Enhanced N channel FET with no inherent diode to Vcc
Low propagation delay
TTL-compatible input and output levels
Undershoot clamp diodes on all switch and control inputs
Available in SSOP and TSSOP packages
DESCRIPTION:
APPLICATIONS:
•
•
•
•
The QS316212 provides a set of 24 high-speed CMOS TTL-compatible
bus-exchange switches. The low ON resistance of the QS316212 allows
inputs to be connected to outputs without adding propagation delay and
without generating additional ground bounce noise. The device operates
as a 24-bit bus switch or a 12-bit bus exchanger, which provides data
exchanging between the four signal ports through the data-select (S0-S2)
terminals.
The QS316212 is characterized for operation at -40°C to +85°C.
Resource sharing
Crossbar switching
Hot-docking
Voltage translation (5V to 3.3V)
FUNCTIONAL BLOCK DIAGRAM
1 of 12 Chann els
1A1
1B1
1A2
1B2
Flow Control
S0
S1
S2
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
INDUSTRIAL TEMPERATURE RANGE
1
c
1999 Integrated Device Technology, Inc.
NOVEMBER 1999
DSC-5569/1
IDTQS316212
HIGH-SPEED CMOS 24-BIT BUS-EXCHANGE SWITCH
INDUSTRIAL TEMPERATURE RANGE
PIN CONFIGURATION
S0
1A1
1A2
2A1
2A2
3A1
3A2
GND
4A1
4A2
5A1
5A2
6A1
6A2
7A1
7A2
V
CC
8A1
GND
8A2
9A1
9A2
10A1
10A2
11A1
11A2
12A1
12A2
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
S1
S2
1B1
1B2
2B1
2B2
3B1
GND
3B2
4B1
4B2
5B1
5B2
6B1
6B2
7B1
7B2
8B1
GND
8B2
9B1
9B2
10B1
10B2
11B1
11B2
12B1
12B2
ABSOLUTE MAXIMUM RATINGS
(1)
Symbol
V
TERM
(2)
V
TERM
(3)
V
TERM
(3)
V
AC
I
OUT
P
MAX
T
STG
Description
Supply Voltage to Ground
DC Switch Voltage V
S
DC Input Voltage V
IN
AC Input Voltage (pulse width
≤20ns)
DC Output Current
Maximum Power
Dissipation (T
A
= 85°C)
Storage Temperature
SSOP
TSSOP
Max
–0.5 to +7
–0.5 to +7
–0.5 to +7
–3
120
0.93
0.77
–65 to +150
°C
Unit
V
V
V
V
mA
W
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)
Pins
Control Inputs
Quickswitch Channels (Switch OFF)
Typ.
4
7.5
Max.
(1)
5
9
Unit
pF
pF
NOTE:
1. This parameter is guaranteed but not production tested.
PIN DESCRIPTION
Pin Names
1
Ax
1
Bx
I/O
I/O
I/O
I
Bus A
Bus B
Data Select
Description
-
-
12
Ax
12
Bx
S
0
- S
2
FUNCTION TABLE
(1)
S
2
S
1
L
L
H
H
L
L
H
H
S
0
L
H
L
H
L
H
L
H
xA
1
Z
xB
1
xB
2
Z
Z
Z
xB
1
xB
2
xA
2
Z
Z
Z
xB
1
xB
2
Z
xB
2
xB
1
Function
Disconnect
xA
1
to xB
1
xA
1
to xB
2
xA
2
to xB
1
xA
2
to xB
2
Disconnect
xA
1
to xB
1,
xA
2
to xB
2
xA
1
to xB
2,
xA
2
to xB
1
L
L
L
L
H
H
H
H
SSOP/ TSSOP
TOP VIEW
NOTE:
1. H = HIGH Voltage Level
L = LOW Voltage Level
Z = High-Impedance
2
IDTQS316212
HIGH-SPEED CMOS 24-BIT BUS-EXCHANGE 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
= 5V ± 10%
Symbol
V
IH
V
IL
I
IN
I
OZ
R
ON
V
P
Parameter
Input HIGH Voltage
Input LOW Voltage
Input Leakage Current (Control Inputs)
Off-State Current (Hi-Z)
Switch ON Resistance
(2)
Pass Voltage
(3)
Test Conditions
Guaranteed Logic HIGH for Control Inputs
Guaranteed Logic LOW for Control Inputs
0V
≤
V
IN
≤
V
CC
0V
≤
V
OUT
≤
V
CC
, Switches OFF
V
CC
= Min., V
IN
= 0V, I
ON
= 30mA
V
CC
= Min., V
IN
= 2.4V, I
ON
= 15mA
V
IN
= V
CC
= 5V, I
OUT
= -5µA
Min.
2
—
—
—
—
—
3.7
Typ.
(1)
Max.
—
—
—
—
5
10
4
—
0.8
±1
±1
7
12
4.2
V
Unit
V
V
µA
µA
Ω
NOTES:
1. Typical values are at V
CC
= 5V and T
A
= 25°C.
2. R
ON
is guaranteed but not production tested.
3. Pass voltage is guaranteed but not production tested.
TYPICAL ON RESISTANCE vs V
IN
AT V
CC
= 5V
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
V
IN
(Volts)
3
IDTQS316212
HIGH-SPEED CMOS 24-BIT BUS-EXCHANGE SWITCH
INDUSTRIAL TEMPERATURE RANGE
POWER SUPPLY CHARACTERISTICS
Symbol
I
CCQ
∆I
CC
I
CCD
Parameter
Quiescent Power Supply Current
Power Supply Current per Control Input HIGH
(2)
Dynamic Power Supply Current per MHz
(3)
Test Conditions
(1)
V
CC
= Max., V
IN
= GND or V
CC
, f = 0
V
CC
= Max., V
IN
= 3.4V, f = 0
V
CC
= Max., A and B Pins Open, Control Inputs Toggling @ 50% Duty Cycle
Max.
3
2.5
0.25
Unit
µA
mA
mA/MHz
NOTES:
1. For conditions shown as Min. or Max., use the appropriate values specified under DC Electrical Characteristics.
2. Per TTL-driven input (V
IN
= 3.4V). A and B pins do not contribute to
∆Icc.
3. This current applies to the control inputs only and represents the current required to switch internal capacitance at the specified frequency. The A and B inputs generate no significant
AC or DC currents as they transition. This parameter is guaranteed but not production tested.
SWITCHING CHARACTERISTICS OVER OPERATING RANGE
T
A
= -40°C to +85°C, V
CC
= 5V ± 10%
C
LOAD
= 50pF, R
LOAD
= 500Ω unless otherwise noted.
Symbol
t
PLH
t
PHL
t
PZL
t
PZH
t
PLZ
t
PHZ
Parameter
Data Propagation Delay
(2)
xAx to xBx, xBx to xAx
Switch Turn-On Delay
Sx to xAx, xBx
Switch Turn-Off Delay
(2)
Sx to xAx, xBx
Min
.
(1)
1.5
1.5
Typ.
Max.
0.25
(3)
6.5
6.2
Unit
ns
ns
ns
NOTES:
1. Minimums are guaranteed but not production tested.
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 0.25ns 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
