1
INDUSTRIAL TEMPERATURE RANGE
IDTQS3VH16800
2.5V / 3.3V 20-BIT HIGH BANDWIDTH BUS SWITCH WITH PRECHARGED OUTPUTS
MARCH 2002
2002 Integrated Device Technology, Inc.
DSC-5961/5
c
INDUSTRIAL TEMPERATURE RANGE
DESCRIPTION:
The QS3VH16800 HotSwitch is a 20-bit high bandwidth bus switch. The
QS3VH16800 has very low ON resistance, resulting in under 250ps propa-
gation delay through the switch. The QS3VH16800 precharges the B port to
a user selectable bias voltage (V
BIAS
) to minimize live insertion noise. 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.
It can be used as two 10-bit bus switches or one 20-bit bus switch. In the OFF
and ON states, the switches are 5V-tolerant. 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 QS3VH16800 ideal for high performance
communications applications.
The QS3VH16800 is characterized for operation from -40
C to +85C.
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
APPLICATIONS:
Hot-swapping
10/100 Base-T, Ethernet LAN switch
Low distortion analog switch
Replaces mechanical relay
ATM 25/155 switching
FEATURES:
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
B port precharged to user-selectable V
BIAS
Low R
ON
- 4
typical
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 SSOP and TSSOP packages
IDTQS3VH16800
PRELIMINARY
QUICKSWITCH
PRODUCTS
2.5V / 3.3V 20-BIT HIGH
BANDWIDTH BUS SWITCH
WITH PRECHARGED OUTPUTS
A
0
A
9
B
9
B
0
V
B IA S
OE1
A
10
A
19
B
19
B
10
V
B IA S
OE2
FUNCTIONAL BLOCK DIAGRAM
2
INDUSTRIAL TEMPERATURE RANGE
IDTQS3VH16800
2.5V / 3.3V 20-BIT HIGH BANDWIDTH BUS SWITCH WITH PRECHARGED OUTPUTS
PIN CONFIGURATION
Symbol
Description
Max
Unit
V
TERM
(2)
SupplyVoltage to Ground
0.5 to +4.6
V
V
TERM
(3)
DC Switch Voltage V
S
0.5 to +5.5
V
V
TERM
(3)
DC Input Voltage V
IN
0.5 to +5.5
V
V
AC
AC Input Voltage (pulse width
20ns)
3
V
I
OUT
DC Output Current (max. sink current/pin)
120
mA
T
STG
Storage Temperature
65 to +150
C
ABSOLUTE MAXIMUM RATINGS
(1)
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
.
Symbol
Parameter
(1)
Typ.
Max.
Unit
C
IN
Control Inputs
3
5
pF
C
I/O
Quickswitch Channels (Switch OFF)
4
6
pF
V
BIAS
= OPEN
C
I/O
Quickswitch Channels (Switch ON)
8
12
pF
CAPACITANCE
(T
A
= +25C, F = 1MHz, V
IN
= 0V, V
OUT
= 0V)
NOTE:
1. H = HIGH Voltage Level
L = LOW Voltage Level
Z = High-Impedence
OEx
Bx
Function
L
A x
Connect
H
V
BIAS
Disconnect Ax = Z
FUNCTION TABLE
(EACH 10-BIT BUS SWITCH)
(1)
SSOP/ TSSOP
TOP VIEW
48
V
BIAS
OE1
1
47
OE2
2
A
0
46
3
A
1
B
0
45
4
A
2
B
1
44
5
A
3
B
2
43
6
A
4
B
3
41
8
A
6
B
5
40
9
A
7
B
6
39
10
A
8
B
7
42
7
A
5
B
4
38
11
A
9
B
8
37
GND
12
B
9
36
13
35
14
A
10
34
15
A
11
B
10
33
16
A
12
B
11
32
17
A
13
B
12
31
18
A
14
B
13
29
20
A
16
B
15
28
21
A
17
B
16
27
22
A
18
B
17
30
19
A
15
B
14
26
23
A
19
B
18
25
GND
24
B
19
V
CC
GND
GND
NOTE:
1. This parameter is guaranteed but not production tested.
Pin Names
I/O
Description
OEx
I
Bus Switch Enable
V
BIAS
I
Bias Voltage
A x
I/O
Bus A
B x
I/O
Bus B
PIN DESCRIPTION
3
INDUSTRIAL TEMPERATURE RANGE
IDTQS3VH16800
2.5V / 3.3V 20-BIT HIGH BANDWIDTH BUS SWITCH WITH PRECHARGED OUTPUTS
TYPICAL ON RESISTANCE vs V
IN
AT V
CC
= 3.3V
R
ON
(ohms)
V
IN
(Volts)
Symbol
Parameter
Test Conditions
Min.
Typ.
(1)
Max.
Unit
V
IH
Input HIGH Voltage
Guaranteed Logic HIGH
V
CC
= 2.3V to 2.7V
1.7
--
--
V
for Control Inputs
V
CC
= 2.7V to 3.6V
2
--
--
V
IL
Input LOW Voltage
Guaranteed Logic LOW
V
CC
= 2.3V to 2.7V
--
--
0.7
V
for Control Inputs
V
CC
= 2.7V to 3.6V
--
--
0.8
V
BIAS
Bias Voltage
V
CC
= 3.3V to 3.6V, I
O
= 0
0
--
5
V
V
CC
= 2.3V to 2.7V, I
O
= 0
0
--
3.3
| I
O
|
Bias Current
(2)
V
CC
= 3.3V, V
BIAS
= 2.4V, V
O
= 0, OEx = HIGH
0.25
--
--
mA
I
IN
Input Leakage Current (Control Inputs)
0V
V
IN
V
CC
--
--
1
A
I
OZ
Off-State Current (Hi-Z)
0V
V
OUT
5V, Switches OFF
--
--
1
A
I
OFF
Data Input/Output Power Off Leakage
V
IN
or V
OUT
0V to 5V, V
CC
= 0V
--
--
1
A
V
CC
= 2.3V
V
IN
= 0V
I
ON
= 30mA
--
6
8
R
ON
Switch ON Resistance
Typ. at V
CC
= 2.5V
V
IN
= 1.7V
I
ON
= 15mA
--
7
9
V
CC
= 3V
V
IN
= 0V
I
ON
= 30mA
--
4
6
V
IN
= 2.4V
I
ON
= 15mA
--
5
8
DC ELECTRICAL CHARACTERISTICS OVER OPERATING RANGE
Following Conditions Apply Unless Otherwise Specified:
Industrial: T
A
= 40C to +85C, V
CC
= 3.3V 0.3V
NOTES:
1. Typical values are at V
CC
= 3.3V and T
A
= 25C.
2. Bias resistance is 5K
typical at V
CC
= 3.3V; V
BIAS
= 2.4V at 25C.
16
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
5.0
4.5
4
INDUSTRIAL TEMPERATURE RANGE
IDTQS3VH16800
2.5V / 3.3V 20-BIT HIGH BANDWIDTH BUS SWITCH WITH PRECHARGED OUTPUTS
POWER SUPPLY CHARACTERISTICS
Symbol
Parameter
Test Conditions
(1)
Min.
Typ.
Max.
Unit
I
CCQ
Quiescent Power Supply Current
V
CC
= Max., V
IN
= GND or V
CC
, f = 0
--
1.5
3
mA
I
CC
Power Supply Current
(2,3)
per Input HIGH
V
CC
= Max., V
IN
= 3V, f = 0 per Control Input
--
--
30
A
I
CCD
Dynamic Power Supply Current
(4)
V
CC
= 3.3V, A and B Pins Open, Control Inputs
See Typical I
CCD
vs Enable Frequency graph below
Toggling @ 50% Duty Cycle
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
Icc.
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
I
CCD
(mA)
ENABLE FREQUENCY (MHz)
0
2
4
6
8
10
12
14
16
18
20
0
2
4
6
8
10
12
14
16
18
20
5
INDUSTRIAL TEMPERATURE RANGE
IDTQS3VH16800
2.5V / 3.3V 20-BIT HIGH BANDWIDTH BUS SWITCH WITH PRECHARGED OUTPUTS
SWITCHING CHARACTERISTICS OVER OPERATING RANGE
T
A
= -40C to +85C
V
CC
= 2.5 0.2V
(1)
V
CC
= 3.3 0.3V
(1)
Symbol
Parameter
Test Conditions
Min
.
(4)
Max.
Min
.
(4)
Max.
Unit
t
PLH
Data Propagation Delay
(2,3)
0.2
0.2
ns
t
PHL
Ax to Bx or Bx to Ax
t
PZL
Switch Turn-On Delay
V
BIAS
= 3V
1.5
8.5
1.5
8
ns
t
PZH
OEx to Ax/Bx
V
BIAS
= GND
t
PLZ
Switch Turn-Off Delay
V
BIAS
= 3V
1.5
7.5
1.5
7.5
ns
t
PHZ
OEx to Ax/Bx
V
BIAS
= GND
f
OEx
Operating Frequency - Enable
(2,5)
V
BIAS
= OPEN
10
20
MHz
(OEx)
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.
5. Maximum toggle frequency for OEx control input (pass voltage > V
CC
, V
IN
= 5V, R
LOAD
> 1M
, no C
LOAD
).
6
INDUSTRIAL TEMPERATURE RANGE
IDTQS3VH16800
2.5V / 3.3V 20-BIT HIGH BANDWIDTH BUS SWITCH WITH PRECHARGED OUTPUTS
PHY
3VH
SWITCH
4.5V
PP
LOGIC
SIDE
Z = 100
10Mbps to 100Mbps
2V
PP
4.5V
PP
LOGIC
SIDE
Z = 100
TWISTED PAIR
>100m
CHARGE PUMP
OE
Vcc = 3.3V
0 to +5V
NFET
+6.5V
DRIVER
0 to +5V
SINGLE HOT
SWITCH
CARD I/O
ON CARD
LOGIC
CON
N
E
CT
O
R
QS
3V
H
X
X
X
CPU
RAM
BUS
CARD I/O
ON CARD
LOGIC
CO
N
N
E
C
T
O
R
QS
3V
H
X
X
X
PLUGGABLE CARD/ LIVE SYSTEM
ZERO DOWN TIME SYSTEM
Rail-to-Rail Switching
SOME APPLICATIONS FOR HOTSWITCH PRODUCTS
Fast Ethernet Data Switching (LAN Switch)
Hot Swapping
7
INDUSTRIAL TEMPERATURE RANGE
IDTQS3VH16800
2.5V / 3.3V 20-BIT HIGH BANDWIDTH BUS SWITCH WITH PRECHARGED OUTPUTS
TEST CIRCUITS AND WAVEFORMS
Open
V
LOAD
G ND
V
CC
Pulse
Generator
D.U.T.
500
500
C
L
R
T
V
IN
V
OUT
(1, 2)
SAM E PH ASE
IN PU T TRANSITION
O PPOSITE PH ASE
IN PUT TR AN SITION
0V
0V
V
OH
V
OL
t
PLH
t
PHL
t
PHL
t
PLH
OU TPUT
V
IH
V
T
V
T
V
IH
V
T
C ON TRO L
IN PU T
t
PLZ
0V
O UTPU T
N OR M ALLY
LOW
t
PZ H
0V
SW ITCH
CLO SED
OUTPU T
N OR M ALLY
H IGH
EN ABLE
D ISABLE
SW ITCH
O PE N
t
PHZ
0 V
V
O L +
V
LZ
V
O H
V
T
V
T
t
PZL
V
LOAD/2
V
LO A D /2
V
IH
V
T
V
O L
V
O H -
V
H Z
TEST CONDITIONS
Symbol
V
CC
(1)
= 3.3V 0.3V
V
CC
(2)
= 2.5V 0.2V
Unit
V
LOAD
6
2 x Vcc
V
V
IH
3
Vcc
V
V
T
1.5
V
CC
/2
V
V
LZ
300
150
mV
V
HZ
300
150
mV
C
L
50
30
pF
NOTE:
1. Diagram shown for input Control Enable-LOW and input Control Disable-HIGH.
NOTES:
1. Pulse Generator for All Pulses: Rate
10MHz; t
F
2.5ns; t
R
2.5ns.
2. Pulse Generator for All Pulses: Rate
10MHz; t
F
2ns; t
R
2ns.
DEFINITIONS:
C
L
= Load capacitance: includes jig and probe capacitance.
R
T
= Termination resistance: should be equal to Z
OUT
of the Pulse Generator.
SWITCH POSITION
Test
Switch
t
PLZ
/
t
PZL
V
LOAD
t
PHZ/
t
PZH
GND
t
PD
Open
Propagation Delay
Test Circuits for All Outputs
Enable and Disable Times
8
INDUSTRIAL TEMPERATURE RANGE
IDTQS3VH16800
2.5V / 3.3V 20-BIT HIGH BANDWIDTH BUS SWITCH WITH PRECHARGED OUTPUTS
ORDERING INFORMATION
IDTQS
XXXXX
XX
Package
Device Type
3VH16800
2.5V/3.3V 20-Bit High Bandwidth Bus Switch
with Precharged Outputs
PV
PA
Shrink Small Outline Package
Thin Shrink Small Outline Package
CORPORATE HEADQUARTERS
for SALES:
for Tech Support:
2975 Stender Way
800-345-7015 or 408-727-6116
logichelp@idt.com
Santa Clara, CA 95054
fax: 408-492-8674
(408) 654-6459
www.idt.com
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