +7.0V
Input Voltage (VIN)
0V to 5.5V
0V to 5.5V
DC Input Diode Current (lIK) VIN < 0V
−50 mA
Output Voltage (VOUT)
DC Output (IOUT) Sink Current
128 mA
Input Rise and Fall Time (tr, tf)
+/− 100 mA
DC VCC/GND Current (ICC/IGND)
Storage Temperature Range (TSTG)
4.0V to 5.5V
Switch Control Input
−65°C to +150 °C
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: The input and output negative voltage ratings may be exceeded if
the input and output diode current ratings are observed.
Note 3: Unused control inputs must be held HIGH or LOW. They may not
float.
DC Electrical Characteristics
Symbol
VCC
(V)
Parameter
TA = −40 °C to +85 °C
Min
Typ
(Note 4)
Max
−1.2
VIK
Clamp Diode Voltage
VIH
HIGH Level Input Voltage
4.0–5.5
VIL
LOW Level Input Voltage
4.0–5.5
0.8
II
Input Leakage Current
5.5
±1.0
0
10
5.5
±1.0
IOZ
RON
4.5
OFF-STATE Leakage Current
2.0
Units
V
Conditions
IIN = −18 mA
V
V
µA
0 ≤ VIN ≤ 5.5V
VIN = 5.5V
µA
0 ≤ A, B ≤ VCC
Switch On Resistance
4.5
4
7
Ω
VIN = 0V, IIN = 64 mA
(Note 5)
4.5
4
7
Ω
VIN = 0V, IIN = 30 mA
4.5
8
15
Ω
VIN = 2.4V, IIN = 15 mA
4.0
11
20
Ω
VIN = 2.4V, IIN = 15 mA
ICC
Quiescent Supply Current
5.5
3
µA
VIN = VCC or GND,
∆ICC
Increase in ICC per Input
5.5
2.5
mA
One input at 3.4V.
VIKU
Voltage Undershoot
5.5
−2.0
V
IOUT = 0
Other inputs at VCC or GND
0.0 mA ≥ IIN ≥ −50 mA
OE = 5.5V
Note 4: Typical values are at VCC = 5.0V and TA = +25°C
Note 5: 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.
3
www.fairchildsemi.com
FSTU3125
Absolute Maximum Ratings(Note 1)
FSTU3125
AC Electrical Characteristics
TA = −40 °C to +85 °C,
CL = 50pF, RU = RD = 500Ω
Symbol
Parameter
VCC = 4.5 – 5.5V
Min
tPHL, tPLH
Propagation Delay Bus to Bus (Note 6)
tPZH, tPZL
Output Enable Time
VCC = 4.0V
Max
1.0
Min
Units
Conditions
Max
0.25
0.25
ns
6.1
6.0
ns
VI = OPEN
Figures
2, 3
VI = 7V for tPZL
VI = OPEN for tPZH
tPHZ, tPLZ
Output Disable Time
1.5
6.4
Figure
Number
6.6
VI = 7V for tPLZ
ns
VI = OPEN for tPHZ
Figures
2, 3
Figures
2, 3
Note 6: 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 7)
Parameter
Typ
Max
Units
Conditions
CIN
Control Pin Input Capacitance
3
pF
VCC = 5.0V
CI/O
Input/Output Capacitance
5
pF
VCC, OE = 5.0V
Note 7: TA = +25°C, f = 1 MHz, Capacitance is characterized but not tested.
Undershoot Characteristic (Note 8)
Symbol
VOUTU
Parameter
Output Voltage During Undershoot
Min
Typ
2.5
VOH − 0.3
Max
Units
V
Conditions
Figure 1
Note 8: 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
www.fairchildsemi.com
Transient
Input Voltage (VIN) Waveform
Units
4
FSTU3125
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 = 500ns
FIGURE 2. AC Test Circuit
FIGURE 3. AC Waveforms
5
www.fairchildsemi.com
FSTU3125
Physical Dimensions inches (millimeters) unless otherwise noted
14-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150" Narrow
Package Number M14A
16-Lead Quarter Size Outline Package (QSOP), JEDEC MO-137, 0.150" Wide
Package Number MQA16
www.fairchildsemi.com
6
FSTU3125 4-Bit Bus Switch with −2V Undershoot Protection
Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
14-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide
Package Number MTC14
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.
www.fairchildsemi.com
7
www.fairchildsemi.com
Similar pages