• N channel FET switches with no parasitic diode to V
CC
– Isolation under power-off conditions
– No DC path to V
CC
or GND
– 5V tolerant in OFF and ON state
• 5V tolerant I/Os
• Low R
ON
- 4Ω typical
Ω
• Flat R
ON
characteristics over operating range
• Rail-to-rail switching 0 - 5V
• Bidirectional dataflow with near-zero delay: no added ground
bounce
• Excellent R
ON
matching between channels
• V
CC
operation: 2.3V to 3.6V
• High bandwidth - up to 500MHz
• LVTTL-compatible control Inputs
• Undershoot Clamp Diodes on all switch and control Inputs
• Low I/O capacitance, 4pF typical
• Available in QSOP, SOIC, and TSSOP packages
IDTQS3VH245
DESCRIPTION:
The QS3VH245 HotSwitch 8-bit bus switch is a high bandwidth bus switch.
The QS3VH245 has very low ON resistance, resulting in under 250ps
propagation delay through the switch. The switches can be turned ON under
the control of the LVTTL-compatible Output Enable signal for bidirectional data
flow with no added delay or ground bounce. In the ON state, the switches can
pass signals up to 5V. In the OFF state, the switches offer very high impedence
at the terminals.
The combination of near-zero propagation delay, high OFF impedance, and
over-voltage tolerance makes the QS3VH245 ideal forhigh performance
communications applications.
The QS3VH245 is characterized for operation from -40°C to +85°C.
APPLICATIONS:
•
•
•
•
•
•
Hot-swapping
10/100 Base-T, Ethernet LAN switch
Low distortion analog switch
Replaces mechanical relay
ATM 25/155 switching
Bus switching and isolation
FUNCTIONAL BLOCK DIAGRAM
A
0
A
1
A
2
A
3
A
4
A
5
A
6
A
7
OE
B
0
B
1
B
2
B
3
B
4
B
5
B
6
B
7
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
INDUSTRIAL TEMPERATURE RANGE
1
c
2003 Integrated Device Technology, Inc.
MARCH 2003
DSC-5775/8
IDTQS3VH245
2.5V / 3.3V 8-BIT HIGH BANDWIDTH BUS SWITCH
INDUSTRIAL TEMPERATURE RANGE
PIN CONFIGURATION
ABSOLUTE MAXIMUM RATINGS
(1)
Symbol
V
TERM
(2)
V
TERM
(3)
Description
SupplyVoltage to Ground
DC Switch Voltage V
S
DC Input Voltage V
IN
AC Input Voltage (pulse width
≤20ns)
DC Output Current (max. sink current/pin)
Storage Temperature
Max
–0.5 to +4.6
–0.5 to +5.5
–0.5 to +5.5
–3
120
–65 to +150
Unit
V
V
V
V
mA
°C
NC
A
0
A
1
A
2
A
3
A
4
A
5
A
6
A
7
GND
1
2
3
4
5
6
7
8
9
1
0
2
0
1
9
1
8
1
7
1
6
1
5
1
4
1
3
1
2
1
1
V
CC
OE
B
0
B
1
B
2
B
3
B
4
B
5
B
6
B
7
V
TERM
(3)
V
AC
I
OUT
T
STG
NOTES:
1. Stresses greater than those listed under ABSOLUTE MAXIMUM RATINGS may cause
permanent damage to the device. This is a stress rating only and functional operation
of the device at these or any other conditions above those indicated in the operational
sections of this specification is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect reliability.
2. V
CC
terminals.
3. All terminals except V
CC
.
CAPACITANCE
(T
A
= +25°C, F = 1MHz, V
IN
= 0V, V
OUT
= 0V)
Symbol
C
IN
C
I/O
C
I/O
Parameter
(1)
Control Inputs
Quickswitch Channels (Switch OFF)
Quickswitch Channels (Switch ON)
Typ.
3
4
8
Max.
5
6
12
Unit
pF
pF
pF
QSOP/ SOIC/ TSSOP
TOP VIEW
NOTE:
1. This parameter is guaranteed but not production tested.
PIN DESCRIPTION
Pin Names
OE
Ax
Bx
Output Enable
Data I/Os
Data I/Os
Description
FUNCTION TABLE
(1)
OE
H
L
NOTE:
1. H = HIGH Voltage Level
L = LOW Voltage Level
Outputs
Disconnected
Ax = Bx
2
IDTQS3VH245
2.5V / 3.3V 8-BIT HIGH BANDWIDTH BUS SWITCH
INDUSTRIAL TEMPERATURE RANGE
DC ELECTRICAL CHARACTERISTICS OVER OPERATING RANGE
Following Conditions Apply Unless Otherwise Specified:
Industrial: T
A
= –40°C to +85°C, V
CC
= 3.3V ±0.3V
Symbol
V
IH
V
IL
I
IN
I
OZ
I
OFF
R
ON
Parameter
Input HIGH Voltage
Input LOW Voltage
Input Leakage Current (Control Inputs)
Off-State Current (Hi-Z)
Data Input/Output Power Off Leakage
Switch ON Resistance
for Control Inputs
Guaranteed Logic LOW
for Control Inputs
0V
≤
V
IN
≤
V
CC
0V
≤
V
OUT
≤
5V, Switches OFF
V
IN
or V
OUT
0V to 5V, V
CC
= 0V
V
CC
= 2.3V
Typical at V
CC
= 2.5V
V
CC
= 3V
V
IN
= 0V
V
IN
= 1.7V
V
IN
= 0V
V
IN
= 2.4V
NOTE:
1. Typical values are at V
CC
= 3.3V and T
A
= 25°C.
Test Conditions
Guaranteed Logic HIGH
V
CC
= 2.3V to 2.7V
V
CC
= 2.7V to 3.6V
V
CC
= 2.3V to 2.7V
V
CC
= 2.7V to 3.6V
Min.
1.7
2
—
—
—
—
—
I
ON
= 30mA
I
ON
= 15mA
I
ON
= 30mA
I
ON
= 15mA
—
—
—
—
Typ.
(1)
Max.
—
—
—
—
—
—
—
6
7
4
5
—
—
0.7
0.8
±1
±1
±1
8
9
6
8
Unit
V
V
µA
µA
µA
Ω
TYPICAL ON RESISTANCE vs V
IN
AT V
CC
= 3.3V
16
R
ON
(ohms)
14
12
10
8
6
4
2
0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
V
IN
(Volts)
3
IDTQS3VH245
2.5V / 3.3V 8-BIT HIGH BANDWIDTH BUS SWITCH
INDUSTRIAL TEMPERATURE RANGE
POWER SUPPLY CHARACTERISTICS
Symbol
I
CCQ
ΔI
CC
I
CCD
Parameter
Quiescent Power Supply Current
Power Supply Current
(2,3)
per Input HIGH
Dynamic Power Supply Current
(4)
Test Conditions
(1)
V
CC
= Max., V
IN
= GND or V
CC
, f = 0
V
CC
= Max., V
IN
= 3V, f = 0 per Control Input
V
CC
= 3.3V, A and B Pins Open, Control Inputs
Toggling @ 50% Duty Cycle
Min.
—
—
Typ.
1
—
Max.
3
30
Unit
mA
µA
See Typical I
CCD
vs Enable Frequency graph below
NOTES:
1. For conditions shown as Min. or Max., use the appropriate values specified under DC Electrical Characteristics.
2. Per input driven at the specified level. A and B pins do not contribute to
ΔIcc.
3. This parameter is guaranteed but not tested.
4. This parameter represents the current required to switch internal capacitance at the specified frequency. The A and B inputs do not contribute to the Dynamic Power Supply
Current. This parameter is guaranteed but not production tested.
TYPICAL I
CCD
vs ENABLE FREQUENCY CURVE AT V
CC
= 3.3V
12
10
8
I
CCD
(mA)
6
4
2
0
0
2
4
6
8
10
12
14
16
18
20
ENABLE FREQUENCY (MHZ)
4
IDTQS3VH245
2.5V / 3.3V 8-BIT HIGH BANDWIDTH BUS SWITCH
INDUSTRIAL TEMPERATURE RANGE
SWITCHING CHARACTERISTICS OVER OPERATING RANGE
T
A
= -40°C to +85°C
V
CC
= 2.5 ± 0.2V
(1)
Symbol
t
PLH
t
PHL
t
PZL
t
PZH
t
PLZ
t
PHZ
f
OE
Parameter
Data Propagation Delay
(2,3)
Ax to/from Bx
Switch Turn-On Delay
OE
to Ax/Bx
Switch Turn-Off Delay
OE
to Ax/Bx
Operating Frequency - Enable
(2,5)
Min
.
(4)
V
CC
= 3.3 ± 0.3V
(1)
Min
.
(4)
⎯
1.5
1.5
Max.
0.2
7
6.5
20
Unit
ns
ns
ns
MHz
Max.
0.2
8
7
10
⎯
1.5
1.5
⎯
⎯
NOTES:
1. See Test Conditions under TEST CIRCUITS AND WAVEFORMS.
2. This parameter is guaranteed but not production tested.
3. The bus switch contributes no propagation delay other than the RC delay of the ON resistance of the switch and the load capacitance. The time constant for the switch alone
is of the order of 0.2ns at C
L
= 50pF. Since this time constant is much smaller than the rise and fall times of typical driving signals, it adds very little propagation delay to the
system. Propagation delay of the bus switch, when used in a system, is determined by the driving circuit on the driving side of the switch and its interaction with the load on
the driven side.
4. Minimums are guaranteed but not production tested.
